Presence of Pathogenic Rickettsiae and Protozoan in Samples of Raw Milk from Cows, Goats, and Sheep.

PubMed

Cisak, Ewa; Zając, Violetta; Sroka, Jacek; Sawczyn, Anna; Kloc, Anna; Dutkiewicz, Jacek; Wójcik-Fatla, Angelina

2017-04-01

The aim of the present work was to determine the presence of various rickettsiae and protozoan in raw milk and the assessment the potential, milk-borne route in the spread of selected zoonotic pathogens. A total of 119 raw milk samples collected randomly from 63 cows, 29 goats, and 27 sheep bred on 34 farms situated on eight communities in eastern Poland were examined by polymerase chain reaction (PCR) method for the presence of pathogenic rickettsiae (Coxiella burnetii, Anaplasma phagocytophilum, and Rickettsia spp.) and protozoan (Toxoplasma gondii). The only prevalent pathogen was T. gondii, which was found in 10 samples of cow milk (15.9%), in one sample of goat milk (3.4%), and in one sample of sheep milk (3.7%). One sample of cow milk was positive for C. burnetii; however, the sequence analysis did not confirm any species of Coxiella or Coxiella-like organisms, but showed 100% homology to Psychrobacter alimentarius. None of the examined samples showed the presence of A. phagocytophilum or Rickettsia spp. The results of this study suggest a potential hazard of milk-borne Toxoplasma infection, mostly by consumption of raw cow milk. The milk-borne spread seems to be limited or nonsignificant in the case of C. burnetii, A. phagocytophilum, and Rickettsia spp. The false-positive sample for Coxiella spp. suggests that some care should be taken in the interpretation of the results obtained by using the PCR method.

'Nano-immuno test' for the detection of live Mycobacterium avium subspecies paratuberculosis bacilli in the milk samples using magnetic nano-particles and chromogen.

PubMed

Singh, Manju; Singh, Shoor Vir; Gupta, Saurabh; Chaubey, Kundan Kumar; Stephan, Bjorn John; Sohal, Jagdip Singh; Dutta, Manali

2018-04-26

Early rapid detection of Mycobacterium avium subspecies paratuberculosis (MAP) bacilli in milk samples is the major challenge since traditional culture method is time consuming and laboratory dependent. We report a simple, sensitive and specific nano-technology based 'Nano-immuno test' capable of detecting viable MAP bacilli in the milk samples within 10 h. Viable MAP bacilli were captured by MAP specific antibody-conjugated magnetic nano-particles using resazurin dye as chromogen. Test was optimized using true culture positive (10-bovine and 12-goats) and true culture negative (16-bovine and 25-goats) raw milk samples. Domestic livestock species in India are endemically infected with MAP. After successful optimization, sensitivity and specificity of the 'nano-immuno test' in goats with respect to milk culture was 91.7% and 96.0%, respectively. Whereas, it was 90.0% (sensitivity) and 92.6% (specificity) with respect to IS900 PCR. In bovine milk samples, sensitivity and specificity of 'nano-immuno test' with respect to milk culture was 90.0% and 93.7%, respectively. However, with respect to IS900 PCR, the sensitivity and specificity was 88.9% and 94.1%, respectively. Test was validated with field raw milk samples (goats-258 and bovine-138) collected from domestic livestock species to detect live/viable MAP bacilli. Of 138 bovine raw milk samples screened by six diagnostic tests, 81 (58.7%) milk samples were positive for MAP infection in one or more than one diagnostic tests. Of 81 (58.7%) positive bovine raw milk samples, only 24 (17.4%) samples were detected positive for the presence of viable MAP bacilli. Of 258 goats raw milk samples screened by six diagnostic tests, 141 (54.6%) were positive for MAP infection in one or more than one test. Of 141 (54.6%) positive raw milk samples from goats, only 48 (34.0%) were detected positive for live MAP bacilli. Simplicity and efficiency of this novel 'nano-immuno test' makes it suitable for wide-scale screening of milk samples in the field. Standardization, validation and re-usability of functionalized nano-particles and the test was successfully achieved in field samples. Test was highly specific, simple to perform and easy to read by naked eyes and does not require laboratory support in the performance of test. Test has potential to be used as screening test to estimate bio-load of MAP in milk samples at National level.

Microbiological quality and antibiotic residues in informally marketed raw cow milk within the coastal savannah zone of Ghana.

PubMed

Addo, K K; Mensah, G I; Aning, K G; Nartey, N; Nipah, G K; Bonsu, C; Akyeh, M L; Smits, H L

2011-02-01

To investigate the microbiological quality and the presence of antibiotic residues in raw cow milk and in some indigenous milk products produced and marketed by the informal sector in the coastal savannah zone of Ghana. Milk samples were aseptically collected from 224 kraals and samples of 26 indigenous milk products were purchased from processors and retailers. Total plate counts, total coliform counts and the presence of Escherichia coli and E. coli O157:H7 were determined in all 250 samples. Milk samples were also tested for antibiotic residues. Total plate counts exceeded 10⁵ CFU/ml in 45.2% of the samples while coliforms exceeded 10³ CFU/ml in 66.0% and E. coli was detected in 11.2%. E. coli was present in raw cow milk but not in the indigenous products and all E. coli isolates were negative for E. coli O157:H7. Antibiotic residues were detected in 3.1% of the raw cow milk samples. Bulk milk contains unacceptable levels of hygiene indicators and antibiotic residues and is a potential source of milk-borne infections. The detection of E. coli and antibiotic residues raises public health concerns about the safety of fresh unpasteurized cow milk in the coastal savannah zone of Ghana and calls for improved farm hygiene, the need for milk pasteurization and the sensible use of antibiotics in the milk industry. © 2010 Blackwell Publishing Ltd.

Characterization of the indigenous microflora in raw and pasteurized buffalo milk during storage at refrigeration temperature by high-throughput sequencing.

PubMed

Li, Ling; Renye, John A; Feng, Ling; Zeng, Qingkun; Tang, Yan; Huang, Li; Ren, Daxi; Yang, Pan

2016-09-01

The effect of refrigeration on bacterial communities within raw and pasteurized buffalo milk was studied using high-throughput sequencing. High-quality samples of raw buffalo milk were obtained from 3 dairy farms in the Guangxi province in southern China. Five liters of each milk sample were pasteurized (72°C; 15 s); and both raw and pasteurized milks were stored at refrigeration temperature (1-4°C) for various times with their microbial communities characterized using the Illumina Miseq platform (Novogene, Beijing, China). Results showed that both raw and pasteurized milks contained a diverse microbial population and that the populations changed over time during storage. In raw buffalo milk, Lactococcus and Streptococcus dominated the population within the first 24h; however, when stored for up to 72h the dominant bacteria were members of the Pseudomonas and Acinetobacter genera, totaling more than 60% of the community. In pasteurized buffalo milk, the microbial population shifted from a Lactococcus-dominated community (7d), to one containing more than 84% Paenibacillus by 21d of storage. To increase the shelf-life of buffalo milk and its products, raw milk needs to be refrigerated immediately after milking and throughout transport, and should be monitored for the presence of Paenibacillus. Results from this study suggest pasteurization should be performed within 24h of raw milk collection, when the number of psychrotrophic bacteria are low; however, as Paenibacillus spores are resistant to pasteurization, additional antimicrobial treatments may be required to extend shelf-life. The findings from this study are expected to aid in improving the quality and safety of raw and pasteurized buffalo milk. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Campylobacter spp. Prevalence and Levels in Raw Milk: A Systematic Review and Meta-Analysis.

PubMed

Christidis, T; Pintar, K D M; Butler, A J; Nesbitt, A; Thomas, M K; Marshall, B; Pollari, F

2016-10-01

Campylobacteriosis is the leading bacterial gastrointestinal disease internationally, contributing significantly to the enteric illness burden. Cases have been associated with the consumption of raw milk, a behavior that has garnered attention recently. Estimates of the prevalence and levels of Campylobacter spp. in raw milk are lacking, which hinders risk assessment attempts. This article is a systematic review and meta-analysis of reported prevalence and levels of zoonotic Campylobacter spp. in the raw milk of cows, goats, and sheep in Canada, the United States, Europe, Australia, and New Zealand. The relevant literature was reviewed, and trained reviewers examined the results for inclusion of articles in the meta-analysis. Relevant data (prevalence and/or level of Campylobacter in raw milk, country of origin, animal species, sample source, Campylobacter species identified, etc.) were extracted, and a meta-analysis was performed in Stata v. 12 (Metaprop command). The weighted mean prevalence of Campylobacter spp. in raw milk samples was 1.18%. Subgroup analyses were conducted to examine how prevalence varied by study characteristics, with the highest prevalence values in studies from the United Kingdom (by country, 6.4%), about cows (by animal species, 1.3%), and including samples taken from inline filters (by sample source, 1.75%) and in studies that included species that are not pathogenic to humans (by Campylobacter species, 1.14%). Two articles each included a single Campylobacter level, 0.16 ± 0.3 and approximately 0.047 most probable number per ml. Despite a relatively low prevalence, consumption of raw milk is inherently risky because no treatment has been used to inactivate pathogens. This potential risk further supports maintaining regulations to limit the sales of raw milk.

Raw milk from vending machines: Effects of boiling, microwave treatment, and refrigeration on microbiological quality.

PubMed

Tremonte, Patrizio; Tipaldi, Luca; Succi, Mariantonietta; Pannella, Gianfranco; Falasca, Luisa; Capilongo, Valeria; Coppola, Raffaele; Sorrentino, Elena

2014-01-01

In Italy, the sale of raw milk from vending machines has been allowed since 2004. Boiling treatment before its use is mandatory for the consumer, because the raw milk could be an important source of foodborne pathogens. This study fits into this context with the aim to evaluate the microbiological quality of 30 raw milk samples periodically collected (March 2013 to July 2013) from 3 vending machines located in Molise, a region of southern Italy. Milk samples were stored for 72 h at 4 °C and then subjected to different treatments, such as boiling and microwaving, to simulate domestic handling. The results show that all the raw milk samples examined immediately after their collection were affected by high microbial loads, with values very close to or even greater than those acceptable by Italian law. The microbial populations increased during refrigeration, reaching after 72 h values of about 8.0 log cfu/mL for Pseudomonas spp., 6.5 log cfu/mL for yeasts, and up to 4.0 log cfu/mL for Enterobacteriaceae. Boiling treatment, applied after 72 h to refrigerated milk samples, caused complete decontamination, but negatively affected the nutritional quality of the milk, as demonstrated by a drastic reduction of whey proteins. The microwave treatment at 900 W for 75 s produced microbiological decontamination similar to that of boiling, preserving the content in whey proteins of milk. The microbiological characteristics of raw milk observed in this study fully justify the obligation to boil the raw milk from vending machines before consumption. However, this study also showed that domestic boiling causes a drastic reduction in the nutritional value of milk. Microwave treatment could represent a good alternative to boiling, on the condition that the process variables are standardized for safe domestic application. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

N2 Gas Flushing Alleviates the Loss of Bacterial Diversity and Inhibits Psychrotrophic Pseudomonas during the Cold Storage of Bovine Raw Milk.

PubMed

Gschwendtner, Silvia; Alatossava, Tapani; Kublik, Susanne; Fuka, Mirna Mrkonjić; Schloter, Michael; Munsch-Alatossava, Patricia

2016-01-01

The quality and safety of raw milk still remains a worldwide challenge. Culture-dependent methods indicated that the continuous N2 gas-flushing of raw milk reduced the bacterial growth during cold storage by up to four orders of magnitude, compared to cold storage alone. This study investigated the influence of N2 gas-flushing on bacterial diversity in bovine raw-milk samples, that were either cold stored at 6°C or additionally flushed with pure N2 for up to one week. Next-generation sequencing (NGS) of the V1-V2 hypervariable regions of 16S rRNA genes, derived from amplified cDNA, which was obtained from RNA directly isolated from raw-milk samples, was performed. The reads, which were clustered into 2448 operational taxonomic units (OTUs), were phylogenetically classified. Our data revealed a drastic reduction in the diversity of OTUs in raw milk during cold storage at 6°C at 97% similarity level; but, the N2-flushing treatment alleviated this reduction and substantially limited the loss of bacterial diversity during the same cold-storage period. Compared to cold-stored milk, the initial raw-milk samples contained less Proteobacteria (mainly Pseudomonadaceae, Moraxellaceae and Enterobacteriaceae) but more Firmicutes (mainly Ruminococcaceaea, Lachnospiraceae and Oscillospiraceaea) and Bacteroidetes (mainly Bacteroidales). Significant differences between cold-stored and additionally N2-flushed milk were mainly related to higher levels of Pseudomononadaceae (including the genera Pseudomonas and Acinetobacter) in cold-stored milk samples; furthermore, rare taxa were better preserved by the N2 gas flushing compared to the cold storage alone. No major changes in bacterial composition with time were found regarding the distribution of the major 9 OTUs, that dominated the Pseudomonas genus in N2-flushed or non-flushed milk samples, other than an intriguing predominance of bacteria related to P. veronii. Overall, this study established that neither bacteria causing milk spoilage nor any well-known human pathogen or anaerobe benefited from the N2 gas flushing even though the N2-flushed and non-flushed cold-stored milk differed in bacterial counts by up to 104-fold.

N2 Gas Flushing Alleviates the Loss of Bacterial Diversity and Inhibits Psychrotrophic Pseudomonas during the Cold Storage of Bovine Raw Milk

PubMed Central

Kublik, Susanne; Fuka, Mirna Mrkonjić; Schloter, Michael; Munsch-Alatossava, Patricia

2016-01-01

The quality and safety of raw milk still remains a worldwide challenge. Culture-dependent methods indicated that the continuous N2 gas-flushing of raw milk reduced the bacterial growth during cold storage by up to four orders of magnitude, compared to cold storage alone. This study investigated the influence of N2 gas-flushing on bacterial diversity in bovine raw-milk samples, that were either cold stored at 6°C or additionally flushed with pure N2 for up to one week. Next-generation sequencing (NGS) of the V1-V2 hypervariable regions of 16S rRNA genes, derived from amplified cDNA, which was obtained from RNA directly isolated from raw-milk samples, was performed. The reads, which were clustered into 2448 operational taxonomic units (OTUs), were phylogenetically classified. Our data revealed a drastic reduction in the diversity of OTUs in raw milk during cold storage at 6°C at 97% similarity level; but, the N2-flushing treatment alleviated this reduction and substantially limited the loss of bacterial diversity during the same cold-storage period. Compared to cold-stored milk, the initial raw-milk samples contained less Proteobacteria (mainly Pseudomonadaceae, Moraxellaceae and Enterobacteriaceae) but more Firmicutes (mainly Ruminococcaceaea, Lachnospiraceae and Oscillospiraceaea) and Bacteroidetes (mainly Bacteroidales). Significant differences between cold-stored and additionally N2-flushed milk were mainly related to higher levels of Pseudomononadaceae (including the genera Pseudomonas and Acinetobacter) in cold-stored milk samples; furthermore, rare taxa were better preserved by the N2 gas flushing compared to the cold storage alone. No major changes in bacterial composition with time were found regarding the distribution of the major 9 OTUs, that dominated the Pseudomonas genus in N2-flushed or non-flushed milk samples, other than an intriguing predominance of bacteria related to P. veronii. Overall, this study established that neither bacteria causing milk spoilage nor any well-known human pathogen or anaerobe benefited from the N2 gas flushing even though the N2-flushed and non-flushed cold-stored milk differed in bacterial counts by up to 104-fold. PMID:26730711

Short communication: Variation in the composition and properties of Swedish raw milk for ultra-high-temperature processing.

PubMed

Karlsson, Maria A; Langton, Maud; Innings, Fredrik; Wikström, Malin; Lundh, Åse Sternesjö

2017-04-01

The composition and properties of raw milk are of great importance for the quality and shelf life of the final dairy product, especially in products with a long shelf life [e.g., ultra-high-temperature (UHT)-treated milk]. The objective of this study was to investigate the compositional variation in raw milk samples before processing at the dairy plant. Moreover, we wanted to investigate the effect of the UHT process on this variation (i.e., if the same variation could be observed in the corresponding UHT milk). The quality traits analyzed included detailed milk composition, counts of total and psychrotrophic bacteria, proteolytic activity, and color, as well as predictive measures of stability (i.e., ethanol stability and heat coagulating time). Samples of raw milk and the corresponding produced UHT milk were collected and analyzed on a monthly basis during 1 yr. Principal component analysis was used to identify months showing similarities and differences with respect to total variation. In contrast to previous studies, we observed only small variations between months and no clear effect of season for the raw milk. For the UHT milk, July and the winter months (December, January, and February) tended to separate from the other months. Quality traits showing significant variation were only to some extent identical in raw milk and UHT-processed milk. A better understanding of the natural variation in raw milk quality will provide opportunities to improve the shelf life of UHT-treated milk products. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Haptoglobin and serum amyloid A in bulk tank milk in relation to raw milk quality.

PubMed

Akerstedt, Maria; Waller, Karin Persson; Sternesjö, Ase

2009-11-01

The aim of the present study was to evaluate relationships between the presence of the two major bovine acute phase proteins haptoglobin (Hp) and serum amyloid A (SAA) and raw milk quality parameters in bulk tank milk samples. Hp and SAA have been suggested as specific markers of mastitis but recently also as markers for raw milk quality. Since mastitis has detrimental effects on milk quality, it is important to investigate whether the presence of Hp or SAA indicates such changes in the composition and properties of the milk. Bulk tank milk samples (n=91) were analysed for Hp, SAA, total protein, casein, whey protein, proteolysis, fat, lactose, somatic cell count and coagulating properties. Samples with detectable levels of Hp had lower casein content, casein number and lactose content, but higher proteolysis than samples without Hp. Samples with detectable levels of SAA had lower casein number and lactose content, but higher whey protein content than samples without SAA. The presence of acute phase proteins in bulk tank milk is suggested as an indicator for unfavourable changes in the milk composition, e.g. protein quality, due to udder health disturbances, with economical implications for the dairy industry.

Occurrence of Mycobacterium bovis and non-tuberculous mycobacteria (NTM) in raw and pasteurized milk in the northwestern region of Paraná, Brazil.

PubMed

Sgarioni, Sônia Aparecida; Hirata, Rosario Dominguez Crespo; Hirata, Mario Hiroyuki; Leite, Clarice Queico Fujimura; de Prince, Karina Andrade; de Andrade Leite, Sergio Roberto; Filho, Dirceu Vedovello; Siqueira, Vera Lucia Dias; Caleffi-Ferracioli, Katiany Rizzieri; Cardoso, Rosilene Fressatti

2014-01-01

Milk is widely consumed in Brazil and can be the vehicle of agent transmission. In this study, was evaluated the occurrence of Mycobacterium bovis and non-tuberculous mycobacteria (NTM) in raw and pasteurized milk consumed in the northwestern region of Paraná, Brazil. Fifty-two milk samples (20 pasteurized and 32 raw) from dairy farms near the municipality of Maringa, Parana State, Brazil were collected. Milk samples were decontaminated using 5% oxalic acid method and cultured on Lowenstein-Jensen and Stonebrink media at 35 °C and 30 °C, with and without 5-10% CO2. Mycobacteria isolates were identified by morphological features, PCR-Restriction Fragment Length Polymorphism Analysis (PCR-PRA) and Mycolic acids analysis. Thirteen (25%) raw and 2 (4%) pasteurized milk samples were positive for acid fast bacilli growth. Nine different species of NTM were isolated (M. nonchromogenicum, M. peregrinum, M. smegmatis, M. neoaurum, M. fortuitum, M. chelonae, M. flavescens, M. kansasii and M. scrofulaceum). M. bovis was not detected. Raw and pasteurized milk may be considered one source for NTM human infection. The paper reinforces the need for intensification of measures in order to avoid the milk contamination and consequently prevent diseases in the south of Brazil.

Occurrence of Mycobacterium bovis and non-tuberculous mycobacteria (NTM) in raw and pasteurized milk in the northwestern region of Paraná, Brazil

PubMed Central

Sgarioni, Sônia Aparecida; Hirata, Rosario Dominguez Crespo; Hirata, Mario Hiroyuki; Leite, Clarice Queico Fujimura; de Prince, Karina Andrade; de Andrade Leite, Sergio Roberto; Filho, Dirceu Vedovello; Siqueira, Vera Lucia Dias; Caleffi-Ferracioli, Katiany Rizzieri; Cardoso, Rosilene Fressatti

2014-01-01

Milk is widely consumed in Brazil and can be the vehicle of agent transmission. In this study, was evaluated the occurrence of Mycobacterium bovis and non-tuberculous mycobacteria (NTM) in raw and pasteurized milk consumed in the northwestern region of Paraná, Brazil. Fifty-two milk samples (20 pasteurized and 32 raw) from dairy farms near the municipality of Maringa, Parana State, Brazil were collected. Milk samples were decontaminated using 5% oxalic acid method and cultured on Lowenstein-Jensen and Stonebrink media at 35 °C and 30 °C, with and without 5–10% CO2. Mycobacteria isolates were identified by morphological features, PCR-Restriction Fragment Length Polymorphism Analysis (PCR-PRA) and Mycolic acids analysis. Thirteen (25%) raw and 2 (4%) pasteurized milk samples were positive for acid fast bacilli growth. Nine different species of NTM were isolated (M. nonchromogenicum, M. peregrinum, M. smegmatis, M. neoaurum, M. fortuitum, M. chelonae, M. flavescens, M. kansasii and M. scrofulaceum). M. bovis was not detected. Raw and pasteurized milk may be considered one source for NTM human infection. The paper reinforces the need for intensification of measures in order to avoid the milk contamination and consequently prevent diseases in the south of Brazil. PMID:25242962

Proteolysis of milk fat globule membrane proteins during in vitro gastric digestion of milk.

PubMed

Ye, A; Cui, J; Singh, H

2011-06-01

The influence of gastric proteolysis on the physicochemical characteristics of milk fat globules and the proteins of the milk fat globule membrane (MFGM) in raw milk and cream was examined in vitro in simulated gastric fluid (SGF) containing various pepsin concentrations at pH 1.6 for up to 2h. Apparent flocculation of the milk fat globules occurred in raw milk samples incubated in SGF containing pepsin, but no coalescence was observed in either raw milk samples or cream samples. The changes in the particle size of the fat globules as a result of the flocculation were dependent on the pepsin concentration. Correspondingly, the physical characteristics of the fat globules and the composition of the MFGM proteins in raw milk changed during incubation in SGF containing pepsin. The major MFGM proteins were hydrolyzed at different rates by the pepsin in the SGF; butyrophilin was more resistant than xanthine oxidase, PAS 6, or PAS 7. Peptides with various molecular weights, which altered with the time of incubation and the pepsin concentration, were present at the surfaces of the fat globules. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Raw Milk Consumption: Risks and Benefits.

PubMed

Lucey, John A

2015-07-01

There continues to be considerable public debate on the possible benefits regarding the growing popularity of the consumption of raw milk. However, there are significant concerns by regulatory, or public health, organizations like the Food and Drug Administration and the Centers for Disease Control and Prevention because of risk of contracting milkborne illnesses if the raw milk is contaminated with human pathogens. This review describes why pasteurization of milk was introduced more than 100 years ago, how pasteurization helped to reduce the incidence of illnesses associated with raw milk consumption, and the prevalence of pathogens in raw milk. In some studies, up to a third of all raw milk samples contained pathogens, even when sourced from clinically healthy animals or from milk that appeared to be of good quality. This review critically evaluates some of the popularly suggested benefits of raw milk. Claims related to improved nutrition, prevention of lactose intolerance, or provision of "good" bacteria from the consumption of raw milk have no scientific basis and are myths. There are some epidemiological data that indicate that children growing up in a farming environment are associated with a decreased risk of allergy and asthma; a variety of environmental factors may be involved and there is no direct evidence that raw milk consumption is involved in any "protective" effect.

Prevalence of virulent Yersinia enterocolitica in bulk raw milk and retail cheese in northern-west of Iran.

PubMed

Hanifian, Shahram; Khani, Sajjad

2012-04-02

To determine the prevalence of virulent Yersinia enterocolitica, 554 samples consisting of 354 bulk raw milks and 200 traditional cheeses were collected from different parts of Eastern-Azerbaijan province, during a 23-month period from 2008 to 2010. The occurrence of virulent strains of Y. enterocolitica in samples enriched in peptone sorbitol bile broth (PSBB) was evaluated via the detection of attachment invasion locus (ail) gene by PCR. The viability of virulent Y. enterocolitica in the PCR-positive samples was tested using conventional culture method and the isolates were confirmed by the second-phase ail-PCR. According to the results, 8.66% of total samples including 7.62% of bulk raw milks and 10.5% of raw milk cheeses were found ail-positive by PCR method; subsequently Y. enterocolitica was isolated by the culture method and confirmed by the second phase ail-PCR in 2.88% of total samples including 2.26% of raw milks and 4% of cheese samples. It was concluded that, a sample enrichment followed by ail-PCR was more sensitive and robust to detect and distinguish the virulent strains of Y. enterocolitica compared to the conventional culture method. Copyright © 2012 Elsevier B.V. All rights reserved.

Microbial quality and associated health risks of raw milk marketed in the Tanga region of Tanzania.

PubMed

Swai, E S; Schoonman, L

2011-06-01

To evaluate microbial quality and associated health risks of raw milk marketed in the Tanga region of Tanzania. A microbial quality assessment of marketed raw milk was undertaken by evaluating 59 samples of milk from selling points (collecting centres =15), bicycle boys (12) and kiosks/restaurants (32) in Tanga city during April-May 2005. Quality and milk-borne hazards were assessed using a combination of tests in order to quantify the occurrence of Brucellosis (milk ring test), Escherichia coli (E. coli) O157:H7 (culture), the coliform bacteria as well as standard plate count (SPC). Specific gravity (SG) determination was used as an indicator of adulteration. The mean coliform plate count (c.f.u/mL) of milk handled by bicycle boys (4.2×10(6)) was significantly higher than that handled by collecting centres (3.0×10(6)) and kiosk/ restaurants (1.4×10(6)), respectively (P < 0.05). Of the 59 milk samples collected, 33 (56%) were Brucella milk ring test (MRT)-positive and 78% and 17% of the samples graded satisfactorily based on SG and coliform plate counts as prescribed by East African Community standards for raw milk. There was no verocytotoxigenic E. coli (VTEC) O157: H7 in any of the milk samples collected and analysed during the present study. It can be concluded that raw market milk in the study area is of poor bacteriological quality and hazardous for human consumption. This highlights the need to implement good hygiene practices and effective monitoring from production through the delivery chain to the consumer. Further studies are needed for detection of toxins that are produced by E. coli, other pathogenic spore forming bacteria (Bacillus spp. and Clostridium spp.) and other harmful microorganisms.

Monitoring of Foodborne Pathogens in Raw Cow Milk in Tuscany

PubMed Central

D’Alonzo, Alessia; Senese, Matteo; Fabbri, Ilaria; Cirri, Cristina; Milioni, Carla; Valenza, Valeria; Tolli, Rita; Campeis, Francesca; Fischetti, Roberto

2014-01-01

Raw milk consumption in Italy has increased over the last few years and although raw milk is characterised by cold chain, short shelf-life and the duty of boiling before domestic consumption, it is still considered a hazard. From 2010 to 2013 a monitoring survey of raw milk sold through vending machines was carried out to investigate the occurrence of several foodborne pathogens stipulated in the national legal requirements, i.e. Listeria monocytogenes, Campylobacter spp., Salmonella spp., Escherichia coli O:157 and coagulase-positive Staphylococci. A total of 127 raw milk samples were collected from 19 dairy herds in Tuscany Region, Italy. In addition, the milk samples were tested for the presence and count of Yersinia genus. Results shown that only one sample was positive for non verocytotoxin-producing E. coli O:157, whereas a total of 38 samples (29.9%) were postive for Yersinia genus; of the total 39 isolated bacteria, 23.6% were Y. enterocolitica, 2.4% Y. kristenseni and 4.7% Y. frederiksenii. None isolate was enteropathogenic; serotypes O:5 and O:8 were found in 16.6 and 13.3% of the isolates respectively, whereas none of the serotypes tested was detected in 70% of the isolates. The most probable number method revealed a count value between 0.03 and 24 MPN/mL. Based on these data a general assurance on health safety of raw milk produced and sold in Tuscany could be assessed. PMID:27800320

ELECTROLYTE AND MINERAL COMPOSITION OF TERM DONOR HUMAN MILK BEFORE AND AFTER PASTEURIZATION AND OF RAW MILK OF PRETERM MOTHERS.

PubMed

Codo, Carla Regina Bianchi; Caldas, Jamil Pedro de Siqueira; Peixoto, Rafaella Regina Alves; Sanches, Vitor Lacerda; Guiraldelo, Tamara Cristina; Cadore, Solange; Marba, Sérgio Tadeu Martins

2018-02-22

To determine and compare the concentrations of electrolytes and minerals in three different types of maternal milk samples: term donor milk before pasteurization, term donor milk after pasteurization and raw milk of mothers of preterm newborns at bedside. Descriptive cross-sectional study. Concentrations of calcium (Ca), phosphorous (P), magnesium (Mg), sodium (Na) and potassium (K) were measured in random samples of three human breast milk groups. Samples were analyzed using acid mineralization assisted by microwave radiation and further analysis by inductively coupled plasma optical emission spectrometry. Concentrations were expressed in mg/L, described as mean and standard deviation. The one-way ANOVA and Tukey's post-test were applied to determine the variability between the means of each group. Significance level was set at 5%. There was a significant reduction in the content of Ca (259.4±96.8 vs. 217.0±54.9; p=0.003), P (139.1±51.7 vs. 116.8±33.3; p=0.004) and K (580.8±177.1 vs. 470.9±109.4; p<0.0001) in donor maternal milk before and after pasteurization. Samples of raw milk presented higher contents of Na than the donated milk (twice). The elements P and Ca would only reach the daily intake levels recommended by the European Society of Pediatric Gastroenterology, Hepatology and Nutrition if at least 60 mL of milk could be offered every 3 hours. Mg levels were not different between the three groups. There was a significant reduction in Ca, P and K levels in samples after pasteurization. The Na value in raw milk, collected at bedside, was higher than in the samples of donor's milk before pasteurization.

Comparative analysis of the microbial communities in raw milk produced in different regions of Korea.

PubMed

Kim, In Seon; Hur, Yoo Kyung; Kim, Eun Ji; Ahn, Young-Tae; Kim, Jong Geun; Choi, Yun-Jaie; Huh, Chul Sung

2017-11-01

The control of psychrotrophic bacteria causing milk spoilage and illness due to toxic compounds is an important issue in the dairy industry. In South Korea, Gangwon-do province is one of the coldest terrains in which eighty percent of the area is mountainous regions, and mainly plays an important role in the agriculture and dairy industries. The purposes of this study were to analyze the indigenous microbiota of raw milk in Gangwon-do and accurately investigate a putative microbial group causing deterioration in milk quality. We collected raw milk from the bulk tank of 18 dairy farms in the Hoengseong and Pyeongchang regions of Gangwon-do. Milk components were analyzed and the number of viable bacteria was confirmed. The V3 and V4 regions of 16S rRNA gene were amplified and sequenced on an Illumina Miseq platform. Sequences were then assigned to operational taxonomic units, followed by the selection of representative sequences using the QIIME software package. The milk samples from Pyeongchang were higher in fat, protein, lactose, total solid, and solid non-fat, and bacterial cell counts were observed only for the Hoengseong samples. The phylum Proteobacteria was detected most frequently in both the Hoengseong and Pyeongchang samples, followed by the phyla Firmicutes and Actinobacteria. Notably, Corynebacterium, Pediococcus, Macrococcus, and Acinetobacter were significantly different from two regions. Although the predominant phylum in raw milk is same, the abundances of major genera in milk samples were different between Hoengseong and Pyeongchang. We assumed that these differences are caused by regional dissimilar farming environments such as soil, forage, and dairy farming equipment so that the quality of milk raw milk from Pyeongchang is higher than that of Hoengseong. These results could provide the crucial information for identifying the microbiota in raw milk of South Korea.

Assessment of raw milk quality and stakeholders' awareness on milk-borne health risks in Arusha City and Meru District, Tanzania.

PubMed

Ngasala, J Uma Bukuku; Nonga, Hezron Emmanuel; Mtambo, Mkumbukwa Madundo Angelo

2015-06-01

A cross-sectional study was conducted to assess the quality of raw milk and stakeholders' awareness on milk-borne health risks and factors for poor milk hygiene in Arusha City and Meru District, Tanzania between October and December 2012. A total of 105 smallholder dairy farmers, milk vendors and milk retailers were interviewed, and milk samples were collected for physical, microbial and antibiotic residue analysis using standard procedures. Questionnaire results indicated high level of awareness (94 %) that drinking raw milk can predispose consumers to milk-borne diseases; nevertheless, 65 % of respondents consumed raw milk. Physicochemical analyses showed some of the milk had sediments (20 %), bad smell (21 %) and had clotted on alcohol test (27 %). About 36 % of milk samples had pH below 6.6, and 25 % had specific gravity below 1.028 g/ml. The mean total viable count (TVC) of milk from vendors is significantly (P < 0.05) higher than that from retailers and smallholder dairy farmers. Generally, 65 % of milk samples assessed had a higher TVC than the level recommended (2.0 × 10(5) cfu/ml) by the East African Community (EAC) standards. Up to 91 % of the milk samples had bacterial growth that included Eschericia coli (66 %), Staphylococcus aureus (33 %), Corynebacterium (11 %) and Pseudomonas (10 %). All smallholder dairy farmers were aware of drug residues, but majority (57 %) were unaware of human health effects caused by veterinary drug residues in milk. Up to 97 % of respondents reported to comply with drug withdrawal periods. This possibly led to all milk samples analysed to be negative from detectable levels of antibiotic residues. It is concluded that the level of awareness on milk quality is high, although practices associated with milking and post-harvest handling predispose milk to bacterial contamination which is a public health risk to milk consumers.

Impact of pasteurization on the antibacterial properties of human milk.

PubMed

Van Gysel, Marjan; Cossey, Veerle; Fieuws, Steffen; Schuermans, Annette

2012-08-01

Growing evidence favours the use of human milk for the feeding of preterm newborns based on its many beneficial effects. Despite the many benefits, human milk has been associated as a possible vehicle of transmission for a number of infections. Although pasteurization of human milk can diminish the risk of neonatal infection, it also significantly reduces the concentrations of immunological components in human milk due to thermal damage. In order to evaluate the impact of pasteurization on the antibacterial properties of human milk, we aimed to compare the capacity of raw and pasteurized human milk to inhibit bacterial proliferation. Therefore, a single milk sample was collected from ten healthy lactating mothers. Each sample was divided into two aliquots; one aliquot was pasteurized, while the other was kept raw. Both aliquots were inoculated either with Escherichia coli or Staphylococcus aureus and incubated at 37 °C during 8 h. Viable colony counts from the inoculated samples were performed at regular time points to compare the bacterial growth in both forms of breast milk. Relative to the tryptic soy broth control sample, both raw and pasteurized milk samples exhibited an inhibitory effect on the growth of E. coli and S. aureus. Compared with the raw portion, growth inhibition was significantly lower in the pasteurized milk at every time point beyond T0 (after 2, 4 and 8 h of incubation) (p = 0.0003 for E. coli and p < 0.0001 for S. aureus). Our study shows that pasteurization adversely affects the antibacterial properties of human milk.

[Detection of a Disease Cluster by the Health Authorities of Stendal District due to Campylobacter jejuni in a Nursery After the Consumption of Raw Milk].

PubMed

Hermann, N; Schubert, I

2015-07-01

A notification from a laboratory concerning the detection of Campylobacter jejuni in a 6-year-old boy initiated the investigation carried out by the health authorities from Stendal district, in order to explain the morbidity rate caused by the germ. The day after the boy's pediatrician informed about a visit to a farm, which was confirmed by the head of the nursery. She told the health authorities about the consumption of raw milk during their visit at the farm.The following days more children fell sick. Within 10 days the total number of diseased children was 21. The health authorities asked for stool samples of the diseased children, nursery nurses and the head of the farm since raw milk presents a potential cause of infection. The health authorities together with the Saxony-Anhalt State Office for Consumer Protection conducted a retrospective cohort study. The aim was to explain the association between the exposure from raw milk consumption and the occurrence of the disease from C. jejuni. Based on a questionnaire data about the food and milk intake at the nursery and at home and about the trip to the farm were collected. 91% of the children's cohort and 86% of the adults' cohort were captured.The exposed group at risk showed a higher risk of falling ill than the group, which was not exposed. The risk factor raw milk explained the difference. Furthermore, the analysis of milk samples taken by the district veterinary office from 2 cows and from the farm's tank was able to detect the germs. The correlation of the illness, the consumption of raw milk, the detection of C. jejuni in the samples taken from the children and the samples taken from the cows was evident. Based on the case the health authorities recommended that heads of nurseries as well as heads of dairy farming in the district of Stendal needed to be advised on raw milk. Nurseries are still allowed to take trips to farms. However, raw animal derivates including milk must not be consumed. © Georg Thieme Verlag KG Stuttgart · New York.

Bacteria and Bioactivity in Holder Pasteurized and Shelf-Stable Human Milk Products

PubMed Central

2017-01-01

Abstract Background: Historically, Holder pasteurization has been used to pasteurize donor human milk available in a hospital setting. There is extensive research that provides an overview of the impact of Holder pasteurization on bioactive components of human milk. A shelf-stable (SS) human milk product, created using retort processing, recently became available; however, to our knowledge, little has been published about the effect of retort processing on human milk. Objective: We aimed to assess the ability of retort processing to eliminate bacteria and to quantify the difference in lysozyme and secretory immunoglobulin A (sIgA) activity between Holder pasteurized (HP) and SS human milk. Methods: Milk samples from 60 mothers were pooled. From this pool, 36 samples were taken: 12 samples were kept raw, 12 samples were HP, and 12 samples were retort processed to create an SS product. All samples were analyzed for total aerobic bacteria, coliform bacteria, Bacillus cereus, sIgA activity, and lysozyme activity. Raw samples served as the control. Results: One raw sample and 3 HP samples contained B. cereus at the time of culture. There were no detectable bacteria in SS samples at the time of culture. Raw samples had significantly greater lysozyme and sIgA activity than HP and SS samples (P < 0.0001). HP samples retained significantly more lysozyme and sIgA activity (54% and 87%, respectively) than SS samples (0% and 11%, respectively). Conclusions: Human milk processed using Holder pasteurization should continue to be screened for the presence of B. cereus. Clinicians should be aware of the differences in the retention of lysozyme and sIgA activity in HP and SS products when making feeding decisions for medically fragile or immunocompromised infants to ensure that patients are receiving the maximum immune protection. PMID:29955718

Impacts of Seasonal Housing and Teat Preparation on Raw Milk Microbiota: a High-Throughput Sequencing Study.

PubMed

Doyle, Conor J; Gleeson, David; O'Toole, Paul W; Cotter, Paul D

2017-01-15

In pasture-based systems, changes in dairy herd habitat due to seasonality results in the exposure of animals to different environmental niches. These niches contain distinct microbial communities that may be transferred to raw milk, with potentially important food quality and safety implications for milk producers. It is postulated that the extent to which these microorganisms are transferred could be limited by the inclusion of a teat preparation step prior to milking. High-throughput sequencing on a variety of microbial niches on farms was used to study the patterns of microbial movement through the dairy production chain and, in the process, to investigate the impact of seasonal housing and the inclusion/exclusion of a teat preparation regime on the raw milk microbiota from the same herd over two sampling periods, i.e., indoor and outdoor. Beta diversity and network analyses showed that environmental and milk microbiotas separated depending on whether they were sourced from an indoor or outdoor environment. Within these respective habitats, similarities between the milk microbiota and that of teat swab samples and, to a lesser extent, fecal samples were apparent. Indeed, SourceTracker identified the teat surface as the most significant source of contamination, with herd feces being the next most prevalent source of contamination. In milk from cows grazing outdoors, teat prep significantly increased the numbers of total bacteria present. In summary, sequence-based microbiota analysis identified possible sources of raw milk contamination and highlighted the influence of environment and farm management practices on the raw milk microbiota. The composition of the raw milk microbiota is an important consideration from both a spoilage perspective and a food safety perspective and has implications for milk targeted for direct consumption and for downstream processing. Factors that influence contamination have been examined previously, primarily through the use of culture-based techniques. We describe here the extensive application of high-throughput DNA sequencing technologies to study the relationship between the milk production environment and the raw milk microbiota. The results show that the environment in which the herd was kept was the primary driver of the composition of the milk microbiota composition. Copyright © 2016 American Society for Microbiology.

Impacts of Seasonal Housing and Teat Preparation on Raw Milk Microbiota: a High-Throughput Sequencing Study

PubMed Central

Doyle, Conor J.; Gleeson, David; O'Toole, Paul W.

2016-01-01

ABSTRACT In pasture-based systems, changes in dairy herd habitat due to seasonality results in the exposure of animals to different environmental niches. These niches contain distinct microbial communities that may be transferred to raw milk, with potentially important food quality and safety implications for milk producers. It is postulated that the extent to which these microorganisms are transferred could be limited by the inclusion of a teat preparation step prior to milking. High-throughput sequencing on a variety of microbial niches on farms was used to study the patterns of microbial movement through the dairy production chain and, in the process, to investigate the impact of seasonal housing and the inclusion/exclusion of a teat preparation regime on the raw milk microbiota from the same herd over two sampling periods, i.e., indoor and outdoor. Beta diversity and network analyses showed that environmental and milk microbiotas separated depending on whether they were sourced from an indoor or outdoor environment. Within these respective habitats, similarities between the milk microbiota and that of teat swab samples and, to a lesser extent, fecal samples were apparent. Indeed, SourceTracker identified the teat surface as the most significant source of contamination, with herd feces being the next most prevalent source of contamination. In milk from cows grazing outdoors, teat prep significantly increased the numbers of total bacteria present. In summary, sequence-based microbiota analysis identified possible sources of raw milk contamination and highlighted the influence of environment and farm management practices on the raw milk microbiota. IMPORTANCE The composition of the raw milk microbiota is an important consideration from both a spoilage perspective and a food safety perspective and has implications for milk targeted for direct consumption and for downstream processing. Factors that influence contamination have been examined previously, primarily through the use of culture-based techniques. We describe here the extensive application of high-throughput DNA sequencing technologies to study the relationship between the milk production environment and the raw milk microbiota. The results show that the environment in which the herd was kept was the primary driver of the composition of the milk microbiota composition. PMID:27815277

A Survey of Naturally-Occurring Steroid Hormones in Raw Milk and the Associated Health Risks in Tangshan City, Hebei Province, China

PubMed Central

Qu, Xueyin; Su, Chuanyou; Zheng, Nan; Li, Songli; Meng, Lu; Wang, Jiaqi

2017-01-01

In recent years, high levels of hormone residue in food, capable of damaging the health of consumers, have been recorded frequently. In this study, 195 raw milk samples were obtained from Tangshan City, China, and the concentrations of 22 steroid hormones were measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Cortisol was detected in 12.5% of raw milk samples (mean 0.61 µg/kg; range:

Real-Time PCR Detection of Paenibacillus spp. in Raw Milk To Predict Shelf Life Performance of Pasteurized Fluid Milk Products

PubMed Central

Ranieri, Matthew L.; Ivy, Reid A.; Mitchell, W. Robert; Call, Emma; Masiello, Stephanie N.; Wiedmann, Martin

2012-01-01

Psychrotolerant sporeformers, specifically Paenibacillus spp., are important spoilage bacteria for pasteurized, refrigerated foods such as fluid milk. While Paenibacillus spp. have been isolated from farm environments, raw milk, processing plant environments, and pasteurized fluid milk, no information on the number of Paenibacillus spp. that need to be present in raw milk to cause pasteurized milk spoilage was available. A real-time PCR assay targeting the 16S rRNA gene was designed to detect Paenibacillus spp. in fluid milk and to discriminate between Paenibacillus and other closely related spore-forming bacteria. Specificity was confirmed using 16 Paenibacillus and 17 Bacillus isolates. All 16 Paenibacillus isolates were detected with a mean cycle threshold (CT) of 19.14 ± 0.54. While 14/17 Bacillus isolates showed no signal (CT > 40), 3 Bacillus isolates showed very weak positive signals (CT = 38.66 ± 0.65). The assay provided a detection limit of approximately 3.25 × 101 CFU/ml using total genomic DNA extracted from raw milk samples inoculated with Paenibacillus. Application of the TaqMan PCR to colony lysates obtained from heat-treated and enriched raw milk provided fast and accurate detection of Paenibacillus. Heat-treated milk samples where Paenibacillus (≥1 CFU/ml) was detected by this colony TaqMan PCR showed high bacterial counts (>4.30 log CFU/ml) after refrigerated storage (6°C) for 21 days. We thus developed a tool for rapid detection of Paenibacillus that has the potential to identify raw milk with microbial spoilage potential as a pasteurized product. PMID:22685148

Changes in the microbial composition of raw milk induced by thermization treatments applied prior to traditional Greek hard cheese processing.

PubMed

Samelis, John; Lianou, Alexandra; Kakouri, Athanasia; Delbès, Céline; Rogelj, Irena; Bogovic-Matijasić, Bojana; Montel, Marie-Christine

2009-04-01

The microbiological quality, safety, and composition of mixtures of ewe's and goat's milk (90:10) used for cheesemaking were evaluated before and after thermization at 60 and 67 degrees C for 30 s. Such mild thermal treatments are commonly applied to reduce natural contaminants of raw milk before processing for traditional hard Greek cheeses. Raw milk samples had an average total bacterial count of 7.3 log CFU/ml; most of these bacteria were lactic acid bacteria (LAB) and pseudomonads. The LAB flora of raw milk was dominated by enterococci (40.8%), followed by lactococci (20.4%), leuconostocs (18.4%), and mesophilic lactobacilli (10.2%). Enterococcus faecalis (30.1%) and Enterococcus faecium (13.7%) were the most common LAB isolates, followed by Enterococcus durans, Lactococcus lactis subsp. lactis, Lactobacillus plantarum, and Leuconostoc lactis. Thermization at 60 degrees C for 30 s was effective for reducing raw milk contamination by enterobacteria (5.1 log CFU/ml), coagulase-positive staphylococci (3.3 log CFU/ml), and Listeria (present in 25-ml samples) to safe levels, but it also reduced mesophilic lactococci, leuconostocs, lactobacilli, and selected enterococci (72.0%) in thermized milk. Thermization at 67 degrees C for 30 s had a major inactivation effect on all bacterial groups. Two nisin-producing L. lactis subsp. lactis strains (M78 and M104) were isolated from raw milk, but neither nisin-producing nor other bacteriocin-producing LAB strains were isolated from thermized milk. Thus, thermization treatments control harmful bacteria but also may have a negative impact on milk quality by reducing desirable LAB and the biodiversity of raw milk bacteria overall, inactivating potentially protective LAB strains and enhancing the ability of potentially pathogenic enterococci to grow in fresh cheese curds.

A rapid method for the detection of foodborne pathogens by extraction of a trace amount of DNA from raw milk based on amino-modified silica-coated magnetic nanoparticles and polymerase chain reaction.

PubMed

Bai, Yalong; Song, Minghui; Cui, Yan; Shi, Chunlei; Wang, Dapeng; Paoli, George C; Shi, Xianming

2013-07-17

A method based on amino-modified silica-coated magnetic nanoparticles (ASMNPs) and polymerase chain reaction (PCR) was developed to rapidly and sensitively detect foodborne pathogens in raw milk. After optimizing parameters such as pH, temperature, and time, a trace amount of genomic DNA of pathogens could be extracted directly from complex matrices such as raw milk using ASMNPs. The magnetically separated complexes of genomic DNA and ASMNPs were directly subjected to single PCR (S-PCR) or multiplex PCR (M-PCR) to detect single or multiple pathogens from raw milk samples. Salmonella Enteritidis (Gram-negative) and Listeria monocytogenes (Gram-positive) were used as model organisms to artificially contaminate raw milk samples. After magnetic separation and S-PCR, the detection sensitivities were 8 CFU mL(-1) and 13 CFU mL(-1) respectively for these two types of pathogens. Furthermore, this method was successfully used to detect multiple pathogens (S. Enteritidis and L. monocytogenes) from artificially contaminated raw milk using M-PCR at sensitivities of 15 CFU mL(-1) and 25 CFU mL(-1), respectively. This method has great potential to rapidly and sensitively detect pathogens in raw milk or other complex food matrices. Copyright © 2013 Elsevier B.V. All rights reserved.

Recurrent outbreak of Campylobacter jejuni infections associated with a raw milk dairy--Pennsylvania, April-May 2013.

PubMed

2013-08-30

During May 2013, the Pennsylvania Department of Health investigated an outbreak of campylobacteriosis among consumers of raw (unpasteurized) milk from a dairy certified by the Pennsylvania Department of Agriculture (PDA) to sell raw milk onsite, at retail stores, and at off-farm pick-up sites. Investigation by the Pennsylvania Department of Health and PDA identified six confirmed and two probable cases of campylobacteriosis associated with raw milk from the dairy. A confirmed case was defined as laboratory-confirmed campylobacteriosis in a person who drank the dairy's raw milk. A probable case was defined as diarrheal illness without laboratory confirmation in a person who had consumed the dairy's raw milk and was linked to a confirmed case. Four cases involved children aged ≤18 years. PDA identified Campylobacter in bulk tank and retail milk samples from the dairy. Available isolates from patient stool (n = 1), bulk tank milk (n = 1), and retail milk (n = 1) were identified by CDC as Campylobacter jejuni and were indistinguishable by pulsed-field gel electrophoresis (PFGE).

Evaluation of a portable test system for assessing endotoxin activity in raw milk

PubMed Central

SUZUKI, Yohko; SUZUKI, Kazuyuki; SHIMAMORI, Toshio; TSUCHIYA, Masakazu; NIEHAUS, Andrew; LAKRITZ, Jeffrey

2015-01-01

The aim of the present study was to compare endotoxin activities detected in raw milk samples obtained from cattle by a commercially available portable test system (PTS) and traditional microplate limulus amebocyte lysate (LAL)-based assay, which determined activities using a kinetic turbidimetric (KT) assay. Raw milk samples were obtained from 53 and 12 dairy cattle without and with clinical mastitis, respectively. Comparison between the KT and PTS was performed by the Friedman test. The Pearson product moment correlation coefficients were calculated to evaluate associations between any two continuous variables. Linear regression model analysis was also performed to obtain the equation describing the relationship between PTS and KT assay. The endotoxin activities detected in 200- or 400-fold diluted milk samples were similar between PTS and KT assay, whereas a significant difference was observed in 100-fold diluted milk (P<0.001). The results obtained from 200- (r2=0.778, P<0.001) and 400-fold diluted milk samples (r2=0.945, P<0.001) using PTS correlated with those using KT assay. The median milk endotoxin activities in Gram-positive and Gram-negative clinical mastitis cows were 0.655 and 11,523.5 EU/ml, respectively. The results of the present study suggest that PTS as a simple and easy test to assess endotoxin activity in raw milk is efficient, simple and reproducible. PMID:26279135

Isolation of microbial pathogens of subclinical mastitis from raw sheep's milk of Epirus (Greece) and their role in its hygiene.

PubMed

Fotou, K; Tzora, A; Voidarou, Ch; Alexopoulos, A; Plessas, S; Avgeris, I; Bezirtzoglou, E; Akrida-Demertzi, K; Demertzis, P G

2011-12-01

The natural raw milk microflora is a factor that expresses its sensorial characteristics. The microbial charge into the mammary gland of healthy animal is low and the application of right and healthy conditions during milking and cheese making procedure, prevents from contaminating as well as maintains the natural microflora in order to lend the particular characteristics of milk. The purpose of the present project was the study of the Total Viable Count (T.V.C.) and the count of total psychrotropic bacteria of raw sheep milk from Boutsiko and Karamaniko breeds, collected from healthy animals, as well as the isolation, identification and enumeration of pathogenic bacteria related with the hygiene and the quality of raw sheep milk (with a particular interest in bacteria that may cause human infection). During the experiment we examined two hundred forty (240) samples of raw sheep milk. In these samples a) Staphylococcus aureus, Salmonella sp., Escherichia coli, Clostridium perfringens (vegetative cells and spores) and Bacillus sp. were isolated and identified b) the Total Viable Count and the total number of psychrotropic bacteria were also specified. The sampling, the preparation of samples and decimal dilutions were based on international methods. The Total viable count was determined using the standard methods of the American Public Health Association, 2002. The total number of psychrotropic bacteria was determined using APHA 1976, 1978 rules. The identification of the bacteria was carried out according to the Bergey's manual. Microscopic examination of Gram stained cells, catalase, oxidase and biochemical tests were performed when necessary to further identify. From the 240 milk samples tested, only 5% were E. coli positive, with mean counts ranged from 2 × 10(3) to 2.4 × 10(4) cfu/ml. S. aureus was isolated from 24% of the samples and the mean count per ml was ranged from <10 to 3.4 × 10(2). Meanwhile, Bacillus spp. was also detected in 29% samples. Vegetative forms and spores of C. perfringens were detected in 13% and 63% of the samples respectively. However, microbiological analyses revealed the presence of a small number of selected pathogens in milk samples such as Salmonella, which was only detected in 5% of the samples. Listeria sp., Pseudomonas sp. and Vibrio cholerae were never found. From the experimental results, the Total Viable Count from raw sheep milk samples, fulfils the microbiological criteria of EU Legislation in a percentage of approximately 97%. Copyright © 2011 Elsevier Ltd. All rights reserved.

Molecular analysis of bacterial communities in raw cow milk and the impact of refrigeration on its structure and dynamics.

PubMed

Raats, Dina; Offek, Maya; Minz, Dror; Halpern, Malka

2011-05-01

The impact of refrigeration on raw cow milk bacterial communities in three farm bulk tanks and three dairy plant silo tanks was studied using two methods: DGGE and cloning. Both methods demonstrated that bacterial taxonomic diversity decreased during refrigeration. Gammaproteobacteria, especially Pseudomonadales, dominated the milk after refrigeration. Farm samples and dairy plant samples differed in their microbial community composition, the former showing prevalence of Gram-positive bacteria affiliated with the classes Bacilli, Clostridia and Actinobacteria, the latter showing prevalence of Gram-negative species belonging to the Gammaproteobacteria class. Actinobacteria prevalence in the farm milk samples immediately after collection stood at about 25% of the clones. A previous study had found that psychrotolerant Actinobacteria identified in raw cow milk demonstrated both lipolytic and proteolytic enzymatic activity. Thus, we conclude that although Pseudomonadales play an important role in milk spoilage after long periods of cold incubation, Actinobacteria occurrence may play an important role when assessing the quality of milk arriving at the dairy plant from different farms. As new cooling technologies reduce the initial bacterial counts of milk to very low levels, more sensitive and efficient methods to evaluate the bacterial quality of raw milk are required. The present findings are an important step towards achieving this goal. Copyright © 2010 Elsevier Ltd. All rights reserved.

A review of the current situation of aflatoxin M1 in cow's milk in Serbia: risk assessment and regulatory aspects.

PubMed

Milićević, Dragan R; Spirić, Danka; Radičević, Tatjana; Velebit, Branko; Stefanović, Srdjan; Milojević, Lazar; Janković, Saša

2017-09-01

The aim of this systematic review is to provide information regarding the incidence and levels of aflatoxin M 1 (AFM 1 ) in raw and heat processed cow's milk in Serbia during 2015-16 and to compare these with collected data on the occurrence of AFM 1 in raw milk and dairy products during the last decade in our region. Estimation of dietary exposure (EDI) and hazard index (HI) calculations for different age groups of the population were also carried out, based on the AFM 1 content of milk samples and on available food consumption data in Serbia. AFM 1 was detected in 69.9% (984/1408) of raw milk samples in 2015 versus 84.9% (3094/3646) in 2016, while in heat-processed milk, AFM 1 was detected in 77.8% (364/468) in 2015 versus 98.5% (753/765) in 2016. On the basis of the obtained results, 450 (9%) of raw and 14 (1.1%) of heat-processed milk samples were contaminated with AFM 1 levels above the maximum permitted level in Serbia (0.25 μg kg -1 ). However, a large percentage of raw and heat processed milk in Serbia (30.1% and 17.3%, respectively) was contaminated with AFM 1 levels above the maximum permitted level regulated in the European Union (0.05 μg kg -1 ). Therefore, in order to protect consumer health, it is extremely important to further control the level of aflatoxins in milk, and this should be considered as a high priority for risk management actions.

High-throughput metataxonomic characterization of the raw milk microbiota identifies changes reflecting lactation stage and storage conditions.

PubMed

Doyle, Conor J; Gleeson, David; O'Toole, Paul W; Cotter, Paul D

2017-08-16

Low temperature is used to control the growth of bacteria in milk, both pre- and post-pasteurization. As the duration of refrigerated storage extends, psychrotrophs dominate the milk microbiota, that can produce heat stable lipases which negatively impact the organoleptic qualities of milk. Here we examine the influence that refrigeration temperature (2°C, 4°C and 6°C) and storage duration (96h) have on the microbiota composition (16S profiling) of raw bulk tank milk (BTM). To reflect a proposed change to current farming practices, raw milk was blended after each milking (8 milkings) and stored for five consecutive days in each temperature-specific tank. Here 16S rRNA-based microbiota compositional analysis was performed after milk was collected on day 1 and again after the final addition of milk at day 5. In addition to assessing the impact of the duration and temperature of storage, the influence of lactation stage, i.e. mid- versus late-lactation, on the microbiota of the blended BTM was also examined. Overall, both temperature and length of storage had surprisingly little influence on the raw milk microbiota, other than an increase in proportions of Gammaproteobacteria in the blended milk samples collected after pooling on day 5, and in samples stored at 6°C. However, lactation stage had a considerable influence on microbiota composition, with milk from mid-lactation containing higher proportions of Bacteroides, Faecalibacterium, Campylobacter and Rhodanobacter, and late-lactation milk containing higher proportions of Actinobacteria. Overall, the study demonstrates that current temperature and storage duration practises impact the microbiota of raw milk, but these impacts are modest relative to the more considerable differences between mid and late-lactation milk. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of processing on the digestibility of milk

USDA-ARS?s Scientific Manuscript database

Processing of milk by homogenization and pasteurization causes changes in the milk proteins and fats, but there is little information about whether these changes affect milk digestibility. In this study, whole and skim milk samples were processed and compared to raw milk after all samples had underg...

Lipolytic and proteolytic activity of Pseudomonas spp. isolated during milking and storage of refrigerated raw milk.

PubMed

Capodifoglio, Eduardo; Vidal, Ana Maria Centola; Lima, Joyce Aparecida Santos; Bortoletto, Fernanda; D'Abreu, Léa Furlan; Gonçalves, Ana Carolina Siqueira; Vaz, Andreia Cristina Nakashima; Balieiro, Julio Cesar de Carvalho; Netto, Arlindo Saran

2016-07-01

The aim of this study was to verify the presence of lipolytic and proteolytic Pseudomonas spp. during milking and storage of refrigerated raw milk. We also intended to compare samples collected during rainy and dry seasons, from farms with manual and mechanical milking systems. For this, samples of milkers' hands, cows' teats, water, expansion tanks, equipment, and utensils used during milking were analyzed regarding Pseudomonas spp. Positive samples were tested for the production of lipolytic and proteolytic enzymes. Microorganisms of the genus Pseudomonas were isolated from all sampling points. A higher isolation rate of the bacterium was found in the rainy season except for 6 sampling points, with all of these associated with mechanical milking systems. Pseudomonas spp. exhibiting lipolytic activity were found to be predominant during the dry season, since no activity was detected during the rainy season in 26 of the 29 sampling sites. The highest number of lipolytic Pseudomonas isolates was obtained from water. Presence of lipase-producing Pseudomonas spp. was verified in 7 and 36% of the samples collected from farms with manual and mechanical milking, respectively. When analyzing raw milk collected from expansion tanks immediately (0 h) and 24h after milking, we observed that for dairy properties with manual milking process, 10% of the Pseudomonas isolates were positive for lipolytic activity. The percentage increased to 12% 48h after milking. Mean averages were 32, 33, and 39% immediately after, 24 and 48h after milking, respectively, for farms with mechanical milking. All sampling points showed the presence of proteolytic strains of Pseudomonas. The highest proteolytic activity was found during the rainy season, except for the samples collected from milkers' hands before milking, buckets, and teat cup inner surfaces after milking and from the water in dairy farms with mechanical milking system. Of these samples, 72, 56, and 50%, respectively, were positive for proteolysis during the dry season. For the water samples, a statistical difference was observed between mechanical (50%) and manual (7%) milking systems in the percentage of proteolytic activity. No production of proteolytic enzyme was detected in the samples from milkers' hands taken after milking and no statistically significant difference was found among manual (19.91%) and mechanical (47.85%) milking. During the rainy months, no proteolysis was detected in the samples taken from cows' teats after the predipping. It is evident, therefore, that preventive measures capable of minimizing the contamination with Pseudomonas spp. during milking and storage of refrigerated raw milk are needed, regardless of season. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Occurrence of Salmonella, Listeria monocytogenes, and enterotoxigenic Staphylococcus in goat milk from small and medium-sized farms located in Minas Gerais State, Brazil.

PubMed

Cavicchioli, V Q; Scatamburlo, T M; Yamazi, A K; Pieri, F A; Nero, L A

2015-12-01

Consumption of goat milk has been increasing due to its nutritional characteristics and health benefits. Therefore, assessment of the presence of foodborne pathogens in this product is critical to ensure its safety to consumers. The present study aimed to identify common foodborne pathogens in raw goat milk. Fifty-three samples of raw goat milk from 11 farms were collected and cultured for the presence of Salmonella spp. and Listeria monocytogenes, as well as for enumeration and isolation of coagulase-positive and coagulase-negative Staphylococcus (CPS and CNS, respectively). All samples tested negative for Salmonella spp. and L. monocytogenes. The CPS counts in raw goat milk samples were predominantly less than 2 log cfu/mL (n=39), and CNS counts were predominantly higher than 3 log cfu/mL (n=42). Based on Staphylococcus counts, 51 isolates were selected (CPS=26; CNS=25) and tested by PCR for the presence of classic enterotoxin-encoding genes (sea, seb, sec, sed, and see). Only 3 isolates (CPS=2, CNS=1) were negative for all enterotoxin-encoding genes tested, and the genotype sec and see was the most frequent (n=16), followed by sea, sec, and see (n=13) and sec (n=13); sed was not detected in any isolate. The frequencies of enterotoxin-encoding genes for CPS and CNS were similar, demonstrating the equivalence of both groups in harboring these virulent markers. These results suggest that Salmonella and L. monocytogenes are not frequent contaminants of raw goat milk, but that Staphylococcus spp. that are capable of producing enterotoxins are prevalent; therefore, consumers of raw goat milk and products made from raw milk are at risk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

High occurrence of Helicobacter pylori in raw goat, sheep and cow milk inferred by glmM gene: a risk of food-borne infection?

PubMed

Quaglia, N C; Dambrosio, A; Normanno, G; Parisi, A; Patrono, R; Ranieri, G; Rella, A; Celano, G V

2008-05-10

Helicobacter pylori is an organism widespread in humans and sometimes responsible for serious illnesses, such as gastric and duodenal ulcers, MALToma and even gastric cancer. It has been hypothesized that the infection route by H. pylori involves multiple pathways including food-borne transmission, as the microorganism has been detected from foods such as sheep and cow milk. This work reports the results of a survey conducted in order to investigate the presence of H. pylori in raw goat, sheep and cow milk produced in Southern Italy, employing a Nested Polymerase Chain Reaction (Nested-PCR) assay for the detection of the phosphoglucosamine mutase gene (glmM), as screening method followed by conventional bacteriological isolation. Out of the 400 raw milk samples examined, 139 (34.7%) resulted positive for the presence of glmM gene, but no strains were isolated. In this work H. pylori DNA has been firstly detected from 41 (25.6%) raw goat milk samples. The results deserve further investigations on the contamination source/s of the milk samples and on the major impact that it may have on consumers.

Technical note: enumeration of mesophilic aerobes in milk: evaluation of standard official protocols and Petrifilm aerobic count plates.

PubMed

Freitas, R; Nero, L A; Carvalho, A F

2009-07-01

Enumeration of mesophilic aerobes (MA) is the main quality and hygiene parameter for raw and pasteurized milk. High levels of these microorganisms indicate poor conditions in production, storage, and processing of milk, and also the presence of pathogens. Fifteen raw and 15 pasteurized milk samples were submitted for MA enumeration by a conventional plating method (using plate count agar) and Petrifilm Aerobic Count plates (3M, St. Paul, MN), followed by incubation according to 3 official protocols: IDF/ISO (incubation at 30 degrees C for 72 h), American Public Health Association (32 degrees C for 48 h), and Brazilian Ministry of Agriculture (36 degrees C for 48 h). The results were compared by linear regression and ANOVA. Considering the results from conventional methodology, good correlation indices and absence of significant differences between mean counts were observed, independent of type of milk sample (raw or pasteurized) and incubation conditions (IDF/ISO, American Public Health Association, or Ministry of Agriculture). Considering the results from Petrifilm Aerobic Count plates, good correlation indices and absence of significant differences were only observed for raw milk samples. The microbiota of pasteurized milk interfered negatively with the performance of Petrifilm Aerobic Count plates, probably because of the presence of microorganisms that poorly reduce the dye indicator of this system.

Detection of Staphylococcus aureus enterotoxigenic strains in bovine raw milk by reversed passive latex agglutination and multiplex polymerase chain reaction.

PubMed

Mansour, Asmaa Samy; Wagih, Gad El-Said; Morgan, Sabry D; Elhariri, Mahmoud; El-Shabrawy, Mona A; Abuelnaga, Azza S M; Elgabry, E A

2017-08-01

This review gives an outline of the assessment of enterotoxigenic Staphylococcus aureus tainting levels in raw milk from different sources in Egypt and characterization of enterotoxigenic strains utilizing a technique in light of PCR to identify genes coding for the production of staphylococcal enterotoxin (SE). The obtained data were compared with results from the application of the reversed passive latex. Multiplex PCR and reversed passive latex agglutination (RPLA) were used. A total of 141 samples of raw milk (cow's milk=33, buffalo's milk=58, and bulk tank milk=50) were investigated for S. aureus contamination and tested for enterotoxin genes presence and toxin production. S. aureus was detected in 23 (16.3%) samples phenotypically and genotypically by amplification of nuc gene. The S. aureus isolates were investigated for SEs genes ( sea to see ) by multiplex PCR and the toxin production by these isolates was screened by RPLA. SEs genes were detected in six isolates (26.1%) molecularly; see was the most observed gene where detected in all isolates, two isolates harbored seb , and two isolates harbored sec . According to RPLA, three isolates produced SEB and SEC. The study revealed the widespread of S. aureus strains caring genes coding for toxins. The real significance of the presence of these strains or its toxins in raw milk and their possible impact a potential hazard for staphylococcal food poisoning by raw milk consumption. Therefore, detection of enterotoxigenic S. aureus strains in raw milk is necessary for consumer safety.

Freezing and thawing effects on fat, protein, and lactose levels of human natural milk administered by gavage and continuous infusion.

PubMed

Abranches, Andrea D; Soares, Fernanda V M; Junior, Saint-Clair G; Moreira, Maria Elisabeth L

2014-01-01

to analyze the changes in human milk macronutrients: fat, protein, and lactose in natural human milk (raw), frozen and thawed, after administration simulation by gavage and continuous infusion. an experimental study was performed with 34 human milk samples. The infrared spectrophotometry using the infrared analysis equipment MilkoScan Minor® (Foss, Denmark) equipment was used to analyze the macronutrients in human milk during the study phases. The analyses were performed in natural (raw) samples and after freezing and fast thawing following two steps: gavage and continuous infusion. The non-parametric Wilcoxon test for paired samples was used for the statistical analysis. the fat content was significantly reduced after administration by continuous infusion (p<0.001) during administration of both raw and thawed samples. No changes in protein and lactose content were observed between the two forms of infusion. However, the thawing process significantly increased the levels of lactose and milk protein. the route of administration by continuous infusion showed the greatest influence on fat loss among all the processes required for human milk administration. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Occurrence and characterization of Shiga toxin-producing Escherichia coli in raw meat, raw milk, and street vended juices in Bangladesh.

PubMed

Islam, Mohammad A; Mondol, Abdus S; Azmi, Ishrat J; de Boer, Enne; Beumer, Rijkelt R; Zwietering, Marcel H; Heuvelink, Annet E; Talukder, Kaisar A

2010-11-01

The major objective of this study was to investigate the prevalence of Shiga toxin (Stx)-producing Escherichia coli (STEC) in different types of food samples and to compare their genetic relatedness with STEC strains previously isolated from animal sources in Bangladesh. We investigated a total of 213 food samples, including 90 raw meat samples collected from retail butcher shops, 20 raw milk samples from domestic cattle, and 103 fresh juice samples from street vendors in Dhaka city. We found that more than 68% (n = 62) of the raw meat samples were positive for the stx gene(s); 34% (n = 21) of buffalo meats and 66% (n = 41) of beef. Approximately 10% (n = 2) of the raw milk and 8% (n = 8) of the fresh juice samples were positive for stx. We isolated STEC O157 from seven meat samples (7.8%), of which two were from buffalo meats and five from beef; and no other STEC serotypes could be isolated. We could not isolate STEC from any of the stx-positive raw milk and juice samples. The STEC O157 isolates from raw meats were positive for the stx(2), eae, katP, etpD, and enterohemorrhagic E. coli hly virulence genes, and they belonged to three different phage types: 8 (14.3%), 31 (42.8%), and 32 (42.8%). Pulsed-field gel electrophoresis (PFGE) typing revealed six distinct patterns among seven isolates of STEC O157, suggesting a heterogeneous clonal diversity. Of the six PFGE patterns, one was identical and the other two were ≥90% related to PFGE patterns of STEC O157 strains previously isolated from animal feces, indicating that raw meats are readily contaminated with fecal materials. This study represents the first survey of STEC in the food chain in Bangladesh.

The analysis of milk components and pathogenic bacteria isolated from bovine raw milk in Korea.

PubMed

Park, Y K; Koo, H C; Kim, S H; Hwang, S Y; Jung, W K; Kim, J M; Shin, S; Kim, R T; Park, Y H

2007-12-01

Bovine mastitis can be diagnosed by abnormalities in milk components and somatic cell count (SCC), as well as by clinical signs. We examined raw milk in Korea by analyzing SCC, milk urea nitrogen (MUN), and the percentages of milk components (milk fat, protein, and lactose). The associations between SCC or MUN and other milk components were investigated, as well as the relationships between the bacterial species isolated from milk. Somatic cell counts, MUN, and the percentages of milk fat, protein, and lactose were analyzed in 30,019 raw milk samples collected from 2003 to 2006. The regression coefficients of natural logarithmic-transformed SCC (SCCt) on milk fat (-0.0149), lactose (-0.8910), and MUN (-0.0096), and those of MUN on milk fat (-0.3125), protein (-0.8012), and SCCt (-0.0671) were negative, whereas the regression coefficient of SCCt on protein was positive (0.3023). When the data were categorized by the presence or absence of bacterial infection in raw milk, SCCt was negatively associated with milk fat (-0.0172), protein (-0.2693), and lactose (-0.4108). The SCCt values were significantly affected by bacterial species. In particular, 104 milk samples infected with Staphylococcus aureus had the highest SCCt (1.67) compared with milk containing other mastitis-causing bacteria: coagulase-negative staphylococci (n = 755, 1.50), coagulase-positive staphylococci (except Staphylococcus aureus; n = 77, 1.59), Streptococcus spp. (Streptococcus dysgalactiae, n = 37; Streptococcus uberis, n = 12, 0.83), Enterococcus spp. (n = 46, 1.04), Escherichia coli (n = 705, 1.56), Pseudomonas spp. (n = 456, 1.59), and yeast (n = 189, 1.52). These results show that high SCC and MUN negatively affect milk components and that a statistical approach associating SCC, MUN, and milk components by bacterial infection can explain the patterns among them. Bacterial species present in raw milk are an important influence on SCC in Korea.

Short communication: Microbial quality of raw milk following commercial long-distance hauling.

PubMed

Darchuk, Emily M; Meunier-Goddik, Lisbeth; Waite-Cusic, Joy

2015-12-01

Hauling is a critical part of the commercial milk supply chain, yet very few studies have aimed to understand its effect on raw milk quality. This study focused on the effect of extended-duration tanker use during hauling on raw milk quality at a commercial facility. Standard tanker use [cleaned-in-place (CIP) once per 24h] served as a control and an incremental between-load water rinse with sanitizer treatment (RS) was evaluated to mitigate any effect from extended duration hauling. During this study, 1 commercial truck with 2 trailers was monitored for 10d. The truck collected milk at a large dairy farm, transported the milk to a manufacturing facility, and then returned to the same farm for a second load. Each round-trip journey took between 10 and 12h, allowing for 2 loads per 24-h use period. Following the second delivery, the truck was cleaned by CIP treatment starting a new treatment day. Producer samples were collected from the raw milk bulk tank on the farm before loading milk into the tanker. The same milk was sampled directly out of the tanker truck before unloading at the manufacturer. Effect on individual bacteria count, thermophilic spore count, and preliminary incubation count was quantified through common industry tests. Surface sponge swabs were also used to monitor tanker sanitation and the efficacy of cleaning treatments. Results did not identify a negative effect on raw milk quality due to extended duration hauling. Whereas the addition of RS did not provide any measurable quality benefits for the microbial milk quality, swab results demonstrated that the RS treatment was able to reduce surface bacteria in the tanker, although not to the same level as the full CIP treatment. Based on this study, current CIP practices for long distance milk hauling appear to be effective in mitigating any measurable effect on raw milk quality. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Modeling the occurrence of Mycobacterium avium subsp. paratuberculosis in bulk raw milk and the impact of management options for exposure mitigation.

PubMed

Boulais, Christophe; Wacker, Ron; Augustin, Jean-Christophe; Cheikh, Mohamed Hedi Ben; Peladan, Fabrice

2011-07-01

Mycobacterium avium subsp. paratuberculosis (MAP) is the causal agent of paratuberculosis (Johne's disease) in cattle and other farm ruminants. The potential role of MAP in Crohn's disease in humans and the contribution of dairy products to human exposure to MAP continue to be the subject of scientific debate. The occurrence of MAP in bulk raw milk from dairy herds was assessed using a stochastic modeling approach. Raw milk samples were collected from bulk tanks in dairy plants and tested for the presence of MAP. Results from this analytical screening were used in a Bayesian network to update the model prediction. Of the 83 raw milk samples tested, 4 were positive for MAP by culture and PCR. We estimated that the level of MAP in bulk tanks ranged from 0 CFU/ml for the 2.5th percentile to 65 CFU/ml for the 97.5th percentile, with 95% credibility intervals of [0, 0] and [16, 326], respectively. The model was used to evaluate the effect of measures aimed at reducing the occurrence of MAP in raw milk. Reducing the prevalence of paratuberculosis has less of an effect on the occurrence of MAP in bulk raw milk than does managing clinically infected animals through good farming practices. Copyright ©, International Association for Food Protection

Detection of Mycobacterium avium subspecies paratuberculosis specific IS900 insertion sequences in bulk-tank milk samples obtained from different regions throughout Switzerland

PubMed Central

Corti, Sabrina; Stephan, Roger

2002-01-01

Background Since Mycobacterium avium subspecies paratuberculosis (MAP) was isolated from intestinal tissue of a human patient suffering Crohn's disease, a controversial discussion exists whether MAP have a role in the etiology of Crohn's disease or not. Raw milk may be a potential vehicle for the transmission of MAP to human population. In a previous paper, we have demonstrated that MAP are found in raw milk samples obtained from a defined region in Switzerland. The aim of this work is to collect data about the prevalence of MAP specific IS900 insertion sequence in bulk-tank milk samples in different regions of Switzerland. Furthermore, we examined eventual correlation between the presence of MAP and the somatic cell counts, the total colony counts and the presence of Enterobacteriaceae. Results 273 (19.7%) of the 1384 examined bulk-tank milk samples tested IS900 PCR-positive. The prevalence, however, in the different regions of Switzerland shows significant differences and ranged from 1.7% to 49.2%. Furthermore, there were no statistically significant (p >> 0.05) differences between the somatic cell counts and the total colony counts of PCR-positive and PCR-negative milk samples. Enterobacteriaceae occur as often in IS900 PCR-positive as in PCR-negative milk samples. Conclusion This is the first study, which investigates the prevalence of MAP in bulk-tank milk samples all over Switzerland and infers the herd-level prevalence of MAP infection in dairy herds. The prevalence of 19.7% IS900 PCR-positive bulk-milk samples shows a wide distribution of subclinical MAP-infections in dairy stock in Switzerland. MAP can therefore often be transmitted to humans by raw milk consumption. PMID:12097144

Food safety in raw milk production: risk factors associated to bacterial DNA contamination.

PubMed

Cerva, Cristine; Bremm, Carolina; Reis, Emily Marques dos; Bezerra, André Vinícius Andrade; Loiko, Márcia Regina; Cruz, Cláudio Estêvão Farias da; Cenci, Alexander; Mayer, Fabiana Quoos

2014-06-01

While human illness from milkborne pathogens may be linked to contamination of the product after pasteurization or improper pasteurization, such diseases are usually associated with consumption of raw milk or its by-products. Molecular biology tools were applied to investigate contamination by Listeria monocytogenes, Salmonella spp., some pathogenic strains of Escherichia coli, and Campylobacter jejuni in 548 raw milk samples from 125 dairy farms established in two regions from southern Brazil. Moreover, 15 variables were evaluated for their association with raw milk contamination levels, and the risk factors were determined by multiple regression analysis. Salmonella spp. were more frequently detected, followed by pathogenic E. coli. There was difference in contamination index between the regions, in which risk factors such as temporary cattle confinement, low milk production, low milking machine cleaning frequency, and milk storage area without tile walls were identified. The risk factors were specific to each region studied. Nevertheless, the data can be used to improve milk quality of dairy farms/herds with similar management practices.

Prevalence and distribution of Arcobacter spp. in raw milk and retail raw beef.

PubMed

Shah, A H; Saleha, A A; Murugaiyah, M; Zunita, Z; Memon, A A

2012-08-01

A total of 106 beef samples which consisted of local (n = 59) and imported (n = 47) beef and 180 milk samples from cows (n = 86) and goats (n = 94) were collected from Selangor, Malaysia. Overall, 30.2% (32 of 106) of beef samples were found positive for Arcobacter species. Imported beef was significantly more contaminated (46.80%) than local beef (16.9%). Arcobacter butzleri was the species isolated most frequently from imported (81.8%) and local (60%) beef, followed by Arcobacter cryaerophilus in local (33.3%) and imported (18.2%) beef samples. Only one local beef sample (10%) yielded Arcobacter skirrowii. Arcobacter species were detected from cow's milk (5.8%), with A. butzleri as the dominant species (60%), followed by A. cryaerophilus (40%), whereas none of the goat's milk samples were found positive for Arcobacter. This is the first report of the detection of Arcobacter in milk and beef in Malaysia.

Detection of non-milk fat in milk fat by gas chromatography and linear discriminant analysis.

PubMed

Gutiérrez, R; Vega, S; Díaz, G; Sánchez, J; Coronado, M; Ramírez, A; Pérez, J; González, M; Schettino, B

2009-05-01

Gas chromatography was utilized to determine triacylglycerol profiles in milk and non-milk fat. The values of triacylglycerol were subjected to linear discriminant analysis to detect and quantify non-milk fat in milk fat. Two groups of milk fat were analyzed: A) raw milk fat from the central region of Mexico (n = 216) and B) ultrapasteurized milk fat from 3 industries (n = 36), as well as pork lard (n = 2), bovine tallow (n = 2), fish oil (n = 2), peanut (n = 2), corn (n = 2), olive (n = 2), and soy (n = 2). The samples of raw milk fat were adulterated with non-milk fats in proportions of 0, 5, 10, 15, and 20% to form 5 groups. The first function obtained from the linear discriminant analysis allowed the correct classification of 94.4% of the samples with levels <10% of adulteration. The triacylglycerol values of the ultrapasteurized milk fats were evaluated with the discriminant function, demonstrating that one industry added non-milk fat to its product in 80% of the samples analyzed.

The Core and Seasonal Microbiota of Raw Bovine Milk in Tanker Trucks and the Impact of Transfer to a Milk Processing Facility

PubMed Central

Kable, Mary E.; Srisengfa, Yanin; Laird, Miles; Zaragoza, Jose; McLeod, Jeremy; Heidenreich, Jessie

2016-01-01

ABSTRACT Currently, the bacterial composition of raw milk in tanker trucks and the outcomes of transfer and storage of that milk at commercial processing facilities are not well understood. We set out to identify the bacteria in raw milk collected for large-scale dairy product manufacturing. Raw bovine milk samples from 899 tanker trucks arriving at two dairy processors in San Joaquin Valley of California during three seasons (spring, summer, and fall) were analyzed by community 16S rRNA gene sequencing. This analysis revealed highly diverse bacterial populations, which exhibited seasonal differences. Raw milk collected in the spring contained the most diverse bacterial communities, with the highest total cell numbers and highest proportions being those of Actinobacteria. Even with this complexity, a core microbiota was present, consisting of 29 taxonomic groups and high proportions of Streptococcus and Staphylococcus and unidentified members of Clostridiales. Milk samples were also collected from five large-volume silos and from 13 to 25 tankers whose contents were unloaded into each of them during 2 days in the summer. Transfer of the milk to storage silos resulted in two community types. One group of silos contained a high proportion of Streptococcus spp. and was similar in that respect to the tankers that filled them. The community found in the other group of silos was distinct and dominated by Acinetobacter. Overall, despite highly diverse tanker milk community structures, distinct milk bacterial communities were selected within the processing facility environment. This knowledge can inform the development of new sanitation procedures and process controls to ensure the consistent production of safe and high-quality dairy products on a global scale. PMID:27555305

Antioxidant capacity and fatty acids characterization of heat treated cow and buffalo milk.

PubMed

Khan, Imran Taj; Nadeem, Muhammad; Imran, Muhammad; Ayaz, Muhammad; Ajmal, Muhammad; Ellahi, Muhammad Yaqoob; Khalique, Anjum

2017-08-24

Antioxidant capacity of milk is largely due to vitamins A, E, carotenoids, zinc, selenium, superoxide dismutase, catalase, glutathione peroxidase and enzyme systems. Cow milk has antioxidant capacity while the antioxidant capacity of buffalo milk has been studied in a limited way. The information regarding the effect of pasteurization and boiling on antioxidant capacity of cow and buffalo milk is also scared. Cow and buffalo milk was exposed to two different heat treatments i.e. 65 °C for 30 min and boiling for 1 min. After heat treatments, milk samples were cooled down to 4 °C packaged in transparent 250 ml polyethylene PET bottles and stored at 4 °C for 6 days. Milk composition, total flavonoid content, total antioxidant capacity, reducing power, DPPH free radical scavenging activity, antioxidant activity in linoleic acid, vitamin C, A, E, selenium, Zinc, fatty acid profile, peroxide value and sensory characteristics were studied in raw, pasteurized and boiled cow and buffalo milk at 0, 3 and 6 days of storage period. Total antioxidant capacity (TAC) of raw, pasteurized and boiled milk for cow (42.1, 41.3 and 40.7%) and buffalo (58.4, 57.6 and 56.5%) samples was found, respectively. Reducing power (RP) of raw cow and buffalo milk was 6.74 and 13.7 while pasteurization and boiling did not showed significant effect on RP of both cow and buffalo milk. DPPH activity of raw, pasteurized and boiled milk for cow (24.3, 23.8 and 23.6%) and buffalo (31.8, 31.5 and 30.4%) samples was noted, respectively. Storage period up to 3 days was non-significant while DPPH assay after 6 days of storage period indicated significant decline in antioxidant activity of milk samples. Antioxidant activity in linoleic acid (AALA) of buffalo and cow milk were recorded 11.7 and 17.4%, respectively. Pasteurization and boiling did not showed any impact on antioxidant capacity of cow and buffalo milk. The Loss of vitamin C in pasteurization (40 and 42%) and boiling (82 and 61%) of cow and buffalo milk was recorded, respectively. Concentration of vitamin A and E in pasteurized cow and buffalo milk was not significantly different from raw milk samples of cow and buffalo. Concentration of selenium and zinc was not influenced by the heat treatment in both cow and buffalo milk samples. After 3 days of refrigerated storage, antioxidant capacity of both cow and buffalo milk decreased. Concentrations of short-chain and medium-chain fatty acids increased in pasteurized and boiled cow and buffalo milk, while long-chain fatty acids decreased in pasteurized and boiled cow and buffalo milk, with no effect on colour and flavor score. Peroxide value of pasteurized and boiled cow and buffalo milk was not influenced by the storage up to 3 days. These results suggest that buffalo milk had a higher antioxidant capacity than cow milk and pasteurized milk should be consumed within 3 days of refrigerated storage for better antioxidant perspectives.

The aflatoxin M1 crisis in the Serbian dairy sector: the year after.

PubMed

Miocinovic, Jelena; Keskic, Tanja; Miloradovic, Zorana; Kos, Andrea; Tomasevic, Igor; Pudja, Predrag

2017-03-01

During the last 3 years, high aflatoxin M1 (AFM1) concentrations in milk and dairy products occurred in Serbia. It resulted in periodical change of the official regulations regarding maximum levels (MLs) of AFM1 as set by the Serbian Government. The aim of this study was to compare the occurrence of AFM1 in raw milk and dairy products during 2015 and also to determine whether there were some differences in AFM1 level among seasons. The AFM1 level exceeded the European Union ML in 29.3% of raw milk and 4.2% of milk product samples. The highest level of AFM1 in raw milk was found during the autumn season, while during the rest of the 2015, it was significantly lower. Although the improvement of dairy products safety was evident in 2015 when compared to 2013 and 2014, the cause of high concentrations in raw milk remained unresolved yet. This study indicates that dairy plants introduced control measures and refused reception of too high contaminated raw milk.

[Isolation of pathogenic bacteria in pasteurized type C milk sold in Recife City, Pernambuco, Brazil].

PubMed

Padilha , M R; Fernandes , Z F; Leal, T C; Leal, N C; Almeida, A M

2001-01-01

In order to improve information about the microbiological quality of the milk commercially available in the city of Recife, 250 samples of pasteurized type-C milk and 50 samples of raw milk were analyzed for Yersinia enterocolitica and Listeria monocytogenes and verify the possible occurrence of Yersinia enterocolitica and Listeria monocytogenes. These bacteria can develop in refrigeration temperatures and are responsible for food-born diseases. Neither Y. enterocolitica nor L. monocytogenes were found in the samples analyzed. However, the presence of Y. intermedia and Y. frederiksenii was detected, these environmental species behave as opportunist pathogens. Through the methodology used for Listeria isolation, one isolate of Salmonella Montevideo was obtained from a sample of pasteurized milk and another isolated from one sample of raw milk. Besides these, several other bacteria species were found. It is likely that the large microbiota present in the samples and the procedures employed to destroy it could have hindered the isolation of Y. enterocolitica and L. monocytogenes.

Effect of Processing Intensity on Immunologically Active Bovine Milk Serum Proteins.

PubMed

Brick, Tabea; Ege, Markus; Boeren, Sjef; Böck, Andreas; von Mutius, Erika; Vervoort, Jacques; Hettinga, Kasper

2017-08-31

Consumption of raw cow's milk instead of industrially processed milk has been reported to protect children from developing asthma, allergies, and respiratory infections. Several heat-sensitive milk serum proteins have been implied in this effect though unbiased assessment of milk proteins in general is missing. The aim of this study was to compare the native milk serum proteome between raw cow's milk and various industrially applied processing methods, i.e., homogenization, fat separation, pasteurization, ultra-heat treatment (UHT), treatment for extended shelf-life (ESL), and conventional boiling. Each processing method was applied to the same three pools of raw milk. Levels of detectable proteins were quantified by liquid chromatography/tandem mass spectrometry following filter aided sample preparation. In total, 364 milk serum proteins were identified. The 140 proteins detectable in 66% of all samples were entered in a hierarchical cluster analysis. The resulting proteomics pattern separated mainly as high (boiling, UHT, ESL) versus no/low heat treatment (raw, skimmed, pasteurized). Comparing these two groups revealed 23 individual proteins significantly reduced by heating, e.g., lactoferrin (log2-fold change = -0.37, p = 0.004), lactoperoxidase (log2-fold change = -0.33, p = 0.001), and lactadherin (log2-fold change = -0.22, p = 0.020). The abundance of these heat sensitive proteins found in higher quantity in native cow's milk compared to heat treated milk, renders them potential candidates for protection from asthma, allergies, and respiratory infections.

Prevalence of tick-borne encephalitis virus (TBEV) in samples of raw milk taken randomly from cows, goats and sheep in eastern Poland.

PubMed

Cisak, Ewa; Wójcik-Fatla, Angelina; Zając, Violetta; Sroka, Jacek; Buczek, Alicja; Dutkiewicz, Jacek

2010-01-01

A total of 119 unpasteurized milk samples taken from 63 cows, 29 goats and 27 sheep bred on 8 farms situated on the territory of the Lublin province (eastern Poland), an area of risk of tick-borne encephalitis (TBE), were examined for the presence of RNA of tick-borne encephalitis virus (TBEV) by the nested RT-PCR method. Milk samples were also tested for the presence of anti-TBEV antibodies by ELISA test. By RT-PCR, the greatest prevalence of TBE virus was found in the milk of sheep (22.2%), followed by milk of goats (20.7%) and cows (11.1%). By ELISA, the greatest prevalence of anti- TBEV antibodies was found also in the milk of sheep (14.8%), followed by milk of cows (3.2%) and goats (0%). The results suggest a potential risk of infection with TBEV by drinking raw milk on endemic areas of TBE, and indicate a need for milk pasteurization before consumption.

N2 Gas Flushing Limits the Rise of Antibiotic-Resistant Bacteria in Bovine Raw Milk during Cold Storage

PubMed Central

Munsch-Alatossava, Patricia; Jääskeläinen, Susanna; Alatossava, Tapani; Gauchi, Jean-Pierrre

2017-01-01

Antibiotic resistance has been noted to be a major and increasing human health issue. Cold storage of raw milk promotes the thriving of psychrotrophic/psychrotolerant bacteria, which are well known for their ability to produce enzymes that are frequently heat stable. However, these bacteria also carry antibiotic resistance (AR) features. In places, where no cold chain facilities are available and despite existing recommendations numerous adulterants, including antibiotics, are added to raw milk. Previously, N2 gas flushing showed real potential for hindering bacterial growth in raw milk at a storage temperature ranging from 6 to 25°C. Here, the ability of N2 gas (N) to tackle antibiotic- resistant bacteria was tested and compared to that of the activated lactoperoxidase system (HT) for three raw milk samples that were stored at 6°C for 7 days. To that end, the mesophiles and psychrotrophs that were resistant to gentamycin (G), ceftazidime (Ce), levofloxacin (L), and trimethoprim-sulfamethoxazole (TS) were enumerated. For the log10 ratio (which is defined as the bacterial counts from a certain condition divided by the counts on the corresponding control), classical Analyses of Variance (ANOVA) was performed, followed by a mean comparison with the Ryan-Einot-Gabriel-Welsch multiple range test (REGWQ). If the storage “time” factor was the major determinant of the recorded effects, cold storage alone or in combination with HT or with N promoted a sample-dependent response in consideration of the AR levels. The efficiency of N in limiting the increase in AR was highest for fresh raw milk and was judged to be equivalent to that of HT for one sample and superior to that of HT for the two other samples; moreover, compared to HT, N seemed to favor a more diverse community at 6°C that was less heavily loaded with antibiotic multi-resistance features. Our results imply that N2 gas flushing could strengthen cold storage of raw milk by tackling the bacterial spoilage potential while simultaneously hindering the increase of bacteria carrying antibiotic resistance/multi-resistance features. PMID:28469611

Spore populations among bulk tank raw milk and dairy powders are significantly different.

PubMed

Miller, Rachel A; Kent, David J; Watterson, Matthew J; Boor, Kathryn J; Martin, Nicole H; Wiedmann, Martin

2015-12-01

To accommodate stringent spore limits mandated for the export of dairy powders, a more thorough understanding of the spore species present will be necessary to develop prospective strategies to identify and reduce sources (i.e., raw materials or in-plant) of contamination. We characterized 1,523 spore isolates obtained from bulk tank raw milk (n=33 farms) and samples collected from 4 different dairy powder-processing plants producing acid whey, nonfat dry milk, sweet whey, or whey protein concentrate 80. The spores isolated comprised 12 genera, at least 44 species, and 216 rpoB allelic types. Bacillus and Geobacillus represented the most commonly isolated spore genera (approximately 68.9 and 12.1%, respectively, of all spore isolates). Whereas Bacillus licheniformis was isolated from samples collected from all plants and farms, Geobacillus spp. were isolated from samples from 3 out of 4 plants and just 1 out of 33 farms. We found significant differences between the spore population isolated from bulk tank raw milk and those isolated from dairy powder plant samples, except samples from the plant producing acid whey. A comparison of spore species isolated from raw materials and finished powders showed that although certain species, such as B. licheniformis, were found in both raw and finished product samples, other species, such as Geobacillus spp. and Anoxybacillus spp., were more frequently isolated from finished powders. Importantly, we found that 8 out of 12 genera were isolated from at least 2 different spore count methods, suggesting that some spore count methods may provide redundant information if used in parallel. Together, our results suggest that (1) Bacillus and Geobacillus are the predominant spore contaminants in a variety of dairy powders, implying that future research efforts targeted at elucidating approaches to reduce levels of spores in dairy powders should focus on controlling levels of spore isolates from these genera; and (2) the spore populations isolated from bulk tank raw milk and some dairy powder products are significantly different, suggesting that targeting in-plant sources of contamination may be important for achieving low spore counts in the finished product. These data provide important insight regarding the diversity of spore populations isolated from dairy powders and bulk tank raw milk, and demonstrate that several spore genera are detected by multiple spore count methods. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Prevalence, characterization, and antimicrobial resistance of Yersinia species and Yersinia enterocolitica isolated from raw milk in farm bulk tanks.

PubMed

Jamali, Hossein; Paydar, Mohammadjavad; Radmehr, Behrad; Ismail, Salmah

2015-02-01

The aims of this study were to investigate the prevalence and to characterize and determine the antibiotic resistance of Yersinia spp. isolates from raw milk. From September 2008 to August 2010, 446 raw milk samples were obtained from farm bulk milk tanks in Varamin, Iran. Yersinia spp. were detected in 29 (6.5%) samples, out of which 23 (79.3%), 5 (17.2%), and 1 (3.4%) were isolated from cow, sheep, and goat raw milk, respectively. The most common species isolated was Yersinia enterocolitica (65.5%), followed by Yersinia frederiksenii (31%), and Yersinia kristensenii (3.4%). Of the 19 Y. enterocolitica isolates, 14 (73.7%) were grouped into bioserotype 1A/O:9, 4 (21.1%) belonged to bioserotype 1B:O8, 1 (5.3%) belonged to bioserotype 4/O:3, and 1 isolate (biotype 1A) was not typable. All the isolates of biotypes 1B and 4harbored both the ystA and ail genes. However, all the isolates of biotype 1A were only positive for the ystB gene. The tested Yersinia spp. showed the highest percentages of resistance to tetracycline (48.3%), followed by ciprofloxacin and cephalothin (each 17.2%), ampicillin (13.8%), streptomycin (6.9%), and amoxicillin and nalidixic acid (each 3.4%). All of the tested isolates demonstrated significant sensitivity to gentamicin and chloramphenicol. Recovery of potentially pathogenic Y. enterocolitica from raw milk indicates high risks of yersiniosis associated with consumption of raw milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Inter-laboratory comparison of radiometric culture for Mycobacterium avium subsp. paratuberculosis using raw milk from known infected herds and individual dairy cattle in Victoria.

PubMed

Ridge, S E; Andreata, S; Jones, K; Cantlon, K; Francis, B; Florisson, N; Gwozdz, J

2010-07-01

To compare the results of radiometric culture conducted in three Australian laboratories for Mycobacterium avium subsp. paratuberculosis (Mptb) using bulk vat and individual animal milk samples. Milk samples were collected from 15 cows exhibiting clinical signs of Johne's disease, and subsequently confirmed as infected with Mptb, and from the bulk milk vats on 91 farms running herds known to be infected with Mptb. Each milk sample was divided into three equivalent samples and one of each of the replicates was forwarded to the three participating laboratories. The identity and nature of the samples was protected from the study collaborators. The laboratories processed the samples and undertook radiometric culture for Mptb using their standard method. Results of testing were provided to the principal investigator for collation and analysis. In total, 2 (2.2%) of 91 vat-milk samples and 8 (53.3%) of 15 individual cows' milk samples returned positive radiometric milk culture results. Only one sample, from a clinical case of Johne's disease, was identified as positive by more than one laboratory. There were differences in the absolute frequency with which Mptb was identified in the milk samples by the collaborating laboratories. Mptb was cultured from a very small percentage of Australian raw bulk milk samples sourced from known infected herds. By contrast, Mptb was successfully cultured from half of the milk samples collected from clinically affected cows. There was no statistical difference between laboratories in the proportion of vat samples or individual animal milk samples in which Mptb was detected.

Evaluation of human milk titratable acidity before and after addition of a nutritional supplement for preterm newborns.

PubMed

Pereira, Cibelle Iáskara do Vale; Dametto, Juliana Fernandes Dos Santos; Oliveira, Janaína Cavalcanti Costa

2016-01-01

To evaluate the initial Dornic acidity in raw human milk, after pasteurization and after heating and dilution of a dietary supplement for preterm infants. A quantitative, descriptive, and experimental study was carried out with a convenience sample at the human milk bank at a Brazilian public maternity, with specialized care for pregnant women and newborns at risk. The eligibility criteria for the study sample included 93 frozen raw human milk in suitable containers with volumes ≥100mL and initial Dornic acidity ≤8° Dornic (°D). Milk acidity of human milk was measured in four stages: in raw human milk (initial); after pasteurization; after the heating of pasteurized milk and dilution of the supplement; and after thirty minutes of supplementation. The initial acidity was 3.8°D±1.3 (95% CI: 3.56-4.09) with no significant difference in Dornic acidity in pasteurized milk, which was 3.6°D±1.2 (95% CI: 3.36-3.87). The dilution of the supplement in pasteurized milk that was heated significantly increased mean Dornic acidity to 18.6°D±2.2 (95% CI: 18.18-19.11), which remained high after thirty minutes of supplementation at 17.8°D±2.2 (95% CI: 17.36-18.27), considering p<0.05. The study observed no significant differences in Dornic acidity of raw human milk and pasteurized human milk; however, the dilution of a human milk supplementation caused a significant increase in acidity. Further investigations are necessary on the influence of this finding on the quality of supplemented milk and its consequences on the health of preterm infants. Copyright © 2016. Published by Elsevier Editora Ltda.

Investigating the relationship between raw milk bacterial composition, as described by intergenic transcribed spacer-PCR fingerprinting, and pasture altitude.

PubMed

Bonizzi, I; Buffoni, J N; Feligini, M; Enne, G

2009-10-01

To assess the bacterial biodiversity level in bovine raw milk used to produce Fontina, a Protected Designation of Origin cheese manufactured at high-altitude pastures and in valleys of Valle d'Aosta region (North-western Italian Alps) without any starters. To study the relation between microbial composition and pasture altitude, in order to distinguish high-altitude milk against valley and lowland milk. The microflora from milks sampled at different alpine pasture, valley and lowland farms were fingerprinted by PCR of the 16S-23S intergenic transcribed spacers (ITS-PCR). The resulting band patterns were analysed by generalized multivariate statistical techniques to handle discrete (band presence-absence) and continuous (altitude) information. The fingerprints featured numerous bands and marked variability indicating complex, differentiated bacterial communities. Alpine pasture milks were distinguished from lowland ones by cluster analysis, while this technique less clearly discriminated alpine pasture and valley samples. Generalized principal component analysis and clustering-after-ordination enabled a more effective distinction of alpine pasture, valley and lowland samples. Alpine raw milks for Fontina production contain highly diverse bacterial communities, the composition of which is related to the altitude of the pasture where milk was produced. This research may provide analytical support to the important issue represented by the authentication of the geographical origin of alpine milk productions.

A Multiplex RT-PCR Assay for S. aureus, L. monocytogenes, and Salmonella spp. Detection in Raw Milk with Pre-enrichment.

PubMed

Ding, Tian; Suo, Yuanjie; Zhang, Zhaohuan; Liu, Donghong; Ye, Xingqian; Chen, Shiguo; Zhao, Yong

2017-01-01

This study firstly developed a multiplex real-time PCR (RT-PCR) technique combined with a pre-enrichment step to simultaneously detect Staphylococcus aureus ( S. aureus ), Listeria monocytogenes ( L. monocytogenes ) and Salmonella spp. in raw milk and the dairy farm environment (feces, soil, feed, water) in one reaction. Brain heart infusion (BHI) broth was selected for the enrichment step to increase the density of the target bacteria by using an incubation of 4 h before multiplex RT-PCR. The results showed that the detection limit of the multiplex real-time assay was approximately 10 2 CFU/mL for pure cultures and artificially contaminated milk without enrichment, while 12, 14, and 10 CFU/25 mL, respectively, for S. aureus, L. monocytogenes , and Salmonella spp. after pre-enrichment. The newly developed multiplex RT-PCR assay was applied to 46 dairy farm environmental samples and raw milk samples covering a wide variety of sample types. The results demonstrated that the multiplex RT-PCR assay coupled with the BHI enrichment broth was suitable for the simultaneous screening of S. aureus, L. monocytogenes , and Salmonella spp. in the pasture environment and in raw milk. The multiplex RT-PCR assay clearly and successfully shortened the total detection time and reduced labor compared to conventional culture-based methods for testing natural samples.

A Multiplex RT-PCR Assay for S. aureus, L. monocytogenes, and Salmonella spp. Detection in Raw Milk with Pre-enrichment

PubMed Central

Ding, Tian; Suo, Yuanjie; Zhang, Zhaohuan; Liu, Donghong; Ye, Xingqian; Chen, Shiguo; Zhao, Yong

2017-01-01

This study firstly developed a multiplex real-time PCR (RT-PCR) technique combined with a pre-enrichment step to simultaneously detect Staphylococcus aureus (S. aureus), Listeria monocytogenes (L. monocytogenes) and Salmonella spp. in raw milk and the dairy farm environment (feces, soil, feed, water) in one reaction. Brain heart infusion (BHI) broth was selected for the enrichment step to increase the density of the target bacteria by using an incubation of 4 h before multiplex RT-PCR. The results showed that the detection limit of the multiplex real-time assay was approximately 102 CFU/mL for pure cultures and artificially contaminated milk without enrichment, while 12, 14, and 10 CFU/25 mL, respectively, for S. aureus, L. monocytogenes, and Salmonella spp. after pre-enrichment. The newly developed multiplex RT-PCR assay was applied to 46 dairy farm environmental samples and raw milk samples covering a wide variety of sample types. The results demonstrated that the multiplex RT-PCR assay coupled with the BHI enrichment broth was suitable for the simultaneous screening of S. aureus, L. monocytogenes, and Salmonella spp. in the pasture environment and in raw milk. The multiplex RT-PCR assay clearly and successfully shortened the total detection time and reduced labor compared to conventional culture-based methods for testing natural samples. PMID:28620364

The effect of pasteurization on transforming growth factor alpha and transforming growth factor beta 2 concentrations in human milk.

PubMed

McPherson, R J; Wagner, C L

2001-01-01

Transforming growth factor alpha (TGF-alpha) and beta 2 (TGF-beta2) are present in human milk and are involved in growth differentiation and repair of neonatal intestinal epithelia. Heat treatment at 56 degrees C has been shown effective for providing safe banked donor milk, with good retention of other biologically active factors. The purpose of our study was to determine the effect of heat sterilization on TGF-alpha and TGF-beta2 concentrations in human milk. Twenty milk samples were collected from 20 lactating mothers in polypropylene containers and frozen at -20 degrees C for transport or storage. Before heat treatment by holder pasteurization, the frozen milk was thawed and divided into 1-mL aliquots. All samples were heated in an accurately regulated water bath until a holding temperature was achieved, then held for 30 minutes using constant agitation. Holding temperature ranged from 56.5 degrees C to 56.9 degrees C. The milk was then stored at 4 degrees C overnight for analysis the following day. The concentration of TGF-alpha was measured by radioimmunoassay. Mean concentration +/- SD of TGF-alpha in raw milk samples was 119+/-50 pg/mL, range 57 to 234. The mean concentration +/- SD of TGF-alpha in heat treated samples was 113+/-50 pg/mL, range 51 to 227. TGF-alpha concentration was minimally affected by pasteurization, with an overall loss of 6.1%. Of 19 samples, 4 had increased and 15 had decreased concentrations after pasteurization (mean percent SEM: 94%+/-7% of raw milk, range 72%+/-107%). The concentration of acid-activated TGF-beta2 was measured by enzyme-linked immunosorbent assay. Mean concentration +/- SD of TGF-beta2 in raw milk samples was 5624+/-5038 pg/mL, range 195 to 15480. The mean concentration +/- SD of TGF-beta2 in heat-treated samples was 5073+/-4646 pg/mL, range 181 to 15140. TGF-beta2 survived with relatively little loss (0.6%): of 18 samples, 11 had increased and 7 had decreased concentrations after pasteurization (mean percent +/- SEM: 99.4+/-6.7% of raw milk, range 79%-120%). In conclusion, both TGF-alpha and TGF-beta2 were well-preserved in whole milk after holder pasteurization at 56.5 degrees C. The relative increase in growth factor concentration in some of the samples may be attributable to the release of that factor from the cellular and/or fat compartments into the aqueous fraction of human milk. These findings have implications regarding use of donor milk as an alternate source of growth factors and cytokines for the newborn gut when mother's milk is unavailable.

Mid-infrared spectrometry of milk for dairy metabolomics: a comparison of two sampling techniques and effect of homogenization.

PubMed

Aernouts, Ben; Polshin, Evgeny; Saeys, Wouter; Lammertyn, Jeroen

2011-10-31

Milk production is a dominant factor in the metabolism of dairy cows involving a very intensive interaction with the blood circulation. As a result, the extracted milk contains valuable information on the metabolic status of the cow. On-line measurement of milk components during milking two or more times a day would promote early detection of systemic and local alterations, thus providing a great input for strategic and management decisions. The objective of this study was to investigate the potential of mid-infrared (mid-IR) spectroscopy to measure the milk composition using two different measurement modes: micro attenuated total reflection (μATR) and high throughput transmission (HTT). Partial least squares (PLS) regression was used for prediction of fat, crude protein, lactose and urea after preprocessing IR data and selecting the most informative wavenumber variables. The prediction accuracies were determined separately for raw and homogenized copies of a wide range of milk samples in order to estimate the possibility for on-line analysis of the milk. In case of fat content both measurement modes resulted in an excellent prediction for homogenized samples (R(2)>0.92) but in poor results for raw samples (R(2)<0.70). Homogenization was however not mandatory to achieve good predictions for crude protein and lactose with both μATR and HTT, and urea with μATR spectroscopy. Excellent results were obtained for prediction of crude protein, lactose and urea content (R(2)>0.99, 0.98 and 0.86 respectively) in raw and homogenized milk using μATR IR spectroscopy. These results were significantly better than those obtained by HTT IR spectroscopy. However, the prediction performance of HTT was still good for crude protein and lactose content (R(2)>0.86 and 0.78 respectively) in raw and homogenized samples. However, the detection of urea in milk with HTT spectroscopy was significantly better (R(2)=0.69 versus 0.16) after homogenization of the milk samples. Based on these observations it can be concluded that μATR approach is most suitable for rapid at line or even on-line milk composition measurement, although homogenization is crucial to achieve good prediction of the fat content. Copyright © 2011 Elsevier B.V. All rights reserved.

Human campylobacteriosis related to the consumption of raw milk sold by vending machines in Italy: Quantitative risk assessment based on official controls over four years.

PubMed

Giacometti, Federica; Bonilauri, Paolo; Amatiste, Simonetta; Arrigoni, Norma; Bianchi, Manila; Losio, Marina Nadia; Bilei, Stefano; Cascone, Giuseppe; Comin, Damiano; Daminelli, Paolo; Decastelli, Lucia; Merialdi, Giuseppe; Mioni, Renzo; Peli, Angelo; Petruzzelli, Annalisa; Tonucci, Franco; Piva, Silvia; Serraino, Andrea

2015-09-01

A quantitative risk assessment (RA) model was developed to describe the risk of campylobacteriosis linked to consumption of raw milk sold in vending machines in Italy. Exposure assessment was based on the official microbiological records of raw milk samples from vending machines monitored by the regional Veterinary Authorities from 2008 to 2011, microbial growth during storage, destruction experiments, consumption frequency of raw milk, serving size, consumption preference and age of consumers. The differential risk considered milk handled under regulation conditions (4°C throughout all phases) and the worst time-temperature field handling conditions detected. Two separate RA models were developed, one for the consumption of boiled milk and the other for the consumption of raw milk, and two different dose-response (D-R) relationships were considered. The RA model predicted no human campylobacteriosis cases per year either in the best (4°C) storage conditions or in the case of thermal abuse in case of boiling raw milk, whereas in case of raw milk consumption the annual estimated campylobacteriosis cases depend on the dose-response relationships used in the model (D-R I or D-R II), the milk time-temperature storage conditions, consumer behaviour and age of consumers, namely young (with two cut-off values of ≤5 or ≤6 years old for the sensitive population) versus adult consumers. The annual estimated cases for young consumers using D-R II for the sensitive population (≤5 years old) ranged between 1013.7/100,000 population and 8110.3/100,000 population and for adult consumers using D-R I between 79.4/100,000 population and 333.1/100,000 population. Quantification of the risks associated with raw milk consumption is necessary from a public health perspective and the proposed RA model represents a useful and flexible tool to perform future RAs based on local consumer habits to support decision-making on safety policies. Further educational programmes for raw milk consumers or potential raw milk consumers are required to encourage consumers to boil milk to reduce the associated risk of illness. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluation of hippuric acid content in goat milk as a marker of feeding regimen.

PubMed

Carpio, A; Bonilla-Valverde, D; Arce, C; Rodríguez-Estévez, V; Sánchez-Rodríguez, M; Arce, L; Valcárcel, M

2013-09-01

Organic producers, traders, and consumers must address 2 issues related to milk: authentication of the production system and nutritional differentiation. The presence of hippuric acid (HA) in goat milk samples has been proposed as a possible marker to differentiate the feeding regimen of goats. The objective of this work is to check the hypothesis that HA could be a marker for the type of feeding regimen of goats by studying the influence of production system (conventional or organic) and feeding regimen (with or without grazing fodder). With this purpose, commercial cow and goat milk samples (n=27) and raw goat milk samples (n=185; collected from different breeds, localizations, and dates) were analyzed. Samples were grouped according to breed, feeding regimen, production system, and origin to compare HA content by ANOVA and honestly significant difference Tukey test at a confidence level of ≥95%. Hippuric acid content was obtained by analyzing milk samples with capillary electrophoresis. This method was validated by analyzing part of the samples with HPLC as a reference technique. Sixty-nine raw goat milk samples (of the total 158 samples analyzed in this work) were quantified by capillary electrophoresis. In these samples, the lowest average content for HA was 7±3 mg/L. This value corresponds to a group of conventional raw milk samples from goats fed with compound feed. The highest value of this group was 28±10 mg/L, corresponding to goats fed compound feed plus grass. Conversely, for organic raw goat milk samples, the highest concentration was 67±14 mg/L, which corresponds to goats fed grass. By contrast, the lowest value of this organic group was 26±10 mg/L, which belongs to goats fed organic compounds. Notice that the highest HA average content was found in samples from grazing animals corresponding to the organic group. This result suggests that HA is a good marker to determine the type of goats feeding regimen; a high content of HA represents a diet based mainly or exclusively on eating green grass (grazing), independently of the production system. Hence, this marker would not be useful for the actual organic policies to distinguish organic milk under the current regulations, because organic dairy ruminants can be fed organic compound feed and conserved fodder without grazing at all. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Analysis of beta-lactam antibiotics in incurred raw milk by rapid test methods and liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

PubMed

Riediker, S; Diserens, J M; Stadler, R H

2001-09-01

A recently developed confirmatory LC-MS method has been applied to the quantification of five major beta-lactam antibiotics in suspect raw bovine milk samples that gave a positive response with receptor-based (BetaStar) and rapid microbial inhibitory screen tests (Delvotest SP). In total, 18 presumptive positive raw milk samples were reanalyzed; 16 samples showed traces of antibiotic residues that could be identified and quantified by the LC-MS method, ranging from the limits of confirmation up to 38 microg/kg. Of the positive samples, only five (approximately 30%) were found to be violative of EU maximum residue limits. The most frequently detected antibiotic residues were cloxacillin and penicillin G, the former often in combination with amoxicillin or ampicillin. This study compares the results obtained by the three methods on identical samples and addresses how these relate to certain criteria such as sensitivity and selectivity. Furthermore, the limitations of the LC-MS method and the potential impact of the presence of frequently more than one residue in the same milk sample on the response of the rapid test methods are discussed.

Survey of physicochemical characteristics and microbial contamination in selected food locally vended in Morogoro Municipality, Tanzania.

PubMed

Nonga, Hezron Emmanuel; Ngowi, Helena Aminiel; Mdegela, Robinson Hammerthon; Mutakyawa, Eliud; Nyahinga, Gabriel Busungu; William, Robert; Mwadini, Mtumwa Mohd

2015-11-26

Raw milk, raw fruit juice and raw fish are enriched with essential nutrients for human diet but are prone to microbial contamination along the value chain. This cross sectional study was conducted to assess physicochemical characteristics and microbial quality of raw milk, fruit juice and fish from food vendors in Morogoro Municipality, Tanzania. The physicochemical assessment of food samples was done by smell, colour, presence of debris, turbidity, consistence, pH and clot on alcohol test. Hygiene of food containers, personnel and the vending environment was also assessed. Qualitative and quantitative microbial assessment of food was done using standard laboratory protocols as described by Tanzania Bureau of Standards and International Systems of Standards. Raw milk sold in Morogoro was of poor quality since was adulterated with water, contained sediments and clotted on alcohol test. Up to 63 % of the milk samples were contaminated with Escherichia coli and 60 % had higher total viable count (TVC) than the recommended values. Raw fruit juice was stored in dirty containers and sold under unhygienic environment. Seventy-three percent of juice samples had TVC beyond the recommendations while E. coli contamination rate was 63.3 %. The raw fish samples had started spoiling as depicted through sensory evaluation. E. coli contamination rate was 55 % and that of Campylobacter jejuni was 0.5 %. The mean TVC of raw fish was 8.1 (Log cfu/g) and 96.2 % of the fish samples had TVC beyond the recommended limits of 5.0 Log cfu/g. The physicochemical characteristics of food vended in Morogoro Municipality were of poor quality. The food had high bacterial contaminations. This situation poses health risks to the public and losses to food vendors due to spoilage. Stakeholders in food value chain should be educated on safe production and good hygienic practices. Routine quality and safety assessment of locally vended food, inspection of selling premises and regular health check-up of the personnel involved in food vending industry should be instituted.

Prevalence and Antimicrobial Susceptibility Pattern of E. coli O157:H7 Isolated from Traditionally Marketed Raw Cow Milk in and around Asosa Town, Western Ethiopia.

PubMed

Disassa, Nigatu; Sibhat, Berhanu; Mengistu, Shimelis; Muktar, Yimer; Belina, Dinaol

2017-01-01

A cross-sectional study was conducted from October 2014 to July 2015 to determine the prevalence and populations of E. coli as well as the prevalence and antimicrobial susceptibility of E. coli O157:H7 isolated from raw milk. Biochemical and serological tests methods were used to confirm E. coli and E. coli O157:H7 and isolates were subjected to antimicrobial susceptibility test using the agar disc diffusion method. Out of 380 raw milk samples examined, 129 (33.9%) and 11 (2.9%) were contaminated with E. coli and E. coli O157:H7, respectively. The highest prevalence was recorded in samples obtained from vendors (39.1%, 4.978 ± 0.180 log 10 /ml) compared with samples from farmers (28.1%, 3.93 ± 0.01 log 10 /ml) with significant differences ( P = 0.02). The frequency of contamination was higher in the samples collected from milk that was stored and transported in plastic containers (39.4%) than in the containers made of stainless steel (23.0%) ( P = 0.002). The antimicrobial susceptibility profile showed that E. coli O157:H7 were resistant to tetracycline (81.8%), streptomycin (81.8%), and kanamycin (63.6%). Milk samples were produced and handled under poor hygienic conditions, stored, and transported in inappropriate containers and under temperature abuse conditions leading to high health risk to the consumers. Additional studies would be needed to establish association between the occurrences of E. coli O157:H7 in raw milk and all the risk factors involved in and around Asosa town.

Preservation of raw milk with CO2. Sensory evaluation of heat-processed milks.

PubMed

Amigo, L; Olano, A; Calvo, M M

1995-04-01

The effect of CO2 on the growth of psychrotrophic milk spoilage organisms was studied, both in raw fresh milk and in pure cultures of three species of Pseudomonas growing in sterilised milk. Changes of sensory properties of CO2-treated samples after heat treatment were also analysed. Inhibition of psychrotrophic growth at 7 degrees C in milk treated with CO2 to a pH 6.2 or 6.0 was impaired by a gradual reduction of the CO2 content during storage. Growth inhibition was considerably improved by pH adjustment at 24-h intervals. Sensory analysis showed significant differences between non-acidified and acidified samples after heat treatment at 75 degrees C for 20 s or 110 degrees C for 5 min. No sensory differences were found between non-acidified and acidified milks degassed before heat treatment.

Detection of Helicobacter pylori in bovine, buffalo, camel, ovine, and caprine milk in Iran.

PubMed

Rahimi, Ebrahim; Kheirabadi, Elahe Kazemi

2012-05-01

Helicobacter pylori infection in humans is one of the most common infections worldwide. However, the origin and transmission of this bacterium has not been clearly explained. One of the suggested theories is transmission via raw milk from animals to human beings. This study was conducted to determine the prevalence rate of H. pylori in bulk milk samples from dairy bovine, buffalo, camel, ovine, and caprine herds in Iran. In the present study, 447 bulk milk samples from 230 dairy bovine, buffalo, camel, ovine, and caprine herds were collected in four provinces and tested for H. pylori by cultural method and polymerase chain reaction (PCR) for the detection of the ureC (glmM) gene. The animals whose milk samples collected for this study were clinically healthy. Using the cultural method, three of 447 milk samples (0.67%), including two sheep (2.2%) and one buffalo (1.6%) milk samples, were found to be contaminated with H. pylori. H. pylori ureC gene was detected in 56 (12.5%) of milk samples, including 19 cow (14.1%), 11 sheep (12.2%), nine goat (8.7%), two camel (3.6%), and 15 buffalo (23.4%) milk samples. Using PCR method, there were significant differences (p<0.05) in the level of contamination with H. pylori between milk samples collected from different species. The present study is the first report of the isolation of H. pylori from raw sheep and buffalo milk in Iran and the first demonstration of H. pylori DNA in camel and buffalo milk.

Food safety hazards associated with consumption of raw milk.

PubMed

Oliver, Stephen P; Boor, Kathryn J; Murphy, Steven C; Murinda, Shelton E

2009-09-01

An increasing number of people are consuming raw unpasteurized milk. Enhanced nutritional qualities, taste, and health benefits have all been advocated as reasons for increased interest in raw milk consumption. However, science-based data to substantiate these claims are limited. People continue to consume raw milk even though numerous epidemiological studies have shown clearly that raw milk can be contaminated by a variety of pathogens, some of which are associated with human illness and disease. Several documented milkborne disease outbreaks occurred from 2000-2008 and were traced back to consumption of raw unpasteurized milk. Numerous people were found to have infections, some were hospitalized, and a few died. In the majority of these outbreaks, the organism associated with the milkborne outbreak was isolated from the implicated product(s) or from subsequent products made at the suspected dairy or source. In contrast, fewer milkborne disease outbreaks were associated with consumption of pasteurized milk during this same time period. Twenty nine states allow the sale of raw milk by some means. Direct purchase, cow-share or leasing programs, and the sale of raw milk as pet food have been used as means for consumers to obtain raw milk. Where raw milk is offered for sale, strategies to reduce risks associated with raw milk and products made from raw milk are needed. Developing uniform regulations including microbial standards for raw milk to be sold for human consumption, labeling of raw milk, improving sanitation during milking, and enhancing and targeting educational efforts are potential approaches to this issue. Development of pre- and postharvest control measures to effectively reduce contamination is critical to the control of pathogens in raw milk. One sure way to prevent raw milk-associated foodborne illness is for consumers to refrain from drinking raw milk and from consuming dairy products manufactured using raw milk.

Detection of Shiga toxin (Stx)-producing Escherichia coli (STEC) in bovine dairy herds in Northern Italy.

PubMed

Trevisani, M; Mancusi, R; Delle Donne, G; Bacci, C; Bassi, L; Bonardi, S

2014-08-01

The aim of this study was to monitor the presence of Shiga toxin (Stx)-producing Escherichia coli in dairy farms authorized to sell raw milk and other farms, located in the same area, which sell milk to industry or use it to produce Parmesan or Grana cheese. Our research was focused on the serogroups O157 and O26, which are the most common in human cases in Italy and genetic markers that characterize the strains that can cause hemorrhagic colitis and hemolytic uremic syndrome (EHEC) in humans. Overall, 255 bulk-milk and 225 milk filter samples were screened for the presence of Shiga toxin genes (stx1 and stx2), O157 and O26 serogroups by using PCR. The samples were collected in 193 bovine dairy farms located in Northern Italy, including 32 farms selling raw milk to consumers. According to the preliminary PCR screening test, 32 out of 255 (12.5%; CI95%, 8.7% to 17.3%) bulk milk samples and 68 out of 225 (30.2%; CI95%, 24.3% to 36.7%) milk filters were positive for stx genes. Of the 32 milk samples that were stx-positive, 4 (1.6%, CI95%, 0.4% to 4%) were also positive by PCR for the rfbEO157 gene and 6 (2.4%, CI95%, 0.9% to 5.1%) were positive for the wzxO26 gene. The culture detection method, which was based on the immunomagnetic separation, achieved isolation rates of E. coli serogroups O157 and O26 in 25-67% of the milk samples that tested positive by PCR for these serogroups. STEC O26 was detected in one milk filter (1.6%) from a farm that sells raw milk to consumers directly and one sample (1.4%) of bulk milk intended for pasteurization. The presence of STEC O157 was also detected in 2 milk filters (1.7%) from farms that use milk to produce Grana cheese. All the STEC stains O157 and O26 isolated carried the genes eae and espK and genes belonging to the pathogenicity island OI-122 (efa1/2, sen, pagC), which are markers suitable for screening the human virulent EHEC strains. These virulence markers were also detected in the three strains of stx-negative E. coli O157 isolated from two filters and one milk sample. These strains could be therefore EHEC strains that have lost the stx genes (EHEC-derivative strains). Concern arise for the presence of EHEC O26 and E. coli O157 isolates that are suspected to be an EHEC-derivative in the milk filters sampled in farms that are used to sell raw milk to consumers and in other dairy farms. Copyright © 2014 Elsevier B.V. All rights reserved.

Spore test parameters matter: Mesophilic and thermophilic spore counts detected in raw milk and dairy powders differ significantly by test method.

PubMed

Kent, D J; Chauhan, K; Boor, K J; Wiedmann, M; Martin, N H

2016-07-01

United States dairy industry exports have steadily risen in importance over the last 10yr, with dairy powders playing a particularly critical role. Currently, approximately half of US-produced nonfat dry milk and skim milk powder is exported. Reaching new and expanding existing export markets relies in part on the control of endospore-forming bacteria in dairy powders. This study reports baseline mesophilic and thermophilic spore counts and spore populations from 55 raw material samples (primarily raw milk) and 33 dairy powder samples from dairy powder processors across the United States. Samples were evaluated using various spore testing methodologies and included initial heat treatments of (1) 80°C for 12 min; (2) 100°C for 30 min; and (3) 106°C for 30 min. Results indicate that significant differences in both the level and population of spores were found for both raw milk and dairy powders with the various testing methods. Additionally, on average, spore counts were not found to increase significantly from the beginning to the end of dairy powder processing, most likely related to the absence of biofilm formation by processing plant-associated sporeformers (e.g., Anoxybacillus sp.) in the facilities sampled. Finally, in agreement with other studies, Bacillus licheniformis was found to be the most prevalent sporeformer in both raw materials and dairy powders, highlighting the importance of this organism in developing strategies for control and reduction of spore counts in dairy powders. Overall, this study emphasizes the need for standardization of spore enumeration methodologies in the dairy powder industry. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Assessment of the application of an automated electronic milk analyzer for the enumeration of total bacteria in raw goat milk.

PubMed

Ramsahoi, L; Gao, A; Fabri, M; Odumeru, J A

2011-07-01

Automated electronic milk analyzers for rapid enumeration of total bacteria counts (TBC) are widely used for raw milk testing by many analytical laboratories worldwide. In Ontario, Canada, Bactoscan flow cytometry (BsnFC; Foss Electric, Hillerød, Denmark) is the official anchor method for TBC in raw cow milk. Penalties are levied at the BsnFC equivalent level of 50,000 cfu/mL, the standard plate count (SPC) regulatory limit. This study was conducted to assess the BsnFC for TBC in raw goat milk, to determine the mathematical relationship between the SPC and BsnFC methods, and to identify probable reasons for the difference in the SPC:BsnFC equivalents for goat and cow milks. Test procedures were conducted according to International Dairy Federation Bulletin guidelines. Approximately 115 farm bulk tank milk samples per month were tested for inhibitor residues, SPC, BsnFC, psychrotrophic bacteria count, composition (fat, protein, lactose, lactose and other solids, and freezing point), and somatic cell count from March 2009 to February 2010. Data analysis of the results for the samples tested indicated that the BsnFC method would be a good alternative to the SPC method, providing accurate and more precise results with a faster turnaround time. Although a linear regression model showed good correlation and prediction, tests for linearity indicated that the relationship was linear only beyond log 4.1 SPC. The logistic growth curve best modeled the relationship between the SPC and BsnFC for the entire sample population. The BsnFC equivalent to the SPC 50,000 cfu/mL regulatory limit was estimated to be 321,000 individual bacteria count (ibc)/mL. This estimate differs considerably from the BsnFC equivalent for cow milk (121,000 ibc/mL). Because of the low frequency of bulk tank milk pickups at goat farms, 78.5% of the samples had their oldest milking in the tank to be 6.5 to 9.0 d old when tested, compared with the cow milk samples, which had their oldest milking at 4 d old when tested. This may be one of the major factors contributing to the larger goat milk BsnFC equivalence. Correlations and interactions between various test results were also discussed to further understand differences between the 2 methods for goat and cow milks. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Longitudinal assessment of dairy farm management practices associated with the presence of psychrotolerant Bacillales spores in bulk tank milk on 10 New York State dairy farms.

PubMed

Masiello, S N; Kent, D; Martin, N H; Schukken, Y H; Wiedmann, M; Boor, K J

2017-11-01

The ability of certain spore-forming bacteria in the order Bacillales (e.g., Bacillus spp., Paenibacillus spp.) to survive pasteurization in spore form and grow at refrigeration temperatures results in product spoilage and limits the shelf life of high temperature, short time (HTST)-pasteurized fluid milk. To facilitate development of strategies to minimize contamination of raw milk with psychrotolerant Bacillales spores, we conducted a longitudinal study of 10 New York State dairy farms, which included yearlong monthly assessments of the frequency and levels of bulk tank raw milk psychrotolerant spore contamination, along with administration of questionnaires to identify farm management practices associated with psychrotolerant spore presence over time. Milk samples were first spore pasteurized (80°C for 12 min) and then analyzed for sporeformer counts on the initial day of spore pasteurization (SP), and after refrigerated storage (6°C) for 7, 14, and 21 d after SP. Overall, 41% of samples showed sporeformer counts of >20,000 cfu/mL at d 21, with Bacillus and Paenibacillus spp. being predominant causes of high sporeformer counts. Statistical analyses identified 3 management factors (more frequent cleaning of the bulk tank area, the use of a skid steer to scrape the housing area, and segregating problem cows during milking) that were all associated with lower probabilities of d-21 Bacillales spore detection in SP-treated bulk tank raw milk. Our data emphasize that appropriate on-farm measures to improve overall cleanliness and cow hygiene will reduce the probability of psychrotolerant Bacillales spore contamination of bulk tank raw milk, allowing for consistent production of raw milk with reduced psychrotolerant spore counts, which will facilitate production of HTST-pasteurized milk with extended refrigerated shelf life. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Seasonal variation in the Dutch bovine raw milk composition.

PubMed

Heck, J M L; van Valenberg, H J F; Dijkstra, J; van Hooijdonk, A C M

2009-10-01

In this study, we determined the detailed composition of and seasonal variation in Dutch dairy milk. Raw milk samples representative of the complete Dutch milk supply were collected weekly from February 2005 until February 2006. Large seasonal variation exists in the concentrations of the main components and milk fatty acid composition. Milk lactose concentration was rather constant throughout the season. Milk true protein content was somewhat more responsive to season, with the lowest content in June (3.21 g/100 g) and the highest content in December (3.38 g/100 g). Milk fat concentration increased from a minimum of 4.10 g/100 g in June to a maximum of 4.57 g/100 g in January. The largest (up to 2-fold) seasonal changes in the fatty acid composition were found for trans fatty acids, including conjugated linoleic acid. Milk protein composition was rather constant throughout the season. Milk unsaturation indices, which were used as an indication of desaturase activity, were lowest in spring and highest in autumn. Compared with a previous investigation of Dutch dairy milk in 1992, the fatty acid composition of Dutch raw milk has changed considerably, in particular with a higher content of saturated fatty acids in 2005 milk.

Paediatric HUS Cases Related to the Consumption of Raw Milk Sold by Vending Machines in Italy: Quantitative Risk Assessment Based on Escherichia coli O157 Official Controls over 7 years.

PubMed

Giacometti, F; Bonilauri, P; Piva, S; Scavia, G; Amatiste, S; Bianchi, D M; Losio, M N; Bilei, S; Cascone, G; Comin, D; Daminelli, P; Decastelli, L; Merialdi, G; Mioni, R; Peli, A; Petruzzelli, A; Tonucci, F; Liuzzo, G; Serraino, A

2017-11-01

A quantitative risk assessment (RA) was developed to estimate haemolytic-uremic syndrome (HUS) cases in paediatric population associated with the consumption of raw milk sold in vending machines in Italy. The historical national evolution of raw milk consumption phenomenon since 2008, when consumer interest started to grow, and after 7 years of marketing adjustment, is outlined. Exposure assessment was based on the official Shiga toxin-producing Escherichia coli O157:H7 (STEC) microbiological records of raw milk samples from vending machines monitored by the regional Veterinary Authorities from 2008 to 2014, microbial growth during storage, consumption frequency of raw milk, serving size, consumption preference and age of consumers. The differential risk considered milk handled under regulation conditions (4°C throughout all phases) and the worst time-temperature field handling conditions detected. In case of boiling milk before consumption, we assumed that the risk of HUS is fixed at zero. The model estimates clearly show that the public health significance of HUS cases due to raw milk STEC contamination depends on the current variability surrounding the risk profile of the food and the consumer behaviour has more impact than milk storage scenario. The estimated HUS cases predicted by our model are roughly in line with the effective STEC O157-associated HUS cases notified in Italy only when the proportion of consumers not boiling milk before consumption is assumed to be 1%. Raw milk consumption remains a source of E. coli O157:H7 for humans, but its overall relevance is likely to have subsided and significant caution should be exerted for temporal, geographical and consumers behaviour analysis. Health education programmes and regulatory actions are required to educate people, primarily children, on other STEC sources. © 2016 Blackwell Verlag GmbH.

The Use of Multiplex PCR to Determine the Prevalence of Enterotoxigenic Staphylococcus aureus Isolated from Raw Milk, Feta Cheese, and Hand Swabs.

PubMed

Zeinhom, Mohamed M A; Abdel-Latef, Gihan K; Jordan, Kieran

2015-12-01

Staphylococcus aureus (S. aureus) can cause mastitis in cattle and, therefore, can be present in milk. This study was undertaken to determine the prevalence of coagulase positive S. aureus and its enterotoxin genes sea, seb, and sec in isolates recovered from raw milk, feta cheese, and human hand swabs of milk and cheese handlers in Beni-Suef province, Egypt. A total of 100 samples of raw milk and 50 samples of pasteurized-milk feta cheese were collected. In addition, 50 hand swabs from milk handlers and 25 hand swabs from cheese handlers were examined for the presence of coagulase positive S. aureus. The isolates were characterized by multiplex PCR for detection of sea, seb, and sec genes, and for resistance to 5 classes of commonly used antibiotics. Twelve (12/100), 12 (6/50), and 17% (13/75) of milk, cheese, and hand swab samples, respectively, were positive for coagulase positive S. aureus. One isolate was obtained from each positive sample (31 isolates), and none contained genes for SEA or SEC production. Twenty-five percent, 33%, and 31%, respectively, of the isolates contained the genes for SEB, resulting in 3%, 4%, and 5% of samples being positive for toxin producing coagulase positive S. aureus, respectively. At least one isolate was resistant to each of the antibiotics tested. Despite the low potential for SEB production shown, preventative measures, such as maintenance of the cold-chain and good hygienic practices should be implemented to further reduce the potential risk to public health from SEB, and to reduce the spread of antimicrobial resistance. © 2015 Institute of Food Technologists®

Detecting Staphylococcus aureus in milk from dairy cows using sniffer dogs.

PubMed

Fischer-Tenhagen, C; Theby, V; Krömker, V; Heuwieser, W

2018-05-01

Fast and accurate identification of disease-causing pathogens is essential for specific antimicrobial therapy in human and veterinary medicine. In these experiments, dogs were trained to identify Staphylococcus aureus and differentiate it from other common mastitis-causing pathogens by smell. Headspaces from agar plates, inoculated raw milk samples, or field samples collected from cows with Staphylococcus aureus and other mastitis-causing pathogens were used for training and testing. The ability to learn the specific odor of Staphylococcus aureus in milk depended on the concentration of the pathogens in the training samples. Sensitivity and specificity for identifying Staphylococcus aureus were 91.3 and 97.9%, respectively, for pathogens grown on agar plates; 83.8 and 98.0% for pathogens inoculated in raw milk; and 59.0 and 93.2% for milk samples from mastitic cows. The results of these experiments underline the potential of odor detection as a diagnostic tool for pathogen diagnosis. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Direct determination of Pb in raw milk by graphite furnace atomic absorption spectrometry (GF AAS) with electrothermal atomization sampling from slurries.

PubMed

de Oliveira, Tatiane Milão; Augusto Peres, Jayme; Lurdes Felsner, Maria; Cristiane Justi, Karin

2017-08-15

Milk is an important food in the human diet due to its physico-chemical composition; therefore, it is necessary to monitor contamination by toxic metals such as Pb. Milk sample slurries were prepared using Triton X-100 and nitric acid for direct analysis of Pb using graphite furnace atomic absorption spectrometry - GF AAS. After dilution of the slurries, 10.00µl were directly introduced into the pyrolytic graphite tube without use of a chemical modifier, which acts as an advantage considering this type of matrix. The limits of detection and quantification were 0.64 and 2.14µgl -1 , respectively. The figures of merit studied showed that the proposed methodology without pretreatment of the raw milk sample and using external standard calibration is suitable. The methodology was applied in milk samples from the Guarapuava region, in Paraná State (Brazil) and Pb concentrations ranged from 2.12 to 37.36µgl -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

Visible and near-infrared bulk optical properties of raw milk.

PubMed

Aernouts, B; Van Beers, R; Watté, R; Huybrechts, T; Lammertyn, J; Saeys, W

2015-10-01

The implementation of optical sensor technology to monitor the milk quality on dairy farms and milk processing plants would support the early detection of altering production processes. Basic visible and near-infrared spectroscopy is already widely used to measure the composition of agricultural and food products. However, to obtain maximal performance, the design of such optical sensors should be optimized with regard to the optical properties of the samples to be measured. Therefore, the aim of this study was to determine the visible and near-infrared bulk absorption coefficient, bulk scattering coefficient, and scattering anisotropy spectra for a diverse set of raw milk samples originating from individual cow milkings, representing the milk variability present on dairy farms. Accordingly, this database of bulk optical properties can be used in future simulation studies to efficiently optimize and validate the design of an optical milk quality sensor. In a next step of the current study, the relation between the obtained bulk optical properties and milk quality properties was analyzed in detail. The bulk absorption coefficient spectra were found to mainly contain information on the water, fat, and casein content, whereas the bulk scattering coefficient spectra were found to be primarily influenced by the quantity and the size of the fat globules. Moreover, a strong positive correlation (r ≥ 0.975) was found between the fat content in raw milk and the measured bulk scattering coefficients in the 1,300 to 1,400 nm wavelength range. Relative to the bulk scattering coefficient, the variability on the scattering anisotropy factor was found to be limited. This is because the milk scattering anisotropy is nearly independent of the fat globule and casein micelle quantity, while it is mainly determined by the size of the fat globules. As this study shows high correlations between the sample's bulk optical properties and the milk composition and fat globule size, a sensor that allows for robust separation between the absorption and scattering properties would enable accurate prediction of the raw milk quality parameters. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Application of in-plant control measures in some Egyptian micro-scale dairy enterprises and its impact on heavy metal contents of their products.

PubMed

Abd El-Salam, Magda Magdy; Farahat, Mohamed F; Abu-Zuid, Gaber I; Saad, Samia G

2017-09-05

Egypt is encouraging micro-scale enterprises as proved to be one of the most important reasons of economic growth. Most of the annual milk production is processed in micro-scale dairy enterprises located in squatter areas with high health risks and negative environmental impact. The aim of this study was to assess the effectiveness of in-plant control measures in controlling lead and cadmium levels in dairy products from nine Egyptian micro-scale enterprises. The results revealed that white cheese enterprises had the highest mean lead and cadmium contents; both in their raw milk (0.712 and 0.134 mg/L, respectively) and final products (0.419 and 0.061 mg/kg). Higher compliance percentages were found with cadmium levels specified in the Egyptian standards than with lead levels and ranged from 59.4% in raw milk to 100% in dry milk for cadmium levels and from 8.3% in white cheese to 66.7% in ice cream for lead; moreover, none of the collected raw milk samples were complying with the lead levels. After implementation of in-plant control measures, lower lead levels were found in all samples with reduction percentages ranging from 35.2% in raw milk from the ice cream enterprises to 73.2% in yoghurt; moreover, higher percentages of samples complied with cadmium levels. This study highlights the urgent need for applying in-plant control measures to the Egyptian micro-scale dairy enterprises to improve both safety and quality of their products.

Evaluation of the bacteriological quality of raw cow's milk at various stages of the milk production chain on farms in Algeria. © OIE (World Organisation for Animal Health), 2016.

PubMed

Hamiroune, M; Berber, A; Boubekeur, S

2016-12-01

This study evaluates hygiene practices on 53 dairy farms in the Jijel and Blida regions of Algeria. A survey questionnaire was drawn up covering milking conditions and cleaning of the equipment. In parallel, bacteriological analyses were carried out to estimate the rate, source and development of bacterial contamination in raw milk produced on the farm. In addition, screening was performed to detect the presence of inhibitor residues. The results of the survey revealed poor livestock conditions and milking practices that could explain the presence of bacteria in cow's milk. The bacteriological results showed that 76.1% of milk samples taken from cow udders complied with legal standards, compared with only 35.8% of milk samples taken from storage tanks. Moreover, bacterial inhibitors were detected in 28.8% of milk samples. These results showed that the hands of milkers, udders, teat cups, utensils, the water used during milking and the milking environment were all potential sources of milk contamination by the bacteria under investigation. These results suggest that, to improve the bacteriological quality of milk, there is a need to introduce a quality policy which places a premium on milk of high bacteriological quality and aims to generalise good hygiene practices throughout the dairy production chain. © OIE (World Organisation for Animal Health), 2016.

Consumption of unprocessed cow's milk protects infants from common respiratory infections.

PubMed

Loss, Georg; Depner, Martin; Ulfman, Laurien H; van Neerven, R J Joost; Hose, Alexander J; Genuneit, Jon; Karvonen, Anne M; Hyvärinen, Anne; Kaulek, Vincent; Roduit, Caroline; Weber, Juliane; Lauener, Roger; Pfefferle, Petra Ina; Pekkanen, Juha; Vaarala, Outi; Dalphin, Jean-Charles; Riedler, Josef; Braun-Fahrländer, Charlotte; von Mutius, Erika; Ege, Markus J

2015-01-01

Breast-feeding is protective against respiratory infections in early life. Given the co-evolutionary adaptations of humans and cattle, bovine milk might exert similar anti-infective effects in human infants. To study effects of consumption of raw and processed cow's milk on common infections in infants. The PASTURE birth cohort followed 983 infants from rural areas in Austria, Finland, France, Germany, and Switzerland, for the first year of life, covering 37,306 person-weeks. Consumption of different types of cow's milk and occurrence of rhinitis, respiratory tract infections, otitis, and fever were assessed by weekly health diaries. C-reactive protein levels were assessed using blood samples taken at 12 months. When contrasted with ultra-heat treated milk, raw milk consumption was inversely associated with occurrence of rhinitis (adjusted odds ratio from longitudinal models [95% CI]: 0.71 [0.54-0.94]), respiratory tract infections (0.77 [0.59-0.99]), otitis (0.14 [0.05-0.42]), and fever (0.69 [0.47-1.01]). Boiled farm milk showed similar but weaker associations. Industrially processed pasteurized milk was inversely associated with fever. Raw farm milk consumption was inversely associated with C-reactive protein levels at 12 months (geometric means ratio [95% CI]: 0.66 [0.45-0.98]). Early life consumption of raw cow's milk reduced the risk of manifest respiratory infections and fever by about 30%. If the health hazards of raw milk could be overcome, the public health impact of minimally processed but pathogen-free milk might be enormous, given the high prevalence of respiratory infections in the first year of life and the associated direct and indirect costs. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Occurrence of Virulence Genes Associated with Diarrheagenic Escherichia coli Isolated from Raw Cow’s Milk from Two Commercial Dairy Farms in the Eastern Cape Province, South Africa

PubMed Central

Caine, Lesley-Anne; Nwodo, Uchechukwu U.; Okoh, Anthony I.; Ndip, Roland N.; Green, Ezekiel

2014-01-01

Escherichia coli remains a public health concern worldwide as an organism that causes diarrhea and its reservoir in raw milk may play an important role in the survival and transport of pathogenic strains. Diarrheagenic E. coli strains are diverse food-borne pathogens and causes diarrhea with varying virulence in humans. We investigated the prevalence of pathogenic E. coli in raw milk from two commercial dairy farms. Four hundred raw milk samples, 200 from each dairy farm, were screened for the presence of fliCH7, eagR, ial, eagg, lt, and papC genes. In dairy farm A, 100 E. coli were identified based on culture, oxidase and Gram staining, while 88 isolates from dairy farm B were identified in the same manner. Gene detection showed fliCH7 27 (54%) to be the highest gene detected from farm A and lt 2 (4%) to be the lowest. The highest gene detected in dairy farm B was fliCH7 16 (43.2%) and papC 1 (2.7%) was the least. The amplification of pathogenic genes associated with diarrheagenic E. coli from cows’ raw milk demonstrates that potentially virulent E. coli strains are widely distributed in raw milk and may be a cause of concern for human health. PMID:25411727

Microbiological quality assessment of milk at different stages of the dairy value chain in a developing country setting.

PubMed

Islam, Mohammad Aminul; Roy, Subarna; Nabi, Ashikun; Solaiman, Sultana; Rahman, Mahdia; Huq, Mohsina; Siddiquee, Nurul Amin; Ahmed, Niyaz

2018-08-02

The main objective of the study was to assess the microbiological quality of milk at different stages of the dairy value chain from farm to the factory in Bangladesh. A total of 438 raw milk samples (387 from primary producers, 32 from collectors, 15 from chilling plants, 4 from local restaurants) and 95 commercially processed milk samples were collected from northern part of Bangladesh. Almost 72% (n = 280) of samples at producer level and 100% from both collectors (n = 32) and chilling plants (n = 15) were contaminated with coliforms while 57% (n = 220) of samples from producers, 91% (n = 29) of samples from collectors and 100% (n = 15) from chilling plants were contaminated with fecal coliforms. Around 31% (n = 119) of samples from producers were positive for E. coli whereas >60% (n = 20) and 100% (n = 15) samples from collectors and chilling plants, respectively were positive for E. coli. One quarter of samples from collectors were positive for B. cereus and coagulase positive staphylococci and 33% (n = 5) of samples from chilling plants were positive for both of these microorganisms. In case of commercially processed milk, 77% (n = 46) and 37% (n = 22) of pasteurized milk samples had a high aerobic plate count (APC) (10 4  CFU/ml) and coliform count (>10 CFU/ml), respectively. None of the samples was positive for Shigella spp., Salmonella spp., and Campylobacter spp. Among 158 E. coli positive raw milk samples, 9% (n = 14) contained pathogenic E. coli, and enteroaggregative E. coli (EAEC) and Shiga-toxin producing E. coli (STEC) were found to be the predominant pathotypes. Of the 23 pathogenic E. coli identified from 14 samples based on their gene contents, >95% (n = 22) were resistant to at least one antibiotic and 13% (n = 3) of isolates were resistant to ≥3 classes of antibiotics. Several factors including the time of milking, hygiene practices of the producers, cow breed and amount of milk produced by the cow were found to be significantly associated with high APC of milk samples. In conclusion, both raw and commercially pasteurized milk are highly contaminated with fecal organisms. For intervention, more emphasis should be given at producer's level as microorganisms introduced to milk at this stage get the longest time for survival and multiplication. Copyright © 2018 Elsevier B.V. All rights reserved.

Raw Cow Milk Bacterial Population Shifts Attributable to Refrigeration

PubMed Central

Lafarge, Véronique; Ogier, Jean-Claude; Girard, Victoria; Maladen, Véronique; Leveau, Jean-Yves; Gruss, Alexandra; Delacroix-Buchet, Agnès

2004-01-01

We monitored the dynamic changes in the bacterial population in milk associated with refrigeration. Direct analyses of DNA by using temporal temperature gel electrophoresis (TTGE) and denaturing gradient gel electrophoresis (DGGE) allowed us to make accurate species assignments for bacteria with low-GC-content (low-GC%) (<55%) and medium- or high-GC% (>55%) genomes, respectively. We examined raw milk samples before and after 24-h conservation at 4°C. Bacterial identification was facilitated by comparison with an extensive bacterial reference database (∼150 species) that we established with DNA fragments of pure bacterial strains. Cloning and sequencing of fragments missing from the database were used to achieve complete species identification. Considerable evolution of bacterial populations occurred during conservation at 4°C. TTGE and DGGE are shown to be a powerful tool for identifying the main bacterial species of the raw milk samples and for monitoring changes in bacterial populations during conservation at 4°C. The emergence of psychrotrophic bacteria such as Listeria spp. or Aeromonas hydrophila is demonstrated. PMID:15345453

Traceability of Plant Diet Contents in Raw Cow Milk Samples

PubMed Central

Ponzoni, Elena; Mastromauro, Francesco; Gianì, Silvia; Breviario, Diego

2009-01-01

The use of molecular marker in the dairy sector is gaining large acceptance as a reliable diagnostic approach for food authenticity and traceability. Using a PCR approach, the rbcL marker, a chloroplast-based gene, was selected to amplify plant DNA fragments in raw cow milk samples collected from stock farms or bought on the Italian market. rbcL-specific DNA fragments could be found in total milk, as well as in the skimmed and the cream fractions. When the PCR amplified fragments were sent to sequence, the nucleotide composition of the chromatogram reflected the multiple contents of the polyphytic diet. PMID:22253982

Effect of commercial hauling practices and tanker cleaning treatments on raw milk microbiological quality.

PubMed

Darchuk, Emily M; Waite-Cusic, Joy; Meunier-Goddik, Lisbeth

2015-10-01

Consolidation of the US milk industry has led to use of tankers for up to 24 h in between thorough cleanings. As the heavy use of tankers has not been previously studied, the effect of this form of hauling on raw milk quality is unknown. This study focused on the effect of frequent tanker use during hauling on raw milk quality at a commercial facility. Standard tanker use (cleaned-in-place once per 24 h) served as our control and incremental cleaning treatments (water rinse after each load, water rinse after each load with a sanitizer treatment after 12 h, and 12 h of sanitizer treatment) were added to the study to understand if any effect could be mitigated by more frequent cleaning. Producer samples were collected from the farm before loading milk into the tanker as well as sampling the same milk directly out of the tanker truck before unloading at the manufacturer. The study was repeated at 2 different dairy manufacturing facilities, once during the summer and once during the winter. Milk quality was quantified through industry-relevant microbiological tests: individual bacteria count, thermophilic spore count, and preliminary incubation count. Within the study we defined a negative effect on milk quality as a statistically significant difference between the tanker and producer samples in any of the 3 microbial tests conducted between treatments. Results from the study showed no clear effect due to hauling in individual bacteria count, thermophilic spore count, or preliminary incubation counts. There was also no difference in milk quality between the 2 plants, suggesting that neither season nor location affected our results in the standard use variable. As we did not see a negative effect on milk quality in the standard use variable, the addition of cleaning treatments did not appear to provide any clear benefit. Tanker surface swabs and ATP swabs were also used to monitor tanker sanitation and the efficacy of cleaning treatments. Both surface and ATP swabs revealed differences between cleaning efficacy at the 2 facilities. Although the differences in efficacy did not influence tanker milk quality within our study, variability in sanitation may provide a source of contamination that could negatively affect raw milk quality in other areas. Based on this study, current hauling practices appear to be effective in mitigating any measurable effect on raw milk quality; however, further investigation is needed before making industry-wide recommendations. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Combined chemometric analysis of (1)H NMR, (13)C NMR and stable isotope data to differentiate organic and conventional milk.

PubMed

Erich, Sarah; Schill, Sandra; Annweiler, Eva; Waiblinger, Hans-Ulrich; Kuballa, Thomas; Lachenmeier, Dirk W; Monakhova, Yulia B

2015-12-01

The increased sales of organically produced food create a strong need for analytical methods, which could authenticate organic and conventional products. Combined chemometric analysis of (1)H NMR-, (13)C NMR-spectroscopy data, stable-isotope data (IRMS) and α-linolenic acid content (gas chromatography) was used to differentiate organic and conventional milk. In total 85 raw, pasteurized and ultra-heat treated (UHT) milk samples (52 organic and 33 conventional) were collected between August 2013 and May 2014. The carbon isotope ratios of milk protein and milk fat as well as the α-linolenic acid content of these samples were determined. Additionally, the milk fat was analyzed by (1)H and (13)C NMR spectroscopy. The chemometric analysis of combined data (IRMS, GC, NMR) resulted in more precise authentication of German raw and retail milk with a considerably increased classification rate of 95% compared to 81% for NMR and 90% for IRMS using linear discriminate analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

An in vitro protocol for direct isolation of potential probiotic lactobacilli from raw bovine milk and traditional fermented milks.

PubMed

Baruzzi, Federico; Poltronieri, Palmiro; Quero, Grazia Marina; Morea, Maria; Morelli, Lorenzo

2011-04-01

A method for isolating potential probiotic lactobacilli directly from traditional milk-based foods was developed. The novel digestion/enrichment protocol was set up taking care to minimize the protective effect of milk proteins and fats and was validated testing three commercial fermented milks containing well-known probiotic Lactobacillus strains. Only probiotic bacteria claimed in the label were isolated from two out of three commercial fermented milks. The application of the new protocol to 15 raw milk samples and 6 traditional fermented milk samples made it feasible to isolate 11 potential probiotic Lactobacillus strains belonging to Lactobacillus brevis, Lactobacillus fermentum, Lactobacillus gasseri, Lactobacillus johnsonii, Lactobacillus plantarum, Lactobacillus reuteri, and Lactobacillus vaginalis species. Even though further analyses need to ascertain functional properties of these lactobacilli, the novel protocol set-up makes it feasible to isolate quickly potential probiotic strains from traditional milk-based foods reducing the amount of time required by traditional procedures that, in addition, do not allow to isolate microorganisms occurring as sub-dominant populations.

Microbial diversity of consumption milk during processing and storage.

PubMed

Porcellato, Davide; Aspholm, Marina; Skeie, Siv Borghild; Monshaugen, Marte; Brendehaug, Johanne; Mellegård, Hilde

2018-02-02

Bovine milk contains a complex microbial community that affects the quality and safety of the product. Detailed knowledge of this microbiota is, therefore, of importance for the dairy industry. In this study, the bacterial composition of consumption milk was assessed during different stages in the production line and throughout the storage in cartons by using culturing techniques and 16S rRNA marker gene sequencing. Monthly samples from two dairies were analyzed to capture the seasonal variations in the milk microbiota. Although there was a core microbiota present in milk samples from both dairies, the composition of the bacterial communities were significantly influenced by sampling month, processing stage and storage temperature. Overall, a higher abundance of operational taxonomic units (OTUs) within the order Bacillales was detected in samples of raw and pasteurized milk from the spring and summer months, while Pseudomonadales and Lactobacillales OTUs were predominant in the winter months. OTUs belonging to the order Lactobacillales, Pseudomonadales, Clostridiales and Bacillales were significantly more abundant in milk samples taken immediately after pasteurization compared to raw milk samples. During storage of milk in cartons at 4°C, the bacterial composition remained stable throughout the product shelf life, while storage at 8°C significantly increased the abundance of OTUs belonging to the genus Bacillus and the plate count levels of presumptive Bacillus cereus. The knowledge obtained in this work will be useful to the dairy industry during their quality assurance work and risk assessment practices. Copyright © 2017 Elsevier B.V. All rights reserved.

Cow's milk quality and energy value during different lactation stages.

PubMed

Salamończyk, Ewa

2013-01-01

The quality of dairy products, raw milk in particular, depends on many factors. Low bacterial and somatic cell counts are basic determinants of the appropriate raw milk quality. The objective of the work was to assess the effect of selected factors, that is, the age of cows and their daily milk performance, on cytological quality (somatic cell count) and energy value of milk produced at individual stages of lactation. Somatic cell count and energy value of cow's milk were assessed. A total of 229 792 milk samples were examined. Data for analysis were taken from milk records of 350 dairy herds. It was demonstrated that, of all the lactations studied, the fi rst lactation (from calving to the 100th day of lactation) was characterised by the highest daily milk performance (25.1 kg) and the lowest somatic cell count (356 thous./1 ml), fat, protein and dry matter contents (4.06, 2.96 and 12.41%, respectively) and milk calorific value (732 kcal/kg). The highest energy value was recorded in cow's milk produced towards the end of lactation, that is from day 300 till the end of lactation (842 kcal/kg). High milk calorific value in late lactation and high fat and protein contents were accompanied by low raw milk quality.

Assessment of Staphylococcus aureus along milk value chain and its public health importance in Sebeta, central Oromia, Ethiopia.

PubMed

Ayele, Yodit; Gutema, Fanta Desissa; Edao, Bedaso Mamo; Girma, Robel; Tufa, Takele Beyene; Beyene, Tariku Jibat; Tadesse, Fanos; Geloye, Mesula; Beyi, Ashenafi Feyisa

2017-06-27

Staphylococcus aureus is one of the leading causes of gastroenteritis acquired from contaminated foods such as milk and milk products. However, such information is limited in Ethiopia. A cross-sectional study was conducted to assess the contamination of milk with S. aureus and knowledge, attitudes and practices (KAP) of actors along the milk value chain in Sebeta, Central Oromia, Ethiopia. A total of 291 samples collected from dairy farms, milk collection centers (MCCs) and processing plant were examined using standard microbiological techniques. The antimicrobial susceptibility profiles of the isolates were also investigated. The KAP of actors in milk value chain were evaluated through a structured questionnaire. Overall, 23.4% (n = 68) of the samples were positive for S. aureus. The prevalence of S. aureus was 19.6% (95% CI: 14.5-25.6) and 80.0% (95% CI: 14.5-25.6) at farm level and MCCs, respectively. Higher isolation rate was observed in the MCCs (p = 0.000) than the farms. The contamination rates of hands of milkers' and milking buckets with S. aureus were 32% and 11.1%, respectively. S. aureus was not isolated from pasteurized milk samples. The isolates were found to be resistant to cefoxitin (100%), penicillin G (98.5%), and streptomycin (77.9%). Among 23 interviewed farmers, 35% of them consumed raw milk, none of them wash their hands and 82.6% did not wash udder and teat before milking. Six percent of consumers had the habit of raw milk consumption. Eighty seven percent of dairy farmers and 54% of consumers had no awareness about milk borne diseases and staphylococcal food poisoning. The study revealed a high prevalence of S. aureus along the milk value chain, poor milk handling practices, raw milk consumption behavior, lack of awareness about milk borne diseases and occurrence of antimicrobials resistant S. aureus. S. aureus seems to pose a public health risk in Sebeta. Authors recommended the urgent need of public awareness creation about the importance of hygienic milk production and proper handling and adequate heat treatment of milk before consumption and further study to assess cost-effective preventive and control options.

Influence of thermal processing conditions on flavor stability in fluid milk: benzaldehyde.

PubMed

Potineni, R V; Peterson, D G

2005-01-01

Flavor loss in dairy products has been associated with enzymatic degradation by xanthine oxidase. This study was conducted to investigate the influence of milk thermal processing conditions (or xanthine oxidase inactivation) on benzaldehyde stability. Benzaldehyde was added to whole milk which had been thermally processed at 4 levels: (1) none or raw, (2) high temperature, short time (HTST) pasteurization, (3) HTST pasteurization, additionally heated to 100 degrees C (PAH), and (4) UHT sterilized. Additionally, PAH and UHT milk samples containing benzaldehyde (with and without ferrous sulfate) were spiked with xanthine oxidase. Azide was added as an antimicrobial agent (one additional pasteurized sample without) and the microbial load (total plate count) was determined on d 0, 2, and 6. The concentration of benzaldehyde and benzoic acid in all milk samples were determined at d 0, 1, 2, 4, and 6 (stored at 5 degrees C) by gas chromatography/mass spectrometry in selective ion monitory mode. Over the 6-d storage period, more than 80% of the benzaldehyde content was converted (oxidized) to benzoic acid in raw and pasteurized milk, whereas no change in the benzaldehyde concentration was found in PAH or UHT milk samples. Furthermore, the addition of xanthine oxidase or xanthine oxidase plus ferrous sulfate to PAH or UHT milk samples did not result in benzaldehyde degradation over the storage period.

Effect of seasonal variation on the composition and properties of raw milk destined for processing in the UK.

PubMed

Chen, Biye; Lewis, Michael J; Grandison, Alistair S

2014-09-01

The composition and physical properties of raw milk from a commercial herd were studied over a 1 year period in order to understand how best to utilise milk for processing throughout the year. Protein and fat levels demonstrated seasonal trends, while minerals and many physical properties displayed considerable variations, which were apparently unrelated to season. However, rennet clotting time, ethanol stability and foaming ability were subject to seasonal variation. Many significant interrelationships in physico-chemical properties were found. It is clear that the milk supply may be more suited to the manufacture of different products at different times of the year or even on a day to day basis. Subsequent studies will report on variation in production and quality of products manufactured from the same milk samples described in the current study and will thus highlight potential advantages of seasonal processing of raw milk. Copyright © 2014 Elsevier Ltd. All rights reserved.

Notes from the field: cryptosporidiosis associated with consumption of unpasteurized goat milk - Idaho, 2014.

PubMed

Rosenthal, Mariana; Pedersen, Randi; Leibsle, Scott; Hill, Vincent; Carter, Kris; Roellig, Dawn M

2015-02-27

On August 27, 2014, the Idaho Department of Health and Welfare's Division of Public Health (DPH) was notified of two cases of cryptosporidiosis in siblings aged <3 years. Idaho's Southwest District Health (SWDH) investigated and found that both children had consumed raw (unpasteurized) goat milk produced at a dairy licensed by the Idaho State Department of Agriculture (ISDA) and purchased at a retail store. Milk produced before August 18, the date of illness onset, was unavailable for testing from retail stores, the household, or the dairy. Samples of raw goat milk produced on August 18, 21, 25, and 28, taken from one opened container from the siblings' household, one unopened container from the retailer, and two unopened containers from the dairy, all tested positive for Cryptosporidium by real-time polymerase chain reaction (PCR) at a commercial laboratory. On August 30, ISDA placed a hold order on all raw milk sales from the producer. ISDA and SWDH issued press releases advising persons not to consume the raw milk; SWDH issued a medical alert, and Idaho's Central District Health Department issued an advisory to health care providers about the outbreak.

Semi-Quantitative Method for Streptococci Magnetic Detection in Raw Milk.

PubMed

Duarte, Carla; Costa, Tiago; Carneiro, Carla; Soares, Rita; Jitariu, Andrei; Cardoso, Susana; Piedade, Moisés; Bexiga, Ricardo; Freitas, Paulo

2016-04-27

Bovine mastitis is the most costly disease for dairy farmers and the most frequent reason for the use of antibiotics in dairy cattle; thus, control measures to detect and prevent mastitis are crucial for dairy farm sustainability. The aim of this study was to develop and validate a sensitive method to magnetically detect Streptococcus agalactiae (a Group B streptococci) and Streptococcus uberis in raw milk samples. Mastitic milk samples were collected aseptically from 44 cows with subclinical mastitis, from 11 Portuguese dairy farms. Forty-six quarter milk samples were selected based on bacterial identification by conventional microbiology. All samples were submitted to PCR analysis. In parallel, these milk samples were mixed with a solution combining specific antibodies and magnetic nanoparticles, to be analyzed using a lab-on-a-chip magnetoresistive cytometer, with microfluidic sample handling. This paper describes a point of care methodology used for detection of bacteria, including analysis of false positive/negative results. This immunological recognition was able to detect bacterial presence in samples spiked above 100 cfu/mL, independently of antibody and targeted bacteria used in this work. Using PCR as a reference, this method correctly identified 73% of positive samples for streptococci species with an anti-S. agalactiae antibody, and 41% of positive samples for an anti-GB streptococci antibody.

Semi-Quantitative Method for Streptococci Magnetic Detection in Raw Milk

PubMed Central

Duarte, Carla; Costa, Tiago; Carneiro, Carla; Soares, Rita; Jitariu, Andrei; Cardoso, Susana; Piedade, Moisés; Bexiga, Ricardo; Freitas, Paulo

2016-01-01

Bovine mastitis is the most costly disease for dairy farmers and the most frequent reason for the use of antibiotics in dairy cattle; thus, control measures to detect and prevent mastitis are crucial for dairy farm sustainability. The aim of this study was to develop and validate a sensitive method to magnetically detect Streptococcus agalactiae (a Group B streptococci) and Streptococcus uberis in raw milk samples. Mastitic milk samples were collected aseptically from 44 cows with subclinical mastitis, from 11 Portuguese dairy farms. Forty-six quarter milk samples were selected based on bacterial identification by conventional microbiology. All samples were submitted to PCR analysis. In parallel, these milk samples were mixed with a solution combining specific antibodies and magnetic nanoparticles, to be analyzed using a lab-on-a-chip magnetoresistive cytometer, with microfluidic sample handling. This paper describes a point of care methodology used for detection of bacteria, including analysis of false positive/negative results. This immunological recognition was able to detect bacterial presence in samples spiked above 100 cfu/mL, independently of antibody and targeted bacteria used in this work. Using PCR as a reference, this method correctly identified 73% of positive samples for streptococci species with an anti-S. agalactiae antibody, and 41% of positive samples for an anti-GB streptococci antibody. PMID:27128950

Microbiota characterization of a Belgian protected designation of origin cheese, Herve cheese, using metagenomic analysis.

PubMed

Delcenserie, V; Taminiau, B; Delhalle, L; Nezer, C; Doyen, P; Crevecoeur, S; Roussey, D; Korsak, N; Daube, G

2014-10-01

Herve cheese is a Belgian soft cheese with a washed rind, and is made from raw or pasteurized milk. The specific microbiota of this cheese has never previously been fully explored and the use of raw or pasteurized milk in addition to starters is assumed to affect the microbiota of the rind and the heart. The aim of the study was to analyze the bacterial microbiota of Herve cheese using classical microbiology and a metagenomic approach based on 16S ribosomal DNA pyrosequencing. Using classical microbiology, the total counts of bacteria were comparable for the 11 samples of tested raw and pasteurized milk cheeses, reaching almost 8 log cfu/g. Using the metagenomic approach, 207 different phylotypes were identified. The rind of both the raw and pasteurized milk cheeses was found to be highly diversified. However, 96.3 and 97.9% of the total microbiota of the raw milk and pasteurized cheese rind, respectively, were composed of species present in both types of cheese, such as Corynebacterium casei, Psychrobacter spp., Lactococcus lactis ssp. cremoris, Staphylococcus equorum, Vagococcus salmoninarum, and other species present at levels below 5%. Brevibacterium linens were present at low levels (0.5 and 1.6%, respectively) on the rind of both the raw and the pasteurized milk cheeses, even though this bacterium had been inoculated during the manufacturing process. Interestingly, Psychroflexus casei, also described as giving a red smear to Raclette-type cheese, was identified in small proportions in the composition of the rind of both the raw and pasteurized milk cheeses (0.17 and 0.5%, respectively). In the heart of the cheeses, the common species of bacteria reached more than 99%. The main species identified were Lactococcus lactis ssp. cremoris, Psychrobacter spp., and Staphylococcus equorum ssp. equorum. Interestingly, 93 phylotypes were present only in the raw milk cheeses and 29 only in the pasteurized milk cheeses, showing the high diversity of the microbiota. Corynebacterium casei and Enterococcus faecalis were more prevalent in the raw milk cheeses, whereas Psychrobacter celer was present in the pasteurized milk cheeses. However, this specific microbiota represented a low proportion of the cheese microbiota. This study demonstrated that Herve cheese microbiota is rich and that pasteurized milk cheeses are microbiologically very close to raw milk cheeses, probably due to the similar manufacturing process. The characterization of the microbiota of this particular protected designation of origin cheese was useful in enabling us to gain a better knowledge of the bacteria responsible for the character of this cheese. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Genetic diversity of thermoduric spoilage microorganisms of milk from Brazilian dairy farms.

PubMed

Ribeiro Júnior, J C; Tamanini, R; de Oliveira, A L M; Alfieri, A A; Beloti, V

2018-05-16

When correctly pasteurized, packaged, and stored, milk with low total bacterial counts (TBC) has a longer shelf life. Therefore, microorganisms that resist heat treatments are especially important in the deterioration of pasteurized milk and in its shelf life. The aim of this work was to quantify the thermoduric microorganisms after the pasteurization of refrigerated raw milk samples with low TBC and to identify the diversity of these isolates with proteolytic or lipolytic potential by RFLP analysis. Twenty samples of raw milk were collected in bulk milk tanks shortly after milking in different Brazilian dairy farms and pasteurized. The mean thermoduric count was 3.2 (±4.7) × 10 2 cfu/mL (2.1% of the TBC). Of the 310 colonies obtained, 44.2% showed milk spoilage potential, 32.6% were proteolytic and lipolytic simultaneously, 31% were exclusively proteolytic, and 48 (36.4%) were only lipolytic. Regarding the diversity, 8 genera were observed (Bacillus, Brachybacterium, Enterococcus, Streptococcus, Micrococcus, Kocuria, Paenibacillus, and Macrococcus); there was a predominance of endospore-forming bacteria (50%), and Bacillus licheniformis was the most common (34.1%) species. Considering the RFLP types, it was observed that the possible clonal populations make up the microbiota of different milk samples, but the same milk samples contain microorganisms of a single species with different RFLP types. Thus, even in milk with a high microbiological quality, it is necessary to control the potential milk-deteriorating thermoduric microorganisms to avoid the risk of compromising the shelf life and technological potential of pasteurized milk. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Bifidobacterium pseudolongum are efficient indicators of animal fecal contamination in raw milk cheese industry

PubMed Central

2011-01-01

Background The contamination of raw milk cheeses (St-Marcellin and Brie) from two plants in France was studied at several steps of production (raw milk, after addition of rennet - St-Marcellin - or after second maturation - Brie -, after removal from the mold and during ripening) using bifidobacteria as indicators of fecal contamination. Results Bifidobacterium semi-quantitative counts were compared using PCR-RFLP and real-time PCR. B. pseudolongum were detected in 77% (PCR-RFLP; 1.75 to 2.29 log cfu ml-1) and 68% (real-time PCR; 2.19 to 2.73 log cfu ml-1) of St-Marcellin samples and in 87% (PCR-RFLP; 1.17 to 2.40 log cfu ml-1) of Brie cheeses samples. Mean counts of B. pseudolongum remained stable along both processes. Two other populations of bifidobacteria were detected during the ripening stage of St-Marcellin, respectively in 61% and 18% of the samples (PCR-RFLP). The presence of these populations explains the increase in total bifidobacteria observed during ripening. Further characterization of these populations is currently under process. Forty-eight percents (St-Marcellin) and 70% (Brie) of the samples were B. pseudolongum positive/E. coli negative while only 10% (St-Marcellin) and 3% (Brie) were B. pseudolongum negative/E. coli positive. Conclusions The increase of total bifidobacteria during ripening in Marcellin's process does not allow their use as fecal indicator. The presence of B. pseudolongum along the processes defined a contamination from animal origin since this species is predominant in cow dung and has never been isolated in human feces. B. pseudolongum was more sensitive as an indicator than E. coli along the two different cheese processes. B. pseudolongum should be used as fecal indicator rather than E. coli to assess the quality of raw milk and raw milk cheeses. PMID:21816092

Characteristics of shiga toxin-producing Escherichia coli isolated from Swiss raw milk cheese within a 3-year monitoring program.

PubMed

Zweifel, C; Giezendanner, N; Corti, S; Krause, G; Beutin, L; Danuser, J; Stephan, R

2010-01-01

Food is an important vehicle for transmission of Shiga toxin-producing Escherichia coli (STEC). To assess the potential public health impact of STEC in Swiss raw milk cheese produced from cow's, goat's, and ewe's milk, 1,422 samples from semihard or hard cheese and 80 samples from soft cheese were examined for STEC, and isolated strains were further characterized. By PCR, STEC was detected after enrichment in 5.7% of the 1,502 raw milk cheese samples collected at the producer level. STEC-positive samples comprised 76 semihard, 8 soft, and 1 hard cheese. By colony hybridization, 29 STEC strains were isolated from 24 semihard and 5 soft cheeses. Thirteen of the 24 strains typeable with O antisera belonged to the serogroups O2, O22, and O91. More than half (58.6%) of the 29 strains belonged to O:H serotypes previously isolated from humans, and STEC O22:H8, O91:H10, O91:H21, and O174:H21 have also been identified as agents of hemolytic uremic syndrome. Typing of Shiga toxin genes showed that stx(1) was only found in 2 strains, whereas 27 strains carried genes encoding for the Stx(2) group, mainly stx(2) and stx(2vh-a/b). Production of Stx(2) and Stx(2vh-a/b) subtypes might be an indicator for a severe outcome in patients. Nine strains harbored hlyA (enterohemorrhagic E. coli hemolysin), whereas none tested positive for eae (intimin). Consequently, semihard and hard raw milk cheese may be a potential source of STEC, and a notable proportion of the isolated non-O157 STEC strains belonged to serotypes or harbored Shiga toxin gene variants associated with human infections.

Development of HPLC-ELSD method for determination of maltodextrin in raw milk.

PubMed

Moraes, Flávia Santana; da Costa, Marion Pereira; de Melo Silva, Vitor Luiz; de Barros Pinto Moreira, Rodrigo Vilela; de Barros, Raphael Ferreira; Mársico, Eliane Teixeira; Conte-Junior, Carlos Adam; de Oliveira Silva, Adriana Cristina

2017-02-15

An analytical method was developed and validated for the determination of maltodextrin in raw milk, using high-performance liquid chromatography with evaporative light scattering detection. Maltodextrin content was evaluated in adulterated raw milk using a Supelcosil LC-NH2 (25cm×4.6mm) column and isocratic elution (68% of acetonitrile). Validation parameters exhibited adequate linearity, with relative standard deviation values between 0.74 and 2.16% (n=10) for repeatability and 0.11-19.39% (n=5) for intermediate precision. Limits of detection and quantification were 0.78 and 1.56mg.mL(-1), respectively, and recovery rates were between 91 and 93% for three levels. The application of this method shows that maltodextrin concentrations found in adulterated samples are lower than expected, which may be related to the quality of the commercial maltodextrin used. The method proposed proved to be simple and appropriate for the determination of maltodextrin in raw milk, with detection down to adulteration levels of 1%. Copyright © 2016 Elsevier Ltd. All rights reserved.

Visible and near-infrared spectroscopic analysis of raw milk for cow health monitoring: reflectance or transmittance?

PubMed

Aernouts, B; Polshin, E; Lammertyn, J; Saeys, W

2011-11-01

The composition of produced milk has great value for the dairy farmer. It determines the economic value of the milk and provides valuable information about the metabolism of the corresponding cow. Therefore, online measurement of milk components during milking 2 or more times per day would provide knowledge about the current health and nutritional status of each cow individually. This information provides a solid basis for optimizing cow management. The potential of visible and near-infrared (Vis/NIR) spectroscopy for predicting the fat, crude protein, lactose, and urea content of raw milk online during milking was, therefore, investigated in this study. Two measurement modes (reflectance and transmittance) and different wavelength ranges for Vis/NIR spectroscopy were evaluated and their ability to measure the milk composition online was compared. The Vis/NIR reflectance measurements allowed for very accurate monitoring of the fat and crude protein content in raw milk (R(2)>0.95), but resulted in poor lactose predictions (R(2)<0.75). In contrast, Vis/NIR transmittance spectra of the milk samples gave accurate fat and crude protein predictions (R(2)>0.90) and useful lactose predictions (R(2)=0.88). Neither Vis/NIR reflectance nor transmittance spectroscopy lead to an acceptable prediction of the milk urea content. Transmittance spectroscopy can thus be used to predict the 3 major milk components, but with lower accuracy for fat and crude protein than the reflectance mode. Moreover, the small sample thickness (1mm) required for NIR transmittance measurement considerably complicates its online use. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Toxoplasma Gondii and Pre-treatment Protocols for Polymerase Chain Reaction Analysis of Milk Samples: A Field Trial in Sheep from Southern Italy.

PubMed

Vismarra, Alice; Barilli, Elena; Miceli, Maura; Mangia, Carlo; Bacci, Cristina; Brindani, Franco; Kramer, Laura

2017-01-24

Toxoplasmosis is a zoonotic disease caused by the protozoan Toxoplasma gondii. Ingestion of raw milk has been suggested as a risk for transmission to humans. Here the authors evaluated pre-treatment protocols for DNA extraction on T. gondii tachyzoite-spiked sheep milk with the aim of identifying the method that resulted in the most rapid and reliable polymerase chain reaction (PCR) positivity. This protocol was then used to analyse milk samples from sheep of three different farms in Southern Italy, including real time PCR for DNA quantification and PCR-restriction fragment length polymorphism for genotyping. The pre-treatment protocol using ethylenediaminetetraacetic acid and Tris-HCl to remove casein gave the best results in the least amount of time compared to the others on spiked milk samples. One sample of 21 collected from sheep farms was positive on one-step PCR, real time PCR and resulted in a Type I genotype at one locus (SAG3). Milk usually contains a low number of tachyzoites and this could be a limiting factor for molecular identification. Our preliminary data has evaluated a rapid, cost-effective and sensitive protocol to treat milk before DNA extraction. The results of the present study also confirm the possibility of T. gondii transmission through consumption of raw milk and its unpasteurised derivatives.

Short communication: Investigation into Mycobacterium avium ssp. paratuberculosis in pasteurized milk in Italy.

PubMed

Serraino, A; Bonilauri, P; Giacometti, F; Ricchi, M; Cammi, G; Piva, S; Zambrini, V; Canever, A; Arrigoni, N

2017-01-01

This study investigated the presence of viable Mycobacterium avium ssp. paratuberculosis (MAP) in pasteurized milk produced by Italian industrial dairy plants to verify the prediction of a previously performed risk assessment. The study analyzed 160 one-liter bottles of pasteurized milk from 2 dairy plants located in 2 different regions. Traditional cultural protocols were applied to 500mL of pasteurized milk for each sample. The investigation focused also on the pasteurization parameters and data on the microbiological characteristics of raw milk (total bacterial count) and pasteurized milk (Enterobacteriaceae and Listeria monocytogenes). No sample was positive for MAP, the pasteurization parameters complied with European Union legislation, and the microbiological analysis of raw and pasteurized milk showed good microbiological quality. The results show that a 7-log (or >7) reduction could be a plausible value for commercial pasteurization. The combination of hygiene practices at farm level and commercial pasteurization yield very low or absent levels of MAP contamination in pasteurized milk, suggesting that pasteurized milk is not a significant source of human exposure to MAP in the dairies investigated. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Microstructure of fat globules in whole milk after thermosonication treatment.

PubMed

Bermúdez-Aguirre, D; Mawson, R; Barbosa-Cánovas, G V

2008-09-01

The structure of fat globules in whole milk was studied after heat and thermosonication treatments to observe what happens during these processes at the microscopic level using scanning electron microscopy. Raw whole milk was thermosonicated in an ultrasonic processor-Hielscher UP400S (400 W, 24 kHz, 120 microm amplitude), using a 22-mm probe at 63 degrees C for 30 min. Heat treatment involved heating the milk at 63 degrees C for 30 min. Color and fat content were measured to correlate the images with analytical measurements. The results showed that the surface of the fat globule was completely roughened after thermosonication. Ultrasound waves were responsible for disintegrating the milk fat globule membrane (MFGM) by releasing the triacylglycerols. Furthermore, the overall structure of milk after sonication showed smaller fat globules (smaller than 1 microm) and a granular surface. This was due to the interaction between the disrupted MFGM and some casein micelles. Minor changes in the aspect of the globules between thermal and raw milks were detected. Color measurements showed higher L* values for sonicated samples. Sonicated milk was whiter (92.37 +/- 0.20) and generally showed a better degree of luminosity and homogenization compared to thermal treated milk (88.25 +/- 0.67) and raw milk (87.82 +/- 0.18). Fat content analysis yielded a higher value after sonication (4.24%) compared to untreated raw milk (4.04%) because fat extraction is more efficient after sonication. The advantages of thermosonicated milk are that it can be pasteurized and homogenized in just 1 step, it can be produced with important cost savings, and it has better characteristics, making thermosonication a potential processing method for milk and most other dairy products.

Determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in Brazilian cow milk.

PubMed

Rocha, Dayse A M; Torres, João P M; Reichel, Klaus; Novotny, Etelvino H; Estrella, Leonardo F; Medeiros, Rebeca O; Netto, Annibal D Pereira

2016-12-01

The determination of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in raw cow milks have never been reported in Brazil. Since the consumption of food of animal origin, including milk and dairy products, is the major source of human exposure to these compounds, this study aimed to establish the levels and profile of seven PCDDs and ten PCDFs in raw cow milk samples collected in eight Brazilian states which among the major milk producer states. Raw milk samples were collected in 34 different dairy cattle farms during the summer of 2013. All PCDD/Fs congeners were found at least in some of the 34 samples studied. The octa-chlorinated congeners (OCDD and OCDF) were ubiquitous and also present in high concentrations. The mean values of WHO-TEQ 1998;2005 were respectively 1.66 and 1.36pgTEQg -1 fat and samples taken in São Paulo showed the highest WHO-TEQ values (2.46 TEQ 1998 g -1 fat and 2.10pgTEQ 2005 g -1 fat). Although all samples showed some contamination level, all values were below the limit established by European Union for total PCDD/Fs in cow milk (3pgWHO-TEQ 1998 g -1 fat). Principal Component Analysis (PCA) showed that OCDD and OCDF were responsible for 73% and 20% of the total data variance, respectively and they presented an independent behavior, probably as a result of distinct origins. The use of TEQ as weights in the PCA, revealed the importance of the penta-chloro congeners and it was possible to identify sample distribution patterns probably associated with the main PeCDD and PeCDF. The importance of local sources to PCDD/Fs concentrations is still to be evaluated and determined. Copyright © 2016 Elsevier B.V. All rights reserved.

Robustness of near-infrared calibration models for the prediction of milk constituents during the milking process.

PubMed

Melfsen, Andreas; Hartung, Eberhard; Haeussermann, Angelika

2013-02-01

The robustness of in-line raw milk analysis with near-infrared spectroscopy (NIRS) was tested with respect to the prediction of the raw milk contents fat, protein and lactose. Near-infrared (NIR) spectra of raw milk (n = 3119) were acquired on three different farms during the milking process of 354 milkings over a period of six months. Calibration models were calculated for: a random data set of each farm (fully random internal calibration); first two thirds of the visits per farm (internal calibration); whole datasets of two of the three farms (external calibration), and combinations of external and internal datasets. Validation was done either on the remaining data set per farm (internal validation) or on data of the remaining farms (external validation). Excellent calibration results were obtained when fully randomised internal calibration sets were used for milk analysis. In this case, RPD values of around ten, five and three for the prediction of fat, protein and lactose content, respectively, were achieved. Farm internal calibrations achieved much poorer prediction results especially for the prediction of protein and lactose with RPD values of around two and one respectively. The prediction accuracy improved when validation was done on spectra of an external farm, mainly due to the higher sample variation in external calibration sets in terms of feeding diets and individual cow effects. The results showed that further improvements were achieved when additional farm information was added to the calibration set. One of the main requirements towards a robust calibration model is the ability to predict milk constituents in unknown future milk samples. The robustness and quality of prediction increases with increasing variation of, e.g., feeding and cow individual milk composition in the calibration model.

Detection of β-Lactams and Chloramphenicol Residues in Raw Milk-Development and Application of an HPLC-DAD Method in Comparison with Microbial Inhibition Assays.

PubMed

Karageorgou, Eftychia; Christoforidou, Sofia; Ioannidou, Maria; Psomas, Evdoxios; Samouris, Georgios

2018-06-01

The present study was carried out to assess the detection sensitivity of four microbial inhibition assays (MIAs) in comparison with the results obtained by the High Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) method for antibiotics of the β-lactam group and chloramphenicol in fortified raw milk samples. MIAs presented fairly good results when detecting β-lactams, whereas none were able to detect chloramphenicol at or above the permissible limits. HPLC analysis revealed high recoveries of examined compounds, whereas all detection limits observed were lower than their respective maximum residue limits (MRL) values. The extraction and clean-up procedure of antibiotics was performed by a modified matrix solid phase dispersion procedure using a mixture of Plexa by Agilent and QuEChERS as a sorbent. The HPLC method developed was validated, determining the accuracy, precision, linearity, decision limit, and detection capability. Both methods were used to monitor raw milk samples of several cows and sheep, obtained from producers in different regions of Greece, for the presence of examined antibiotic residues. Results obtained showed that MIAs could be used effectively and routinely to detect antibiotic residues in several milk types. However, in some cases, spoilage of milk samples revealed that the kits' sensitivity could be strongly affected, whereas this fact does not affect the effectiveness of HPLC-DAD analysis.

Adulteration detection in milk using infrared spectroscopy combined with two-dimensional correlation analysis

NASA Astrophysics Data System (ADS)

He, Bin; Liu, Rong; Yang, Renjie; Xu, Kexin

2010-02-01

Adulteration of milk and dairy products has brought serious threats to human health as well as enormous economic losses to the food industry. Considering the diversity of adulterants possibly mixed in milk, such as melamine, urea, tetracycline, sugar/salt and so forth, a rapid, widely available, high-throughput, cost-effective method is needed for detecting each of the components in milk at once. In this paper, a method using Fourier Transform Infrared spectroscopy (FTIR) combined with two-dimensional (2D) correlation spectroscopy is established for the discriminative analysis of adulteration in milk. Firstly, the characteristic peaks of the raw milk are found in the 4000-400 cm-1 region by its original spectra. Secondly, the adulterant samples are respectively detected with the same method to establish a spectral database for subsequent comparison. Then, 2D correlation spectra of the samples are obtained which have high time resolution and can provide information about concentration-dependent intensity changes not readily accessible from one-dimensional spectra. And the characteristic peaks in the synchronous 2D correlation spectra of the suspected samples are compared with those of raw milk. The differences among their synchronous spectra imply that the suspected milk sample must contain some kinds of adulterants. Melamine, urea, tetracycline and glucose adulterants in milk are identified respectively. This nondestructive method can be used for a correct discrimination on whether the milk and dairy products are adulterated with deleterious substances and it provides a new simple and cost-effective alternative to test the components of milk.

Nicotinamide Riboside Is a Major NAD+ Precursor Vitamin in Cow Milk.

PubMed

Trammell, Samuel Aj; Yu, Liping; Redpath, Philip; Migaud, Marie E; Brenner, Charles

2016-05-01

Nicotinamide riboside (NR) is a recently discovered NAD(+) precursor vitamin with a unique biosynthetic pathway. Although the presence of NR in cow milk has been known for more than a decade, the concentration of NR with respect to the other NAD(+) precursors was unknown. We aimed to determine NAD(+) precursor vitamin concentration in raw samples of milk from individual cows and from commercially available cow milk. LC tandem mass spectrometry and isotope dilution technologies were used to quantify NAD(+) precursor vitamin concentration and to measure NR stability in raw and commercial milk. Nuclear magnetic resonance (NMR) spectroscopy was used to test for NR binding to substances in milk. Cow milk typically contained ∼12 μmol NAD(+) precursor vitamins/L, of which 60% was present as nicotinamide and 40% was present as NR. Nicotinic acid and other NAD(+) metabolites were below the limits of detection. Milk from samples testing positive for Staphylococcus aureus contained lower concentrations of NR (Spearman ρ = -0.58, P = 0.014), and NR was degraded by S. aureus Conventional milk contained more NR than milk sold as organic. Nonetheless, NR was stable in organic milk and exhibited an NMR spectrum consistent with association with a protein fraction in skim milk. NR is a major NAD(+) precursor vitamin in cow milk. Control of S. aureus may be important to preserve the NAD(+) precursor vitamin concentration of milk. © 2016 American Society for Nutrition.

Evaluation of Antibiotic Residues in Pasteurized and Raw Milk Distributed in the South of Khorasan-e Razavi Province, Iran.

PubMed

Moghadam, Mortez Mohammadzadeh; Amiri, Mostafa; Riabi, Hamed Ramezani Awal; Riabi, Hamid Ramezani Awal

2016-12-01

The presence of antibiotic residues in milk and other products livestock is a health problem which can endanger public health. Antibiotics are used widely in animal husbandry to treat diseases related to bacterial infections. Antimicrobial drugs have been in use for decades in industry. They are commonly used in livestock facilities to treat mastitis. This study aimed to investigate antibiotic residues in pasteurized milk distributed in schools, in milk collection centers, and in milk production factories in Gonabad city. This cross-sectional study was conducted on 251 samples of commercial pasteurized milk packet distributed in schools (code A), raw milk collection centers in Gonabad city (code B), and pasteurized milk production factories (code C) in Gonabad city. The Copan test kit of Denmark Christian Hansen Company was used to monitor antibiotic residues in milk. The data were analysed employing Chi-square test and one-way analysis of variance (ANOVA) to determine significant differences using SPSS software version 20. The significant level was considered at p<0.05. In total, 251 milk samples were collected out of which 143 (57%) were code A, 84 (33.5%) code B and 24 (9.6%) code C. Total number of 189 samples (75.2%) were negative and 62 (24.8%) were positive. From the three types of milk samples, 41 samples (28.7%) of the code A, 18 samples (21.4%) of the code B and 3 samples (12.5%) of the code C were positive. In general, from the milk samples most contaminated with antibiotics, 17 samples were positive in January and regarding code A, 13 samples were positive in the same month. There was not a significant difference among the three types of milk (p>0.05). The highest number of milk samples (n=7) contaminated with antibiotics were related to code B (38.5%). Most positive cases were related to code A in winter. Also, there was no significant difference among the three types of contaminated milk regarding the year and month (p=0.164 and p=0.917, respectively). Pasteurized milk supplied in the studied city has high level of contamination due to high use of antibiotics. A standard limit needs to be set for the right level of residue of antibiotics in milk to avoid the harmful effects.

Evaluation of Antibiotic Residues in Pasteurized and Raw Milk Distributed in the South of Khorasan-e Razavi Province, Iran

PubMed Central

Moghadam, Mortez Mohammadzadeh; Amiri, Mostafa; Riabi, Hamid Ramezani Awal

2016-01-01

Introduction The presence of antibiotic residues in milk and other products livestock is a health problem which can endanger public health. Antibiotics are used widely in animal husbandry to treat diseases related to bacterial infections. Antimicrobial drugs have been in use for decades in industry. They are commonly used in livestock facilities to treat mastitis. Aim This study aimed to investigate antibiotic residues in pasteurized milk distributed in schools, in milk collection centers, and in milk production factories in Gonabad city. Materials and Methods This cross-sectional study was conducted on 251 samples of commercial pasteurized milk packet distributed in schools (code A), raw milk collection centers in Gonabad city (code B), and pasteurized milk production factories (code C) in Gonabad city. The Copan test kit of Denmark Christian Hansen Company was used to monitor antibiotic residues in milk. The data were analysed employing Chi-square test and one-way analysis of variance (ANOVA) to determine significant differences using SPSS software version 20. The significant level was considered at p<0.05. Results In total, 251 milk samples were collected out of which 143 (57%) were code A, 84 (33.5%) code B and 24 (9.6%) code C. Total number of 189 samples (75.2%) were negative and 62 (24.8%) were positive. From the three types of milk samples, 41 samples (28.7%) of the code A, 18 samples (21.4%) of the code B and 3 samples (12.5%) of the code C were positive. In general, from the milk samples most contaminated with antibiotics, 17 samples were positive in January and regarding code A, 13 samples were positive in the same month. There was not a significant difference among the three types of milk (p>0.05). The highest number of milk samples (n=7) contaminated with antibiotics were related to code B (38.5%). Most positive cases were related to code A in winter. Also, there was no significant difference among the three types of contaminated milk regarding the year and month (p=0.164 and p=0.917, respectively). Conclusion Pasteurized milk supplied in the studied city has high level of contamination due to high use of antibiotics. A standard limit needs to be set for the right level of residue of antibiotics in milk to avoid the harmful effects. PMID:28208877

Human milk antibacterial factors: the effect of temperature on defense systems.

PubMed

Chen, H Y; Allen, J C

2001-01-01

Bovine milk will eventually spoil at refrigeration temperatures, but endogenous or exogenous pathogenic or spoilage bacteria in human milk stored for delayed feeding will die. We investigated the mechanism for these antibacterial properties and their response to high-tempertature, short-time (HTST, 72 degrees C-75 degrees C, 15 sec) and low-temperature long-time (LTLT, 65 degrees C, 30 min) pasteurization. Nonpathogenic Listeria innocua (10(6) cfu/mL) was inoculated into raw and processed bovine and human milk; bacterial plate counts twice weekly determined antibacterial activities. Up to 99% of L. innocua were killed and further growth was inhibited in raw and pasteurized human milk for at least 60 days at 4 degrees C. Reactive IgA antibodies against Listeria antigens were demonstrated by enzyme immunoassay in some human milk samples; sIgA activity against Escherichia coli O antigens was significantly decreased by heat treatments (raw, 1.8; HTST, 1.1; LTLT, 1.3 activity units). Adding human lactoferrin (0.5-20 mg/mL) to the Listeria inoculum (approximately 10(7) cfu/mL) in 1% peptone water did not inhibit bacterial growth.

Determination of haemolytic and non haemolytic genes profiles of Bacillus cereus strains isolated from food samples by polymerase chain reaction (pcr) technique

NASA Astrophysics Data System (ADS)

Jawad, Nisreen; Ahemd, Asmat; Abdullah, Aminah

2018-04-01

The aim of this study was to investigate the presence of Bacillus cereus and detection of enterotoxigenic genes in food samples by utilizing a Polymerase Chain Reaction technique (PCR). In this study the providence of B. cereus was carried out to food samples. The B. cereus isolates were investigated for enterotoxigenic gene. The cooked seafood, and raw milk samples were purchased from several restaurants and market in the area of (Bangi, Kajang, Serdang and UKM) Selangor, Malaysia. A total of 60 samples have been analyzed. B. cereus contamination has been formed between 1.4×105 - 3×105 cfu/mL of cooked seafood and raw milk samples. Five colonies have been detected as B. cereus using biochemical test. All B. cereus isolates named BC1 to BC27, were characterized for haemolytic enterotoxin (HBL) complex encoding genes (hblA), non-haemolytic enterotoxin encoding gene (NheA). 10 isolates have been reported to be positive towards hblA and 12 isolates were positive towards NheA. The presence of B. cereus and their enterotoxigenic genes in cooked seafood and raw milk from to food samples obtained may pose a potential risk for public health.

Identification and antibiogram pattern of Bacillus cereus from the milk and milk products in and around Jammu region

PubMed Central

Yusuf, Umar; Kotwal, S. K.; Gupta, Sanjolly; Ahmed, Touqeer

2018-01-01

Aim: The aims of the present study were to assess the prevalence, identification, and antibiogram pattern of Bacillus cereus from 215 samples of different milk and milk products in and around Jammu region. Materials and Methods: In the present study, 215 samples of milk, rasgulla, burfi, rasmalai, kalaari, paneer, ice cream, and pastry were collected and analyzed for the isolation of the B. cereus using PEMBA, and antibiogram pattern was observed for all the milk and milk products. Results: B. cereus was detected in 61/215 samples with an overall prevalence of 28.37%. Biotyping revealed predominantly 5, 7, and 2 biotypes in raw milk. Burfi and ice cream revealed 2, 3, 5, and 7 biotypes. Rasgulla had 2, 3, and 5 biotypes; paneer and rasmalai had biotypes 2 and 5, while kalaari revealed biotype 5. Antibiogram pattern revealed that isolates were highly sensitive to gentamicin (100%), intermediate to ampicillin (40.98%), tetracycline (31.14%), erythromycin (29.50%), and amoxicillin (26.22%), and high resistance against penicillin G (100%). Adulteration of starch was detected in 16.66 % raw milk samples. All starch positive samples were positive for B. cereus. However, 12 starch negative samples also yielded B. cereus. Conclusion: From this study, it was concluded that highest prevalence of B. cereus was found in ice cream. Several isolates of B. cereus showed toxigenic activity, so the presence of B. cereus in milk and milk products may be of public health hazard. The antibiogram pattern of B. cereus isolates showed sensitivity to gentamicin, ciprofloxacin, chloramphenicol, streptomycin, and resistance to penicillin-G and cephalexin. The presence of B. cereus in milk and milk products showed a strong association besides establishing the fact that starch adulteration can be indicative of the presence of B. cereus. PMID:29657402

Consumption of raw or unpasteurized milk and milk products by pregnant women and children.

PubMed

2014-01-01

Sales of raw or unpasteurized milk and milk products are still legal in at least 30 states in the United States. Raw milk and milk products from cows, goats, and sheep continue to be a source of bacterial infections attributable to a number of virulent pathogens, including Listeria monocytogenes, Campylobacter jejuni, Salmonella species, Brucella species, and Escherichia coli O157. These infections can occur in both healthy and immunocompromised individuals, including older adults, infants, young children, and pregnant women and their unborn fetuses, in whom life-threatening infections and fetal miscarriage can occur. Efforts to limit the sale of raw milk products have met with opposition from those who are proponents of the purported health benefits of consuming raw milk products, which contain natural or unprocessed factors not inactivated by pasteurization. However, the benefits of these natural factors have not been clearly demonstrated in evidence-based studies and, therefore, do not outweigh the risks of raw milk consumption. Substantial data suggest that pasteurized milk confers equivalent health benefits compared with raw milk, without the additional risk of bacterial infections. The purpose of this policy statement was to review the risks of raw milk consumption in the United States and to provide evidence of the risks of infectious complications associated with consumption of unpasteurized milk and milk products, especially among pregnant women, infants, and children.

[Identification and isolation of non-tuberculous mycobacteria from environmental samples].

PubMed

Cafri, Uğur; Aslan, Gönül; Direkel, Sahin; Tarhan, Gülnur; Ceyhan, Ismail; Emekdaş, Gürol

2010-07-01

Non-tuberculous mycobacteria (NTM) found frequently in tap water and environment cause important opportunistic infections in immunocompromised patients. The aim of this study was to isolate and identify non-tuberculous mycobacteria in soil, raw milk and water distribution system samples in Mersin (a province located at Mediterranean region of Turkey). A total of 101 water, 124 soil and 40 milk samples collected from the central part and suburban parts of Mersin during November 2003-May 2004 period were included in the study. Water samples were collected from 29 different water distribution systems; soil samples from different parks and gardens and milk samples from raw milks sold at different districts. After the samples were processed by homogenization and decontamination, acid-fast staining and culture into Löwenstein-Jensen medium were performed. Acid-fast bacilli isolated from culture medium were identified by using conventional methods, polymerase chain reaction (PCR)-RFLP (Restriction Fragment Length Polymorphism) and INNO-LIPA Mycobacteria methods. NTM were identified from 4.9% (5/101) of water samples and 0.8% (1/124) of soil samples by culture and PCR. No NTM were detected in the raw milk samples. Three of the NTM strains isolated from water samples were defined as Mycobacterium chelonae type III and two as Mycobacterium kansasii type II. One NTM strain isolated from soil was defined as Mycobacterium fortuitum. It was of note that two of the five NTM positive water samples were tap water samples collected from hospitals. It was concluded that NTM colonization/contamination of water and environment in the hospitals was a potential risk factor in terms of nosocomial infections. Thus surveillance cultures of the water systems and the medical devices in the hospital are necessary to fix the source of NTM, to identify and type the strains and to establish effective control measures such as sterilization, disinfection, maintenance and modernization of water systems.

Exposure Assessment of Acetamide in Milk, Beef, and Coffee Using Xanthydrol Derivatization and Gas Chromatography/Mass Spectrometry

PubMed Central

2017-01-01

Acetamide has been classified as a possible human carcinogen, but uncertainties exist about its levels in foods. This report presents evidence that thermal decomposition of N-acetylated sugars and amino acids in heated gas chromatograph injectors contributes to artifactual acetamide in milk and beef. An alternative gas chromatography/mass spectrometry protocol based on derivatization of acetamide with 9-xanthydrol was optimized and shown to be free of artifactual acetamide formation. The protocol was validated using a surrogate analyte approach based on d3-acetamide and applied to analyze 23 pasteurized whole milk, 44 raw sirloin beef, and raw milk samples from 14 different cows, and yielded levels about 10-fold lower than those obtained by direct injection without derivatization. The xanthydrol derivatization procedure detected acetamide in every food sample tested at 390 ± 60 ppb in milk, 400 ± 80 ppb in beef, and 39 000 ± 9000 ppb in roasted coffee beans. PMID:29186951

Microbiological quality of raw milk attributable to prolonged refrigeration conditions.

PubMed

Vithanage, Nuwan R; Dissanayake, Muditha; Bolge, Greg; Palombo, Enzo A; Yeager, Thomas R; Datta, Nivedita

2017-02-01

Refrigerated storage of raw milk is a prerequisite in dairy industry. However, temperature abused conditions in the farming and processing environments can significantly affect the microbiological quality of raw milk. Thus, the present study investigated the effect of different refrigeration conditions such as 2, 4, 6, 8, 10 and 12 °C on microbiological quality of raw milk from three different dairy farms with significantly different initial microbial counts. The bacterial counts (BC), protease activity (PA), proteolysis (PL) and microbial diversity in raw milk were determined during storage. The effect of combined heating (75 ± 0·5 °C for 15 s) and refrigeration on controlling those contaminating microorganisms was also investigated. Results of the present study indicated that all of the samples showed increasing BC, PA and PL as a function of temperature, time and initial BC with a significant increase in those criteria ≥6 °C. Similar trends in BC, PA and PL were observed during the extended storage of raw milk at 4 °C. Both PA and PL showed strong correlation with the psychrotrophic proteolytic count (PPrBC: at ≥4 °C) and thermoduric psychrotrophic count (TDPC: at ≥8 °C) compared to total plate count (TPC) and psychrotrophic bacterial count (PBC), that are often used as the industry standard. Significant increases in PA and PL were observed when PPrBC and TDPC reached 5 × 104 cfu/ml and 1 × 104 cfu/ml, and were defined as storage life for quality (S LQ), and storage life for safety (S LS) aspects, respectively. The storage conditions also significantly affected the microbial diversity, where Pseudomonas fluorescens and Bacillus cereus were found to be the most predominant isolates. However, deep cooling (2 °C) and combination of heating and refrigeration (≤4 °C) significantly extended the S LQ and S Ls of raw milk.

Influence of Homogenization and Thermal Processing on the Gastrointestinal Fate of Bovine Milk Fat: In Vitro Digestion Study.

PubMed

Liang, Li; Qi, Ce; Wang, Xingguo; Jin, Qingzhe; McClements, David Julian

2017-12-20

Dairy lipids are an important source of energy and nutrients for infants and adults. The dimensions, aggregation state, and interfacial properties of fat globules in raw milk are changed by dairy processing operations, such as homogenization and thermal processing. These changes influence the behavior of fat globules within the human gastrointestinal tract (GIT). The gastrointestinal fate of raw milk, homogenized milk, high temperature short time (HTST) pasteurized milk, and ultrahigh temperature (UHT) pasteurized milk samples was therefore determined using a simulated GIT. The properties of particles in different regions of the GIT depended on the degree of milk processing. Homogenization increased the initial lipid digestion rate but did not influence the final digestion extent. Thermal processing of homogenized milk decreased the initial rate and final extent of lipid digestion, which was attributed to changes in interfacial structure. These results provide insights into the impact of dairy processing on the gastrointestinal fate of milk fat.

21 CFR 1210.26 - Permits for raw milk or cream.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Permits for raw milk or cream. 1210.26 Section... FEDERAL IMPORT MILK ACT Permit Control § 1210.26 Permits for raw milk or cream. Except as provided in § 1210.27, permits to ship or transport raw milk or cream into the United States will be granted only...

21 CFR 1210.26 - Permits for raw milk or cream.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Permits for raw milk or cream. 1210.26 Section... FEDERAL IMPORT MILK ACT Permit Control § 1210.26 Permits for raw milk or cream. Except as provided in § 1210.27, permits to ship or transport raw milk or cream into the United States will be granted only...

Influence of raw milk quality on processed dairy products: How do raw milk quality test results relate to product quality and yield?

PubMed

Murphy, Steven C; Martin, Nicole H; Barbano, David M; Wiedmann, Martin

2016-12-01

This article provides an overview of the influence of raw milk quality on the quality of processed dairy products and offers a perspective on the merits of investing in quality. Dairy farmers are frequently offered monetary premium incentives to provide high-quality milk to processors. These incentives are most often based on raw milk somatic cell and bacteria count levels well below the regulatory public health-based limits. Justification for these incentive payments can be based on improved processed product quality and manufacturing efficiencies that provide the processor with a return on their investment for high-quality raw milk. In some cases, this return on investment is difficult to measure. Raw milks with high levels of somatic cells and bacteria are associated with increased enzyme activity that can result in product defects. Use of raw milk with somatic cell counts >100,000cells/mL has been shown to reduce cheese yields, and higher levels, generally >400,000 cells/mL, have been associated with textural and flavor defects in cheese and other products. Although most research indicates that fairly high total bacteria counts (>1,000,000 cfu/mL) in raw milk are needed to cause defects in most processed dairy products, receiving high-quality milk from the farm allows some flexibility for handling raw milk, which can increase efficiencies and reduce the risk of raw milk reaching bacterial levels of concern. Monitoring total bacterial numbers in regard to raw milk quality is imperative, but determining levels of specific types of bacteria present has gained increasing importance. For example, spores of certain spore-forming bacteria present in raw milk at very low levels (e.g., <1/mL) can survive pasteurization and grow in milk and cheese products to levels that result in defects. With the exception of meeting product specifications often required for milk powders, testing for specific spore-forming groups is currently not used in quality incentive programs in the United States but is used in other countries (e.g., the Netherlands). Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Chemical Contaminants in Raw and Pasteurized Human Milk.

PubMed

Hartle, Jennifer C; Cohen, Ronald S; Sakamoto, Pauline; Barr, Dana Boyd; Carmichael, Suzan L

2018-05-01

Environmental contaminants ranging from legacy chemicals like p,p'-dichlorodiphenyltrichloroethane (DDT) to emerging chemicals like phthalates are ubiquitous. Research aims/questions: This research aims to examine the presence and co-occurrence of contaminants in human milk and effects of pasteurization on human milk chemical contaminants. We analyzed human milk donated by 21 women to a milk bank for 23 chemicals, including the persistent organic pollutants (POPs) polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dichlorodiphenyltrichloroethane (DDT), and dichlorodiphenyldichloroethylene (DDE) isomers that are known to sequester in adipose tissue, along with the current-use and nonpersistent pesticides chlorpyrifos and permethrin, phthalates, and bisphenol A (BPA). Human milk was analyzed raw and pasteurized for these chemicals using gas chromatography-tandem mass spectrometry for the POPs and high-performance liquid chromatography-tandem mass spectrometry for non-POPs. Within the different chemical classes, PBDE47, PCB153, ppDDE, and MEHHP (phthalate metabolite) had the highest median concentrations and were observed in all samples. We also observed chlorpyrifos and BPA in all samples and permethrin in 90% of the samples tested. Only two chemicals, chlorpyrifos and permethrin, were susceptible to substantial degradation from pasteurization, a standard method for processing donated human milk. We detected 19 of 23 chemicals in all of our prepasteurized milk and 18 of 23 chemicals in all of our pasteurized milk. Pasteurization did not affect the presence of most of the chemicals. Future research should continue to explore human milk for potential chemical contamination and as a means to surveil exposures among women and children.

Ensuring Resiliency of the Milk and Dairy Industry in California

DTIC Science & Technology

2011-12-01

cannot be zero. Also, the upper bound cannot exceed the capacity of raw milk that the milk producing cows can make in each county. Between the...the amount of milk producing cows in each county and multiplying by the daily average amount of raw milk produced. RawMilkProd = NumMilkProdCows...the total number of milk producing cows . 365 TotalMilkProdDailyAvgAmtMilkProdPerCow TotalMilkProdCows = × We get the number of milk producing cows

7 CFR 58.519 - Dairy products.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Material § 58.519 Dairy products. (a) Raw skim milk. All raw skim milk obtained from a secondary source... used, shall be prepared from raw milk or skim milk that meets the same quality requirements outlined...

Quantification of lactose content in human and cow's milk using UPLC-tandem mass spectrometry.

PubMed

Fusch, Gerhard; Choi, Arum; Rochow, Niels; Fusch, Christoph

2011-12-01

A sensitive, accurate, and specific quantitative UPLC-MS/MS method was developed for lactose measurement of cow's and human milk and validated with cow's milk samples certified by an external laboratory. The new method employs only a dilution of raw cow's and human milk for simple preparation with no need to remove protein and fat prior to analysis with UPLC-MS/MS. It was operated in negative mode to detect lactose molecules and labeled (13)C(12)-lactose with the highest sensitivity. The principle advantages of the new LC-MS/MS method were: completed lactose determination in 5 min, absolute recovery of 97-107%, lower limit of detection <5 ng/L, and 99% linearity over the concentration range of 0.7-4.4 mg/L for both cow's and human milk. The mean lactose concentration of 51 human milk samples was measured as 56.8 ± 5.5 g/L ranging from 43 to 65 g/L. The described method represents validated lactose analysis with high accuracy and precision for a routine lactose determination in raw human milk. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Helicobacteraceae in Bulk Tank Milk of Dairy Herds from Northern Italy

PubMed Central

Bianchini, Valentina; Recordati, Camilla; Borella, Laura; Gualdi, Valentina; Scanziani, Eugenio; Selvatico, Elisa; Luini, Mario

2015-01-01

Helicobacter pylori is responsible for gastritis and gastric adenocarcinoma in humans, but the routes of transmission of this bacterium have not been clearly defined. Few studies led to supposing that H. pylori could be transmitted through raw milk, and no one investigated the presence of other Helicobacteraceae in milk. In the current work, the presence of Helicobacteraceae was investigated in the bulk tank milk of dairy cattle herds located in northern Italy both by direct plating onto H. pylori selective medium and by screening PCR for Helicobacteraceae, followed by specific PCRs for H. pylori, Wolinella spp., and “Candidatus Helicobacter bovis.” Three out of 163 bulk milk samples tested positive for Helicobacteraceae, but not for the subsequent PCRs. H. pylori was not isolated in any case. However, given similar growth conditions, Arcobacter butzleri, A. cryaerophilus, and A. skirrowii were recovered. In conclusion, the prevalence of Helicobacteraceae in raw milk was negligible (1.8%), and H. pylori was not identified in any of the positive samples, suggesting that, at least in the farming conditions of the investigated area, bovine milk does not represent a potential source of infection. PMID:26090429

Variability of bacterial biofilms of the "tina" wood vats used in the ragusano cheese-making process.

PubMed

Licitra, G; Ogier, J C; Parayre, S; Pediliggieri, C; Carnemolla, T M; Falentin, H; Madec, M N; Carpino, S; Lortal, S

2007-11-01

Ragusano cheese is a "protected denomination of origin" cheese made in the Hyblean region of Sicily from raw milk using traditional wooden tools, without starter. To explore the Ragusano bacterial ecosystem, molecular fingerprinting was conducted at different times during the ripening and biofilms from the wooden vats called "tinas" were investigated. Raw milks collected at two farm sites, one on the mountain and one at sea level, were processed to produce Ragusano cheese. Raw milk, curd before and after cooking, curd at stretching time (cheese 0 time), and cheese samples (4 and 7 months) were analyzed by PCR-temporal temperature gel electrophoresis (PCR-TTGE) and by classical enumeration microbiology. With the use of universal primers, PCR-TTGE revealed many differences between the raw milk profiles, but also notable common bands identified as Streptococcus thermophilus, Lactobacillus lactis, Lactobacillus delbrueckii, and Enterococcus faecium. After the stretching, TTGE profiles revealed three to five dominant species only through the entire process of ripening. In the biofilms of the two tinas used, one to five species were detected, S. thermophilus being predominant in both. Biofilms from five other tinas were also analyzed by PCR-TTGE, PCR-denaturating gradient gel electrophoresis, specific PCR tests, and sequencing, confirming the predominance of lactic acid bacteria (S. thermophilus, L. lactis, and L. delbrueckii subsp. lactis) and the presence of a few high-GC-content species, like coryneform bacteria. The spontaneous acidification of raw milks before and after contact with the five tinas was followed in two independent experiments. The lag period before acidification can be up to 5 h, depending on the raw milk and the specific tina, highlighting the complexity of this natural inoculation system.

Effect of heat and homogenization on in vitro digestion of milk.

PubMed

Tunick, Michael H; Ren, Daxi X; Van Hekken, Diane L; Bonnaillie, Laetitia; Paul, Moushumi; Kwoczak, Raymond; Tomasula, Peggy M

2016-06-01

Central to commercial fluid milk processing is the use of high temperature, short time (HTST) pasteurization to ensure the safety and quality of milk, and homogenization to prevent creaming of fat-containing milk. Ultra-high-temperature sterilization is also applied to milk and is typically used to extend the shelf life of refrigerated, specialty milk products or to provide shelf-stable milk. The structures of the milk proteins and lipids are affected by processing but little information is available on the effects of the individual processes or sequences of processes on digestibility. In this study, raw whole milk was subjected to homogenization, HTST pasteurization, and homogenization followed by HTST or UHT processing. Raw skim milk was subjected to the same heating regimens. In vitro gastrointestinal digestion using a fasting model was then used to detect the processing-induced changes in the proteins and lipids. Using sodium dodecyl sulfate-PAGE, gastric pepsin digestion of the milk samples showed rapid elimination of the casein and α-lactalbumin bands, persistence of the β-lactoglobulin bands, and appearance of casein and whey peptide bands. The bands for β-lactoglobulin were eliminated within the first 15min of intestinal pancreatin digestion. The remaining proteins and peptides of raw, HTST, and UHT skim samples were digested rapidly within the first 15min of intestinal digestion, but intestinal digestion of raw and HTST pasteurized whole milk showed some persistence of the peptides throughout digestion. The availability of more lipid droplets upon homogenization, with greater surface area available for interaction with the peptides, led to persistence of the smaller peptide bands and thus slower intestinal digestion when followed by HTST pasteurization but not by UHT processing, in which the denatured proteins may be more accessible to the digestive enzymes. Homogenization and heat processing also affected the ζ-potential and free fatty acid release during intestinal digestion. Stearic and oleic acids were broken down faster than other fatty acids due to their positions on the outside of the triglyceride molecule. Five different casein phosphopeptide sequences were observed after gastric digestion, and 31 sequences were found after intestinal digestion, with activities yet to be explored. Processing affects milk structure and thus digestion and is an important factor to consider in design of foods that affect health and nutrition. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Proteolysis during ripening of Manchego cheese made from raw or pasteurized ewes' milk. Seasonal variation.

PubMed

Gaya, Pilar; Sánchez, Carmen; Nuñez, Manuel; Fernández-García, Estrella

2005-08-01

Changes in nitrogen compounds during ripening of 40 batches of Manchego cheese made from raw milk (24 batches) or pasteurized milk (16 batches) at five different dairies throughout the year were investigated. After ripening for six months, degradation of p-kappa- and beta-caseins was more intense in raw milk cheese and degradation of alpha(s2)-casein in pasteurized milk cheese. Milk pasteurization had no significant effect on breakdown of alpha(s1)-casein. Hydrophobic peptide content did not differ between raw and pasteurized milk cheese, whereas hydrophilic peptide content was higher in raw milk cheese. There were no significant differences between seasons for residual caseins, but hydrophobic peptides were at a higher level in cheese made in autumn and winter and hydrophilic peptides in cheese made in winter and spring. Raw milk cheese had a higher content of total free amino acids and of most individual free amino acids than pasteurized milk cheese. The relative percentages of the individual free amino acids were significantly different for raw milk and pasteurized milk cheeses. The relative percentages of Lys and lie increased, while those of Val, Leu and Phe decreased during ripening. There were also seasonal variations within the relative percentages of free amino acids. In raw milk cheeses, Asp and Cys were relatively more abundant in those made in autumn, Glu and Arg in cheeses made in winter, and Lys and Ile in cheeses made in spring and summer. Biogenic amines were detected only in raw milk cheese, with the highest levels of histamine, tryptamine and tyramine in cheeses made in spring, winter and spring, respectively.

Prevalence and characterization of listeria species in domestic and industrial cheeses of isfahan region.

PubMed

Zamani-Zadeh, M; Sheikh-Zeinoddin, M; Soleimanian-Zad, S

2011-01-01

Listeria monocytogenes is of major concern to the food industry in general and the dairy industry in particular. Little is known about incidence of this pathogenic bacterium in dairy products in Iran. A survey was made from 23 September 2006 to 22 June 2007 for Listeria species in ninety samples of traditional and industrial cheeses, in milk and surface where the cheeses were manufactured from unpasteurized raw milk in the province of Isfahan (Iran). Listeria murrayi, L. grayi and L. ivanovii, were detected in nine traditional cheeses and one raw milk sample. None of the different Listeria species were isolated from the industrial cheeses and their environment. There are almost good hygienic conditions in domestic cheese manufacturing farmhouses in Isfahan area, but we should try to improve hygienic levels until we have none of the Listeria spp. in our samples.

Prevalence and Characterization of Listeria Species in Domestic and Industrial Cheeses of Isfahan Region

PubMed Central

Zamani-Zadeh, M; Sheikh-Zeinoddin, M; Soleimanian-Zad, S

2011-01-01

Background: Listeria monocytogenes is of major concern to the food industry in general and the dairy industry in particular. Little is known about incidence of this pathogenic bacterium in dairy products in Iran. Methods: A survey was made from 23 September 2006 to 22 June 2007 for Listeria species in ninety samples of traditional and industrial cheeses, in milk and surface where the cheeses were manufactured from unpasteurized raw milk in the province of Isfahan (Iran). Results: Listeria murrayi, L. grayi and L. ivanovii, were detected in nine traditional cheeses and one raw milk sample. None of the different Listeria species were isolated from the industrial cheeses and their environment. Conclusion: There are almost good hygienic conditions in domestic cheese manufacturing farmhouses in Isfahan area, but we should try to improve hygienic levels until we have none of the Listeria spp. in our samples. PMID:23113091

Short communication: The effect of raw milk cooling on sensory perception and shelf life of high-temperature, short-time (HTST)-pasteurized skim milk.

PubMed

Lee, A P; Barbano, D M; Drake, M A

2016-12-01

The cooling rate of raw milk may influence sensory properties and pasteurized shelf life. Under the Pasteurized Milk Ordinance for grade A milk, raw milk may be cooled instantaneously by on-farm heat exchangers but is also acceptable if "cooled to 10°C or less within four (4) hours of the commencement of the first milking." The objective of this study was to determine the effect of raw milk cooling on consumer perception and shelf life. Raw milk (18-21°C) was obtained and transported within 1h of milking to North Carolina State University (Raleigh). The batch of raw milk was split in 2 portions, and a plate heat exchanger was used to quickly cool one portion to <6°C within 1min. The second portion was stored in a jacketed bulk tank and slowly cooled over 4h to <10°C. Milk from 3 consecutive milkings was collected every 12h, with subsequent milkings added to the previous collections. The bulk milk was kept below 10°C while adding milk for the slow cool milk treatment. After 72h, each whole milk was separated; the skim milk was pasteurized at 73 or 78°C for 20 s, homogenized, and held at 4°C. Difference tests (n=75) and consumer acceptance tests (n=100) were conducted to determine if consumers could detect differences among milks. Descriptive analysis and microbial testing for aerobic, psychrotrophic, and psychrotolerant spore counts were conducted through shelf life. The entire experiment was repeated in triplicate. Raw milks averaged 3.3 logcfu/mL by aerobic plate count, <25cfu/mL coliforms, somatic cell count of 300,000 cells/mL, and 3.15±0.07% protein. Psychrotolerant spores were not found in the raw milk. Consumers could not detect differences between cooling treatments of the same pasteurization temperature or between different temperatures of the same cooling treatment. Milks reached sensory failure 49±4d on average after processing, and aerobic counts were between 5 to 7 logcfu/mL. Cooling treatment had no effect on shelf life. These results suggest that pasteurized milk quality is due to a combination of many factors. Raw milk cooling rate is not the most important factor affecting milk quality when raw milk quality is excellent. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Prevalence, Virulence Potential, and Antibiotic Susceptibility Profile of Listeria monocytogenes Isolated From Bovine Raw Milk Samples Obtained From Rajasthan, India.

PubMed

Sharma, Sanjita; Sharma, Vishnu; Dahiya, Dinesh Kumar; Khan, Aarif; Mathur, Manisha; Sharma, Amit

2017-03-01

Listeriosis is a serious foodborne disease of a global concern, and can effectively be controlled by a continuous surveillance of the virulent and multidrug-resistant strains of Listeria monocytogenes. This study was planned to investigate prevalence of L. monocytogenes in bovine raw milk samples. A total of 457 raw milk samples collected from 15 major cities in Rajasthan, India, were analyzed for the presence of L. monocytogenes by using standard microbiological and molecular methods. Five of the 457 samples screen tested positive for L. monocytogenes. Multiplex serotyping showed that 3/5 strains belonged to serotype 4b followed by one strain each to 1/2a and to 1/2c. Further virulence potential assessment indicated that all strains possessed inlA and inlC internalins, and, in addition, two strains also possessed the gene for inlB. All strains were positive for Listeriolysin O (LLO) and showed phosphatidylinositol-specific phospholipase C (PI-PLC) activity on an in vitro agar medium with variations in production levels among the strains. A good correlation between the in vitro pathogenicity test and the chick embryo test was observed, as the strains showing higher LLO and PI-PLC activity were found to be lethal to fertilized chick embryos. All strains were resistant to the majority of antibiotics and were designated as multidrug-resistant strains. However, these strains were susceptible to 9 of the 22 tested antibiotics. The maximum zone of inhibition (mm) and acceptable minimum inhibitory concentration were observed with azithromycin, and thus it could be the first choice of a treatment. Overall, the presence of multidrug-resistant L. monocytogenes strains in the raw milk of Rajasthan region is an indicator of public health hazard and highlighting the need of consumer awareness in place and implementation of stricter food safety regulations at all levels of milk production.

First study on characterization of virulence and antibiotic resistance genes in verotoxigenic and enterotoxigenic E. coli isolated from raw milk and unpasteurized traditional cheeses in Romania.

PubMed

Tabaran, Alexandra; Mihaiu, Marian; Tăbăran, Flaviu; Colobatiu, Liora; Reget, Oana; Borzan, Mihai Marian; Dan, Sorin Daniel

2017-03-01

The study focused on the incidence of enterotoxigenic Escherichia coli (ETEC) and verotoxigenic E. coli (VTEC) in raw milk and traditional dairy cheeses marketed in Romania, characterizing the virulence and antibiotic resistance genes of these isolates. One hundred and twenty samples of raw milk and 80 samples of unpasteurized telemy cheese were collected and cultured according to the international standard protocol. All the characteristic E. coli cultures were analyzed for the presence of STa, STb, LT, stx1, and stx2 toxicity genes. The ETEC/VTEC strains were tested for the presence of antibiotic resistance genes, such as aadA1, tetA, tetB, tetC, tetG, dfrA1, qnrA, aaC, sul1, bla SHV , bla CMY , bla TEM , and ere(A), using PCR. The results showed that 27 samples (18.62%) were positive for one of the virulence genes investigated. 48.1% (n = 13) tested positive at the genes encoding for tetracycline resistance, tetA being the most prevalent one (61.5%; n = 8). A high percent (33.3%; n = 9) revealed the beta-lactamase (bla TEM ) resistance gene, and none of the samples tested positive for bla CMY and bla SHV genes. The genes responsible for resistance to sulfonamides (sul1) and trimethoprim (dfrA1) were detected in rates of 14.8% (n = 4) and 7.4% (n = 2), respectively. E. coli is highly prevalent in raw milk and unpasteurized cheeses marketed in Romania. These strains might represent an important reservoir of resistance genes which can easily spread into other European countries, given the unique market.

The changes of proteins fractions shares in milk and fermented milk drinks.

PubMed

Bonczar, Genowefa; Walczycka, Maria; Duda, Iwona

2016-01-01

The aim of this research was to observe the changes which take place in the electrophoretic picture of milk proteins after pasteurisation and inoculation with different starter cultures (both traditional and probiotic). After incubation, the yoghurt, kefir, acidified milk, fermented Bifidobacterium bifidum drink and Lactobacillus acidophillus drink were chilled for 14 days to observe the changes which occurred. The research materials were raw and pasteurised milk, as well as fermented milk- based drinks. The raw milk used for research came from Polish Holstein-Fresian black and white cows. The milk was sampled 3 times and divided into 5 parts, each of which was pasteurised at 95°C for 10 min and then cooled for inoculation: yoghurt to 45°C, kefir and acidified milk to 22°C and drinks with Bifidobacterium bifidum and Lactobacillus acidophillus to 38°C. Milk was inoculated with lyophilised, direct vat starter cultures, in an amount equal to 2% of the working starter. For the production of fermented drinks, the subsequent starters were applied: "YC-180" Christian Hansen for yoghurt, "D" Biolacta-Texel-Rhodia for kefir, CH-N--11 Christian Hansen for acidified milk, starter by Christian Hansen for the probiotic Bifidobacterium bifidum milk, starter by Biolacta-Texel-Rhodia for the probiotic Lactobacillus acidophillus milk. The analyses were conducted in raw, pasteurised and freshly fermented milk as well as in milk drinks stored for 14 days. The total solid content was estimated by the drying method; the fat content by the Gerber method; the lactose content by the Bertrand method; the protein content by the Kjeldahl method with Buchi apparatus; the density of milk was measured with lactodensimeter; acidity with a pH-meter; and potential acidity by Soxhlet-Henkl method (AOAC, 1990). The electrophoretic separation of proteins in raw and pasteurised milk, as well as in freshly produced milk drinks and those stored for 14 days, was performed with SDS-PAGE (on polyacrylamid gel) basing on procedure described by Laemmli (1970). It was shown that, in comparison with raw milk, the pasteurised milk had smaller amounts of αs-, β- and κ-casein, whereas the shares of γ-casein and peptides were greater, and there were no changes in immunoglobulin, α-lactalbumin or β-lactoglobulin levels, which indicated that hydrolysis of caseins had occurred. In all freshly fermented milk drinks, a drop in αs- and β-casein was observed relative to raw milk. An increase in peptides and γ-casein was also noticed (with the exception of acidified milk). There were differences in α-lactalbumin and β-lactoglobulin levels between the different drinks: raw, pasteurised or freshly fermented milk. It was shown that kefir, compared to the other drinks, had the lowest levels of αs- and β-casein, α-lactalbumin and of peptides, as well as the highest level of γ-casein, which is evidence of an increased rate of hydrolysis in that drink. It was stated that, during the storage of fermented milk drinks, the levels of lactoferrin, serum albumin and peptides significantly increased whereas the content of κ-casein diminished. The proportions of serum albumin and lactoferrin in fermented milk drinks increased relative to raw milk and/or after storage, which is evidence of aggregation of proteins of low molecular mass into bigger conglomerates. The observed differences between fermented milks, including during chilled storage, in the amounts of individual proteins proves the different proteolytic abilities of starter cultures used in fermented milk production. α-lactoalbumin and β-lactoglobulin are, besides caseins, the most allergenic milk proteins. So, kefir, because of its low α-lactoalbumin content, and Bifidobacterium bifidum milk, with the lowest content of β-lactoglobulin, were the most advantageous and least allergenic drinks examined.

Lactosylated casein phosphopeptides as specific indicators of heated milks.

PubMed

Pinto, Gabriella; Caira, Simonetta; Cuollo, Marina; Fierro, Olga; Nicolai, Maria Adalgisa; Chianese, Lina; Addeo, Francesco

2012-02-01

Casein phosphopeptides (CPP) were identified in small amounts in milks heated at various intensities by using matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry. CPP selectively concentrated on hydroxyapatite (HA) were regenerated using phosphoric acid mixed in the matrix. Unphosphorylated peptides not retained by HA were removed by buffer washing. This procedure enhanced the MALDI signals of CPP that are ordinarily suppressed by the co-occurrence of unphosphorylated peptides. CPP, belonging to the β-casein (CN) family, i.e., (f1-29) 4P, (f1-28) 4P, and (f1-27) 4P, and the α(s2)-CN family, i.e., (f1-21) 4P and (f1-24) 4P, were observed in liquid and powder milk. The lactosylated counterparts were specific to intensely heated milks, but absent in raw and thermized/pasteurized milk. Most CPP with C-terminal lysines probably arose from the activity of plasmin; an enzyme most active in casein hydrolysis. A CPP analogue was used as the internal standard. The raw milk signature peptide β-CN (f1-28) 4P constituted ~4.3% of the total β-CN. Small amounts of lactosylated peptides, which varied with heat treatment intensity, were detected in the milk samples. The limit of detection of ultra-high-temperature milk adjunction in raw or pasteurized milk was ~10%.

Effect of microbiological testing on subsequent mid-infrared milk component analysis of the same milk sample.

PubMed

Wojciechowski, Karen L; Melilli, Caterina; Barbano, David M

2014-09-01

Our objectives were to determine if mixing and sampling of a raw milk sample at 4°C for determination of total bacteria count (TBC) and if incubation at 14°C for 18h and sampling for a preliminary incubation (PI) count influenced the accuracy of subsequent fat, protein, or lactose measurement by mid-infrared (IR) analysis of milk from the same sample container due to either nonrepresentative sampling or the presence of microbial metabolites produced by microbial growth in the milk from the incubation. Milks of 4 fat levels (2.2, 3, 4, and 5%) reflected the range of fat levels encountered in producer milks. If the portion of milk removed from a cold sample was not representative, then the effect on a milk component test would likely be larger as fat content increases. Within the milks at each fat level, 3 treatments were used: (1) 20 vials of the same milk sampled for testing TBC using a BactoScan FC and then used for a milk component test; (2) 20 vials for testing TBC plus PI count followed by component test; and (3) 20 vials to run for IR component test without a prior micro sampling and testing. This was repeated in 3 different weeks using a different batch of milk each week. No large effect on the accuracy of component milk testing [IR fat B (carbon hydrogen stretch) and fat A (carbonyl stretch)] due to the cold milk sample handling and mixing procedures used for TBC was detected, confirming the fact that the physical removal of milk from the vial by the BactoScan FC (Foss Electric, Hillerød, Denmark) was a representative portion of the milk. However, the representativeness of any other sampling procedure (manual or automated) of a cold milk sample before running milk component testing on the same container of milk should be demonstrated and verified periodically as a matter of routine laboratory quality assurance. Running TBC with a BactoScan FC first and then IR milk analysis after had a minimal effect on milk component tests by IR when milk bacteria counts were within pasteurized milk ordinance limits of <100,000 cfu/mL. Running raw milk PI counts (18h of incubation at 13-14°C) with the BactoScan FC before milk component testing by IR milk analysis had an effect on component tests. The effect was largest on fat test results and would decrease the accuracy of milk payment testing on individual producer milks. The effect was most likely due to the absorption of light by bacterial metabolites resulting from microbial growth or other chemical degradation processes occurring in the milk during the PI count incubation, not by the sampling procedure of the BactoScan. The direction of the effect on component test results will vary depending on the bacteria count and the type of bacteria that grew in the milk, and this could be different in every individual producer milk sample. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Phenotypic and genotypic characterization of lactic acid bacteria isolated from raw goat milk and effect of farming practices on the dominant species of lactic acid bacteria.

PubMed

Tormo, Hélène; Ali Haimoud Lekhal, Djamila; Roques, C

2015-10-01

Lactic acid bacteria, in particular Lactococcus lactis, play a decisive role in the cheese making process and more particularly in lactic cheeses which are primarily produced on goat dairy farms. The objective of this study was therefore to identify the main lactic acid bacteria found in raw goats' milk from three different regions in France and evaluate if certain farming practices have an effect on the distribution of species of lactic acid bacteria in the various milk samples. Identification at genus or species level was carried out using phenotypic tests and genotypic methods including repetitive element REP-PCR, species-specific PCR and 16S rRNA gene sequencing. The distribution of the main bacterial species in the milk samples varied depending on farms and their characteristics. Out of the 146 strains identified, L. lactis was the dominant species (60% of strains), followed by Enterococcus (38%) of which Enterococcus faecalis and Enterococcus faecium. Within the species L. lactis, L. lactis subsp lactis was detected more frequently than L. lactis subsp cremoris (74% vs. 26%). The predominance of L. lactis subsp cremoris was linked to geographical area studied. It appears that the animals' environment plays a role in the balance between the dominance of L. lactis and enterococci in raw goats' milk. The separation between the milking parlor and the goat shed (vs no separation) and only straw in the bedding (vs straw and hay) seems to promote L. lactis in the milk (vs enterococci). Copyright © 2015 Elsevier B.V. All rights reserved.

High temperature, short time pasteurization temperatures inversely affect bacterial numbers during refrigerated storage of pasteurized fluid milk.

PubMed

Ranieri, M L; Huck, J R; Sonnen, M; Barbano, D M; Boor, K J

2009-10-01

The grade A Pasteurized Milk Ordinance specifies minimum processing conditions of 72 degrees C for at least 15 s for high temperature, short time (HTST) pasteurized milk products. Currently, many US milk-processing plants exceed these minimum requirements for fluid milk products. To test the effect of pasteurization temperatures on bacterial numbers in HTST pasteurized milk, 2% fat raw milk was heated to 60 degrees C, homogenized, and treated for 25 s at 1 of 4 different temperatures (72.9, 77.2, 79.9, or 85.2 degrees C) and then held at 6 degrees C for 21 d. Aerobic plate counts were monitored in pasteurized milk samples at d 1, 7, 14, and 21 postprocessing. Bacterial numbers in milk processed at 72.9 degrees C were lower than in milk processed at 85.2 degrees C on each sampling day, indicating that HTST fluid milk-processing temperatures significantly affected bacterial numbers in fluid milk. To assess the microbial ecology of the different milk samples during refrigerated storage, a total of 490 psychrotolerant endospore-forming bacteria were identified using DNA sequence-based subtyping methods. Regardless of processing temperature, >85% of the isolates characterized at d 0, 1, and 7 postprocessing were of the genus Bacillus, whereas more than 92% of isolates characterized at d 14 and 21 postprocessing were of the genus Paenibacillus, indicating that the predominant genera present in HTST-processed milk shifted from Bacillus spp. to Paenibacillus spp. during refrigerated storage. In summary, 1) HTST processing temperatures affected bacterial numbers in refrigerated milk, with higher bacterial numbers in milk processed at higher temperatures; 2) no significant association was observed between genus isolated and pasteurization temperature, suggesting that the genera were not differentially affected by the different processing temperatures; and 3) although typically present at low numbers in raw milk, Paenibacillus spp. are capable of growing to numbers that can exceed Pasteurized Milk Ordinance limits in pasteurized, refrigerated milk.

Fully automated screening of veterinary drugs in milk by turbulent flow chromatography and tandem mass spectrometry

PubMed Central

Stolker, Alida A. M.; Peters, Ruud J. B.; Zuiderent, Richard; DiBussolo, Joseph M.

2010-01-01

There is an increasing interest in screening methods for quick and sensitive analysis of various classes of veterinary drugs with limited sample pre-treatment. Turbulent flow chromatography in combination with tandem mass spectrometry has been applied for the first time as an efficient screening method in routine analysis of milk samples. Eight veterinary drugs, belonging to seven different classes were selected for this study. After developing and optimising the method, parameters such as linearity, repeatability, matrix effects and carry-over were studied. The screening method was then tested in the routine analysis of 12 raw milk samples. Even without internal standards, the linearity of the method was found to be good in the concentration range of 50 to 500 µg/L. Regarding repeatability, RSDs below 12% were obtained for all analytes, with only a few exceptions. The limits of detection were between 0.1 and 5.2 µg/L, far below the maximum residue levels for milk set by the EU regulations. While matrix effects—ion suppression or enhancement—are obtained for all the analytes the method has proved to be useful for screening purposes because of its sensitivity, linearity and repeatability. Furthermore, when performing the routine analysis of the raw milk samples, no false positive or negative results were obtained. PMID:20379812

Improved outcomes of feeding low birth weight infants with predominantly raw human milk versus donor banked milk and formula.

PubMed

Dritsakou, Kalliopi; Liosis, Georgios; Valsami, Georgia; Polychronopoulos, Evangelos; Skouroliakou, Maria

2016-01-01

To investigate the benefits of treating low birth weight infants predominantly with mother's own raw milk and early initiation of breastfeeding (raw human milk/breast-fed infants), in comparison to feeding only with donor banked milk (until the third week of life) and afterwards a preterm formula until hospital discharge (donor banked/formula-fed infants). One hundred and ninety-two predominantly raw human milk-fed infants (70% of raw and 30% of donor milk) were matched to 192 donor/formula-fed ones (on 1:1 ratio). Aggressive nutrition policy and targeted fortification of human milk were implemented in both groups. The two groups show similar demographic and perinatal characteristics. Predominantly raw milk-fed infants regained earlier their birth weight, suffered less episodes of feeding intolerance and presented a higher body length and head circumference at discharge (p < 0.001). Those treated mainly with their mothers' milk were able to initiate breastfeeding almost 2 weeks earlier compared to those fed with donor milk who achieved to be bottle-fed later on post-conceptual age (p < 0.001). Infants being breastfed until the 8th month of life conducted less visits for a viral infection to a pediatrician compared to those in the other group (p < 0.001). Feeding predominantly with mother's raw milk seems to result in optimal neonatal outcomes.

Comparing the effect of homogenization and heat processing on the properties and in vitro digestion of milk from organic and conventional dairy herds.

PubMed

Van Hekken, D L; Tunick, M H; Ren, D X; Tomasula, P M

2017-08-01

We compared the effects of homogenization and heat processing on the chemical and in vitro digestion traits of milk from organic and conventional herds. Raw milk from organic (>50% of dry matter intake from pasture) and conventional (no access to pasture) farms were adjusted to commercial whole and nonfat milk fat standards, and processed with or without homogenization, and with high-temperature-short-time or UHT pasteurization. The milk then underwent in vitro gastrointestinal digestion. Comparison of milk from organic and conventional herds showed that the milks responded to processing in similar ways. General composition was the same among the whole milk samples and among the nonfat milk samples. Protein profiles were similar, with intact caseins and whey proteins predominant and only minor amounts of peptides. Whole milk samples from grazing cows contained higher levels of α-linolenic (C18:3), vaccenic (C18:1 trans), and conjugated linoleic acids, and lower levels of palmitic (C16:0) and stearic (C18:0) acids than samples from nongrazing cows. Processing had no effect on conjugated linoleic acid and linolenic acid levels in milk, although homogenization resulted in higher levels of C8 to C14 saturated fatty acids. Of the 9 volatile compounds evaluated, milk from grazing cows contained lower levels of 2-butanone than milk from nongrazing cows, and milk from both farms showed spikes for heptanal in UHT samples and spikes for butanoic, octanoic, nonanoic, and N-decanoic acids in homogenized samples. At the start of in vitro digestion, nonfat raw and pasteurized milk samples formed the largest acid clots, and organic milk clots were larger than conventional milk clots; UHT whole milk formed the smallest clots. Milk digests from grazing cows had lower levels of free fatty acids than digests from nongrazing cows. In vitro proteolysis was similar in milk from both farms and resulted in 85 to 95% digestibility. Overall, milk from organic/grass-fed and conventional herds responded in similar ways to typical homogenization and heat processing used in United States dairy plants and showed only minor differences in chemical traits and in vitro digestion. Findings from this research enhance our knowledge of the effect of processing on the quality traits and digestibility of milk from organic/pasture-fed and confined conventional herds and will help health-conscious consumers make informed decisions about dairy selections. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The Biodiversity of the Microbiota Producing Heat-Resistant Enzymes Responsible for Spoilage in Processed Bovine Milk and Dairy Products.

PubMed

Machado, Solimar G; Baglinière, François; Marchand, Sophie; Van Coillie, Els; Vanetti, Maria C D; De Block, Jan; Heyndrickx, Marc

2017-01-01

Raw bovine milk is highly nutritious as well as pH-neutral, providing the ideal conditions for microbial growth. The microbiota of raw milk is diverse and originates from several sources of contamination including the external udder surface, milking equipment, air, water, feed, grass, feces, and soil. Many bacterial and fungal species can be found in raw milk. The autochthonous microbiota of raw milk immediately after milking generally comprises lactic acid bacteria such as Lactococcus , Lactobacillus , Streptococcus , and Leuconostoc species, which are technologically important for the dairy industry, although they do occasionally cause spoilage of dairy products. Differences in milking practices and storage conditions on each continent, country and region result in variable microbial population structures in raw milk. Raw milk is usually stored at cold temperatures, e.g., about 4°C before processing to reduce the growth of most bacteria. However, psychrotrophic bacteria can proliferate and contribute to spoilage of ultra-high temperature (UHT) treated and sterilized milk and other dairy products with a long shelf life due to their ability to produce extracellular heat resistant enzymes such as peptidases and lipases. Worldwide, species of Pseudomonas , with the ability to produce these spoilage enzymes, are the most common contaminants isolated from cold raw milk although other genera such as Serratia are also reported as important milk spoilers, while for others more research is needed on the heat resistance of the spoilage enzymes produced. The residual activity of extracellular enzymes after high heat treatment may lead to technological problems (off flavors, physico-chemical instability) during the shelf life of milk and dairy products. This review covers the contamination patterns of cold raw milk in several parts of the world, the growth potential of psychrotrophic bacteria, their ability to produce extracellular heat-resistant enzymes and the consequences for dairy products with a long shelf life. This problem is of increasing importance because of the large worldwide trade in fluid milk and milk powder.

Mycobacterium paratuberculosis detection in cow's milk in Argentina by immunomagnetic separation-PCR.

PubMed

Gilardoni, Liliana Rosa; Fernández, Bárbara; Morsella, Claudia; Mendez, Laura; Jar, Ana María; Paolicchi, Fernando Alberto; Mundo, Silvia Leonor

2016-01-01

The aim of this study was to standardize a diagnosis procedure to detect Mycobacterium avium subsp. paratuberculosis (Map) DNA in raw cow milk samples under field conditions. A procedure that combines both immunomagnetic separation and IS900-PCR detection (IMS-IS1 PCR) was employed on milk samples from 265 lactating Holstein cows from Map infected and uninfected herds in Argentina. IMS-IS1 PCR results were analyzed and compared with those obtained from milk and fecal culture and serum ELISA. The extent of agreement between both tests was determined by the Kappa test. IMS-IS1 PCR showed a detection limit of 10(1) CFU of Map/mL of milk, when 50:50 mix of monoclonal and polyclonal antibodies were used to coat magnetic beads. All of the 118 samples from the Map uninfected herds were negative for the set of the tests. In Map infected herds, 80 out of 147 cows tested positive by milk IMS-IS1 PCR (55%), of which 2 (1.4%) were also positive by milk culture, 15 (10%) by fecal culture, and 20 (14%) by serum ELISA. Kappa statistics (95% CI) showed a slight agreement between the different tests (<0.20), and the proportions of agreement were ≤0.55. The IMS-IS1 PCR method detected Map in milk of the cows that were not positive in other techniques. This is the first report dealing with the application of IMS-IS1 PCR in the detection of Map in raw milk samples under field conditions in Argentina. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Modification of IgE binding to αS1-casein by proteolytic activity of Enterococcus faecium isolated from Iranian camel milk samples.

PubMed

Kordesedehi, Reihane; Taheri-Kafrani, Asghar; Rabbani-Khorasgani, Mohammad; Kazemi, Rezvan; Mutangadura, Daniel; Haertle, Thomas

2018-06-20

Milk is a perfect source of nutrients for neonates. When breast feeding cannot be done, an infant's alimentation is usually initiated to cow's milk, among the primary foods. It has been reported that about 2.5% of juveniles under the age of 3 years manifest allergic reactions to cow's milk proteins. Among the cow's milk proteins, casein fractions are considered as the strongest allergenic proteins. The proteolytic enzymes of lactic acid bacteria (LAB), during fermentation of dairy products, can break down milk proteins especially caseins and subsequently reduce the immune reactivity of allergenic proteins. In this research, raw bovine and camel milk samples were screened for cocci LAB strains and after isolation, their proteolytic activity against bovine milk caseins were evaluated by SDS-PAGE and RP-HPLC. The potential of cocci LAB strains on α S1 -casein degradation and their potential to break down the principle allergenic epitopes of this protein was detected using indirect competitive ELISA. Molecular identification of the best proteolytic strain was fulfilled by 16S rDNA fragment sequencing with universal primers. The obtained results demonstrated that Enterococcus faecium isolated from raw camel milk samples was the most efficient isolate in hydrolyzing Na-caseinate and α S1 -casein. Hydrolysated α S1 -casein by Enterococcus faecium was also less recognized by IgE of bovine milk allergic patients' sera in comparison with native α S1 -casein. It has been proposed that Enterococcus faecium could be an efficient strain in allergenicity reduction of cow's milk proteins. So it could be an excellent candidate to be potentially used in dairy industries. Copyright © 2018 Elsevier B.V. All rights reserved.

Development of an immunochromatographic strip test for rapid detection of melamine in raw milk, milk products, and animal feed

USDA-ARS?s Scientific Manuscript database

A simple, rapid and sensitive immunogold chromatographic strip test based on a monoclonal antibody was developed for the detection of melamine (MEL) residues in raw milk, milk products and animal feed. The limit of detection was estimated to be 0.05 µg/mL in raw milk, since the detection test line ...

Contributions to ultrasound monitoring of the process of milk curdling.

PubMed

Jiménez, Antonio; Rufo, Montaña; Paniagua, Jesús M; Crespo, Abel T; Guerrero, M Patricia; Riballo, M José

2017-04-01

Ultrasound evaluation permits the state of milk being curdled to be determined quickly and cheaply, thus satisfying the demands faced by today's dairy product producers. This paper describes the non-invasive ultrasonic method of in situ monitoring the changing physical properties of milk during the renneting process. The basic objectives of the study were, on the one hand, to confirm the usefulness of conventional non-destructive ultrasonic testing (time-of-flight and attenuation of the ultrasound waves) in monitoring the process in the case of ewe's milk, and, on the other, to include other ultrasound parameters which have not previously been considered in studies on this topic, in particular, parameters provided by the Fast Fourier Transform technique. The experimental study was carried out in a dairy industry environment on four 52-l samples of raw milk in which were immersed 500kHz ultrasound transducers. Other physicochemical parameters of the raw milk (pH, dry matter, protein, Gerber fat test, and lactose) were measured, as also were the pH and temperature of the curdled samples simultaneously with the ultrasound tests. Another contribution of this study is the linear correlation analysis of the aforementioned ultrasound parameters and the physicochemical properties of the curdled milk. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of 22 Elements in Milk, Feed, and Water of Dairy Cow, Goat, and Buffalo from Different Regions of China.

PubMed

Zhou, Xuewei; Qu, Xueyin; Zhao, Shengguo; Wang, Jiaqi; Li, Songli; Zheng, Nan

2017-03-01

The objectives of this study were to measure the concentrations of elements in raw milk by inductively coupled plasma-mass spectrometry (ICP-MS) and evaluate differences in element concentrations among animal species and regions of China. Furthermore, drinking water and feed samples were analyzed to investigate whether the element concentrations in raw milk are correlated with those in water and feed. All samples were analyzed by ICP-MS following microwave-assisted acid digestion. The mean recovery of the elements was 98.7 % from milk, 103.7 % from water, and 93.3 % from a certified reference material (cabbage). Principal component analysis results revealed that element concentrations differed among animal species and regions. Correlation analysis showed that trace elements Mn, Fe, Ni, Ga, Se, Sr, Cs, U in water and Co, Ni, Cu, Se, U in feed were significantly correlated with those in milk (p < 0.05). Toxic and potential toxic elements Cr, As, Cd, Tl, Pb in water and Al, Cr, As, Hg, Tl in feed were significantly correlated with those in milk (p < 0.05). Results of correlation analysis revealed that elements in water and feed might contribute to the elements in milk.

Influence of Storage Conditions on the Growth of Pseudomonas Species in Refrigerated Raw Milk▿ †

PubMed Central

De Jonghe, Valerie; Coorevits, An; Van Hoorde, Koenraad; Messens, Winy; Van Landschoot, Anita; De Vos, Paul; Heyndrickx, Marc

2011-01-01

The refrigerated storage of raw milk throughout the dairy chain prior to heat treatment creates selective conditions for growth of psychrotolerant bacteria. These bacteria, mainly belonging to the genus Pseudomonas, are capable of producing thermoresistant extracellular proteases and lipases, which can cause spoilage and structural defects in pasteurized and ultra-high-temperature-treated milk (products). To map the influence of refrigerated storage on the growth of these pseudomonads, milk samples were taken after the first milking turn and incubated laboratory scale at temperatures simulating optimal and suboptimal preprocessing storage conditions. The outgrowth of Pseudomonas members was monitored over time by means of cultivation-independent denaturing gradient gel electrophoresis (DGGE). Isolates were identified by a polyphasic approach. These incubations revealed that outgrowth of Pseudomonas members occurred from the beginning of the dairy chain (farm tank) under both optimal and suboptimal storage conditions. An even greater risk for outgrowth, as indicated by a vast increase of about 2 log CFU per ml raw milk, existed downstream in the chain, especially when raw milk was stored under suboptimal conditions. This difference in Pseudomonas outgrowth between optimal and suboptimal storage was already statistically significant within the farm tank. The predominant taxa were identified as Pseudomonas gessardii, Pseudomonas gessardii-like, Pseudomonas fluorescens-like, Pseudomonas lundensis, Pseudomonas fragi, and Pseudomonas fragi-like. Those taxa show an important spoilage potential as determined on elective media for proteolysis and lipolysis. PMID:21115713

Seasonal Variability of Thermophilic Campylobacter Spp. in Raw Milk Sold by Automatic Vending Machines in Lombardy Region.

PubMed

Bertasi, Barbara; Losio, Marina Nadia; Daminelli, Paolo; Finazzi, Guido; Serraino, Andrea; Piva, Silvia; Giacometti, Federica; Massella, Elisa; Ostanello, Fabio

2016-06-03

In temperate climates, a seasonal trend was observed in the incidence of human campylobacteriosis cases, with peaks reported in spring and autumn in some countries, or in summer in others; a similar trend was observed in Campylobacter spp. dairy cattle faecal shedding, suggesting that cattle may play a role in the seasonal peak of human infection. The objectives of this study were to assess if a seasonal trend in thermophilic Campylobacter spp. contamination of raw milk exists and to evaluate a possible relation between this and the increase of human campylobacteriosis incidence in summer months. The results showed a mean prevalence of 1.6% of milk samples positive for thermophilic Campylobacter spp. with a wide range (0.0-3.1%) in different months during the three years considered. The statistical analysis showed a significant difference (P<0.01) of the prevalence of positive samples for thermophilic Campylobacter spp. between warmer and cooler months (2.3 vs 0.6%). The evidence of a seasonal trend in thermophilic Campylobacter spp. contamination of raw milk sold for direct consumption, with an increase of the prevalence in warmer months, may represent one of the possible links between seasonal trend in cattle faecal shedding and seasonal trend in human campylobacteriosis.

Analysis of trace metal concentrations in raw cow's milk from three dairy farms in North Gondar, Ethiopia: chemometric approach.

PubMed

Akele, M L; Abebe, D Z; Alemu, A K; Assefa, A G; Madhusudhan, A; de Oliveira, R R

2017-09-11

Concentrations of essential (Cu, Mn, and Zn) and toxic (Cr, Cd, and Pb) trace metals in 30 raw cow's milk samples were quantified using flame atomic absorption spectrometry. The samples were collected from the Nara-Awudarda, Tana-Abo, and Kosoye Amba-Rass sites in North Gondar, Ethiopia, preserved in a deep freezer (-20 °C), and then digested by Kjeldahl apparatus with HNO 3 /H 2 O 2 (5:2; v/v) at 300 °C for 2.5 h. The data were subject to principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA). Overall hazard quotient (HQ) and carcinogenic risk (CR) values were also estimated to assess metal-related health risks. The mean concentrations of Cr, Mn, Cu, Zn, Cd, and Pb in the milk samples ranged 0.468-0.828, 1.614-2.806, 0.840-1.532, 1.208-5.267, ND-0.330, and ND-0.186 mg/kg, respectively. The lowest values were obtained for Kosoye Amba-Rass milk samples, while the highest were found for those collected from Nara-Awudarda milk samples, probably due to high mineral enrichment and metal leaching (especially Cd and Pb) from coal deposits. PCA revealed clustering of samples with respect to their geographic origin. Validation of PLS-DA model showed 100% classification efficiency using external validation samples and detected Cd and Cu as trace metal markers. The HQ and CR values were within the safe level; however, the former is close to the alert threshold level for Nara-Awudarda milk samples. Thus, further studies on common foodstuffs, constituting a higher proportion in the local diet, are required in this area to provide a complete risk assessment.

Aflatoxin M1 Concentration in Various Dairy Products: Evidence for Biologically Reduced Amount of AFM1 in Yoghurt

PubMed Central

RAHIMIRAD, Amir; MAALEKINEJAD, Hassan; OSTADI, Araz; YEGANEH, Samal; FAHIMI, Samira

2014-01-01

Abstract Background Aflatoxin M1 (AFM1), a carcinogenic substance is found in milk and dairy products. The effect of season and type of dairy products on AFMi level in northern Iran was investigated in this study. Methods Three hundred samples (each season 75 samples) including raw and pasteurized milk, yoghurt, cheese, and cream samples were collected from three distinct milk producing farms. The samples were subjected to chemical and solid phase extractions and were analyzed by using HPLC technique. Recovery percentages, limit of detection and limit of quantification values were determined. Results Seventy percent and 98% were the minimum and maximum recoveries for cheese and raw milk, respectively and 0.021 and 0.063 ppb were the limit of detection and limit of quantification values for AFM1. We found that in autumn and winter the highest level (0.121 ppb) of AFM1 in cheese and cream samples and failed to detect any AFM1 in spring samples. Interestingly, our data showed that the yoghurt samples had the lowest level of AFM1 in all seasons. Conclusion There are significant differences between the AFM1 levels in dairy products in various seasons and also various types of products, suggesting spring and summer yoghurt samples as the safest products from AFM1 level point of view. PMID:25927044

Estrone and 17beta-estradiol concentrations in pasteurized-homogenized milk and commercial dairy products.

PubMed

Pape-Zambito, D A; Roberts, R F; Kensinger, R S

2010-06-01

Some individuals fear that estrogens in dairy products may stimulate growth of estrogen-sensitive cancers in humans. The presence of estrone (E(1)) and 17beta-estradiol (E(2)) in raw whole cow's milk has been demonstrated. The objectives of this study were to determine if pasteurization-homogenization affects E(2) concentration in milk and to quantify E(1) and E(2) concentrations in commercially available dairy products. The effects of pasteurization-homogenization were tested by collecting fresh raw milk, followed by pasteurization and homogenization at 1 of 2 homogenization pressures. All treated milks were tested for milk fat globule size, percentages of milk fat and solids, and E(2) concentrations. Estrone and E(2) were quantified from organic or conventional skim, 1%, 2%, and whole milks, as well as half-and-half, cream, and butter samples. Estrone and E(2) were quantified by RIA after organic solvent extractions and chromatography. Pasteurization-homogenization reduced fat globule size, but did not significantly affect E(2), milk fat, or milk solids concentrations. Estrone concentrations averaged 2.9, 4.2, 5.7, 7.9, 20.4, 54.1 pg/mL, and 118.9 pg/g in skim, 1%, 2%, and whole milks, half-and-half, cream, and butter samples, respectively. 17Beta-estradiol concentrations averaged 0.4, 0.6, 0.9, 1.1, 1.9, 6.0 pg/mL, and 15.8 pg/g in skim, 1%, 2%, whole milks, half-and-half, cream, and butter samples, respectively. The amount of fat in milk significantly affected E(1) and E(2) concentrations in milk. Organic and conventional dairy products did not have substantially different concentrations of E(1) and E(2). Compared with information cited in the literature, concentrations of E(1) and E(2) in bovine milk are small relative to endogenous production rates of E(1) and E(2) in humans. 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Antioxidative Activity of Colostrum and Human Milk: Effects of Pasteurization and Storage.

PubMed

Marinković, Vesna; Ranković-Janevski, Milica; Spasić, Snežana; Nikolić-Kokić, Aleksandra; Lugonja, Nikoleta; Djurović, Dijana; Miletić, Srdjan; Vrvić, Miroslav M; Spasojević, Ivan

2016-06-01

Milk banks collect, pasteurize, and freeze/store human milk. The processing may alter redox properties of milk, but the effects have not been fully examined. We collected 10 mature milk and 10 colostrum samples and applied a battery of biochemical assays and electron paramagnetic resonance spectroscopy to inspect changes that milk undergoes with pasteurization and 30 days storage at -20°C. Pasteurization and storage of raw milk did not affect total nonenzymatic antioxidative capacity, but specific components and features were altered. Urate radical and ascorbyl radical emerge as products of exposure of milk to hydroxyl radical-generating system. Processing shifted the load of antioxidative activity from ascorbate to urate and lowered the capacity of milk to diminish hydroxyl radical. Pasteurization caused a significant drop in the activity of 2 major antioxidative enzymes-superoxide dismutase and glutathione peroxidase, whereas freezing/storage of raw milk affected only superoxide dismutase. Colostrum showed drastically higher total nonenzymatic antioxidative capacity, hydroxyl radical scavenging ability, and glutathione reductase activity compared with mature milk. Pasteurization and storage affect nonenzymatic and enzymatic antioxidative agents in human milk. It appears that nonenzymatic antioxidative systems in colostrum and milk are different. The effects of processing may be partially compensated by fortification/spiking with ascorbate before use.

Effects of light and copper ions on volatile aldehydes of milk and milk fractions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeno, W.; Bassette, R.; Crang, R.E.

1988-09-01

Raw, laboratory-pasteurized and plant-pasteurized homogenized milks were exposed to copper ions (5 ppm), to sunlight or fluorescent light and the effects determined on the composition of volatile aldehydes. The greatest change due to copper treatment was an increase in n-hexanal; acetaldehyde showed the least response in each of the sources of milk. The responses were similar from all three sources of milk with laboratory-pasteurized milk samples showing the greatest responses for each aldehyde analyzed. Similar milk samples exposed to sunlight also showed an increase in volatile aldehydes from all milk sources but with the greatest response being acetaldehyde and n-pentanalmore » components. The milk fraction most susceptible to changes in the presence of light was neutralized whey, whereas resuspended cream was most susceptible to copper exposure. Overall, dialyzed whey appeared to be influenced more than other milk fractions by both light and copper ions.« less

Bioactive peptides released during of digestion of processed milk

USDA-ARS?s Scientific Manuscript database

Most of the proteins contained in milk consist of alpha-s1-, alpha-s2-, beta- and kappa-casein, and some of the peptides contained in these caseins may impart health benefits. To determine if processing affected release of peptides, samples of raw (R), homogenized (H), homogenized and pasteurized (...

The effects of microfluidization on the physical, microbial, chemical, and coagulation properties of milk

USDA-ARS?s Scientific Manuscript database

This work examines the use of mild heat treatments in conjunction with multiple pass microfluidization to generate unique cheesemilk for potential use in soft cheeses such as Queso Fresco and Cottage Cheese. Raw, thermized, and high temperature, short time pasteurized milk samples, standardized to ...

The Biodiversity of the Microbiota Producing Heat-Resistant Enzymes Responsible for Spoilage in Processed Bovine Milk and Dairy Products

PubMed Central

Machado, Solimar G.; Baglinière, François; Marchand, Sophie; Van Coillie, Els; Vanetti, Maria C. D.; De Block, Jan; Heyndrickx, Marc

2017-01-01

Raw bovine milk is highly nutritious as well as pH-neutral, providing the ideal conditions for microbial growth. The microbiota of raw milk is diverse and originates from several sources of contamination including the external udder surface, milking equipment, air, water, feed, grass, feces, and soil. Many bacterial and fungal species can be found in raw milk. The autochthonous microbiota of raw milk immediately after milking generally comprises lactic acid bacteria such as Lactococcus, Lactobacillus, Streptococcus, and Leuconostoc species, which are technologically important for the dairy industry, although they do occasionally cause spoilage of dairy products. Differences in milking practices and storage conditions on each continent, country and region result in variable microbial population structures in raw milk. Raw milk is usually stored at cold temperatures, e.g., about 4°C before processing to reduce the growth of most bacteria. However, psychrotrophic bacteria can proliferate and contribute to spoilage of ultra-high temperature (UHT) treated and sterilized milk and other dairy products with a long shelf life due to their ability to produce extracellular heat resistant enzymes such as peptidases and lipases. Worldwide, species of Pseudomonas, with the ability to produce these spoilage enzymes, are the most common contaminants isolated from cold raw milk although other genera such as Serratia are also reported as important milk spoilers, while for others more research is needed on the heat resistance of the spoilage enzymes produced. The residual activity of extracellular enzymes after high heat treatment may lead to technological problems (off flavors, physico-chemical instability) during the shelf life of milk and dairy products. This review covers the contamination patterns of cold raw milk in several parts of the world, the growth potential of psychrotrophic bacteria, their ability to produce extracellular heat-resistant enzymes and the consequences for dairy products with a long shelf life. This problem is of increasing importance because of the large worldwide trade in fluid milk and milk powder. PMID:28298906

Exclusion of phospholipases (PLs)-producing bacteria in raw milk flushed with nitrogen gas (N(2)).

PubMed

Munsch-Alatossava, Patricia; Gursoy, Oguz; Alatossava, Tapani

2010-01-01

Prolonged cold storage of raw milks favors the growth of psychrotrophs, which produce heat-resistant exoenzymes of considerable spoilage potential; the bacterial proteases and lipases affect raw milk quality; among them phospholipases (PLs) may target the milk fat globule. More importantly, bacterial PLs are key virulence factors for numerous species. Two studies examined the use of nitrogen (N(2)) gas and examined its effect on psychrotrophs, proteases and lipase producers when the milk was stored in closed vessels; however, the effect on PLs producers is unknown. Here we show that by considering an open system the PLs producers were sooner or later excluded in raw milk (whereas the PLs producers in the non-treated controls culminated at 10(8)CFU/ml), by effective gas treatments that bring oxygen (O(2)) levels in milk lower than 0.1ppm. No increase of the PLs producers among the anaerobes was noticed during the course of the experiments. In the experiments performed at 6.0 degrees C, the delay after which the PLs producers were no longer detectable seemed independent of the initial level of PLs producers in raw milk (lower than 10(3)CFU/ml). We anticipate that flushing pure N(2) gas in raw milk tanks, considered as open systems, along the cold chain of raw milk storage and transportation, may be an additional technique to control psychrotrophs, and may also constitute an interesting perspective for limiting their spoilage and pathogenic potential in food materials in general.

Validation of a rapid lateral flow test for the simultaneous determination of β-lactam drugs and flunixin in raw milk.

PubMed

Douglas, David; Banaszewski, Katie; Juskelis, Rima; Al-Taher, Fadwa; Chen, Yang; Cappozzo, Jack; McRobbie, Lindsay; Salter, Robert S

2012-07-01

β-Lactam antibiotics are the most commonly used drugs on dairy farms. β-Lactam residues in milk are kept out of the human milk supply with good agricultural practices and mandatory truck screening performed by the dairy industry under Appendix N of the Pasteurized Milk Ordinance. Flunixin, a nonsteroidal and anti-inflammatory drug, appears in dairy cattle tissue residues with a frequency similar to the occurrence of penicillin G. This creates concern that flunixin residues could be in milk and would go undetected under current milk screening programs. A single test that combines mandatory β-lactam screening with voluntary flunixin screening is an economical approach for monitoring and controlling for potential flunixin or 5-hydroxyflunixin, the primary flunixin metabolite marker in milk. The objective of this study was to validate a β-lactam and flunixin rapid lateral flow test (LFT) and compare the results obtained with a liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of flunixin and 5-hydroxyflunixin in raw milk with a limit of detection of , 1 ppb, equivalent to 1 ng/ml. Using the LFT, three combined manufactured lots of test strips detected penicillin G at 2.0 ppb, ampicillin at 6.8 ppb, amoxicillin at 5.9 ppb, cephapirin at 13.4 ppb, ceftiofur (total metabolites) at 63 ppb, and 5-hydroxyflunixin at 1.9 ppb at least 90% of the time with 95% confidence. The LFT also detected incurred flunixin milk samples that were analyzed with the LC-MS/MS and diluted to tolerance in raw milk. The detection levels for the LFT are lower than the U.S. safe levels or tolerances and qualify the test to be used in compliance with U.S. milk screening programs.

Molecular Typing and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolated from Bovine Milk in Tanzania.

PubMed

Mohammed, Jibril; Ziwa, Michael Henry; Hounmanou, Yaovi Mahuton Gildas; Kisanga, Adela; Tuntufye, Huruma Nelwike

2018-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) in raw milk can be transmitted from animals to humans, and in Tanzania raw milk is sold in local markets and consumed as purchased. This study was performed to determine the molecular characteristics and antimicrobial susceptibility pattern of MRSA strains isolated from raw bovine milk sold at local markets in Tanzania. A total of 117 raw milk samples were cultured on Baird-Parker medium to isolate S. aureus and PCR was used for amplification of gltB gene for S. aureus identification and the presence of mecA gene for methicillin-resistant strains. Coagulase-negative (CN) S. aureus were reconfirmed using tube coagulase, DNase, and API Staph tests. MRSA isolates were spa typed whereas antimicrobial susceptibility testing was performed by the disc diffusion method. Forty-six coagulase positives (CP) and two CN S. aureus were identified. Most strains were resistant to penicillin (72%), and 3 isolates: 2 CN S. aureus and 1 coagulase-negative Staphylococci (CNS), were phenotypically resistant to vancomycin, oxacillin, and cefoxitin and were confirmed to carry mecA. Resistance to clindamycin, trimethoprim-sulfamethoxazole, and tetracycline was 23.9%, 30.4%, and 41.3%, respectively. Twelve isolates exhibited multidrug resistance; however, only one mecA positive strain among the three was typeable and belonged to spa type t2603. This study reports for the first time the presence of CN variant of MRSA, which was assigned the spa type t2603, and the presence of multidrug resistant S. aureus isolates from bovine milk in Morogoro, Tanzania.

Molecular Typing and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolated from Bovine Milk in Tanzania

PubMed Central

Mohammed, Jibril; Ziwa, Michael Henry; Kisanga, Adela; Tuntufye, Huruma Nelwike

2018-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) in raw milk can be transmitted from animals to humans, and in Tanzania raw milk is sold in local markets and consumed as purchased. This study was performed to determine the molecular characteristics and antimicrobial susceptibility pattern of MRSA strains isolated from raw bovine milk sold at local markets in Tanzania. A total of 117 raw milk samples were cultured on Baird-Parker medium to isolate S. aureus and PCR was used for amplification of gltB gene for S. aureus identification and the presence of mecA gene for methicillin-resistant strains. Coagulase-negative (CN) S. aureus were reconfirmed using tube coagulase, DNase, and API Staph tests. MRSA isolates were spa typed whereas antimicrobial susceptibility testing was performed by the disc diffusion method. Forty-six coagulase positives (CP) and two CN S. aureus were identified. Most strains were resistant to penicillin (72%), and 3 isolates: 2 CN S. aureus and 1 coagulase-negative Staphylococci (CNS), were phenotypically resistant to vancomycin, oxacillin, and cefoxitin and were confirmed to carry mecA. Resistance to clindamycin, trimethoprim-sulfamethoxazole, and tetracycline was 23.9%, 30.4%, and 41.3%, respectively. Twelve isolates exhibited multidrug resistance; however, only one mecA positive strain among the three was typeable and belonged to spa type t2603. This study reports for the first time the presence of CN variant of MRSA, which was assigned the spa type t2603, and the presence of multidrug resistant S. aureus isolates from bovine milk in Morogoro, Tanzania. PMID:29721021

Verocytotoxin-producing Escherichia coli O26 in raw water buffalo (Bubalus bubalis) milk products in Italy.

PubMed

Lorusso, Vanessa; Dambrosio, Angela; Quaglia, Nicoletta Cristiana; Parisi, Antonio; La Salandra, Giovanna; Lucifora, Giuseppe; Mula, Giuseppina; Virgilio, Sebastiano; Carosielli, Leonardo; Rella, Addolorata; Dario, Marco; Normanno, Giovanni

2009-08-01

Escherichia coli 026 is known as a verocytotoxin-producing E. coli (VTEC) organism that causes severe foodborne diseases such as hemorrhagic colitis and hemolytic uremic syndrome. Although cattle are the most important reservoir of VTEC, only a few reports on the role of water buffalo (Bubalus bubalis) as a reservoir of VTEC and on the presence of these organisms in their milk are available. However, in Southern Italy, where water buffalo are intensively reared, an outbreak of hemolytic uremic syndrome due to E. coli 026 has recently been reported, in which the consumption of typical dairy products was considered to be a common risk factor. The aims of this work were to assess the prevalence of E. coli O26 in raw water buffalo milk, to characterize the virulence gene profiles of the isolates, and to evaluate their phenotypic antimicrobial resistance pattern. Of 160 analyzed samples, 1 (0.6%) tested positive for E. coli O26, and the isolate showed the stx1+/stx2+/eae-/hlyA+ genotypic profile. The strain showed resistance against glycopeptides, macrolides, and penicillins. The presence of VTEC organisms in raw water buffalo milk could be considered to be a potential threat to consumers; however, the strict adherence to the processes used in the preparation of the most common buffalo dairy products could strongly mitigate the foodborne risk. To our knowledge, this article reports the first isolation and characterization of E. coli O26 VTEC in raw water buffalo milk.

Lead Concentrations in Raw Cow and Goat Milk Collected in Rural Areas of Croatia from 2010 to 2014.

PubMed

Bilandžić, Nina; Sedak, Marija; Čalopek, Bruno; Luburić, Đurđica Božić; Solomun Kolanović, Božica; Varenina, Ivana; Đokić, Maja; Kmetič, Ivana; Murati, Teuta

2016-05-01

A total of 249 cow and 33 goat milk samples were collected in rural areas of Croatia during the period 2010-2014. Lead concentrations in milk samples were analyzed by graphite furnace-atomic absorption spectroscopy. Mean Pb concentrations in milk ranged from (μg/kg): cow 10.8-12.2; goat 9.33-60.0. The highest Pb level of 131 μg/kg in cow milk was measured during 2014. There were no significant differences in Pb levels between cow and goat milk and also in goat milk among the analysed years. However, significant differences were found in cow milk among years. The highest Pb was determined in 2011 (157 μg/kg in goat milk). The calculated estimated weekly intakes of Pb concentrations for cow and goat milk contribute only 1.37 % and 1.84 % to the provisional tolerable weekly intake. Therefore, the consumption of milk from both species should not pose a consumer health risk.

Effect of Raw Milk on Lactose Intolerance: A Randomized Controlled Pilot Study

PubMed Central

Mummah, Sarah; Oelrich, Beibei; Hope, Jessica; Vu, Quyen; Gardner, Christopher D.

2014-01-01

PURPOSE This pilot study aimed to determine whether raw milk reduces lactose malabsorption and/or lactose intolerance symptoms relative to pasteurized milk. METHODS We performed a crossover trial involving 16 adults with self-reported lactose intolerance and lactose malabsorption confirmed by hydrogen (H2) breath testing. Participants underwent 3, 8-day milk phases (raw vs 2 controls: pasteurized, soy) in randomized order separated by 1-week washout periods. On days 1 and 8 of each phase, milk consumption was 473 mL (16 oz); on days 2 to 7, milk dosage increased daily by 118 mL (4 oz), beginning with 118 mL (4 oz) on day 2 and reaching 710 mL (24 oz) on day 7. Outcomes were area under the breath H2 curve (AUC ∆H2) and self-reported symptom severity (visual analog scales: flatulence/gas, audible bowel sounds, abdominal cramping, diarrhea). RESULTS AUC ∆H2 (mean ± standard error of the mean) was higher for raw vs pasteurized on day 1 (113 ± 21 vs 71 ± 12 ppm·min·10−2, respectively, P = .01) but not day 8 (72 ± 14 vs 74 ± 15 ppm·min·10−2, respectively, P = .9). Symptom severities were not different for raw vs pasteurized on day 7 with the highest dosage (P >.7). AUC ∆H2 and symptom severities were higher for both dairy milks compared with soy milk. CONCLUSIONS Raw milk failed to reduce lactose malabsorption or lactose intolerance symptoms compared with pasteurized milk among adults positive for lactose malabsorption. These results do not support widespread anecdotal claims that raw milk reduces the symptoms of lactose intolerance. PMID:24615309

Effect of raw milk on lactose intolerance: a randomized controlled pilot study.

PubMed

Mummah, Sarah; Oelrich, Beibei; Hope, Jessica; Vu, Quyen; Gardner, Christopher D

2014-01-01

This pilot study aimed to determine whether raw milk reduces lactose malabsorption and/or lactose intolerance symptoms relative to pasteurized milk. We performed a crossover trial involving 16 adults with self-reported lactose intolerance and lactose malabsorption confirmed by hydrogen (H2) breath testing. Participants underwent 3, 8-day milk phases (raw vs 2 controls: pasteurized, soy) in randomized order separated by 1-week washout periods. On days 1 and 8 of each phase, milk consumption was 473 mL (16 oz); on days 2 to 7, milk dosage increased daily by 118 mL (4 oz), beginning with 118 mL (4 oz) on day 2 and reaching 710 mL (24 oz) on day 7. Outcomes were area under the breath H2 curve (AUC H2) and self-reported symptom severity (visual analog scales: flatulence/gas, audible bowel sounds, abdominal cramping, diarrhea). AUC H2 (mean ± standard error of the mean) was higher for raw vs pasteurized on day 1 (113 ± 21 vs 71 ± 12 ppm·min·10(-2), respectively, P = .01) but not day 8 (72 ± 14 vs 74 ± 15 ppm·min·10(-2), respectively, P = .9). Symptom severities were not different for raw vs pasteurized on day 7 with the highest dosage (P >.7). AUC H2 and symptom severities were higher for both dairy milks compared with soy milk. Raw milk failed to reduce lactose malabsorption or lactose intolerance symptoms compared with pasteurized milk among adults positive for lactose malabsorption. These results do not support widespread anecdotal claims that raw milk reduces the symptoms of lactose intolerance.

Enterohemorrhagic Escherichia coli O157 in milk and dairy products from Libya: Isolation and molecular identification by partial sequencing of 16S rDNA

PubMed Central

Garbaj, Aboubaker M.; Awad, Enas M.; Azwai, Salah M.; Abolghait, Said K.; Naas, Hesham T.; Moawad, Ashraf A.; Gammoudi, Fatim T.; Barbieri, Ilaria; Eldaghayes, Ibrahim M.

2016-01-01

Aim: The aim of this work was to isolate and molecularly identify enterohemorrhagic Escherichia coli (EHEC) O157 in milk and dairy products in Libya, in addition; to clear the accuracy of cultural and biochemical identification as compared with molecular identification by partial sequencing of 16S rDNA for the existing isolates. Materials and Methods: A total of 108 samples of raw milk (cow, she-camel, and goat) and locally made dairy products (fermented cow’s milk, Maasora, Ricotta and ice cream) were collected from some regions (Janzour, Tripoli, Kremiya, Tajoura and Tobruk) in Libya. Samples were subjected to microbiological analysis for isolation of E. coli that was detected by conventional cultural and molecular method using polymerase chain reaction and partial sequencing of 16S rDNA. Results: Out of 108 samples, only 27 isolates were found to be EHEC O157 based on their cultural characteristics (Tellurite-Cefixime-Sorbitol MacConkey) that include 3 isolates from cow’s milk (11%), 3 isolates from she-camel’s milk (11%), two isolates from goat’s milk (7.4%) and 7 isolates from fermented raw milk samples (26%), isolates from fresh locally made soft cheeses (Maasora and Ricotta) were 9 (33%) and 3 (11%), respectively, while none of the ice cream samples revealed any growth. However, out of these 27 isolates, only 11 were confirmed to be E. coli by partial sequencing of 16S rDNA and E. coli O157 Latex agglutination test. Phylogenetic analysis revealed that majority of local E. coli isolates were related to E. coli O157:H7 FRIK944 strain. Conclusion: These results can be used for further studies on EHEC O157 as an emerging foodborne pathogen and its role in human infection in Libya. PMID:27956766

Rapid Membrane Filtration-Epifluorescent Microscopy Technique for Direct Enumeration of Bacteria in Raw Milk

PubMed Central

Pettipher, Graham L.; Mansell, Roderick; McKinnon, Charles H.; Cousins, Christina M.

1980-01-01

Membrane filtration and epifluorescent microscopy were used for the direct enumeration of bacteria in raw milk. Somatic cells were lysed by treatment with trypsin and Triton X-100 so that 2 ml of milk containing up to 5 × 106 somatic cells/ml could be filtered. The majority of the bacteria (ca. 80%) remained intact and were concentrated on the membrane. After being stained with acridine organe, the bacteria fluoresced under ultraviolet light and could easily be counted. The clump count of orange fluorescing cells on the membrane correlated well (r = 0.91) with the corresponding plate count for farm, tanker, and silo milks. Differences between counts obtained by different operators and between the membrane clump count and plate count were not significant. The technique is rapid, taking less than 25 min, inexpensive, costing less than 50 cents per sample, and is suitable for milks containing 5 × 103 to 5 × 108 bacteria per ml. Images PMID:16345515

A new comprehensive index for discriminating adulteration in bovine raw milk.

PubMed

Liu, Jing; Ren, Jing; Liu, Zhen-Min; Guo, Ben-Heng

2015-04-01

This paper proposes a new comprehensive index, called Q, which can effectively discriminate artificial adulterated milk from unadulterated milk. Both normal and adulterated samples of bovine raw milk were analysed by Fourier transform infrared spectroscopic instrument to measure the traditional indices of quality, including fat (FAT), protein (PRO), lactose (LAC), total solids (TS), non-fat solid (NFS), freezing point (FP) and somatic cell counts (SCC). From these traditional indices, this paper elaborates a method to build the index Q. First, correlated analysis and principle component analysis were used to select parameter pairs TS-FAT and FP-LAC as predominant variables. Second, linear-regression analysis and residual analysis are applied to determine the index Q and its discriminating ranges. The verification and two-blind trial results suggested that index Q could accurately detect milk adulteration with maltodextrin and water (as low as 1.0% of adulteration proportions), and with other nine kinds of synthetic adulterants (as low as 0.5% of adulteration proportions). Copyright © 2014 Elsevier Ltd. All rights reserved.

Simultaneous determination of 20 pharmacologically active substances in cow's milk, goat's milk, and human breast milk by gas chromatography-mass spectrometry.

PubMed

Azzouz, Abdelmonaim; Jurado-Sánchez, Beatriz; Souhail, Badredine; Ballesteros, Evaristo

2011-05-11

This paper reports a systematic approach to the development of a method that combines continuous solid-phase extraction and gas chromatography-mass spectrometry for the simultaneous determination of 20 pharmacologically active substances including antibacterials (chloramphenicol, florfenicol, pyrimethamine, thiamphenicol), nonsteroideal anti-inflammatories (diclofenac, flunixin, ibuprofen, ketoprofen, naproxen, mefenamic acid, niflumic acid, phenylbutazone), antiseptic (triclosan), antiepileptic (carbamazepine), lipid regulator (clofibric acid), β-blockers (metoprolol, propranolol), and hormones (17α-ethinylestradiol, estrone, 17β-estradiol) in milk samples. The sample preparation procedure involves deproteination of the milk, followed by sample enrichment and cleanup by continuous solid-phase extraction. The proposed method provides a linear response over the range of 0.6-5000 ng/kg and features limits of detection from 0.2 to 1.2 ng/kg depending on the particular analyte. The method was successfully applied to the determination of pharmacologically active substance residues in food samples including whole, raw, half-skim, skim, and powdered milk from different sources (cow, goat, and human breast).

Characterization of Staphylococcus species isolated from raw milk and milk products (lben and jben) in North Morocco.

PubMed

Bendahou, Abdrezzak; Lebbadi, Mariam; Ennanei, Latifa; Essadqui, Fatima Z; Abid, Mohammed

2008-06-01

To investigate the incidence and antibiotic resistance of staphylococcal strains isolated from milk and milk products and to trace the ecological origin of the Staphylococcus aureus isolated. Eighty-one samples of raw milk, lben (whey) and jben (cheese) were analyzed for the presence of staphylococcal strains. Isolates were identified by Gram stains, tests for coagulase, the API staph system and the WalkAway 40/96, which also determines the antimicrobial susceptibility profiles. The S. aureus strains were biotyped, and variable regions of the coagulase gene were amplified using the polymerase chain reaction. The identification results showed a predominance of coagulase-negative staphylococci (54 %). Coagulase-positive staphylococci that were identified were divided into 3 groups comprising S. aureus (40%), Staphylococcus intermedius (2 %) and Staphylococcus hyicus (4%). Among the S. aureus that was isolated, biotype C was the predominant biotype. Among 40 coagulase gene PCR-amplification products, 37 produced a single band, while 3 isolates produced two bands. The antimicrobial susceptibility-profile of the staphylococcal strains revealed a high incidence of S. aureus to penicillin G. In addition, Staphylococcus lentus presented considerable resistance to the oxacillin, erythromycin and lincomycin. The presence of staphylococci in raw milk, lben and jben in areas of northern Morocco poses a health hazard, so it is necessary for the public health inspectors to properly examine the conditions during production, storage and commercialization of all products made with unpasteurized milk.

Occurrence of mycobacteria in bovine milk samples from both individual and collective bulk tanks at farms and informal markets in the southeast region of Sao Paulo, Brazil

PubMed Central

2013-01-01

Background Mycobacterium spp. is one of the most important species of zoonotic pathogens that can be transmitted from cattle to humans. The presence of these opportunistic, pathogenic bacteria in bovine milk has emerged as a public-health concern, especially among individuals who consume raw milk and related dairy products. To address this concern, the Brazilian control and eradication program focusing on bovine tuberculosis, was established in 2001. However, bovine tuberculosis continues to afflict approximately 1,3 percent of the cattle in Brazil. In the present study, 300 samples of milk from bovine herds, obtained from both individual and collective bulk tanks and informal points of sale, were cultured on Löwenstein-Jensen and Stonebrink media. Polymerase chain reaction (PCR)-based tests and restriction-enzyme pattern analysis were then performed on the colonies exhibiting phenotypes suggestive of Mycobacterium spp., which were characterized as acid-fast bacilli. Results Of the 300 bovine milk samples that were processed, 24 were positively identified as Mycobacterium spp. Molecular identification detected 15 unique mycobacterial species: Mycobacterium bovis, M. gordonae, M. fortuitum, M. intracellulare, M. flavescens, M. duvalii, M. haemophilum, M. immunogenum, M. lentiflavum, M. mucogenicum, M. novocastrense, M. parafortuitum, M. smegmatis, M. terrae and M. vaccae. The isolation of bacteria from the various locations occurred in the following proportions: 9 percent of the individual bulk-tank samples, 7 percent of the collective bulk-tank samples and 8 percent of the informal-trade samples. No statistically significant difference was observed between the presence of Mycobacterium spp. in the three types of samples collected, the milk production profiles, the presence of veterinary assistance and the reported concerns about bovine tuberculosis prevention in the herds. Conclusion The microbiological cultures associated with PCR-based identification tests are possible tools for the investigation of the presence of Mycobacterium spp. in milk samples. Using these methods, we found that the Brazilian population may be regularly exposed to mycobacteria by consuming raw bovine milk and related dairy products. These evidences reinforces the need to optimize quality programs of dairy products, to intensify the sanitary inspection of these products and the necessity of further studies on the presence of Mycobacterium spp. in milk and milk-based products. PMID:23618368

The effect of milk processing on the microstructure of the milk fat globule and rennet induced gel observed using confocal laser scanning microscopy.

PubMed

Ong, L; Dagastine, R R; Kentish, S E; Gras, S L

2010-04-01

Confocal laser scanning microscopy (CLSM) was successfully used to observe the effect of milk processing on the size and the morphology of the milk fat globule in raw milk, raw ultrafiltered milk, and standardized and pasteurized milk prepared for cheese manufacture (cheese-milk) and commercial pasteurized and homogenized milk. Fat globule size distributions for the milk preparations were analyzed using both image analysis and light scattering and both measurements produced similar data trends. Changes to the native milk fat globule membrane (MFGM) were tracked using a MFGM specific fluorescent stain that allowed MFGM proteins and adsorbed proteins to be differentiated on the fat globule surface. Sodium dodecyl sulfate polyacrylamide gel electrophoresis confirmed the identity of native MFGM proteins isolated from the surface of fat globules within raw, UF retentate, and cheese-milk preparations, whereas only casein was detected on the surface of fat globules in homogenized milk. The microstructure, porosity, and gel strength of the rennet induced gel made from raw milk and cheese-milk was also found to be comparable and significantly different to that made from homogenized milk. Our results highlight the potential use of CLSM as a tool to observe the structural details of the fat globule and associated membrane close to its native environment.

Effect of food processing on degradation of hexachlorocyclohexane and its isomers in milk

PubMed Central

Singh, Sujatha; Nelapati, Krishnaiah

2017-01-01

Aim: To study the effect of different food processing techniques on the degradation of organochlorine compounds (α, β, ɣ and δ hexachlorocyclohexane isomers (HCH)) residues in both natural and fortified samples of milk. Materials and Methods: Raw milk samples are collected from the local areas of Hyderabad, India. Naturally and fortified milk samples (HCH) were subjected to various food processing techniques, pasteurization (63ºC for ½ h), sterilization (121ºC for 15 min) and boiling for 5 min and analyzed by gas chromatography with electron capture detector using quick, easy, cheap, effective, rugged and safe method for multiresidue analysis of pesticides in milk with slight modification. Results: The final mean residual concentration of pesticide in milk after heat processing and percentage of degradation were calculated with respective treatments. Conclusion: Heat treatments are highly effective on reduction of mean residual concentration of HCH in milk. In which Sterilization and boiling proved to be more effective in degradation of HCH isomers. PMID:28435187

Effect of food processing on degradation of hexachlorocyclohexane and its isomers in milk.

PubMed

Singh, Sujatha; Nelapati, Krishnaiah

2017-03-01

To study the effect of different food processing techniques on the degradation of organochlorine compounds (α, β, ɣ and δ hexachlorocyclohexane isomers (HCH)) residues in both natural and fortified samples of milk. Raw milk samples are collected from the local areas of Hyderabad, India. Naturally and fortified milk samples (HCH) were subjected to various food processing techniques, pasteurization (63ºC for ½ h), sterilization (121ºC for 15 min) and boiling for 5 min and analyzed by gas chromatography with electron capture detector using quick, easy, cheap, effective, rugged and safe method for multiresidue analysis of pesticides in milk with slight modification. The final mean residual concentration of pesticide in milk after heat processing and percentage of degradation were calculated with respective treatments. Heat treatments are highly effective on reduction of mean residual concentration of HCH in milk. In which Sterilization and boiling proved to be more effective in degradation of HCH isomers.

Contribution of natural milk culture to microbiota, safety and hygiene of raw milk cheese produced in alpine malga.

PubMed

Lucchini, Rosaria; Cardazzo, Barbara; Carraro, Lisa; Negrinotti, Michele; Balzan, Stefania; Novelli, Enrico; Fasolato, Luca; Fasoli, Franco; Farina, Giovanni

2018-03-31

Processing of alpine milk in malga farms is carried out under conditions that can favor contamination by coliforms, coagulase-positive staphylococci, or pathogens such as Listeria monocytogenes . With the aim to improve the hygienic characteristics and safety of cheese produced in four malga farms the use of lyophilized Natural Milk Culture prepared with selected strains was tested.. Two cheesemaking tests were carried out in the same day always starting from the same milk: in the first case following the malga recipe that uses either Natural Whey Culture or without the addition of a starter, in the second one using a Natural Milk Culture. Cheesemaking were carried out in four malga farms located in the west area of Trentino region within the same week. For hygienic and safety evaluation, aerobic colony count, coagulase-positive staphylococci, Escherichia coli , staphylococcal toxins, Listeria monocytogenes , and Salmonella spp, pH and a w were determined in raw milk from evening and morning milking, curd in vat, curd after extraction and two months-ripened cheese. Pathogens or toxins, high values of coagulase- positive staphylococci and E. coli were not found in cheese samples. However, in the curd coagulase-positive staphylococci reached values almost of 5 Log CFU/g in the two malga without starter cultures. The use of Natural Milk Culture reduced E. coli counts. In addition, DNA was extracted from cheese samples and from Natural Milk Culture and the composition of the microbial community determined by Next Generation Sequencing method. The determination of cheese microbial communities demonstrated that the use of Natural Milk Culture exerted different effects in the different malga , in any case preserving bacterial biodiversity.

Influence of storage and preservation on microbiological quality of silo ovine milk.

PubMed

de Garnica, M L; Santos, J A; Gonzalo, C

2011-04-01

This study was designed to analyze the effects of the storage and preservation conditions on counts of mesophilic, thermoduric, psychotrophic, coliform, Escherichia coli, Streptococcus agalactiae, and Staphylococcus aureus organisms in silo ovine milk. A total of 910 analytical determinations were conducted from aliquots of 10 silo ovine milks. The conditions tested were unpreserved and azidiol-preserved milk stored at 4°C, and unpreserved milk stored at -20°C. Milk aged 2, 24, 48, 72, and 96 h post-collection for refrigerated aliquots, and 7, 15, and 30 d post-collection for frozen aliquots. The factors silo and storage conditions significantly contributed to variation of all microbiological variables, although milk age effect within storage was only significant for mesophilic, psychrotrophic, and coliform bacteria counts. In refrigerated raw milk, mesophile, psychrotroph, and coliform counts significantly increased over 96 h post-collection, whereas the other groups and bacteria species tested maintained their initial concentration. In all cases, azidiol preservation maintained the initial bacterial concentration in raw sheep milk under refrigeration throughout 96 h. Thus, azidiol was a suitable preservative for microbiological studies in sheep milk. Smallest counts were registered for frozen samples, particularly for coliforms, E. coli, Strep. agalactiae and Staph. aureus. Estimates of mesophilic, thermoduric and psychrotrophic organisms showed similar values on both azidiol-preserved and frozen milk samples. Coliforms and E. coli counts significantly decrease over time after freezing. Consequently, freezing at -20°C could also be appropriate for analysis of mesophilic, thermoduric, and psychrotrophic bacterial groups, but not for coliforms or mammary pathogens. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Contribution of natural milk culture to microbiota, safety and hygiene of raw milk cheese produced in alpine malga

PubMed Central

Lucchini, Rosaria; Cardazzo, Barbara; Carraro, Lisa; Negrinotti, Michele; Balzan, Stefania; Novelli, Enrico; Fasolato, Luca; Fasoli, Franco; Farina, Giovanni

2018-01-01

Processing of alpine milk in malga farms is carried out under conditions that can favor contamination by coliforms, coagulase-positive staphylococci, or pathogens such as Listeria monocytogenes. With the aim to improve the hygienic characteristics and safety of cheese produced in four malga farms the use of lyophilized Natural Milk Culture prepared with selected strains was tested.. Two cheesemaking tests were carried out in the same day always starting from the same milk: in the first case following the malga recipe that uses either Natural Whey Culture or without the addition of a starter, in the second one using a Natural Milk Culture. Cheesemaking were carried out in four malga farms located in the west area of Trentino region within the same week. For hygienic and safety evaluation, aerobic colony count, coagulase-positive staphylococci, Escherichia coli, staphylococcal toxins, Listeria monocytogenes, and Salmonella spp, pH and awwere determined in raw milk from evening and morning milking, curd in vat, curd after extraction and two months-ripened cheese. Pathogens or toxins, high values of coagulase- positive staphylococci and E. coli were not found in cheese samples. However, in the curd coagulase-positive staphylococci reached values almost of 5 Log CFU/g in the two malga without starter cultures. The use of Natural Milk Culture reduced E. coli counts. In addition, DNA was extracted from cheese samples and from Natural Milk Culture and the composition of the microbial community determined by Next Generation Sequencing method. The determination of cheese microbial communities demonstrated that the use of Natural Milk Culture exerted different effects in the different malga, in any case preserving bacterial biodiversity. PMID:29732331

Low Temperature Plasma for decontamination of E. coli in milk.

PubMed

Gurol, C; Ekinci, F Y; Aslan, N; Korachi, M

2012-06-15

Raw milk is a natural, highly nutritious product and a quick and easy supplement for human dietary requirements. Elimination of bacteria in milk has been a problem for decades and new methods with regards to non-thermal applications which do not harm the chemical composition of milk, are currently under investigation. The objective of the study was to determine the potential use of a novel, Low Temperature Plasma (LTP) system for its capability of killing Escherichia coli in milk with different fat contents. The time dependent effect of atmospheric corona discharge generated with 9kV of AC power supply on E. coli ATCC 25922 dispersed in whole, semi skimmed and skimmed milk was examined. Plasma was applied at time intervals of 0, 3, 6, 9, 12, 15 and 20min. A significant 54% reduction in the population of E. coli cells after only 3min was observed regardless of the fat content of the milk. The initial pre-plasma bacterial count of 7.78 Log CFU/ml in whole milk was decreased to 3.63 Log CFU/ml after 20min of plasma application. LTP did not cause any significant change to the pH and color values of raw milk samples. No viable cells were detected after one week examination in whole milk samples and remained so over the 6week storage period. The findings of this study show that the novel LTP system tested was able to significantly reduce E. coli in milk by more than a 3 fold log reduction without significantly affecting pH or color properties. Copyright © 2012 Elsevier B.V. All rights reserved.

Essential elements, cadmium, and lead in raw and pasteurized cow and goat milk

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopez, A.; Collins, W.F.; Williams, H.L.

1985-08-01

Fifteen essential elements plus cadmium and lead were determined in raw and pasteurized cow and goat milks by atomic absorption spectrophotometry. When results were compared on a wet weight basis, there were no significant differences between the raw and pasteurized milks except for cobalt, iron, and lead in goat milk. When copper in goat milk was expressed on a dry weight basis, there was a significant difference between raw and pasteurized milk. There were significantly higher amounts of cobalt, copper, iron, lead, magnesium, and phosphorus, wet weight basis, in pasteurized goat milk than in pasteurized cow milk. Significantly more nickelmore » and sodium were in pasteurized cow milk. No difference in the content of chloride, calcium, potassium, and zinc was significant between the two milks. When dry weights of the two milks were compared, statistical differences were the same, except there was significantly more calcium and potassium in pasteurized cow milk than in pasteurized goat milk and there were no significant differences in the content of lead and phosphorus between the two milks. Percentages of the established and estimated recommended daily allowances show both cow and goat milk to be excellent sources of calcium, phosphorus, and potassium and fair sources of iron, magnesium, and sodium.« less

Foodborne pathogens in unpasteurized milk in Sweden.

PubMed

Artursson, Karin; Schelin, Jenny; Thisted Lambertz, Susanne; Hansson, Ingrid; Olsson Engvall, Eva

2018-05-19

Raw milk may be a risk for public health if it is contaminated with zoonotic pathogens. To study the prevalence in unpasteurized milk from Swedish farms, bovine and small ruminant dairy farms were sampled. Since the sampling method and transport conditions may influence the outcome of analyses, efforts were made to optimize the methodology. Culturing of bacteria was done from in-line milk filters collected from the milk pipe at the point where it enters the milk bulk tank at the farms and this way of sampling was compared to sampling bulk tank milk (BTM) directly. Analysing milk filters were found to be superior to analysing BTM directly. Conditions for transport of milk filter samples were further improved by the addition of Cary Blair transport medium, which significantly increased the number of positive samples for pathogenic bacteria. The isolation of several foodborne pathogens from milk filters was demonstrated. The prevalence of samples with Staphylococcus aureus was 71% and 64%, and Listeria spp. 21% and 29% from dairy cow and goat/sheep farms, respectively. Campylobacter jejuni, Yersinia enterocolitica and verotoxigenic Escherichia coli (VTEC) O157 were detected in 9%, 2% and 2% of samples from bovine milk, respectively. We conclude that the choice of sampling method and sample handling influence the results of bacterial culturing. From the results of this study, we strongly recommend to sample in-line milk filters instead of BTM directly and to use Cary Blair medium during transport, especially if the samples are to be analysed for Campylobacter spp. and/or Listeria spp. The findings also show that unpasteurized milk from Swedish farms occasionally contain bacteria with zoonotic potential. Copyright © 2018 Elsevier B.V. All rights reserved.

Antimicrobial Resistance and Virulence-Associated Genes of Campylobacter spp. Isolated from Raw Milk, Fish, Poultry, and Red Meat.

PubMed

Raeisi, Mojtaba; Khoshbakht, Rahem; Ghaemi, Ezzat Allah; Bayani, Mahsan; Hashemi, Mohammad; Seyedghasemi, Navisa Sadat; Shirzad-Aski, Hesamaddin

2017-10-01

This study was designed and conducted to evaluate the frequency, antimicrobial resistance, and presence of six virulence-associated genes among thermophilic Campylobacters isolated from raw milk, poultry (chicken, turkey, and duck), fish, cattle, and sheep meat. Out of 590 samples, which were recovered from different origins, 141 (23.9%) samples were positive for Campylobacters. Campylobacter spp. was isolated in 40.8% (106/260), 14% (28/200), and 8.7% (7/80) of poultry meat, red meat, and milk samples, respectively. Antimicrobial susceptibility test indicated a high frequency of resistance to ciprofloxacin, tetracycline, and nalidixic acid among the isolates. Furthermore, prevalence of waaC, ciaB, and pldA genes were 91.7%, 86.7%, and 80.8%, respectively; and, none of the isolates harbored both wlaN and cgtB genes, simultaneously. Moreover, there was a weak correlation between antibiotics resistance and presence of the pathogen genes. However, the existence of Campylobacter spp. isolates in food animal products, with high resistance to antibiotics and several virulence gene possessions, is alarming and increases the attention to the widespread use of antibiotics.

7 CFR 58.430 - Milk.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Material § 58... milk used. Such dairy products shall have originated from raw milk meeting the same requirements as...

7 CFR 58.430 - Milk.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Material § 58... milk used. Such dairy products shall have originated from raw milk meeting the same requirements as...

Identification of milk origin and process-induced changes in milk by stable isotope ratio mass spectrometry.

PubMed

Scampicchio, Matteo; Mimmo, Tanja; Capici, Calogero; Huck, Christian; Innocente, Nadia; Drusch, Stephan; Cesco, Stefano

2012-11-14

Stable isotope values were used to develop a new analytical approach enabling the simultaneous identification of milk samples either processed with different heating regimens or from different geographical origins. The samples consisted of raw, pasteurized (HTST), and ultrapasteurized (UHT) milk from different Italian origins. The approach consisted of the analysis of the isotope ratio of δ¹³C and δ¹⁵N for the milk samples and their fractions (fat, casein, and whey). The main finding of this work is that as the heat processing affects the composition of the milk fractions, changes in δ¹³C and δ¹⁵N were also observed. These changes were used as markers to develop pattern recognition maps based on principal component analysis and supervised classification models, such as linear discriminant analysis (LDA), multivariate regression (MLR), principal component regression (PCR), and partial least-squares (PLS). The results give proof of the concept that isotope ratio mass spectroscopy can discriminate simultaneously between milk samples according to their geographical origin and type of processing.

Influence of raw milk quality on fluid milk shelf life.

PubMed

Barbano, D M; Ma, Y; Santos, M V

2006-03-01

Pasteurized fluid milk shelf life is influenced by raw milk quality. The microbial count and somatic cell count (SCC) determine the load of heat-resistant enzymes in milk. Generally, high levels of psychrotrophic bacteria in raw milk are required to contribute sufficient quantities of heat-stable proteases and lipases to cause breakdown of protein and fat after pasteurization. Sanitation, refrigeration, and the addition of CO2 to milk are used to control both total and psychrotrophic bacteria count. It is not uncommon for total bacterial counts of raw milk to be < 10,000 cfu/mL. In the past, fluid milk processors have not focused much attention on milk SCC. Increased SCC is correlated with increased amounts of heat-stable protease (plasmin) and lipase (lipoprotein lipase) in milk. When starting with raw milk that has a low bacterial count, and in the absence of microbial growth in pasteurized milk, enzymes associated with high SCC will cause protein and fat degradation during refrigerated storage, and produce off-flavors. As the ability to kill, remove, or control microbial growth in pasteurized refrigerated milk continues to improve, the original milk SCC will be the factor limiting the time of refrigerated storage before development of an off-flavor in milk. Most healthy cows in a dairy herd have a milk SCC < 50,000 cell/mL. Bulk tank SCC > 200,000 cell/mL are usually due to the contribution of high SCC milk from a small number of cows in the herd. Technology to identify these cows and keep their milk out of the bulk tank could substantially increase the value of the remaining milk for use in fluid milk processing. To achieve a 60- to 90-d shelf life of refrigerated fluid milk, fluid processors and dairy farmers need to work together to structure economic incentives that allow farmers to produce milk with the SCC needed for extended refrigerated shelf life.

Validation of the BetaStar® Advanced for Tetracyclines Test Kit for the Screening of Bulk Tank and Tanker Truck Milks for the Presence of Tetracycline Drug Residues.

PubMed

Ankrapp, David; Schaus, Benjamin; Clements, Lauren; Klein, Frank; Rice, Jennifer; Rejman, John

2018-05-09

A validation study was conducted for an immunochromatographic method (BetaStar ® Advanced for Tetracyclines) for detection of tetracycline antibiotic residues in raw, commingled bovine milk. The assay was demonstrated to detect tetracycline, chlortetracycline, and oxytetracycline at levels below the FDA tolerance levels but above the maximum sensitivity thresholds established by the National Conference on Interstate Milk Shipments. Results of internal and independent laboratory dose-response studies employing spiked samples were in agreement. All three drugs at the approximate 90/95% sensitivity levels were detected in milk collected from cows that had been treated with the specific drug. Selectivity of the assay was 100%, as no false-positive results were obtained in testing 881 control milk samples. Testing the estimated 90/95 sensitivity level for tetracycline (213 ppb), chlortetracycline (272 ppb), and oxytetracycline (180 ppb) and at 1000 ppb for each antibiotic resulted in 100% positive tests for each tetracycline. Results of ruggedness experiments established the operating parameter tolerances for the test. Results of cross-reactivity testing established that the assay detects certain other tetracycline drugs but does not cross-react with any of 32 drugs belonging to seven different drug classes. Abnormally high bacterial or somatic cell counts (SCC) in raw milk produced no assay interference.

Aluminium sensitized spectrofluorimetric determination of fluoroquinolones in milk samples coupled with salting-out assisted liquid-liquid ultrasonic extraction

NASA Astrophysics Data System (ADS)

Xia, Qinghai; Yang, Yaling; Liu, Mousheng

2012-10-01

An aluminium sensitized spectrofluorimetric method coupled with salting-out assisted liquid-liquid ultrasonic extraction for the determination of four widely used fluoroquinolones (FQs) namely norfloxacin (NOR), ofloxacin (OFL), ciprofloxacin (CIP) and gatifloxacin (GAT) in bovine raw milk was described. The analytical procedure involves the fluorescence sensitization of aluminium (Al3+) by complexation with FQs, salting-out assisted liquid-liquid ultrasonic extraction (SALLUE), followed by spectrofluorometry. The influence of several parameters on the extraction (the salt species, the amount of salt, pH, temperature and phase volume ratio) was investigated. Under optimized experimental conditions, the detection limits of the method in milk varied from 0.009 μg/mL for NOR to 0.016 μg/mL for GAT (signal-to-noise ratio (S/N) = 3). The relative standard deviations (RSD) values were found to be relatively low (0.54-2.48% for four compounds). The calibration graph was linear from 0.015 to 2.25 μg/mL with coefficient of determinations not less than 0.9974. The methodology developed was applied to the determination of FQs in bovine raw milk samples. The main advantage of this method is simple, accurate and green. The method showed promising applications for analyzing polar analytes especially polar drugs in various sample matrices.

[On-site evaluation of raw milk qualities by portable Vis/NIR transmittance technique].

PubMed

Wang, Jia-Hua; Zhang, Xiao-Wei; Wang, Jun; Han, Dong-Hai

2014-10-01

To ensure the material safety of dairy products, visible (Vis)/near infrared (NIR) spectroscopy combined with che- mometrics methods was used to develop models for fat, protein, dry matter (DM) and lactose on-site evaluation. A total of 88 raw milk samples were collected from individual livestocks in different years. The spectral of raw milk were measured by a porta- ble Vis/NIR spectrometer with diffused transmittance accessory. To remove the scatter effect and baseline drift, the diffused transmittance spectra were preprocessed by 2nd order derivative with Savitsky-Golay (polynomial order 2, data point 25). Changeable size moving window partial least squares (CSMWPLS) and genetic algorithms partial least squares (GAPLS) meth- ods were suggested to select informative regions for PLS calibration. The PLS and multiple linear regression (MLR) methods were used to develop models for predicting quality index of raw milk. The prediction performance of CSMWPLS models were similar to GAPLS models for fat, protein, DM and lactose evaluation, the root mean standard errors of prediction (RMSEP) were 0.115 6/0.103 3, 0.096 2/0.113 7, 0.201 3/0.123 7 and 0.077 4/0.066 8, and the relative standard deviations of prediction (RPD) were 8.99/10.06, 3.53/2.99, 5.76/9.38 and 1.81/2.10, respectively. Meanwhile, the MLR models were also cal- ibrated with 8, 10, 9 and 7 variables for fat, protein, DM and lactose, respectively. The prediction performance of MLR models was better than or close to PLS models. The MLR models to predict fat, protein, DM and lactose yielded the RMSEP of 0.107 0, 0.093 0, 0.136 0 and 0.065 8, and the RPD of 9.72, 3.66, 8.53 and 2.13, respectively. The results demonstrated the usefulness of Vis/NIR spectra combined with multivariate calibration methods as an objective and rapid method for the quality evaluation of complicated raw milks. And the results obtained also highlight the potential of portable Vis/NIR instruments for on-site assessing quality indexes of raw milk.

Milk production, raw milk quality and fertility of dromedary camels (Camelus Dromedarius) under intensive management.

PubMed

Nagy, Péter; Thomas, Sonia; Markó, Orsolya; Juhász, Jutka

2013-03-01

In many arid countries, dromedaries play an important role as a milk source in rural areas. However, the milk and meat production potential of this species is not well understood and documented. A large-scale camel dairy farm was established in 2006 in the United Arab Emirates. This study summarises the most important data on milk production, raw milk quality and reproductive efficiency collected on this farm during the first three years of operation. The average daily milk production, the mean length of lactation and the mean total milk production per lactation of 174 dromedaries were 6.0 ± 0.12 kg (± SEM), 586 ± 11.0 days (± SEM) and 3314 ± 98.5 kg (± SEM), respectively. The lactation curve reached its peak during the 4th month after parturition (mean ± SEM, 8.9 ± 0.04 kg), then it declined gradually, falling to 50% of the maximum by the 16th month postpartum (mean ± SEM, 4.3 ± 0.06 kg). Milking three times a day did not increase daily milk production compared to two times milking. Mean total viable bacterial count (TVC) and mean somatic cell count (SCC, ± SEM) of bulk raw camel milk were 4,403 ± 94 CFU/cm3 and 392,602 ± 5,999 cells/cm3 for a one-year period, respectively. There was a significant difference among months (P < 0.001). Coliform count was < 10 CFU/cm3 in most cases (96.5%). The average (± SEM) fat, protein, lactose, total solids (TS) and solid-non-fat (SNF) concentrations of individual milk samples were 2.51 ± 0.03%, 2.60 ± 0.01%, 4.03 ± 0.03%, 9.98 ± 0.03% and 7.56 ± 0.03%, respectively. Lactation period, average daily milk production and morning vs. evening milking significantly influenced milk chemical composition. For the 470 camels in the breeding programme, end-of-season pregnancy rate and birth rate were 87.0% and 82.6%, respectively, after natural mating. We have demonstrated that sustainable milk production is possible from a traditional species, the dromedary camel, under an intensive management system.

MALDI-TOF mass spectrometry for the monitoring of she-donkey's milk contamination or adulteration.

PubMed

Cunsolo, Vincenzo; Muccilli, Vera; Saletti, Rosaria; Foti, Salvatore

2013-02-01

Donkey's milk (DM), representing a safe and alternative food in both IgE-mediated and non-IgE-mediated cow's milk protein allergy, can be categorized as precious pharma-food. Moreover, an economically relevant interest for the use of DM in cosmetology is also developing. The detection of adulterations and contaminations of DM is a matter of fundamental importance from both an economic and allergenic standpoint, and, to this aim, fast and efficient analytical approaches to assess the authenticity of this precious nutrient are desirable. Here, a rapid matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS)-based method aimed to the detection of bovine or caprine milk in raw DM is reported. The presence of the extraneous milks was revealed by monitoring the protein profiles of the most abundant whey proteins, α-lactalbumin (α-LA) and β-lactoglobulin, used as molecular markers. The possibility of obtaining a quantitative analysis of the level of cow or goat milk in DM based on the MALDI-TOF peak areas of α-LAs was also explored. The results showed that the experimental quantitative values were in good agreement with the real composition of each mixture. As pretreatment of the milk samples is not required, and owing to the speed and the high sensitivity of MALDI-MS, the protocol here reported could represent a reliable method for routine analyses aimed to assess the absence of contamination in raw fresh DM samples. Copyright © 2013 John Wiley & Sons, Ltd.

Detection and quantitation of Escherichia coli O157:H7 in raw milk by direct qPCR

USDA-ARS?s Scientific Manuscript database

There has been a shift in US food consumption patterns toward unprocessed foods perceived to be healthier. Part of this trend is increasing consumption of raw, unpasteurized milk. Raw milk can be a source of pathogens that cause serious or fatal illness, particularly in immuno-compromised individ...

7 CFR 58.232 - Milk.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Materials § 58.232 Milk. Raw milk shall meet the requirements as outlined in §§ 58.132 through 58.138 and, unless...

7 CFR 58.232 - Milk.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Materials § 58.232 Milk. Raw milk shall meet the requirements as outlined in §§ 58.132 through 58.138 and, unless...

Short communication: incorporation of inulin and transglutaminase in fermented goat milk containing probiotic bacteria.

PubMed

Mituniewicz-Małek, A; Ziarno, M; Dmytrów, I

2014-01-01

Goat milk is a good carrier for probiotic bacteria; however, it is difficult to produce fermented goat milk with a consistency comparable to that of fermented cow milks. It can be improved by the addition of functional stabilizers, such as inulin, or treatment with transglutaminase. The aim of this study was to determine the effect of cold storage of inulin and microbial transglutaminase on the viability of Lactobacillus acidophilus La-5 and Bifidobacterium animalis ssp. lactis Bb-12 in fermented goat milk. Microbiological analysis included the determination of the probiotic bacteria cell count in fermented milk samples, whereas physico-chemical analysis included the analysis of fat content, titratable acidity, and pH of raw, pasteurized, and fermented goat milk samples. No positive influence of inulin or microbial transglutaminase on the viability of probiotics in fermented goat's milk samples was observed. Nevertheless, the population of probiotics remained above 6 log cfu/g after 8 wk of storage at 5 °C. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Microbiota of an Italian Grana-Like Cheese during Manufacture and Ripening, Unraveled by 16S rRNA-Based Approaches.

PubMed

Alessandria, Valentina; Ferrocino, Ilario; De Filippis, Francesca; Fontana, Mauro; Rantsiou, Kalliopi; Ercolini, Danilo; Cocolin, Luca

2016-07-01

The microbial ecology of cheese involves a rich and complex interaction between starter lactic acid bacteria and nonstarter lactic acid bacteria (NSLAB), mainly originating from raw milk and/or from the environment, that can contribute to the final characteristics of cheese. The aim of the present research was the exploration of the active microbiota by RNA-based approaches during the manufacturing and ripening of a Grana-like cheese. Reverse transcriptase PCR (RT-PCR)-denaturing gradient gel electrophoresis (DGGE) and RNA-based high-throughput sequencing were applied to profile microbial populations, while the enumeration of active bacteria was carried out by using quantitative PCR (qPCR). Three different cheese productions (named D, E, and F) collected in the same month from the same dairy plant were analyzed. The application of the qPCR protocol revealed the presence of 7 log CFU/ml of bacterial load in raw milk, while, during ripening, active bacterial populations ranged from <4 to 8 log CFU/ml. The natural whey starters used in the three productions showed the same microbiota composition, characterized by the presence of Lactobacillus helveticus and Lactobacillus delbrueckii Nevertheless, beta-diversity analysis of the 16S rRNA sequencing data and RT-PCR-DGGE showed a clear clustering of the samples according to the three productions, probably driven by the different milks used. Milk samples were found to be characterized by the presence of several contaminants, such as Propionibacterium acnes, Acidovorax, Acinetobacter, Pseudomonas, and NSLAB. The core genera of the starter tended to limit the development of the spoilage bacteria only in two of the three batches. This study underlines the influence of different factors that can affect the final microbiota composition of the artisanal cheese. This study highlights the importance of the quality of the raw milk in the production of a hard cheese. Independent from the use of a starter culture, raw milk with low microbiological quality can negatively affect the populations of lactic acid bacteria and, as a consequence, impact the quality of the final product due to metabolic processes associated with spoilage bacteria. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

The biofilm-positive Staphylococcus epidermidis isolates in raw materials, foodstuffs and on contact surfaces in processing plants.

PubMed

Schlegelová, J; Babák, V; Holasová, M; Dendis, M

2008-01-01

Isolates from the "farm to fork" samples (182 isolates from 2779 samples) were examined genotypically (icaAB genes) and phenotypically (in vitro biofilm formation, typical growth on Congo red agar; CRA) with the aim to assess the risk of penetration of virulent strains of Staphylococcus epidermidis into the food chain. The contamination of meat and milk products was significantly higher in comparison with raw materials. Contamination of contact surfaces in the meat-processing plants was significantly lower than that of contact surfaces in the dairy plants. The ica genes (which precondition the biofilm formation) were concurrently detected in 20 isolates that also showed a typical growth on CRA. Two ica operon-negative isolates produced biofilm in vitro but perhaps by an ica-independent mechanism. The surfaces in the dairy plants and the milk products were more frequently contaminated with ica operon-positive strains (2.3 and 1.2 % samples) than the other sample types (0-0.6 % samples).

Simultaneous determination of carotenoids, tocopherols, retinol and cholesterol in ovine lyophilised samples of milk, meat, and liver and in unprocessed/raw samples of fat.

PubMed

Bertolín, J R; Joy, M; Rufino-Moya, P J; Lobón, S; Blanco, M

2018-08-15

An accurate, fast, economic and simple method to determine carotenoids, tocopherols, retinol and cholesterol in lyophilised samples of ovine milk, muscle and liver and raw samples of fat, which are difficult to lyophilise, is sought. Those analytes have been studied in animal tissues to trace forage feeding and unhealthy contents. The sample treatment consisted of mild overnight saponification, liquid-liquid extraction, evaporation with vacuum evaporator and redissolution. The quantification of the different analytes was performed by the use of ultra-high performance liquid chromatography with diode-array detector for carotenoids, retinol and cholesterol and fluorescence detector for tocopherols. The retention times of the analytes were short and the resolution between analytes was very high. The limits of detection and quantification were very low. This method is suitable for all the matrices and analytes and could be adapted to other animal species with minor changes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Shelf life of donkey milk subjected to different treatment and storage conditions.

PubMed

Giacometti, Federica; Bardasi, Lia; Merialdi, Giuseppe; Morbarigazzi, Michele; Federici, Simone; Piva, Silvia; Serraino, Andrea

2016-06-01

The aim of this study was to investigate the effects of different treatment conditions on microbiological indicators of donkey milk hygiene and their evolution during shelf life at 4 and 12°C from 3 to 30d, simulating a farm-scale pasteurization and packing system. Four treatment conditions were tested: no treatment (raw milk), pasteurization (65°C × 30 min), high-pressure processing (HPP), and pasteurization plus HPP. The microbiological quality of the raw donkey milk investigated was not optimal; our results highlight the importance of raw milk management with the need for animal hygiene management and good dairy farming practices on donkey farms to improve handling procedures. The raw milk treated with HPP alone showed visible alterations with flocks, making the milk unfit for sale. The microbiological risk posed by consumption of raw donkey milk was significantly reduced by heat treatment but farm-scale packing systems cannot guarantee an extended shelf life. In contrast, the pasteurization plus HPP treatment was the most effective method to maintain microbiological milk quality. Microflora growth had little effect on pH in donkey milk: pH values were significantly different only between raw milk and pasteurized and pasteurized plus HPP milk stored at 12°C for 3d. Alkaline phosphatase activity and furosine could be used as indicators of proper pasteurization and thermal processing in donkey milk. Moreover, the presence and growth of Bacillus cereus in the case of thermal abuse hamper the wide-scale marketing of donkey milk due to the potential consequences for sensitive consumers and therefore further tests with time/temperature/high-pressure protocols associated with B. cereus are needed. Finally, our study shows that an HPP treatment of pasteurized milk after packing extends the shelf life of donkey milk and assures its microbial criteria up to 30d if properly stored at 4°C until opening; therefore, combined heat treatment and storage strategies are recommended to enhance the shelf life of donkey milk. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Gravity separation of fat, somatic cells, and bacteria in raw and pasteurized milks.

PubMed

Caplan, Z; Melilli, C; Barbano, D M

2013-04-01

The objective of experiment 1 was to determine if the extent of gravity separation of milk fat, bacteria, and somatic cells is influenced by the time and temperature of gravity separation or the level of contaminating bacteria present in the raw milk. The objective of experiment 2 was to determine if different temperatures of milk heat treatment affected the gravity separation of milk fat, bacteria, and somatic cells. In raw milk, fat, bacteria, and somatic cells rose to the top of columns during gravity separation. About 50 to 80% of the fat and bacteria were present in the top 8% of the milk after gravity separation of raw milk. Gravity separation for 7h at 12°C or for 22h at 4°C produced equivalent separation of fat, bacteria, and somatic cells. The completeness of gravity separation of fat was influenced by the level of bacteria in the milk before separation. Milk with a high bacterial count had less (about 50 to 55%) gravity separation of fat than milk with low bacteria count (about 80%) in 22h at 4°C. Gravity separation caused fat, bacteria, and somatic cells to rise to the top of columns for raw whole milk and high temperature, short-time pasteurized (72.6°C, 25s) whole milk. Pasteurization at ≥76.9°C for 25s prevented all 3 components from rising, possibly due to denaturation of native bovine immunoglobulins that normally associate with fat, bacteria, and somatic cells during gravity separation. Gravity separation can be used to produce reduced-fat milk with decreased bacterial and somatic cell counts, and may be a critical factor in the history of safe and unique traditional Italian hard cheeses produced from gravity-separated raw milk. A better understanding of the mechanism of this natural process could lead to the development of new nonthermal thermal technology (that does not involve heating the milk to high temperatures) to remove bacteria and spores from milk or other liquids. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Behavior of Escherichia coli O157:H7 during the manufacture and aging of Gouda and stirred-curd Cheddar cheeses manufactured from raw milk.

PubMed

D'Amico, Dennis J; Druart, Marc J; Donnelly, Catherine W

2010-12-01

This study was conducted to examine the fate of Escherichia coli O157:H7 during the manufacture and aging of Gouda and stirred-curd Cheddar cheeses made from raw milk. Cheeses were manufactured from unpasteurized milk experimentally contaminated with one of three strains of E. coli O157:H7 at an approximate population level of 20 CFU/ml. Samples of milk, whey, curd, and cheese were collected for enumeration of bacteria throughout the manufacturing and aging process. Overall, bacterial counts in both cheese types increased almost 10-fold from initial inoculation levels in milk to approximately 145 CFU/g found in cheeses on day 1. From this point, counts dropped significantly over 60 days to mean levels of 25 and 5 CFU/g in Cheddar and Gouda, respectively. Levels of E. coli O157:H7 fell and stayed below 5 CFU/g after an average of 94 and 108 days in Gouda and Cheddar, respectively, yet remained detectable after selective enrichment for more than 270 days in both cheese types. Changes in pathogen levels observed throughout manufacture and aging did not significantly differ by cheese type. In agreement with results of previous studies, our results suggest that the 60-day aging requirement alone is insufficient to completely eliminate levels of viable E. coli O157:H7 in Gouda or stirred-curd Cheddar cheese manufactured from raw milk contaminated with low levels of this pathogen.

Raw milk consumption and health.

PubMed

Vranješ, Anka Popović; Popović, Milka; Jevtić, Marija

2015-01-01

Contrary to the safe practices of milk pasteurization or sterilization, which effectively reduce foodborne outbreaks incidence associated with raw milk and dairy products use, outbreaks caused by such products continue to occur. Despite this fact, a worldwide movement advocating for the rights of raw milk and cheese selling and consumption, due to their specific nutritive characteristics, has strengthened significantly in recent years. Traditional agricultural manufacturers from Serbia still sell products related to thermally unprocessed milk, such as cottage cheese and raw cream. In AP Vojvodina during the period of 1981-2010 a total of 179 foodborne outbreaks were reported, where the incriminated cause of the outbreak were milk or diary. In 126 (70.39%) outbreaks, totaling 2276 sick individuals and one casualty, it was confirmed that the incriminated food was from the group of dairy products. In 48 instances (26.82%), bacteriological tests confirmed that milk and dairy products were excluded as the outbreak causes, while in another 5 (2.79%) outbreaks, microbiological analysis of food failed to confirm any relation to the actual epidemiological instances. In some cases, bacteriological testing of incriminated foods was not possible. In the cases of outbreaks associated with the consumption of milk and dairy products, traditional raw milk products were cited as being used. Consumption of unpasteurized milk and cheese represents public health threat. National and international rules ensuring use of safe products for human consumption have to set rules of trade of thermally processed milk and products on the market.

An assessment of the microbiological quality and safety of raw drinking milk on retail sale in England.

PubMed

Willis, C; Jørgensen, F; Aird, H; Elviss, N; Fox, A; Jenkins, C; Fenelon, D; Sadler-Reeves, L; McLauchlin, J

2018-02-01

This study aimed to review the microbiological results for raw drinking milk (RDM) samples submitted to Public Health England laboratories between 2014 and 2016 in order to produce up-to-date data on the microbiological safety of RDM and inform future risk assessments on its sale. A total of 902 samples of RDM were collected from retail sale in England for microbiological examination. Overall, 454 of 770 samples (59·0%) taken for routine monitoring were of a satisfactory quality, whilst eight (1·0%) were 'unsatisfactory and potentially injurious to health' due to the presence of Shiga toxin-producing Escherichia coli, Campylobacter or elevated levels of Listeria monocytogenes or coagulase-positive staphylococci. In contrast, 16 of 114 (14·0%) of samples taken in follow-up to a previous unsatisfactory result and 5 of 18 (27·8%) of samples related to illness were potentially injurious. A total of 229 of 902 samples (25·4%) gave unsatisfactory results due to elevated aerobic colony counts and/or coliforms, whilst 139 of 902 samples (15·4%) were of borderline quality due to coagulase-positive staphylococci. Listeria monocytogenes was detected at levels of <100 CFU per ml in 66 of 902 samples (7·3%) and other Listeria species in 44 of 902 samples (4·9%). Pathogens and/or indicators of poor hygiene were present in almost half of samples examined. Cows' milk samples gave a significantly greater proportion of unsatisfactory results compared to milk from other species (i.e. goat, sheep, buffalo, camel). These results demonstrate the importance of maintaining strict controls on the production and sale of this product. © 2017 The Society for Applied Microbiology.

Environmental sampling to predict fecal prevalence of Salmonella in an intensively monitored dairy herd.

PubMed

Van Kessel, J S; Karns, J S; Wolfgang, D R; Hovingh, E; Jayarao, B M; Van Tassell, C P; Schukken, Y H

2008-10-01

Although dairy cattle are known reservoirs for salmonellae, cattle that are shedding this organism are often asymptomatic and difficult to identify. A dairy herd that was experiencing a sustained, subclinical outbreak of Salmonella enterica subsp. enterica Cerro was monitored for 2 years. Fecal samples from the lactating cows were collected every 6 to 8 weeks and tested for the presence of Salmonella. Fecal prevalence of Salmonella fluctuated throughout the observation period and ranged from 8 to 88%. Manure composites and water trough samples were collected along with the fecal samples, and bulk milk and milk filters were cultured for the presence of Salmonella on a weekly basis. Over 90% of the manure composites--representing high-animal-traffic areas-were positive at each sampling. Salmonella was detected in 11% of milk samples and in 66% of the milk filters. Results of weekly bulk milk quality testing (i.e., bulk tank somatic cell score, standard plate count, preliminary incubation count) were typically well within acceptable ranges. Milk quality variables had low correlations with herd Salmonella fecal prevalence. When observed over time, sampling period average prevalence of Salmonella in milk filters closely paralleled fecal prevalence of Salmonella in the herd. Based on results of this study, milk filters appear to be an effective method for monitoring shedding prevalence at the herd level. In-line filter testing is also a more sensitive measure of Salmonella, and perhaps other pathogens, in raw milk than testing the milk alone.

Iodine content in commonly consumed food in Hong Kong and its changes due to cooking.

PubMed

Chung, Stephen; Chan, Andy; Xiao, Ying; Lin, Violette; Ho, Y Y

2013-01-01

Levels of iodine of foods found in Hong Kong were analysed in 271 samples from 11 groups, including (i) cereals and grain products, (ii) legumes and vegetables, (iii) meat and poultry, (iv) egg and egg products, (v) milk and milk products, (vi) fish, (vii) crustaceans and mollusks, (viii) non-alcoholic beverages, (ix) condiments and sauces, (x) sashimi and (xi) seaweeds. All food samples were analysed individually as purchased. The iodine in all samples ranged from undetectable to 2.9 g kg(-1). Seaweeds, iodised salt, seafood, milk and milk products as well as egg and egg products were rich sources of iodine. To estimate the influence of cooking on iodine levels in foods, a total of 15 individual samples were analysed as raw and respective cooked food. The influence of cooking on the iodine level was minimal, except for boiling, as iodine dissolved into the soup.

Molecular detection of Mycobacterium bovis in cattle herds of the state of Pernambuco, Brazil.

PubMed

Cezar, Renata Duarte da Silva; Lucena-Silva, Norma; Filho, Antônio Fernando Barbosa Batista; Borges, Jonas de Melo; de Oliveira, Pollyane Raysa Fernandes; Lúcio, Érica Chaves; Arruda-Lima, Maíra; Santana, Vania Lucia de Assis; Pinheiro Junior, José Wilton

2016-02-20

The present study aimed to direct detect Mycobacterium bovis in milk (n = 401) and blood (n = 401) samples collected from 401 dairy cows of 20 properties located in the state of Pernambuco, Brazil, by real-time quantitative PCR (qPCR) targeting the region of difference 4 (RD4). Risk factors possibly associated with bovine tuberculosis (BTB) were also evaluated. Of the 802 samples analyzed, one milk (0.25%) and eight blood (2%) samples were positive for M. bovis in the qPCR and their identities were confirmed by sequencing. Animals positive for M. bovis were found in six (30%) of the 20 properties visited. None of the risk factors evaluated were statistically associated with BTB. M. bovis DNA was detected in one milk sample what may pose a risk to public health because raw milk is commonly consumed in Brazil.

Why semicarbazide (SEM) is not an appropriate marker for the usage of nitrofurazone on agricultural animals.

PubMed

Stadler, Richard H; Verzegnassi, Ludovica; Seefelder, Walburga; Racault, Lucie

2015-01-01

A comprehensive global database on semicarbazide (SEM) in foodstuffs and food ingredients is presented, with over 4000 data collected in foods such as seafood (crustaceans, fish powders), meat (beef, chicken powders), dairy products (e.g. raw milk, milk powders, whey, sweet buttermilk powder, caseinate, yoghurt, cheese), honey and other ingredients. The results provide evidence that the presence of SEM in certain dairy ingredients (whey, milk protein concentrates) is a by-product of chemical reactions taking place during the manufacturing process. Of the dairy ingredients tested (c. 2000 samples), 5.3% showed traces of SEM > 0.5 µg/kg. The highest incidence of SEM-positive samples in the dairy category were whey (powders, liquid) and milk protein concentrates (35% positive), with up to 13 µg/kg measured in a whey powder. Sweet buttermilk powder and caseinate followed, with 27% and 9.3% positives, respectively. SEM was not detected in raw milk, or in yoghurt or cheese. Of the crustacean products (shrimp and prawn powders) tested, 44% were positive for SEM, the highest value measured at 284 µg/kg. Fish powders revealed an unexpectedly high incidence of positive samples (25%); in this case, fraudulent addition of shellfish shells or carry-over during processing cannot be excluded. Overall, the data provide new insights into the occurrence of SEM (for dairy products and fish powders), substantially strengthening the arguments that SEM in certain food categories is not a conclusive marker of the use of the illegal antibiotic nitrofurazone.

Prevalence, antimicrobial resistance, and molecular characterization of Campylobacter spp. in bulk tank milk and milk filters from US dairies.

PubMed

Del Collo, Laura P; Karns, Jeffrey S; Biswas, Debabrata; Lombard, Jason E; Haley, Bradd J; Kristensen, R Camilla; Kopral, Christine A; Fossler, Charles P; Van Kessel, Jo Ann S

2017-05-01

Campylobacter spp. are frequently isolated from dairy cows as commensal organisms. Sporadic Campylobacter infections in humans in the United States are generally attributed to poultry, but outbreaks are also commonly associated with dairy products, particularly unpasteurized or raw milk. Bulk tank milk samples and milk filters from US dairy operations were collected during the National Animal Health Monitoring System Dairy 2014 study and analyzed using real-time PCR and traditional culture techniques for the presence of thermophilic Campylobacter species. The weighted prevalence of operations from which we detected Campylobacter spp. in either bulk tank milk or milk filters was 24.9%. We detected Campylobacter spp. in a higher percentage of operations with 100-499 cows (42.8%) and 500 or more cows (47.5%) than in operations with 30-99 cows (6.5%). Campylobacter spp. were also more frequently detected in operations in the west than the east (45.9 and 22.6%, respectively). We isolated Campylobacter spp. from approximately half of PCR-positive samples, representing 12.5% (weighted prevalence) of operations. The majority (91.8%) of isolates were C. jejuni, but C. lari and C. coli were also isolated. We detected resistance to tetracycline in 68.4% of C. jejuni isolates, and resistance to ciprofloxacin and nalidixic acid in 13.2% of C. jejuni isolates. Based on pulsed-field gel electrophoresis, we found that dairy-associated C. jejuni were genotypically diverse, although clonal strains were isolated from different geographic regions. These results suggest that bulk tank milk can be contaminated with pathogenic Campylobacter spp., and that the consumption of unpasteurized or raw milk presents a potential human health risk. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Experimental infection of goats with tick-borne encephalitis virus and the possibilities to prevent virus transmission by raw goat milk.

PubMed

Balogh, Zsuzsanna; Egyed, László; Ferenczi, Emőke; Bán, Enikő; Szomor, Katalin N; Takács, Mária; Berencsi, György

2012-01-01

The aim of this work was to study the tick-borne encephalitis virus (TBEV) infection of goats and the possibilities to prevent human milk-borne infections either by immunizing animals or the heat treatment of milk. An experiment was conducted with 20 milking goats. Ten goats (half of them immunized) were challenged with live TBEV and 10 were left uninfected. Clinical signs and body temperatures of the animals were recorded and milk samples were collected daily. The presence of viral RNA and infectious virions in milk were detected by RT-PCR and intracerebral inoculation of suckling mice, respectively. Milk samples containing infectious virions were subjected to various heat treatment conditions and retested afterwards to assess the effect on infectivity. The infected goats did not show any clinical signs or fever compared to uninfected ones. Infectious virions were detected for 8-19 days from the milk samples (genome for 3-18 days by PCR) of infected goats. Immunized goats did not shed the virus. After heat treatment of the milk, the inoculated mice survived. Goats shed the virus with their milk without showing any symptoms. Human milk-borne infections can be avoided both by immunizing goats and boiling/pasteurizing infected milk. Copyright © 2011 S. Karger AG, Basel.

Building global models for fat and total protein content in raw milk based on historical spectroscopic data in the visible and short-wave near infrared range.

PubMed

Melenteva, Anastasiia; Galyanin, Vladislav; Savenkova, Elena; Bogomolov, Andrey

2016-07-15

A large set of fresh cow milk samples collected from many suppliers over a large geographical area in Russia during a year has been analyzed by optical spectroscopy in the range 400-1100 nm in accordance with previously developed scatter-based technique. The global (i.e. resistant to seasonal, genetic, regional and other variations of the milk composition) models for fat and total protein content, which were built using partial least-squares (PLS) regression, exhibit satisfactory prediction performances enabling their practical application in the dairy. The root mean-square errors of prediction (RMSEP) were 0.09 and 0.10 for fat and total protein content, respectively. The issues of raw milk analysis and multivariate modelling based on the historical spectroscopic data have been considered and approaches to the creation of global models and their transfer between the instruments have been proposed. Availability of global models should significantly facilitate the dissemination of optical spectroscopic methods for the laboratory and in-line quantitative milk analysis. Copyright © 2016. Published by Elsevier Ltd.

Incidence of Listeria spp. in Dairy Cows Feed and Raw Milk in Latvia

PubMed Central

Konosonoka, I. H.; Jemeljanovs, A.; Osmane, B.; Ikauniece, D.; Gulbe, G.

2012-01-01

Feed is a risk factor for poisoning the farm environment thus also fresh milk with pathogenic microorganisms of Listeria genus species. Listeria ivanovii, Listeria innocua, and Listeria seeligeri were isolated from 9.2%, but Listeria monocytogenes from 20.0% of feed samples. Most often different fodders (9.3%) and silage (4.7%) were contaminated with Listeria monocytogenes. Listeria genus species were isolated more often from feed prepared and used in organic dairy farm than from that used in conventional dairy farm, correspondingly 44.4% and 18.3%. No Listeria monocytogenes was found in bulk milk samples of organic dairy farm. PMID:23738125

Microbial Quality of and Biochemical Changes in Fresh Soft, Acid-Curd Xinotyri Cheese Made from Raw or Pasteurized Goat’s Milk

PubMed Central

Tasioula-Margari, Maria

2017-01-01

Summary The microbiological quality of and changes in the main physicochemical parameters, together with the evolution of proteolysis, lipolysis and volatile profiles of soft Xinotyri, a traditional Greek acid-curd cheese (pH≈4.4, moisture 65%, salt 1%) made from raw (RMC) or pasteurized (PMC) goat’s milk without starters, were evaluated during aerobic storage at 4 oC for 60 days. No statistically significant differences between the total nitrogen (TN) and nitrogen fraction (% of TN) contents, the degradation of intact αs- or β-caseins, total free amino acid (FAA) contents, and the ratio of hydrophilic and hydrophobic peptides in the water-soluble fraction of RMC and PMC were found. Threonine, alanine and lysine were the principal FAAs. Oleic, palmitic, capric and caprylic acids, and ethyl hexonate, ethyl octanoate, ethyl decanoate, ethanol, 3-methyl butanol, phenyl ethyl alcohol and acetone were the most abundant free fatty acids and volatile compounds, respectively. Cheese lipolysis evolved slowly at 4 oC, and milk pasteurization had no significant effect on it. Mesophilic lactic acid bacteria (LAB) were predominant in fresh cheese samples. PMC samples had significantly lower levels of enterococci and enterobacteria than RMC samples, while yeasts grew at similar levels during storage at 4 oC. All cheese samples (25 g) were free of Salmonella and Listeria monocytogenes. Coagulase-
-positive staphylococci exceeded the 5-log safety threshold in fresh RMC samples, whereas they were suppressed (<100 CFU/g) in all PMC samples. Consequently, pasteurization of raw goat milk’s and utilization of commercially defined or natural mesophilic LAB starters are recommended for standardizing the biochemical, microbial and safety qualities of fresh soft Xinotyri cheese. PMID:29540984

Comparison of the in vitro digestion of raw pasture milk and commercial HTST and UHT pasteurized milk

USDA-ARS?s Scientific Manuscript database

Consumption of raw milk from pasture-fed cows, typically purchased at local farms, is steadily increasing in the US because many consumers believe that high-temperature short-time (HTST) or ultrahigh temperature (UHT) pasteurization affects the digestibility of milk proteins and thus the bioavailabi...

Inhibition of bacterial growth in sweet cheese whey by carbon dioxide as determined by culture-independent community profiling.

PubMed

Lo, Raquel; Xue, Tian; Weeks, Mike; Turner, Mark S; Bansal, Nidhi

2016-01-18

Whey is a valuable co-product from cheese making that serves as a raw material for a wide range of products. Its rich nutritional content lends itself to rapid spoilage, thus it typically needs to be pasteurised and refrigerated promptly. Despite the extensive literature on milk spoilage bacteria, little is known about the spoilage bacteria of whey. The utility of carbon dioxide (CO2) to extend the shelf-life of raw milk and cottage cheese has been well established, but its application in whey preservation has not yet been explored. This study aims to characterise the microbial populations of fresh and spoiled sweet whey by culture-independent community profiling using 454 pyrosequencing of 16S rRNA gene amplicons and to determine whether carbonation is effective in inhibiting bacterial growth in sweet whey. The microbiota of raw Cheddar and Mozzarella whey was dominated by cheese starter bacteria. After pasteurisation, two out of the three samples studied became dominated by diverse environmental bacteria from various phyla, with Proteobacteria being the most dominant. Diverse microbial profiles were maintained until spoilage occurred, when the entire population was dominated by just one or two genera. Whey spoilage bacteria were found to be similar to those of milk. Pasteurised Cheddar and Mozzarella whey was spoiled by Bacillus sp. or Pseudomonas sp., and raw Mozzarella whey was spoiled by Pseudomonas sp., Serratia sp., and other members of the Enterobacteriaceae family. CO2 was effective in inhibiting bacterial growth of pasteurised Cheddar and Mozzarella whey stored at 15°C and raw Mozzarella whey stored at 4°C. The spoilage bacteria of the carbonated samples were similar to those of the non-carbonated controls. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of the lactoperoxidase system on Listeria monocytogenes behavior in raw milk at refrigeration temperatures.

PubMed Central

Gaya, P; Medina, M; Nuñez, M

1991-01-01

Activity of raw milk lactoperoxidase-thiocyanate-hydrogen peroxide (LP) system on four Listeria monocytogenes strains at refrigeration temperatures after addition of 0.25 mM sodium thiocyanate and 0.25 mM hydrogen peroxide was studied. The LP system exhibited a bactericidal activity against L. monocytogenes at 4 and 8 degrees C; the activity was dependent on temperature, length of incubation, and strain of L. monocytogenes tested. D values in activated-LP system milk for the four strains tested ranged from 4.1 to 11.2 days at 4 degrees C and from 4.4 to 9.7 days at 8 degrees C. The lactoperoxidase level in raw milk declined during a 7-day incubation, the decrease being more pronounced at 8 degrees C than at 4 degrees C and in control milk than in activated-LP system milk. The thiocyanate concentration decreased considerably in activated-LP system milk at both temperatures during the first 8 h of incubation. LP system activation was shown to be a feasible procedure for controlling development of L. monocytogenes in raw milk at refrigeration temperatures. PMID:1781693

Protect Your Unborn Baby or Newborn from Infections

MedlinePlus

... following these guidelines: Avoid eating cheese made from raw (unpasteurized) milk. Soft cheeses made with pasteurized milk, including commercial ... Listeria during processing. This could occur again. Avoid raw (unpasteurized) milk and products made from it, such as cheese, ...

Methionine sulfoxide profiling of milk proteins to assess the influence of lipids on protein oxidation in milk.

PubMed

Wüst, Johannes; Pischetsrieder, Monika

2016-06-15

Thermal treatment of milk and milk products leads to protein oxidation, mainly the formation of methionine sulfoxide. Reactive oxygen species, responsible for the oxidation, can be generated by Maillard reaction, autoxidation of sugars, or lipid peroxidation. The present study investigated the influence of milk fat on methionine oxidation in milk. For this purpose, quantitative methionine sulfoxide profiling of all ten methionine residues of β-lactoglobulin, α-lactalbumin, and αs1-casein was carried out by ultrahigh-performance liquid chromatography-electrospray ionization tandem mass spectrometry with scheduled multiple reaction monitoring (UHPLC-ESI-MS/MS-sMRM). Analysis of defatted and regular raw milk samples after heating for up to 8 min at 120 °C and analysis of ultrahigh-temperature milk samples with 0.1%, 1.5%, and 3.5% fat revealed that methionine oxidation of the five residues of the whey proteins and of residues M 123, M 135, and M 196 of αs1-casein was not affected or even suppressed in the presence of milk fat. Only the oxidation of residues M 54 and M 60 of αs1-casein was promoted by lipids. In evaporated milk samples, formation of methionine sulfoxide was hardly influenced by the fat content of the samples. Thus, it can be concluded that lipid oxidation products are not the major cause of methionine oxidation in milk.

Validation of a liquid chromatography-electrospray ionization tandem mass spectrometric method to determine six polyether ionophores in raw, UHT, pasteurized and powdered milk.

PubMed

Pereira, Mararlene Ulberg; Spisso, Bernardete Ferraz; Jacob, Silvana do Couto; Monteiro, Mychelle Alves; Ferreira, Rosana Gomes; Carlos, Betânia de Souza; da Nóbrega, Armi Wanderley

2016-04-01

This study aimed to validate a method developed for the determination of six antibiotics from the polyether ionophore class (lasalocid, maduramicin, monensin, narasin, salinomycin and semduramicin) at residue levels in raw, UHT, pasteurized and powdered milk using QuEChERS extraction and high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The validation was conducted under an in-house laboratory protocol that is primarily based on 2002/657/EC Decision, but takes in account the variability of matrix sources. Overall recoveries between 93% and 113% with relative standard deviations up to 16% were obtained under intermediate precision conditions. CCα calculated values did not exceed 20% the Maximum Residue Limit for monensin and 25% the Maximum Levels for all other substances. The method showed to be simple, fast and suitable for verifying the compliance of raw and processed milk samples regarding the limits recommended by Codex Alimentarius and those adopted in European Community for polyether ionophores. Copyright © 2015 Elsevier Ltd. All rights reserved.

Longevity of Mycobacterium bovis in Raw and Traditional Souring Milk as a Function of Storage Temperature and Dose

PubMed Central

Hlokwe, Tiny; Raseleka, Keneilwe; Getz, Wayne M.; Marcotty, Tanguy

2015-01-01

Background Unpasteurised fresh and souring dairy products form an essential component of household diets throughout many rural communities in southern Africa. The presence of milk-borne zoonotic pathogens such as Mycobacterium bovis (M. bovis), the causative agent of bovine tuberculosis and zoonotic tuberculosis in humans, constitute a public health threat, especially in remote areas with poor disease surveillance in livestock and highly compromised human health due to HIV/AIDS. Methods In this study we used culture to determine the longevity of M. bovis in experimentally inoculated fresh and naturally souring milk obtained from communal cattle in the KwaZulu-Natal province of South Africa. The effect of bacterial load and storage temperature on the survival of M. bovis was evaluated by spiking mixtures of fresh milk and starter soured milk (aMasi) culture with three concentrations of bacteria (102, 104, 107 colony forming units/ml), followed by incubation under controlled laboratory conditions that mimicked ambient indoor (20°C) and outdoor (33°C) temperatures and periodic sampling and testing over time (0-56 days). Results M. bovis cultured from samples of the fresh and souring milk was identified by PCR analysis. At the highest spiking concentration (107cfu/ml), M. bovis survived for at least 2 weeks at 20°C; but, at all concentrations in the 33°C treatment, M. bovis was absent by three days after inoculation. Logistic regression analysis was used to assess the effects of bacterial concentration and time since inoculation, as well as determine the potential half-life of M. bovis in raw souring milk. Given the most favourable tested conditions for bacterial survival (20°C), approximately 25% of mycobacteria were alive after one day of storage (95% CI: 9-53%), giving an estimated half-life of M. bovis in raw souring milk of approximately 12 hours (95% CI: 7-27 hours). Conclusions This study demonstrates that M. bovis may survive in fresh and souring milk for periods of time that represent a risk of exposure to people consuming these products, as well as domestic or wild animal populations that have reported opportunities to consume homemade unpasteurised dairy products. The temperature at which the milk is soured and stored substantially affects the survival time of M. bovis. PMID:26121261

Total tract nutrient digestion and milk fatty acid profile of dairy cows fed diets containing different levels of whole raw soya beans.

PubMed

Venturelli, B C; de Freitas Júnior, J E; Takiya, C S; de Araújo, A P C; Santos, M C B; Calomeni, G D; Gardinal, R; Vendramini, T H A; Rennó, F P

2015-12-01

Whole oilseeds such as soya beans have been utilized in dairy rations to supply additional fat and protein. However, antinutritional components contained in soya beans, such as trypsin inhibitors and haemagglutinins (lectins) may alter digestibility of nutrients and consequently affect animal performance. The objective of the present experiment was to quantify the effect of different levels of whole raw soya beans in diets of dairy cows on nutrient intake, total tract digestion, nutrient balances and milk yield and composition. Sixteen mid to late-lactation cows (228 ± 20 days in milk; mean ± SD) were used in four replicated 4 × 4 Latin square design experiment with 21-d periods. Cows were assigned to each square according to milk yield and DIM. The animals were randomly allocated to treatments: control (without soya beans addition; CO), WS9, WS18 and WS27, with addition of 9%, 18% and 27% of whole raw soya bean in diet on a dry matter (DM) basis respectively. All diets contained identical forage and concentrate components and consisted of maize silage and concentrate based on ground corn and soya beans at a ratio of 60:40. There were no differences in OM, CP, NDF and NEL intakes (kg/day and MJ/day) among the treatments (p > 0.05). However, DM and NFC intakes were negatively affected (p = 0.04 and p < 0.01, respectively) and ether extract (EE) intake was positively affected (p < 0.01). Total tract digestion increased linearly with whole raw soya beans for EE (p < 0.01) and NDF (p = 0.01). The excretion (kg/day) of digested soya beans grains increased linearly according to addition of whole raw soya beans. However, the nutritive characteristics of excreted grains were not altered. Milk (kg), milk lactose (kg) and protein (kg) yield decreased linearly (p < 0.01, p < 0.01 and p = 0.04, respectively) milk fat content (%) increased linearly (p < 0.01) with whole raw soya beans inclusion. Increasing addition of whole raw soya beans affected milk fatty acid profile with a linear decrease of cis-9-trans 11CLA and total saturated FA; and linear increase of total unsaturated and C18:3 FA. Energy balance was positively affected (p = 0.03) by whole raw soya beans as well as efficiency of NEL milk/DE intake (p = 0.02). Nitrogen balance and microbial protein synthesis were not affected by whole raw soya beans. Increasing doses of whole raw soya beans decreased dry matter intake and milk yield, however, led to an increase of unsaturated acids in milk and higher milk fat concentration. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

The Brucellosis Eradication Program in Texas

DTIC Science & Technology

1983-09-01

humans acquire the disease from infected animals or dnimal by-products, such as milk , cheese and other dairy products. Texas initiated a brucellosis...that tests composite raw milk samples from dairies to detect infected herds. ELISA - Enzyme Linked Immunosorbent Assay. A highly sensitive laboratory...concerned about the disease brucellosis because it is truly a zoonotic disease. Control of the disease therefore, depends primarily on elimination of the

Validation of the BetaStar® Advanced for Beta-lactams Test Kit for the Screening of Bulk Tank and Tanker Truck Milks for the Presence of Beta-lactam Drug Residues.

PubMed

Denhartigh, Andrew; Reynolds, Lindsay; Palmer, Katherine; Klein, Frank; Rice, Jennifer; Rejman, John J

2018-05-18

A validation study was conducted for an immunochromatographic method (BetaStar ® Advanced for Beta-lactams) for the detection of beta-lactam residues in raw, commingled bovine milk. The assay detected amoxicillin, ampicillin, cloxacillin, penicillin, cephapirin, and ceftiofur below the U.S. Food and Drug Administration tolerance levels but above the maximum sensitivity thresholds established by the National Conference on Interstate Milk Shipments. The results of internal and independent laboratory dose-response studies employing spiked samples were in agreement. The test detected all six drugs at the approximate 90/95% sensitivity levels in milk from cows treated with each drug. Selectivity of the assay was 100%, as no false-positive results were obtained in testing 1148 control milk samples. Testing the estimated 90/95% sensitivity level for amoxicillin (8.5 ppb), ampicillin (6.9 ppb), cloxacillin (8.9 ppb), penicillin (4.2 ppb), and cephapirin (17.6 ppb), and at 100 ppb for each antibiotic, resulted in 94-100% positive tests for each of the beta-lactam drugs. The results of ruggedness experiments established the operating parameter tolerances for the assay. Cross-reactivity testing established that the assay detects other certain beta-lactam drugs, but it does not cross-react with any of 30 drugs belonging to seven different drug classes. Abnormally high bacterial or somatic cell counts in raw milk produced no assay interference.

OXA-48 and CTX-M-15 extended-spectrum beta-lactamases in raw milk in Lebanon: epidemic spread of dominant Klebsiella pneumoniae clones.

PubMed

Diab, Mohamad; Hamze, Monzer; Bonnet, Richard; Saras, Estelle; Madec, Jean-Yves; Haenni, Marisa

2017-11-01

Raw milk has recently been reported as a source of extended-spectrum beta-lactamase (ESBL) and carbapenemase genes. We thus investigated the prevalence of ESBL- and carbapenemase-producing Enterobacteriaceae in raw milk in Lebanon in order to assess the risk of transfer of these bacteria to humans. A high prevalence (30.2 %) of CTX-M-15-producing K. pneumoniae was detected in raw bovine milk. Three main K. pneumoniae clones were identified by PFGE and MLST typing. Southern blot experiments revealed that one of these clones carried the blaCTX-M-15 gene chromosomally. Moreover, one OXA-48-producing K. pneumoniae ST530 and seven CTX-M-15-producing Escherichia coli sharing the same ST were also detected. These findings highlight the spread of dominant CTX-M-15-producing K. pneumoniae clones and OXA-48-producing isolates in the food chain. Milk, which is mostly consumed raw in Lebanon, may be a source of human exposure to ESBLs and carbapenemases.

Multivariate Optimization for Extraction of Pyrethroids in Milk and Validation for GC-ECD and CG-MS/MS Analysis

PubMed Central

Zanchetti Meneghini, Leonardo; Rübensam, Gabriel; Claudino Bica, Vinicius; Ceccon, Amanda; Barreto, Fabiano; Flores Ferrão, Marco; Bergold, Ana Maria

2014-01-01

A simple and inexpensive method based on solvent extraction followed by low temperature clean-up was applied for determination of seven pyrethroids residues in bovine raw milk using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) and gas chromatography with electron-capture detector (GC-ECD). Sample extraction procedure was established through the evaluation of seven different extraction protocols, evaluated in terms of analyte recovery and cleanup efficiency. Sample preparation optimization was based on Doehlert design using fifteen runs with three different variables. Response surface methodologies and polynomial analysis were used to define the best extraction conditions. Method validation was carried out based on SANCO guide parameters and assessed by multivariate analysis. Method performance was considered satisfactory since mean recoveries were between 87% and 101% for three distinct concentrations. Accuracy and precision were lower than ±20%, and led to no significant differences (p < 0.05) between results obtained by GC-ECD and GC-MS/MS techniques. The method has been applied to routine analysis for determination of pyrethroid residues in bovine raw milk in the Brazilian National Residue Control Plan since 2013, in which a total of 50 samples were analyzed. PMID:25380457

Determination of fat and total protein content in milk using conventional digital imaging.

PubMed

Kucheryavskiy, Sergey; Melenteva, Anastasiia; Bogomolov, Andrey

2014-04-01

The applicability of conventional digital imaging to quantitative determination of fat and total protein in cow's milk, based on the phenomenon of light scatter, has been proved. A new algorithm for extracting features from digital images of milk samples has been developed. The algorithm takes into account spatial distribution of light, diffusely transmitted through a sample. The proposed method has been tested on two sample sets prepared from industrial raw milk standards, with variable fat and protein content. Partial Least-Squares (PLS) regression on the features calculated from images of monochromatically illuminated milk samples resulted in models with high prediction performance when analysed the sets separately (best models with cross-validated R(2)=0.974 for protein and R(2)=0.973 for fat content). However when analysed the sets jointly with the obtained results were significantly worse (best models with cross-validated R(2)=0.890 for fat content and R(2)=0.720 for protein content). The results have been compared with previously published Vis/SW-NIR spectroscopic study of similar samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Transformation of serum-susceptible Escherichia coli O111 with p16Slux plasmid to allow for real-time monitoring of complement-based inactivation of bacterial growth in bovine milk.

PubMed

Maye, S; Stanton, C; Fitzgerald, G F; Kelly, P M

2016-01-01

Complement activity has only recently been characterized in raw bovine milk. However, the activity of this component of the innate immune system was found to diminish as milk was subjected to heat or partitioning during cream separation. Detection of complement in milk relies on a bactericidal assay. This assay exploits the specific growth susceptibility of Escherichia coli O111 to the presence of complement. Practical application of the assay was demonstrated when a reduction in complement activity was recorded in the case of pasteurized and reduced-fat milks. This presented an opportunity to improve the functionality of the bactericidal assay by incorporating bioluminescence capability into the target organism. Following some adaptation, the strain was transformed by correctly integrating the p16Slux plasmid. Growth properties of the transformed strain of E. coli O111 were unaffected by the modification. The efficacy of the strain adaptation was correlated using the LINEST function analysis [r=0.966; standard error of prediction (SEy)=0.957] bioluminescence with that of bactericidal assay total plate counts within the range of 7.5 to 9.2 log cfu/mL using a combination of raw and processed milk samples. Importantly, the transformed E. coli O111 p16Slux strain could be identified in milk and broth samples using bioluminescence measurement, thus enabling the bactericidal assay-viability test to be monitored in real time throughout incubation. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

7 CFR 58.439 - Cheese from unpasteurized milk.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Cheese from unpasteurized milk. 58.439 Section 58.439... Procedures § 58.439 Cheese from unpasteurized milk. If the cheese is labeled as “heat treated”, “unpasteurized,” “raw milk”, or “for manufacturing” the milk may be raw or heated at temperatures below...

7 CFR 58.439 - Cheese from unpasteurized milk.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Cheese from unpasteurized milk. 58.439 Section 58.439... Procedures § 58.439 Cheese from unpasteurized milk. If the cheese is labeled as “heat treated”, “unpasteurized,” “raw milk”, or “for manufacturing” the milk may be raw or heated at temperatures below...

7 CFR 58.439 - Cheese from unpasteurized milk.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Cheese from unpasteurized milk. 58.439 Section 58.439... Procedures § 58.439 Cheese from unpasteurized milk. If the cheese is labeled as “heat treated”, “unpasteurized,” “raw milk”, or “for manufacturing” the milk may be raw or heated at temperatures below...

Determination of protein concentration in raw milk by mid-infrared fourier transform infrared/attenuated total reflectance spectroscopy.

PubMed

Etzion, Y; Linker, R; Cogan, U; Shmulevich, I

2004-09-01

This study investigates the potential use of attenuated total reflectance spectroscopy in the mid-infrared range for determining protein concentration in raw cow milk. The determination of protein concentration is based on the characteristic absorbance of milk proteins, which includes 2 absorbance bands in the 1500 to 1700 cm(-1) range, known as the amide I and amide II bands, and absorbance in the 1060 to 1100 cm(-1) range, which is associated with phosphate groups covalently bound to casein proteins. To minimize the influence of the strong water band (centered around 1640 cm(-1)) that overlaps with the amide I and amide II bands, an optimized automatic procedure for accurate water subtraction was applied. Following water subtraction, the spectra were analyzed by 3 methods, namely simple band integration, partial least squares (PLS) and neural networks. For the neural network models, the spectra were first decomposed by principal component analysis (PCA), and the neural network inputs were the spectra principal components scores. In addition, the concentrations of 2 constituents expected to interact with the protein (i.e., fat and lactose) were also used as inputs. These approaches were tested with 235 spectra of standardized raw milk samples, corresponding to 26 protein concentrations in the 2.47 to 3.90% (weight per volume) range. The simple integration method led to very poor results, whereas PLS resulted in prediction errors of about 0.22% protein. The neural network approach led to prediction errors of 0.20% protein when based on PCA scores only, and 0.08% protein when lactose and fat concentrations were also included in the model. These results indicate the potential usefulness of Fourier transform infrared/attenuated total reflectance spectroscopy for rapid, possibly online, determination of protein concentration in raw milk.

Can farm milk consumption prevent allergic diseases?

PubMed

Braun-Fahrländer, C; von Mutius, E

2011-01-01

Cow's milk is an important part of human diet and a source of food allergy for some individuals. Medical guidance strongly discourages consumption of raw milk because of the known health risk associated with pathogenic bacteria present in unpasteurized milk. Despite these risks there is a growing body of epidemiological evidence suggesting that consumption of unprocessed cow's milk does not increase but rather decreases the risk of asthma, hay fever and atopic sensitisation. The article reviews the epidemiological literature and discusses components of unprocessed milk potentially responsible for this protection. It focuses on the role of bacteria in raw milk, the fatty acid profile, whey proteins and finally the role of allergens in milk. Although the epidemiological evidence consistently suggest a protective role of unprocessed cow's milk consumption on the development of asthma, hay fever and atopic sensitization the underlying mechanisms are not yet understood and the consumption of raw milk cannot be recommended as a preventive measure for allergic diseases. © 2010 Blackwell Publishing Ltd.

Occurrence and quantification of Shiga toxin-producing Escherichia coli from food matrices

PubMed Central

Sethulekshmi, C.; Latha, C.; Anu, C. J.

2018-01-01

Aim: The objective of the study was to detect Shiga toxin-producing Escherichia coli (STEC) and develop a quantitative polymerase chain reaction (qPCR) assay to quantify the bacterial DNA present in different food matrices. Materials and Methods: A total of 758 samples were collected during a period from January 2015 to December 2016 from Kozhikode, Thrissur, and Alappuzha districts of Kerala. The samples consisted of raw milk (135), pasteurized milk (100), beef (132), buffalo meat (130), chevon (104), beef kheema (115), and beef sausage (42). All the samples collected were subjected to isolation and identification of STEC by conventional culture technique. Confirmation of virulence genes was carried out using PCR. For the quantification of STEC in different food matrices, a qPCR was standardized against stx1 gene of STEC by the construction of standard curve using SYBR green chemistry. Results: The overall occurrence of STEC in raw milk (n=135), beef (n=132), buffalo meat (n=130), chevon (n=104), and beef kheema (n=115) samples collected from Kozhikode, Thrissur, and Alappuzha districts of Kerala was 19.26%, 41.6%, 16.92%, 28.85%, and 41.74%, respectively. PCR revealed the presence of stx 1 and stx 2 genes in 88.46 and 83.64 and 30.77 and 40.00% of STEC isolates from raw milk and beef samples, respectively, while 100% of the STEC isolates from buffalo beef and beef kheema samples carried stx 1 gene. Real-time qPCR assay was used to quantify the bacterial cells present in different food matrices. The standard curve was developed, and the slopes, intercept, and R2 of linear regression curves were −3.10, 34.24, and 0.99, respectively. Conclusion: The considerably high occurrence of STEC in the study confirms the importance of foods of animal origin as a vehicle of infection to humans. In the present study, on comparing the overall occurrence of STEC, the highest percentage of occurrence was reported in beef kheema samples. The study shows the need for rigid food safety measures to combat the potential pathogenic effects of harmful bacteria throughout the production chain from production to consumption. PMID:29657388

Biodiversity of antifungal lactic acid bacteria isolated from raw milk samples from cow, ewe and goat over one-year period.

PubMed

Delavenne, E; Mounier, J; Déniel, F; Barbier, G; Le Blay, G

2012-04-16

Antifungal lactic acid bacteria (ALAB) biodiversity was evaluated in raw milk from ewe, cow and goat over one year period. Lactic acid bacteria were enumerated using 8 semi-selective media, and systematically screened for their antifungal activity against 4 spoilage fungi commonly encountered in dairy products. Depending on the selective medium, between 0.05% (Elliker agar) and 5.5% (LAMVAB agar) screened colonies showed an antifungal activity. The great majority of these active colonies originated from cow (49%) and goat (43%) milks, whereas only 8% were isolated from ewe milk. Penicillium expansum was the most frequently inhibited fungus with 48.5% of colonies active against P. expansum among the 1235 isolated, followed by Mucor plumbeus with 30.6% of active colonies, Kluyveromyces lactis with only 12.1% of active colonies and Pichia anomala with 8.7% of active colonies. In the tested conditions, 94% of the sequenced active colonies belonged to Lactobacillus. Among them, targeted fungal species differed according to the Lactobacillus group, whose presence largely depended on year period and milk origin. The Lb. casei and Lb. reuteri groups, predominantly recovered in summer/fall, were overrepresented in the population targeting M. plumbeus, whereas isolates from the Lb. plantarum group, predominantly recovered in spring, were overrepresented in the population targeting K. lactis, the ones belonging to the Lb. buchneri group, predominantly recovered in spring, were overrepresented in the population targeting P. anomala. Raw milk, especially cow and goat milks from the summer/fall period appeared to be a productive reservoir for antifungal lactobacilli. Copyright © 2012 Elsevier B.V. All rights reserved.

Analysis of 27 antibiotic residues in raw cow's milk and milk-based products--validation of Delvotest® T.

PubMed

Bion, Cindy; Beck Henzelin, Andrea; Qu, Yajuan; Pizzocri, Giuseppe; Bolzoni, Giuseppe; Buffoli, Elena

2016-01-01

Delvotest® T was evaluated for its capability at detecting residues of 27 antibiotics in raw cow's milk and in some dairy ingredients (skimmed and full-cream milk powders). The kit was used as a screening tool for the qualitative determination of antibiotics from different families in a single test. Results delivered by such a method are expressed as 'positive' or 'negative', referring to the claimed screening target concentration (STC). Validation was conducted according to the European Community Reference Laboratories' (CRLs) residues guidelines of 20 January 2010 and performed by two laboratories, one located in Europe and the other in Asia. Five criteria were evaluated including detection capability at STC, false-positive (FP) rate, false-negative (FN) rate, robustness and cross-reactivity using visual reading and Delvoscan®. STCs were set at or below the corresponding maximum residue limit (MRL), as fixed by European Regulation EC No. 37/2010. Four antibiotics (nafcillin, oxytetracycline, tetracycline and rifaximin) out of 27 had a false-negative rate ranging from 1.7% to 4.9%; however, it was still compliant with the CRLs' requirements. Globally, Delvotest T can be recommended for the analysis of the surveyed antibiotics in raw cow's milk, skimmed and full-cream milk powders. Additional compounds were tested such as sulfamethazine, spiramycin and erythromycin; however, detection at the corresponding MRL was not achievable and these compounds were removed from the validation. Other drugs from the sulfonamide, aminoglycoside or macrolide families not detected by the test at the MRL were not evaluated in this study. Regarding the reliability of this rapid test to milk-based preparations, additional experiments should be performed on a larger range of compounds and samples to validate the Delvotest T in such matrices.

Formation of Kokumi-Enhancing γ-Glutamyl Dipeptides in Parmesan Cheese by Means of γ-Glutamyltransferase Activity and Stable Isotope Double-Labeling Studies.

PubMed

Hillmann, Hedda; Behr, Jürgen; Ehrmann, Matthias A; Vogel, Rudi F; Hofmann, Thomas

2016-03-02

Recently, γ-glutamyl dipeptides (γ-GPs) were found to be responsible for the attractive kokumi flavor of Parmesan cheese (PC). Quantitation of γ-GPs and their parent amino acids in 13-, 24-, and 30-month ripened PC samples by LC-MS/MS and stable isotope dilution analysis (SIDA), in-cheese (13)C-labeling studies, followed by analysis of the γ-glutamyl transferase (GGT) activity revealed γ-GPs to be generated most efficiently after 24 months of ripening by a GGT-catalyzed transfer of the γ-glutamyl moiety of L-glutamine onto various acceptor amino acids released upon casein proteolysis. Following the identification of milk as a potential GGT source in PC, the functionality of the milk's GGT to generate the target γ-GPs was validated by stable isotope double-labeling (SIDL) experiments. Therefore, raw and heat-treated milk samples were incubated with L-glutamine-[U-(13)C] and acceptor amino acids (X) and the hetero- (γ-Glu-[(13)C5]-X) and homotranspeptidation products (γ-Glu-Gln-[(13)C10]) were quantitated by LC-MS/MS-SIDA using γ-Glu-Ala-[(13)C3] as the internal standard. High GGT activity to generate the γ-GPs and preference for L-phenylalanine and L-methionine as acceptor amino acids were found in raw milk and milk samples heat-treated for 10 min up to a maximum of 65 °C. In comparison, GGT activity and SIDL studies performed with inoculated Lactobacillus strains, including Lactobacillus harbinensis and Lactobacillus casei identified in PC by means of 16S rRNA gene sequencing, did not show any significant GGT activity and unequivocally demonstrated unpasteurized cow's milk, rather than microorganisms, as a key factor in γ-glutamyl dipeptide generation in Parmesan cheese.

Influence of pulsed electric field treatments on the volatile compounds of milk in comparison with pasteurized processing.

PubMed

Zhang, Sha; Yang, Ruijin; Zhao, Wei; Hua, Xiao; Zhang, Wenbin; Zhang, Zhong

2011-01-01

Effects of pulsed electric field (PEF) treatments on the volatile profiles of milk were studied and compared with pasteurized treatment of high temperature short time (HTST) (75 °C, 15 s). Volatile compounds were extracted by solid-phase micro-extraction (SPME) and identified by gas chromatography/mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). A total of 37 volatile compounds were determined by GC-MS, and 19 volatile compounds were considered to be major contributors to the characteristic flavor of milk samples. PEF treatment resulted in an increase in aldehydes. Milk treated with PEF at 30 kV/cm showed the highest content of pentanal, hexanal, and nonanal, while heptanal and decanal contents were lower than in pasteurized milk, but higher than in raw milk. All the methyl ketones detected in PEF milk were lower than in pasteurized milk. No significant differences in acids (acetic acid, butanoic acid, hexanoic acid, octanoic acid, and decanoic acid), lactones, and alcohols were observed between pasteurized and PEF-treated samples; however, 2(5H)-furanone was only detected in PEF-treated milk. Although GC-MS results showed that there were some volatile differences between pasteurized and PEF-treated milk, GC-O data showed no significant difference between the 2 samples.

A case of sporadic ovine mastitis caused by Listeria monocytogenes and its effect on contamination of raw milk and raw-milk cheeses produced in the on-farm dairy.

PubMed

Schoder, Dagmar; Winter, Petra; Kareem, Abdoulla; Baumgartner, Walter; Wagner, Martin

2003-11-01

We describe a case of listerial mastitis in a flock of 130 sheep. The animals were housed at a farm where the bulk raw ewe milk was processed to produce raw milk soft cheese. List. monocytogenes was shed from the right mammary complex. Shedding was observed over a period of 99 d. A mean level of 4-56 x 10(4) cfu (colony forming units) Listeria monocytogenes/ml was recovered from the raw milk originating from the infected udder. The numbers ranged from 9 x10(1) to 2.95 x 10(5). The bulk milk was contaminated by approx. 5.7 x 10(3) cfu/ml. In the cheese product, 2.0 x 10(2) cfu List. monocytogenes/g were constantly detectable for a period of 7 d post manufacture. The starter culture used for coagulation had a pivotal influence on the behaviour of List. monocytogenes during cheesemaking. Using the same mesophilic buttermilk culture as used by the farmer allowed numbers of Listeria to increase 60-fold within 12 h owing to a delayed acidification of the bulk milk. Addition of a thermophilic yogurt culture reduced the numbers of Listeria within 8 h of incubation.

Consensus categorization of cheese based on water activity and pH-A rational approach to systemizing cheese diversity.

PubMed

Trmčić, A; Ralyea, R; Meunier-Goddik, L; Donnelly, C; Glass, K; D'Amico, D; Meredith, E; Kehler, M; Tranchina, N; McCue, C; Wiedmann, M

2017-01-01

Development of science-based interventions in raw milk cheese production is challenging due to the large diversity of production procedures and final products. Without an agreed upon categorization scheme, science-based food safety evaluations and validation of preventive controls would have to be completed separately on each individual cheese product, which is not feasible considering the large diversity of products and the typically small scale of production. Thus, a need exists to systematically group raw milk cheeses into logically agreed upon categories to be used for food safety evaluations. This paper proposes and outlines one such categorization scheme that provides for 30 general categories of cheese. As a base for this systematization and categorization of raw milk cheese, we used Table B of the US Food and Drug Administration's 2013 Food Code, which represents the interaction of pH and water activity for control of vegetative cells and spores in non-heat-treated food. Building on this table, we defined a set of more granular pH and water activity categories to better represent the pH and water activity range of different raw milk cheeses. The resulting categorization scheme was effectively validated using pH and water activity values determined for 273 different cheese samples collected in the marketplace throughout New York State, indicating the distribution of commercially available cheeses among the categories proposed here. This consensus categorization of cheese provides a foundation for a feasible approach to developing science-based solutions to assure compliance of the cheese processors with food safety regulations, such as those required by the US Food Safety Modernization Act. The key purpose of the cheese categorization proposed here is to facilitate product assessment for food safety risks and provide scientifically validated guidance on effective interventions for general cheese categories. Once preventive controls for a given category have been defined, these categories would represent safe havens for cheesemakers, which would allow cheesemakers to safely and legally produce raw milk cheeses that meet appropriate science-based safety requirements (e.g., risk to human health equivalent to pasteurized milk cheeses). Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effects of seasonal changes in feeding management under part-time grazing on the evolution of the composition and coagulation properties of raw milk from ewes.

PubMed

Abilleira, E; Virto, M; Nájera, A I; Salmerón, J; Albisu, M; Pérez-Elortondo, F J; Ruiz de Gordoa, J C; de Renobales, M; Barron, L J R

2010-09-01

Ewe raw milk composition, rennet coagulation parameters, and curd texture were monitored throughout the milk production season in 11 commercial flocks reared under a part-time grazing system. Milking season lasted from February to July. During that period, the diet of the animals shifted from indoor feeding, consisting of concentrate and forage, to an outdoor grazing diet. Lean dry matter, fat, protein, calcium, and magnesium contents increased throughout the milking season, as did rennet coagulation time, curd firmness, and curd resistance to compression. However, lean dry matter, protein content, and curd resistance to compression stabilized when sheep started to graze. Principal component analysis correlated curd resistance to compression and proteins, whereas curd firmness was highly correlated with fat content and minerals. Discriminant analysis distributed milk samples according to the feeding management. Curd firmness, fat, and magnesium turned out to be discriminant variables. Those variables reflected the evolution of the composition and coagulation parameters when fresh pasture prevailed over other feeds in the diet of the flocks. The present study shows that seasonal changes associated with feeding management influence milk technological quality and that milk of good processing quality can be obtained under part-time grazing. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Protocol for diversion of confirmed positive bulk raw milk tankers to calf ranches - A review of the Pharmacokinetics of tetracyclines and sulfonamides in veal calves.

PubMed

DeDonder, K D; Gehring, R; Tell, L A; Riviere, J E

2016-12-01

The tetracyclines (TTC) and sulfonamides are among the most common residues found in bulk raw milk samples. Detection of drug residues in bulk milk (BM) tankers demonstrates that the product is not suitable for human consumption. Discarding BM with residue-contaminated milk is a waste of a valuable commodity, and a repurposing for consumption at calf ranches is a way to recapture some value. However, if calves consuming milk with drug residues are slaughtered for veal, their meat could contain drug residues. The objective of this review is to provide a residue avoidance strategy for TTC and sulfonamide residues in veal. To determine the pharmacokinetic properties of each drug a structured review of the literature was performed and the study inclusion criteria were that the publication used dairy breed calves, with body weight <330 kg or <6 months of age. The most pertinent parameters were determined to be plasma, tissue elimination half-lives, and systemic bioavailability. The results of this review were integrated with milk and tissue testing levels of quantification and tissue tolerances to formulate a recommended withdrawal interval for calves ingesting this milk. The suggested withdrawal interval of 20 days will ensure that no veal calves will test positive for residues from being fed this milk.

Enhanced Control of Listeria monocytogenes by Enterococcus faecium KE82, a Multiple Enterocin-Producing Strain, in Different Milk Environments.

PubMed

Vandera, Elpiniki; Lianou, Alexandra; Kakouri, Athanasia; Feng, Jinbo; Koukkou, Anna-Irini; Samelis, John

2017-01-01

Enterococcus faecium KE82, isolated from traditional Greek Graviera cheese, was identified in pure broth cultures in vitro as a multiple enterocin-producing bacterial strain possessing the structural entA, entB, and entP enterocin genes. E. faecium KE82 was further assessed for in situ antilisterial activity in raw milk (RM) and commercially thermized milk (TM; 63°C for 30 s) in the presence of the indigenous microbiota and in sterile raw milk (SRM; 121°C for 5 min) with or without the addition of two commercial starter culture (CSC) strains Streptococcus thermophilus and Lactococcus lactis . Growth of Listeria monocytogenes was completely inhibited in RM incubated at 37°C for 6 h, whereas the pathogen was significantly inactivated in RM+KE82 samples during further incubation at 18°C for 66 h. In contrast, L. monocytogenes levels increased by approximately 2 log CFU/ml in TM, but in TM+KE82 samples, pathogen growth was retarded during the first 6 h at 37°C followed by growth cessation and partial inactivation at 18°C. After 48 to 72 h, growth of L. monocytogenes in SRM+CSC samples decreased by 4 to 5 log CFU/ml compared with the SRM control, whereas additional 10-fold decreases in the pathogen were observed in SRM+CSC+KE82 samples. Reverse transcription PCR analysis of SRM+KE82 and SRM+CSC+KE82 samples confirmed that the entA and entB genes were transcribed, but entP gene transcription was not detected. All RM and SRM samples inoculated with E. faecium KE82 displayed strong in situ inhibitory activity against L. monocytogenes in well diffusion bioassays, whereas activity was weaker to undetectable in comparable or additional TM+KE82 samples; no milk sample without E. faecium KE82 had activity against L. monocytogenes . The findings of this study indicate that E. faecium KE82 is an antilisterial agent that could be used in traditional dairy foods because it concomitantly produces enterocins A and B in situ in milk.

The prevalence of aflatoxin M1 in milk of Middle East region: A systematic review, meta-analysis and probabilistic health risk assessment.

PubMed

Rahmani, Jamal; Alipour, Solmaz; Miri, Ali; Fakhri, Yadolah; Riahi, Seyed-Mohammad; Keramati, Hassan; Moradi, Masoud; Amanidaz, Nazak; Pouya, Rokhsane Hosseini; Bahmani, Zohreh; Mousavi Khaneghah, Amin

2018-06-15

The current investigation was undertaken to take a review of the performed studies regarding the concentration and prevalence of aflatoxin M 1 (AFM 1 ) of the consumed cow milk in the Middle East. In this context, all available studies published in databases include Science Direct, PubMed, Scopus, and Web of Science among 1995 to December 2017; were screened accordingly. Also, the carcinogenic risk was estimated by calculating hazard index (HI) using the Monte Carlo simulation (MCS). The result of conducted meta-analysis for 49 articles containing 7484 data indicated that the rank order of type of milk based on the concentration of aflatoxin M 1 was Ultra-high temperature processing (UHT) milk (82.57 ng/kg) > raw milk (60.37 ng/kg) > pasteurized milk (PAS) (45.81 ng/kg). The pooled concentration of aflatoxin M 1 in raw and UHT milk was higher than EC (European Committee, 50 ng/kg) standard limit. The rank order of countries based on the concentration of aflatoxin M 1 in raw milk was Syria > Turkey > Iran > Egypt > Lebanon > Palestine; pasteurized milk, Turkey > Iran > Lebanon; and UHT milk, Iran > Turkey > Saudi Arabia. The overall prevalence of aflatoxin M 1 in the raw milk of Iran, Turkey, Lebanon, Palestine, Egypt, and Syria was identified as 76%, 12%, 67%, 85%, 38%, and 14%; pasteurized milk, in the Iran, Lebanon, and Turkey was 77%, 36%, and 11%; and finally UHT milk in Iran, Saudi Arabia, and Turkey was 81%, 82%, and 62%, respectively. HI in the adult's consumer's raw milk in the Iran, Turkey, Syria, Palestine, Lebanon, and Egypt were calculated as 0.26, 0.47, 0.52, 0.34, 0.23 and 0.18; However, the HI for adult consumers of pasteurized milk in the Iran, Turkey, and Lebanon were 0.28, 0.31 and 0.11. Also, the measured HI for adult consumers of UHT milk in the Saudi Arabia, Turkey, and Iran was 0.20, 0.33 and 0.50, respectively. The obtained HI for consumers of raw milk in the children age group of the Iran, Turkey, Syria, Palestine, Lebanon, and Egypt were 1.03,2.20, 2.42, 1.59, 1.05, and 0.84. The calculated HI for consumers of pasteurized milk in the children age group of the pasteurized milk in of Iran, Turkey, and Lebanon were 1.30, 1.56, and 0.50. Finally, in term of UHT milk in Saudi Arabia, Turkey, and Iran were 0.94, 1.44 and 2.35, respectively. Unlike Adults, children consumers in the several Middle East countries are at considerable cancer risk due to consumption of raw, pasteurized and UHT milk contain AFM 1 (HI > 1). Copyright © 2018 Elsevier Ltd. All rights reserved.

Bioavailability of Fe and Zn in selected legumes, cereals, meat and milk products consumed in Fiji.

PubMed

Singh, Poonam; Prasad, Surendra; Aalbersberg, William

2016-09-15

The present study reports contents and the bioavailability of Fe and Zn from 25 selected raw and cooked food samples. The results showed highest variation of Fe content in raw food samples ranging from 2.19 ± 0.04 to 0.93 ± 0.03 mg/100g in legumes. The raw black eye bean, cheese and fish showed high Zn content up to 8.85 ± 0.01, 12.93 ± 0.26 and 172.03 ± 5.09 mg/100g, respectively. Pulses and cereals showed high level of ionizable Fe. Zn bioavailability was quite low in cereals as compared to pulses; 4.02% in yellow split to 17.40% in Bengal gram. Zn bioavailability of 17.40% is in cheese. Fe bioavailability is high in cooked rice 160.60%, white bread 428.30% and milk powder 241.67% showing that Fe bioavailability increased after cooking whereas the lowest in fish 0.84%. The multivariate and cluster analysis categorized studied foods into two main groups. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tick-borne Encephalitis Associated with Consumption of Raw Goat Milk, Slovenia, 2012

PubMed Central

Hudopisk, Neda; Korva, Miša; Janet, Evgen; Simetinger, Marjana; Grgič-Vitek, Marta; Gubenšek, Jakob; Natek, Vladimir; Kraigher, Alenka; Strle, Franc

2013-01-01

Tick-borne encephalitis (TBE) developed in 3 persons in Slovenia who drank raw milk; a fourth person, who had been vaccinated against TBE, remained healthy. TBE virus RNA was detected in serum and milk of the source goat. Persons in TBE-endemic areas should be encouraged to drink only boiled/pasteurized milk and to be vaccinated. PMID:23697658

[Effect of freezing on the "creamatocrit" measurement of the lipid content of human donor milk].

PubMed

Vázquez-Román, S; Alonso-Díaz, C; García-Lara, N R; Escuder-Vieco, D; Pallás-Alonso, C R

2014-09-01

To determine, by the creamatocrit measurement, the effect on the fat content of raw and pasteurized donor milk of freezing during 3 months at -20 °C. The evolution of the creamatocrit measurement (following Lucas technique) on frozen (-20 °C), raw and pasteurized human milk, was analyzed during 3 months. The fat content of raw milk (n=44) was 3.19 g/dl at the beginning and 2.86 g/dl after 3 months frozen (p=0.02). In pasteurized milk (n=36) fat content at the first determination was 2.59 g/dl and 2.20 g/dl after 1 month frozen (p=0.01). Afterwards there were no significant changes up to 3 months frozen. Variability was observed in the intermediate values. A reduction on the fat content measurement of raw and pasteurized donor human milk after freezing was observed. Freezing does not inactivate the milk lipase but does destroy the fat globule. Creamatocrit measurement may not be the best method to determine the fat content of processed human milk. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Evaluation of the repeatability of a crude adult indirect Ostertagia ostertagi ELISA and methods of expressing test results.

PubMed

Sanchez, J; Dohoo, I R; Markham, F; Leslie, K; Conboy, G

2002-10-16

An indirect enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against Ostertagia ostertagi using a crude adult worm antigen was evaluated using serum and milk samples from adult cows, as well as from bulk tank milk. Within and between plate repeatabilities were determined. In addition, the effects of factors such as antigen batch, freezing, preserving of the samples and somatic cell counts (SCCs) of the samples were evaluated. Raw optical densities (ODs) and normalized values were compared using the concordance correlation coefficient (CCC), the coefficient of variation (CV), Bland-Altman plots (BA). Based on raw OD values, there was a high repeatability within a plate (CCC approximately 0.96 and CV<10%). Repeatability between plates was evaluated following normalization of OD values by four methods. Computing normalized values as (OD-Nt)/(Pst-Nt), gave the most repeatable results, with the CCC being approximately 0.95 and the CV approximately 11%. When the OD values were higher than 1.2 and 0.3 for the positive and the negative controls, respectively, none of the normalization methods evaluated provided highly repeatable results and it was necessary to repeat the test. Two batches of the crude antigen preparation were evaluated for repeatability, and no difference was found (CCC=0.96). The use of preservative (bronopol) did not affect test results, nor did freezing the samples for up to 8 months. A significant positive relationship between ELISA OD for milk samples and SCC score was found. Therefore, the use of composite milk samples, which have less variable SCC than samples taken from each quarter, would be more suitable when the udder health status is unknown. The analytical methods used to evaluate repeatability provided a practical way to select among normalization procedures.

Trace elements in raw milk of buffaloes (Bubalus bubalis) from Campania, Italy.

PubMed

Esposito, Mauro; Miedico, Oto; Cavallo, Stefania; Pellicanò, Roberta; Rosato, Guido; Baldi, Loredana; Chiaravalle, A Eugenio

2017-10-15

The profile of 18 trace elements was traced in 68 milk samples collected from buffalo farms in the territory known as the "Land of Fires" in the Campania region (Italy). This area has been polluted by the illegal dumping in fields of industrial or domestic waste, wich is sometimes then burned spreading toxic contaminants. Milk from buffaloes raised on rural farms might be a good indicator of environmental contamination risk in the human food chain. Trace element analysis in milk was performed using mass spectrometry. One milk sample was found to be non-compliant due to high Pb concentration. In the absence of threshold values for the elements, established through legislation, the results were compared with similar studies from other countries, and in most cases the content determined in this study was in agreement with values reported elsewhere and do not represent a risk to human health. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Persistent Isolation of Salmonella typhimurium from the Mammary Gland of a Dairy Cow

PubMed Central

Ogilvie, Timothy H.

1986-01-01

The contamination of cheese by Salmonella typhimurium serotype 10 resulted in the bacteriological examination of raw milk from 327 farms on Prince Edward Island. A milk sample from a bulk tank from one farm was positive for this pathogen. The possible source was linked to the isolation of the strain from the milk from one quarter of one cow. Although the cow was asymptomatic for any clinical illness other than a chronic staphylococcal mastitis in two quarters, the animal continued to shed Salmonella in the milk during a 36 day period. Necropsy failed to reveal a source of the infection. PMID:17422692

Evaluation of a microbiological indicator test for antibiotic detection in ewe and goat milk.

PubMed

Comunian, R; Paba, A; Dupré, I; Daga, E S; Scintu, M F

2010-12-01

Antibiotics are widely used for therapeutic and prophylactic purposes in dairy animals. The presence of residual antibiotics in milk could cause potentially serious problems in human health and have technological implication in the manufacturing of dairy products. The aim of this study was to evaluate Delvotest Accelerator (DSM Food Specialties, Delft, the Netherlands), a new system for a fully automated microbial test to detect antibiotic residues in ewe and goat milk. Forty-three samples of raw, whole, refrigerated bulk-tank milk samples (22 of ewe milk and 21 of goat milk) were analyzed during the whole lactation period. Four concentrations of 4 antibiotics were diluted in milk: penicillin G at 1, 2, 3, and 4 μg/L; sulfadiazine at 25, 50, 100, and 200 μg/L; tetracycline at 50, 100, 200, and 400 μg/L; and gentamicin at 25, 50, 100, and 200 μg/L. The detection limit of the Delvotest Accelerator was calculated as the range of antibiotic concentrations within which 95% of positive result lie. The range of detection limit of penicillin G and sulfadiazine was easily detected by Delvotest Accelerator at or below the European Union maximum residue limits, both for ewe and goat milk samples. In contrast, the system showed a lower ability to detect tetracycline and gentamicin both for ewe and goat milk samples. Very low percentages of false-positive outcomes were obtained. Lactation phase did not seem to be a crucial factor affecting the ability of the Delvotest Accelerator to detect spiked milk samples. A higher detection ability was observed for goat milk samples compared with ewe milk samples. A negative correlation between the percentage of positive milk samples detected and milk fat, protein, and lactose contents was observed for gentamicin only. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

A systematic review and meta-analysis of the effects of pasteurization on milk vitamins, and evidence for raw milk consumption and other health-related outcomes.

PubMed

Macdonald, Lauren E; Brett, James; Kelton, David; Majowicz, Shannon E; Snedeker, Kate; Sargeant, Jan M

2011-11-01

Pasteurization of milk ensures safety for human consumption by reducing the number of viable pathogenic bacteria. Although the public health benefits of pasteurization are well established, pro-raw milk advocate organizations continue to promote raw milk as "nature's perfect food." Advocacy groups' claims include statements that pasteurization destroys important vitamins and that raw milk consumption can prevent and treat allergies, cancer, and lactose intolerance. A systematic review and meta-analysis was completed to summarize available evidence for these selected claims. Forty studies assessing the effects of pasteurization on vitamin levels were found. Qualitatively, vitamins B12 and E decreased following pasteurization, and vitamin A increased. Random effects meta-analysis revealed no significant effect of pasteurization on vitamin B6 concentrations (standardized mean difference [SMD], -2.66; 95% confidence interval [CI], -5.40, 0.8; P = 0.06) but a decrease in concentrations of vitamins B1 (SMD, -1.77; 95% CI, -2.57, -0.96; P < 0.001), B2 (SMD, -0.41; 95% CI, -0.81, -0.01; P < 0.05), C (SMD, -2.13; 95% CI, -3.52, -0.74; P < 0.01), and folate (SMD, -11.99; 95% CI, -20.95, -3.03; P < 0.01). The effect of pasteurization on milk's nutritive value was minimal because many of these vitamins are naturally found in relatively low levels. However, milk is an important dietary source of vitamin B2, and the impact of heat treatment should be further considered. Raw milk consumption may have a protective association with allergy development (six studies), although this relationship may be potentially confounded by other farming-related factors. Raw milk consumption was not associated with cancer (two studies) or lactose intolerance (one study). Overall, these findings should be interpreted with caution given the poor quality of reported methodology in many of the included studies.

Field findings about milk ethanol stability: a first report of interrelationship between α-lactalbumin and lactose.

PubMed

Fagnani, Rafael; de Araújo, João Paulo Andrade; Botaro, Bruno Garcia

2018-05-01

Milk ethanol stability is not only associated with microbiological acidification, but is a phenomenon with many variables that influence the balance of soluble salts, mainly calcium ion activity. On this basis, we wanted to find out more about milk ethanol stability by studying its relationship with milk protein fractions and others major components. The influence of milk composition on ethanol stability was assessed through a predictive model comprising 180 individual raw milk samples. An additional model was used to assess the ethanol stability status as a response to the proteins fractions quantified by electrophoresis. Of the total samples, 68% were classified as stable and 32% as unstable to alcohol. Milk ethanol instability increased at low values of lactose content and high values of ash percentage. α-Lactalbumin (α-La) was also associated with ethanol stability, and the higher the α-La percentage the lower were the chances of ethanol instability. The lower values of α-La in unstable milk samples might be related to lower content of lactose, as α-La promotes lactose synthesis, a key component for the osmotic balance of milk and thus its ethanol stability. This is the first field report linking ethanol stability indirectly with α-La. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Effect of raw soya bean particle size on productive performance and digestion of dairy cows.

PubMed

Naves, A B; Freitas Júnior, J E; Barletta, R V; Gandra, J R; Calomeni, G D; Gardinal, R; Takiya, C S; Vendramini, T H A; Mingoti, R D; Rennó, F P

2016-08-01

Differing soya bean particle sizes may affect productive performance and ruminal fermentation due to the level of fatty acid (FA) exposure of the cotyledon in soya bean grain and because the protein in small particles is more rapidly degraded than the protein in large particles, which influence ruminal fibre digestion and the amounts of ruminally undegradable nutrients. The objective of this experiment was to investigate the effects of raw soya bean particle size on productive performance, digestion and milk FA profile of dairy cows. Twelve Holstein cows were assigned to three 4 × 4 Latin squares with 21-day periods. At the start of the experiment, cows were 121 days in milk (DIM) and yielded 30.2 kg/day of milk. Cows were fed 4 diets: (i) control diet (CO), without raw soya bean; (ii) whole raw soya bean (WRS); (iii) cracked raw soya bean in Wiley mill 4-mm screen (CS4); and (iv) cracked raw soya bean in Wiley mill 2-mm screen (CS2). The inclusion of soya beans (whole or cracked) was 200 g/kg on dry matter (DM) basis and partially replaced ground corn and soya bean meal. Uncorrected milk yield and composition were not influenced by experimental diets; however, fat-corrected milk (FCM) decreased when cows were fed soya bean treatments. Soya bean diets increased the intake of ether extract (EE) and net energy of lactation (NEL ), and decreased the intake of DM and non-fibre carbohydrate (NFC). Ruminal propionate concentration was lower in cows fed WRS than cows fed CS2 or CS4. Cows fed cracked raw soya bean presented lower nitrogen in faeces than cows fed WRS. The milk of cows fed WRS, CS2 and CS4 presented higher unsaturated FA than cows fed CO. The addition of raw soya bean in cow diets, regardless of the particle size, did not impair uncorrected milk yield and nutrient digestion, and increased the concentration of unsaturated FA in milk. Cows fed cracked raw soya bean presented similar productive performance to cows fed whole raw soya bean. Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.

Rapid discrimination between buffalo and cow milk and detection of adulteration of buffalo milk with cow milk using synchronous fluorescence spectroscopy in combination with multivariate methods.

PubMed

Durakli Velioglu, Serap; Ercioglu, Elif; Boyaci, Ismail Hakki

2017-05-01

This research paper describes the potential of synchronous fluorescence (SF) spectroscopy for authentication of buffalo milk, a favourable raw material in the production of some premium dairy products. Buffalo milk is subjected to fraudulent activities like many other high priced foodstuffs. The current methods widely used for the detection of adulteration of buffalo milk have various disadvantages making them unattractive for routine analysis. Thus, the aim of the present study was to assess the potential of SF spectroscopy in combination with multivariate methods for rapid discrimination between buffalo and cow milk and detection of the adulteration of buffalo milk with cow milk. SF spectra of cow and buffalo milk samples were recorded between 400-550 nm excitation range with Δλ of 10-100 nm, in steps of 10 nm. The data obtained for ∆λ = 10 nm were utilised to classify the samples using principal component analysis (PCA), and detect the adulteration level of buffalo milk with cow milk using partial least square (PLS) methods. Successful discrimination of samples and detection of adulteration of buffalo milk with limit of detection value (LOD) of 6% are achieved with the models having root mean square error of calibration (RMSEC) and the root mean square error of cross-validation (RMSECV) and root mean square error of prediction (RMSEP) values of 2, 7, and 4%, respectively. The results reveal the potential of SF spectroscopy for rapid authentication of buffalo milk.

An overview of molecular stress response mechanisms in Escherichia coli contributing to survival of Shiga toxin-producing Escherichia coli during raw milk cheese production.

PubMed

Peng, Silvio; Tasara, Taurai; Hummerjohann, Jörg; Stephan, Roger

2011-05-01

The ability of foodborne pathogens to survive in certain foods mainly depends on stress response mechanisms. Insight into molecular properties enabling pathogenic bacteria to survive in food is valuable for improvement of the control of pathogens during food processing. Raw milk cheeses are a potential source for human infections with Shiga toxin-producing Escherichia coli (STEC). In this review, we focused on the stress response mechanisms important for allowing STEC to survive raw milk cheese production processes. The major components and regulation pathways for general, acid, osmotic, and heat shock stress responses in E. coli and the implications of these responses for the survival of STEC in raw milk cheeses are discussed.

Characterization of Escherichia coli and other Enterobacteriaceae in producer-distributor bulk milk.

PubMed

Ntuli, V; Njage, P M K; Buys, E M

2016-12-01

The current study was undertaken to characterize Escherichia coli and other Enterobacteriaceae in raw and pasteurized producer-distributor bulk milk (PDBM). A total of 258 samples were collected from purchase points in 8 provinces in South Africa. The samples were tested for antibiotic residues, phosphatase, total aerobic bacteria, coliforms, and E. coli counts. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used for identification of isolates. Escherichia coli isolates were characterized for virulence factors, antimicrobial resistance, serotypes, and presumptive E. coli O157:H7. Antibiotic residues and alkaline phosphatase were detected in 2% of both raw and pasteurized PDBM (n=258) and 21% pasteurized PDBM (n=104) samples, respectively. A total of 729 isolates belonging to 21 genera and 59 species were identified. Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, and Raoultella ornithinolytica were the most abundant species. Spoilage Enterobacteriaceae species exceeded 50% of the total isolates. Escherichia coli was detected and isolated from 36% of the milk samples. Thirty-one E. coli isolates harbored virulence genes stx1/stx2 and 38% (n=121) were presumptive O157:H7. The prevalence of samples with presumptive shigatoxin producing E. coli was 10%. Antimicrobial-resistant E. coli isolates were detected in 70% of the milk samples with 36% of stx1/stx2 positive E. coli showing multi-drug resistance. Information obtained from the study will be used for modeling the public health risk posed by milkborne pathogens in PDBM, which in many cases is consumed by poor and vulnerable members of the population. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Organochlorine pesticide residues in bovine milk from organic farms in Chiapas, Mexico.

PubMed

Gutiérrez, Rey; Ruíz, Jorge Luis; Ortiz, Rutilio; Vega, Salvador; Schettino, Beatriz; Yamazaki, Alberto; de Lourdes Ramírez, María

2012-10-01

Thirty six samples of bovine milk were collected from Chiapas State, Mexico between January 2011 and December 2011 with the intention of identifying and quantifying organochlorine pesticide residues in organic farms. The analyses were done using gas chromatography with an electron capture detector (Ni(63)). In general the values found in raw milk were lower than the permissible limit proposed by FAO/WHO/Codex Alimentarius 2006. Average concentrations for alpha + beta HCH were 3.62 ng/g, gamma HCH 0.34 ng/g, heptachlor + epoxide 0.67 ng/g, DDT and isomers 1.53 ng/g, aldrin + dieldrin 0.77 ng/g, and endrin 0.66 ng/g (only present in samples from farm 2). The organic milk from Chiapas has shown low concentrations of pesticide residues in recent years and satisfies international and national regulations for commercialization.

Characterization of casein phosphopeptides from fermented milk products.

PubMed

Kawahara, Takeshi; Aruga, Kaori; Otani, Hajime

2005-10-01

This study dealt with the potential of fermented milk products as a source of functional casein phosphopeptides (CPPs) using plain yogurts and Camembert cheeses. The CPPs were prepared by tryptic digestion from four commercially available plain yogurts (P1-P4), five Camembert cheeses (C1-C5), and raw milk. From portions with a 1-g protein content of the plain yogurts, the Camembert cheeses, and the raw milk, 171 mg, 139 mg, and 146 mg of CPPs were obtained, respectively. The Camembert cheeses retained high amounts of organic phosphorus (32 microg) per 1 mg CPPs compared to the raw milk (15 microg) and plain yogurts (16 microg). Reverse-phase high-performance liquid chromatographic analysis showed that the elution patterns and retention times of the three major peaks of CPPs from P1 and C1 were similar to those from raw milk. Moreover, CPPs from P1 and C1 showed a mitogenic effect, while CPPs from C1 showed an IgA-enhancing effect in mouse spleen cell cultures. These results suggest that fermented milk products such as plain yogurts and Camembert cheeses generate functional CPPs in the body and exert beneficial effects on the immune system.

7 CFR 58.132 - Basis for classification.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Milk § 58.132 Basis for classification. The quality classification of raw milk for manufacturing...

7 CFR 58.132 - Basis for classification.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Milk § 58.132 Basis for classification. The quality classification of raw milk for manufacturing...

Novel sensitive monoclonal antibody based competitive enzyme-linked immunosorbent assay for the detection of raw and processed bovine beta-casein

PubMed Central

Castillo, Daniela S.

2017-01-01

Cow milk protein allergy (CMPA) is the most common childhood food allergy, which can sometimes persist or can newly develop in adulthood with severe symptoms. CMPA's treatment is complete dietary avoidance of milk proteins. To achieve this task, patients have to be aware of milk proteins found as "hidden allergens" in food commodities. In regard to milk proteins, it has been reported that allergenicity of caseins remains unaffected upon heat treatment. For these reasons, we aimed to obtain monoclonal antibodies (mAbs) against native and denatured β-casein, one of the most abundant and antigenic caseins, in order to develop an indirect competitive ELISA (icELISA) to detect and quantify traces of this milk allergen in raw and processed foodstuffs. We developed two specific hybridoma clones, 1H3 and 6A12, which recognized β-casein in its denatured and native conformations by indirect ELISA (iELISA). Cross-reaction analysis by Western blot and iELISA indicated that these mAbs specifically recognized β-casein from bovine and goat milk extracts, while they did not cross-react with proteins present in other food matrixes. These highly specific mAbs enabled the development of sensitive, reliable and reproducible icELISAs to detect and quantify this milk protein allergen in food commodities. The extraction of β-casein from foodstuff was efficiently carried out at 60°C for 15 minutes, using an extraction buffer containing 1% SDS. The present study establishes a valid 1H3 based-icELISA, which allows the detection and quantification -0.29 ppm and 0.80 ppm, respectively- of small amounts of β-casein in raw and processed foods. Furthermore, we were able to detect milk contamination in incurred food samples with the same sensitivity as a commercial sandwich ELISA thus showing that this icELISA constitutes a reliable analytical method for control strategies in food industry and allergy prevention. PMID:28759641

Novel sensitive monoclonal antibody based competitive enzyme-linked immunosorbent assay for the detection of raw and processed bovine beta-casein.

PubMed

Castillo, Daniela S; Cassola, Alejandro

2017-01-01

Cow milk protein allergy (CMPA) is the most common childhood food allergy, which can sometimes persist or can newly develop in adulthood with severe symptoms. CMPA's treatment is complete dietary avoidance of milk proteins. To achieve this task, patients have to be aware of milk proteins found as "hidden allergens" in food commodities. In regard to milk proteins, it has been reported that allergenicity of caseins remains unaffected upon heat treatment. For these reasons, we aimed to obtain monoclonal antibodies (mAbs) against native and denatured β-casein, one of the most abundant and antigenic caseins, in order to develop an indirect competitive ELISA (icELISA) to detect and quantify traces of this milk allergen in raw and processed foodstuffs. We developed two specific hybridoma clones, 1H3 and 6A12, which recognized β-casein in its denatured and native conformations by indirect ELISA (iELISA). Cross-reaction analysis by Western blot and iELISA indicated that these mAbs specifically recognized β-casein from bovine and goat milk extracts, while they did not cross-react with proteins present in other food matrixes. These highly specific mAbs enabled the development of sensitive, reliable and reproducible icELISAs to detect and quantify this milk protein allergen in food commodities. The extraction of β-casein from foodstuff was efficiently carried out at 60°C for 15 minutes, using an extraction buffer containing 1% SDS. The present study establishes a valid 1H3 based-icELISA, which allows the detection and quantification -0.29 ppm and 0.80 ppm, respectively- of small amounts of β-casein in raw and processed foods. Furthermore, we were able to detect milk contamination in incurred food samples with the same sensitivity as a commercial sandwich ELISA thus showing that this icELISA constitutes a reliable analytical method for control strategies in food industry and allergy prevention.

Proteolysis produced within biofilms of bacterial isolates from raw milk tankers.

PubMed

Teh, Koon Hoong; Flint, Steve; Palmer, Jon; Andrewes, Paul; Bremer, Phil; Lindsay, Denise

2012-06-15

In this study, six bacterial isolates that produced thermo-resistant enzymes isolated from the internal surfaces of raw milk tankers were evaluated for their ability to produce proteolysis within either single culture biofilms or co-culture biofilms. Biofilms were formed in an in vitro model system that simulated the upper internal surface of a raw milk tanker during a typical summer's day of milk collection in New Zealand. The bacterial isolates were further evaluated for their ability to form biofilms at 25, 30 and 37°C. Mutual and competitive effects were observed in some of the co-culture biofilms, with all isolates being able to form biofilms in either single culture or co-culture at the three temperatures. The proteolysis was also evaluated in both biofilms and corresponding planktonic cultures. The proteolysis per cell decreased as the temperature of incubation (20-37°C) increased. Furthermore, mutualistic interactions in terms of proteolysis were observed when cultures were grown as co-culture biofilms. This is the first study to show that proteolytic enzymes can be produced in biofilms on the internal surfaces of raw milk tankers. This has important implications for the cleaning and the temperature control of raw milk transport tankers. Copyright © 2012 Elsevier B.V. All rights reserved.

Listeria Infections

MedlinePlus

... systems. To reduce your risk Use precooked and ready-to-eat foods as soon as you can Avoid raw milk and raw milk products Heat ready-to-eat foods and leftovers until they are steaming hot Wash ...

7 CFR 58.143 - Raw product storage.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Raw product storage. 58.143 Section 58.143 Agriculture... Procedures § 58.143 Raw product storage. (a) All milk shall be held and processed under conditions and at... source shall not be used for the manufacture of dairy products. Bulk milk in storage tanks within the...

7 CFR 58.143 - Raw product storage.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Raw product storage. 58.143 Section 58.143 Agriculture... Procedures § 58.143 Raw product storage. (a) All milk shall be held and processed under conditions and at... source shall not be used for the manufacture of dairy products. Bulk milk in storage tanks within the...

Which factors in raw cow's milk contribute to protection against allergies?

PubMed

van Neerven, R J Joost; Knol, Edward F; Heck, Jeroen M L; Savelkoul, Huub F J

2012-10-01

Several epidemiologic studies have shown that growing up in a farming environment is associated with a decreased risk of allergies. A factor that correlates strongly with this effect is the early ingestion of unheated cow's milk. Although, to date, no controlled studies on raw milk consumption have been performed to formally demonstrate this effect, several factors in bovine milk have been described that might explain how raw cow's milk consumption can decrease the risk of allergies. In addition, increasing knowledge on the immunologically active factors in breast milk have also contributed to our understanding of the effects of bovine milk in infants because many of the factors in bovine milk are expected to have functional effects in human subjects as well. Here we review these factors and their mechanisms of action and compare their presence in bovine milk and breast milk. A better understanding of these factors, as well as how to retain them, might ultimately lead to the development of mildly processed milk and infant nutrition products that could become a part of preventive strategies to reduce the incidence of allergic disease. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

[Yeast microbiota in artisanal cheeses from Corrientes, Argentina].

PubMed

Cardozo, Marina C; Fusco, Ángel J V; Carrasco, Marta S

The artisanal cheese from Corrientes (from the Spanish acronym QAC-Queso Artesanal de Corrientes/Artisanal Cheese from Corrientes) is a soft cheese elaborated with raw cow milk and an artisanal coagulant agent. Lactic bacteria contitute the main flora of this cheese although yeasts are also present in high quantities as secondary microbiota and might play a relevant role in cheese ripening. The aim of this work was to evaluate yeast occurrence during QAC elaboration and ripening, and the effect of seasonal variation. Yeasts were isolated and purified from raw materials and cheese at different ripening stagesl elaborated during the different seasons. Yeast sample counts were in the order of 10 3 - 10 7 UFC/ml o UFC/g. Ninety yeast strains were classified: 9 from milk, 28 from the coagulant agent, 10 from curd and 43 from cheese. Candida predominated in milk samples while other yeast genera had low incidence. Candida also predominated in the coagulant agent samples, followed by genera Myxozyma and Debaryomyces. The isolates obtained from cheese belonged to the same genera predominating in the coagulant agent, and showed the same order of prevalence. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Cow’s Milk and Immune Function in the Respiratory Tract: Potential Mechanisms

PubMed Central

Perdijk, Olaf; van Splunter, Marloes; Savelkoul, Huub F. J.; Brugman, Sylvia; van Neerven, R. J. Joost

2018-01-01

During the last decades, the world has witnessed a dramatic increase in allergy prevalence. Epidemiological evidence shows that growing up on a farm is a protective factor, which is partly explained by the consumption of raw cow’s milk. Indeed, recent studies show inverse associations between raw cow’s milk consumption in early life and asthma, hay fever, and rhinitis. A similar association of raw cow’s milk consumption with respiratory tract infections is recently found. In line with these findings, controlled studies in infants with milk components such as lactoferrin, milk fat globule membrane, and colostrum IgG have shown to reduce respiratory infections. However, for ethical reasons, it is not possible to conduct controlled studies with raw cow’s milk in infants, so formal proof is lacking to date. Because viral respiratory tract infections and aeroallergen exposure in children may be causally linked to the development of asthma, it is of interest to investigate whether cow’s milk components can modulate human immune function in the respiratory tract and via which mechanisms. Inhaled allergens and viruses trigger local immune responses in the upper airways in both nasal and oral lymphoid tissue. The components present in raw cow’s milk are able to promote a local microenvironment in which mucosal immune responses are modified and the epithelial barrier is enforced. In addition, such responses may also be triggered in the gut after exposure to allergens and viruses in the nasal cavity that become available in the GI tract after swallowing. However, these immune cells that come into contact with cow’s milk components in the gut must recirculate into the blood and home to the (upper and lower) respiratory tract to regulate immune responses locally. Expression of the tissue homing-associated markers α4β7 and CCR9 or CCR10 on lymphocytes can be influenced by vitamin A and vitamin D3, respectively. Since both vitamins are present in milk, we speculate that raw milk may influence homing of lymphocytes to the upper respiratory tract. This review focuses on potential mechanisms via which cow’s milk or its components can influence immune function in the intestine and the upper respiratory tract. Unraveling these complex mechanisms may contribute to the development of novel dietary approaches in allergy and asthma prevention. PMID:29483908

Cow's Milk and Immune Function in the Respiratory Tract: Potential Mechanisms.

PubMed

Perdijk, Olaf; van Splunter, Marloes; Savelkoul, Huub F J; Brugman, Sylvia; van Neerven, R J Joost

2018-01-01

During the last decades, the world has witnessed a dramatic increase in allergy prevalence. Epidemiological evidence shows that growing up on a farm is a protective factor, which is partly explained by the consumption of raw cow's milk. Indeed, recent studies show inverse associations between raw cow's milk consumption in early life and asthma, hay fever, and rhinitis. A similar association of raw cow's milk consumption with respiratory tract infections is recently found. In line with these findings, controlled studies in infants with milk components such as lactoferrin, milk fat globule membrane, and colostrum IgG have shown to reduce respiratory infections. However, for ethical reasons, it is not possible to conduct controlled studies with raw cow's milk in infants, so formal proof is lacking to date. Because viral respiratory tract infections and aeroallergen exposure in children may be causally linked to the development of asthma, it is of interest to investigate whether cow's milk components can modulate human immune function in the respiratory tract and via which mechanisms. Inhaled allergens and viruses trigger local immune responses in the upper airways in both nasal and oral lymphoid tissue. The components present in raw cow's milk are able to promote a local microenvironment in which mucosal immune responses are modified and the epithelial barrier is enforced. In addition, such responses may also be triggered in the gut after exposure to allergens and viruses in the nasal cavity that become available in the GI tract after swallowing. However, these immune cells that come into contact with cow's milk components in the gut must recirculate into the blood and home to the (upper and lower) respiratory tract to regulate immune responses locally. Expression of the tissue homing-associated markers α4β7 and CCR9 or CCR10 on lymphocytes can be influenced by vitamin A and vitamin D3, respectively. Since both vitamins are present in milk, we speculate that raw milk may influence homing of lymphocytes to the upper respiratory tract. This review focuses on potential mechanisms via which cow's milk or its components can influence immune function in the intestine and the upper respiratory tract. Unraveling these complex mechanisms may contribute to the development of novel dietary approaches in allergy and asthma prevention.

Microflora associated with the internal surfaces of rubber and stainless steel milk transfer pipeline.

PubMed

Lewis, S J; Gilmour, A

1987-04-01

Sterile sections of rubber and stainless steel milk transfer pipeline were inserted sequentially into a milking installation and soiled with fresh raw milk over a period of 5 d. The resultant adherent microbial population was removed and the generic composition of mesophilic and psychotropic types was determined. In all cases Acinetobacter spp. were found to predominate (59.5-75.6%). The generic composition of the raw milk used to soil the milking unit (with inserted pipe section) was determined once during each 5-d soiling period. In general the milk was found to contain a mixed flora in which Gram-positive organisms predominated.

Encephalitozoon cuniculi in Raw Cow's Milk Remains Infectious After Pasteurization.

PubMed

Kváč, Martin; Tomanová, Vendula; Samková, Eva; Koubová, Jana; Kotková, Michaela; Hlásková, Lenka; McEvoy, John; Sak, Bohumil

2016-02-01

This study describes the prevalence of Encephalitozoon cuniculi in raw cow's milk and evaluates the effect of different milk pasteurization treatments on E. cuniculi infectivity for severe combined immunodeficient (SCID) mice. Using a nested polymerase chain reaction approach, 1 of 50 milking cows was found to repeatedly shed E. cuniculi in its feces and milk. Under experimental conditions, E. cuniculi spores in milk remained infective for SCID mice following pasteurization treatments at 72 °C for 15 s or 85 °C for 5 s. Based on these findings, pasteurized cow's milk should be considered a potential source of E. cuniculi infection in humans.

Spoilage of Microfiltered and Pasteurized Extended Shelf Life Milk Is Mainly Induced by Psychrotolerant Spore-Forming Bacteria that often Originate from Recontamination

PubMed Central

Doll, Etienne V.; Scherer, Siegfried; Wenning, Mareike

2017-01-01

Premature spoilage and varying product quality due to microbial contamination still constitute major problems in the production of microfiltered and pasteurized extended shelf life (ESL) milk. Spoilage-associated bacteria may enter the product either as part of the raw milk microbiota or as recontaminants in the dairy plant. To identify spoilage-inducing bacteria and their routes of entry, we analyzed end products for their predominant microbiota as well as the prevalence and biodiversity of psychrotolerant spores in bulk tank milk. Process analyses were performed to determine the removal of psychrotolerant spores at each production step. To detect transmission and recontamination events, strain typing was conducted with isolates obtained from all process stages. Microbial counts in 287 ESL milk packages at the end of shelf life were highly diverse ranging from <1 to 7.9 log cfu/mL. In total, 15% of samples were spoiled. High G+C Gram-positive bacteria were the most abundant taxonomic group, but were responsible for only 31% of spoilage. In contrast, psychrotolerant spores were isolated from 55% of spoiled packages. In 90% of samples with pure cultures of Bacillus cereus sensu lato and Paenibacillus spp., counts exceeded 6 log cfu/mL. In bulk tank milk, the concentration of psychrotolerant spores was low, accounting for merely 0.5 ± 0.8 MPN/mL. Paenibacillus amylolyticus/xylanexedens was by far the most dominant species in bulk tank milk (48% of all isolates), but was never detected in ESL milk, pointing to efficient removal during manufacturing. Six large-scale process analyses confirmed a high removal rate for psychrotolerant spores (reduction by nearly 4 log-units). B. cereus sensu lato, on the contrary, was frequently found in spoiled end products, but was rarely detected in bulk tank milk. Due to low counts in bulk tank samples and efficient spore removal during production, we suggest that shelf life is influenced only to a minor extent by raw-milk-associated factors. In contrast, recontamination with spores, particularly from the B. cereus complex, seems to occur. To enhance milk quality throughout the entire shelf life, improved plant sanitation and disinfection that target the elimination of spores are necessary. PMID:28197147

Spoilage of Microfiltered and Pasteurized Extended Shelf Life Milk Is Mainly Induced by Psychrotolerant Spore-Forming Bacteria that often Originate from Recontamination.

PubMed

Doll, Etienne V; Scherer, Siegfried; Wenning, Mareike

2017-01-01

Premature spoilage and varying product quality due to microbial contamination still constitute major problems in the production of microfiltered and pasteurized extended shelf life (ESL) milk. Spoilage-associated bacteria may enter the product either as part of the raw milk microbiota or as recontaminants in the dairy plant. To identify spoilage-inducing bacteria and their routes of entry, we analyzed end products for their predominant microbiota as well as the prevalence and biodiversity of psychrotolerant spores in bulk tank milk. Process analyses were performed to determine the removal of psychrotolerant spores at each production step. To detect transmission and recontamination events, strain typing was conducted with isolates obtained from all process stages. Microbial counts in 287 ESL milk packages at the end of shelf life were highly diverse ranging from <1 to 7.9 log cfu/mL. In total, 15% of samples were spoiled. High G+C Gram-positive bacteria were the most abundant taxonomic group, but were responsible for only 31% of spoilage. In contrast, psychrotolerant spores were isolated from 55% of spoiled packages. In 90% of samples with pure cultures of Bacillus cereus sensu lato and Paenibacillus spp., counts exceeded 6 log cfu/mL. In bulk tank milk, the concentration of psychrotolerant spores was low, accounting for merely 0.5 ± 0.8 MPN/mL. Paenibacillus amylolyticus/xylanexedens was by far the most dominant species in bulk tank milk (48% of all isolates), but was never detected in ESL milk, pointing to efficient removal during manufacturing. Six large-scale process analyses confirmed a high removal rate for psychrotolerant spores (reduction by nearly 4 log-units). B. cereus sensu lato, on the contrary, was frequently found in spoiled end products, but was rarely detected in bulk tank milk. Due to low counts in bulk tank samples and efficient spore removal during production, we suggest that shelf life is influenced only to a minor extent by raw-milk-associated factors. In contrast, recontamination with spores, particularly from the B. cereus complex, seems to occur. To enhance milk quality throughout the entire shelf life, improved plant sanitation and disinfection that target the elimination of spores are necessary.

A gel-based visual immunoassay for non-instrumental detection of chloramphenicol in food samples.

PubMed

Yuan, Meng; Sheng, Wei; Zhang, Yan; Wang, Junping; Yang, Yijin; Zhang, Shuguang; Goryacheva, Irina Yu; Wang, Shuo

2012-11-02

A gel-based non-instrumental immuno-affinity assay was developed for the rapid screening of chloramphenicol (CAP) in food samples with the limit of detection (LOD) of 1 μg L(-1). The immuno-affinity test column (IATC) consisted of a test layer containing anti-CAP antibody coupled gel, and a control layer with anti-HRP antibody coupled gel. Based on the direct competitive immuno-reaction and the horseradish peroxidase enzymatic reaction, the test results could be evaluated visually. Basically, blue color development represented the negative results, while the absence of color development represented the positive results. In this study, CAP spiked samples of raw milk, pasteurized milk, UHT milk, skimmed milk powder, acacia honey, date honey, fish and shrimp were tested. Little or none sample pretreatment was required for this assay. The whole procedure was completed within 10min. In conclusion, the gel-based immuno-affinity test is a simple, rapid, and promising on-site screening method for CAP residues in food samples, with no instrumental requirement. Copyright © 2012 Elsevier B.V. All rights reserved.

The impact of maternal- and neonatal-associated factors on human milk's macronutrients and energy.

PubMed

Dritsakou, Kalliopi; Liosis, Georgios; Valsami, Georgia; Polychronopoulos, Evangelos; Skouroliakou, Maria

2017-06-01

To test the impact of specific maternal- and neonatal-associated factors on human milk's macronutrients and energy. This study was conducted with the use of a human milk analyzer (HMA, MIRIS, Uppsala, Sweden). Six hundred and thirty samples of raw milk and 95 samples of donor pasteurized milk were delivered from a total of 305 mothers. A significant inverse correlation of fat, protein and energy content with gestational age and birth weight was established. Fat and energy were lower in colostrum, increased in transitional milk and decreased on the 30th day's mature milk compared to transitional. The rate of protein decline from colostrum to mature milk was lower in premature deliveries compared to that of full-terms, resulting in greater contents of protein in preterm mature milk. The upmost amounts of carbohydrates were found in mature milk of preterm deliveries. A positive correlation was found between maternal age and fat contents. In women with higher post-pregnancy BMI levels greater analogies of fat and energy were presented. In women suffering diet-controlled gestational diabetes (GD), lower protein and higher fat and energy levels were found. Prematurity, maternal age, diet-controlled GD and high post-pregnancy BMI levels were found to impose statistical significant effect on milk's macronutrients and energy.

Consumers' acceptance of innovations in traditional cheese. A comparative study in France and Norway.

PubMed

Almli, Valérie Lengard; Naes, Tormod; Enderli, Géraldine; Sulmont-Rossé, Claire; Issanchou, Sylvie; Hersleth, Margrethe

2011-08-01

This study explores consumers' acceptance of innovations in traditional cheese in France (n=120) and Norway (n=119). The respondents were presented with 16 photographs of a traditional cheese from their respective countries, varying according to six factors: pasteurisation, organic production, omega-3, packaging, price and appropriateness. For each of the scenarios the consumers indicated their willingness to buy the cheese on a nine-point scale. Results show that consumers' willingness to buy traditional cheese is highly driven by price, appropriateness and pasteurisation in both countries. However, on average consumers in the French sample prefer buying raw milk cheese, while consumers in the Norwegian sample prefer buying pasteurised cheese. These general trends are led by a pro-raw milk segment in France and a pro-pasteurised milk segment in Norway. Several interaction effects involving appropriateness are detected, indicating the importance of the consumption context on the acceptance of innovations in traditional cheese. On a general level, the results indicate that well-accepted innovations in traditional cheese are those that reinforce the traditional and authentic character of the product. Copyright © 2011 Elsevier Ltd. All rights reserved.

Sensitive determination of melamine in milk and powdered infant formula samples by high-performance liquid chromatography using dabsyl chloride derivatization followed by dispersive liquid-liquid microextraction.

PubMed

Faraji, M; Adeli, M

2017-04-15

A new and sensitive pre-column derivatization with dabsyl chloride followed by dispersive liquid-liquid microextraction was developed for the analysis of melamine (MEL) in raw milk and powdered infant formula samples by high performance liquid chromatography (HPLC) with visible detection. Derivatization with dabsyl chloride leads to improving sensitivity and hydrophobicity of MEL. Under optimum conditions of derivatization and microextraction steps, the method yielded a linear calibration curve ranging from 1.0 to 500μgL -1 with a determination coefficient (R 2 ) of 0.9995. Limit of detection and limit of quantification were 0.1 and 0.3μgL -1 , respectively. The relative standard deviation (RSD%) for intra-day (repeatability) and inter-day (reproducibility) at 25 and 100μgL -1 levels of MEL was less than 7.0% (n=6). Finally, the proposed method was successfully applied for the preconcentration and determination of MEL in different raw milk and powdered infant formula, and satisfactory results were obtained (relative recovery ⩾94%). Copyright © 2016 Elsevier Ltd. All rights reserved.

7 CFR 58.133 - Methods for quality and wholesomeness determination.

Code of Federal Regulations, 2010 CFR

2010-01-01

... and Grading Service 1 Quality Specifications for Raw Milk § 58.133 Methods for quality and wholesomeness determination. (a) Appearance and odor. The appearance of acceptable raw milk shall be normal and...

7 CFR 58.133 - Methods for quality and wholesomeness determination.

Code of Federal Regulations, 2011 CFR

2011-01-01

... and Grading Service 1 Quality Specifications for Raw Milk § 58.133 Methods for quality and wholesomeness determination. (a) Appearance and odor. The appearance of acceptable raw milk shall be normal and...

Food Safety and Raw Milk

MedlinePlus

... where raw milk is legal. “Getting back to nature” – that’s what many Americans are trying to do ... YouTube Instagram Listen Watch RSS ABOUT About CDC Jobs Funding LEGAL Policies Privacy FOIA No Fear Act ...

Aflatoxin Contamination in Food and Body Fluids in Relation to Malnutrition and Cancer Status in Cameroon

PubMed Central

Tchana, Angele N.; Moundipa, Paul F.; Tchouanguep, Félicité M.

2010-01-01

Aflatoxins are food contaminants usually associated with hepatitis, immunodepression, impairment of fertility and cancer. The present work was to determine the presence of aflatoxins in eggs, milk, urine, and blood samples that were collected from various sources and periods; and hepatitis B virus antigen in blood samples. Aflatoxin was found in eggs (45.2%), cow raw milk (15.9%), breast milk (4.8%), urine from kwashiorkor and marasmic kwashiorkor children (45.5%), and sera from primary liver cancer patients (63.9%); HbsAg was also detected in 69.4% of the serum samples, but there was no association between both factors. Both AF and hepatitis B virus seem to be risk factors that could increase the incidence and prevalence rates of malnutrition and cancer in Cameroon. PMID:20195440

On-line milk spectrometry: analysis of bovine milk composition

NASA Astrophysics Data System (ADS)

Spitzer, Kyle; Kuennemeyer, Rainer; Woolford, Murray; Claycomb, Rod

2005-04-01

We present partial least squares (PLS) regressions to predict the composition of raw, unhomogenised milk using visible to near infrared spectroscopy. A total of 370 milk samples from individual quarters were collected and analysed on-line by two low cost spectrometers in the wavelength ranges 380-1100 nm and 900-1700 nm. Samples were collected from 22 Friesian, 17 Jersey, 2 Ayrshire and 3 Friesian-Jersey crossbred cows over a period of 7 consecutive days. Transmission spectra were recorded in an inline flowcell through a 0.5 mm thick milk sample. PLS models, where wavelength selection was performed using iterative PLS, were developed for fat, protein, lactose, and somatic cell content. The root mean square error of prediction (and correlation coefficient) for the nir and visible spectrometers respectively were 0.70%(0.93) and 0.91%(0.91) for fat, 0.65%(0.5) and 0.47%(0.79) for protein, 0.36%(0.49) and 0.45%(0.43) for lactose, and 0.50(0.54) and 0.48(0.51) for log10 somatic cells.

Antibiotic residues in milk and eggs of commercial and local farms at Chittagong, Bangladesh.

PubMed

Chowdhury, Suchayan; Hassan, Mohammad Mahmudul; Alam, Mahabub; Sattar, Sarmina; Bari, Md Saiful; Saifuddin, A K M; Hoque, Md Ahasanul

2015-04-01

The study was conducted to detection and determination of concentration or level of antibiotic residues in milk and egg of local and commercial farms at Chittagong during December 2011 to June 2012. A total of 400 (200 milk and 200 egg) samples were collected from local and commercial dairy cows and local scavenging and commercial poultry farms, respectively. Microbial inhibition test and thin layer chromatography were used for screening and ultra-high performance liquid chromatography was used to estimate the concentrations of antibiotic residues in samples. Tetracycline, amoxicillin, and ciprofloxacin residues were significantly (p ≤ 0.05) higher in commercial farms than local. The boiling insignificantly (p>0.05) reduced residues level in milk and egg. The average concentrations of amoxicillin residue in local milk, commercial milk, local egg, and commercial egg were 9.84 µg/ml, 56.16 µg/ml, 10.46 µg/g and 48.82 µg/g, respectively, in raw samples and were reduced to 9.81 µg/ml, 55.54 µg/ml, 10.29 µg/g, and 48.38 µg/g, respectively, after boiling. Proper maintaining of the withdrawal period and development of active surveillance system are highly recommended for public health security.

Enterotoxin-producing Staphylococcus aureus genotype B as a major contaminant in Swiss raw milk cheese.

PubMed

Hummerjohann, J; Naskova, J; Baumgartner, A; Graber, H U

2014-03-01

The objective of this study was to characterize Staphylococcus aureus isolates from Swiss raw milk cheeses that had been found to be contaminated with coagulase-positive staphylococci and to estimate the frequency of the various genotypes, in particular the mastitis-associated Staph. aureus genotype B (GTB). The isolates were also tested for staphylococcal enterotoxin (SE) genes and other virulence factors. From 623 coagulase-positive staphylococci isolated from 78 contaminated raw milk cheeses, 609 were found to be Staphylococcus aureus. Genotyping of all Staph. aureus isolates was performed by PCR amplification of the 16S-23S rRNA intergenic spacer region, as this method was used previously to differentiate between mastitis subtypes associated with their clinical outcome. In total, 20 different genotypes were obtained and the 5 most frequently occurring genotypes were distributed in 6.4% or more of the samples. The enterotoxin-producing Staph. aureus GTB, known for its high contagiousness and increased pathogenicity in Swiss mastitis herds, was found to be the most abundant subtype at the sample level (71.8%) as well as among the isolates (62.0%). A subset of 107 isolates of the different genotypes were analyzed for the presence of SE genes and revealed 9 different SE gene patterns, with sed being most frequently detected and 26% being PCR-negative for SE genes. Almost all isolates of the major contaminant GTB contained the SE gene pattern sed, sej, ser, with half of them additionally carrying sea. Production of SE in vitro was consistent with the SE genes detected in most of the cases; however, some isolated GTB did not produce SEA. Staphylococcus aureus Protein A (spa) typing revealed 30 different subtypes and most GTB isolates belonged to the bovine spa type t2953; GTB/t2953 was linked among other subtypes to SE production in cheese and staphylococcal intoxication cases. Furthermore, 1 of the 623 isolates was a methicillin-resistant Staph. aureus, which was an seh-carrying Staph. aureus spa type tbl 0635 (non-GTB). We conclude that control and reduction of enterotoxigenic Staph. aureus GTB in dairy herds in Switzerland will not only prevent economic losses at the farm level but also improve the safety of raw milk cheeses; distribution of methicillin-resistant Staph. aureus via raw milk cheese is of less concern. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

In vitro screening of mare's milk antimicrobial effect and antiproliverative activity.

PubMed

Guri, Anilda; Paligot, Michele; Crèvecoeur, Sebastien; Piedboeuf, Benoit; Claes, Jonathan; Daube, Georges; Corredig, Milena; Griffiths, M W; Delcenserie, Veronique

2016-01-01

The aims of this study were to examine the effect of mare's milk on virulence gene expression of Salmonella Typhimurium and observe its potential activity on proliferation of adenocarcinoma Caco-2 cells. Different supernatants of mare's milk, raw or heat-treated at 65°C for 15 s or 30 min, were studied. The changes in hilA gene expression of Salmonella Typhimurium in presence of mare's milk supernatants were assessed using a reporter luminescent strain. A significant decrease in hilA gene expression was observed with all tested supernatants. Virulence gene expression was then assessed using qPCR on a wild-type strain of Salmonella Typhimurium. A significant decrease of hilA and ssrB2 gene expression was observed with raw milk supernatants but not with heat-treated supernatants. The same supernatants were administered to Caco-2 cells to measure their proliferation rate. A significant reduction of proliferative effect was observed only with raw milk supernatants. This study reports that raw mare's milk was able to modulate virulence gene expression of Salmonella Typhimurium and exerts antiproliferative effects on Caco-2 cells. These results may offer new approaches for promoting gastrointestinal health. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Evaluation of milk sample fractions for characterization of milk microbiota from healthy and clinical mastitis cows

PubMed Central

Lima, Svetlana Ferreira; Bicalho, Marcela Lucas de Souza

2018-01-01

Amplicon sequencing technique has been increasingly applied to the clinical setting as a sensitive diagnostic tool. Therefore, it is of great importance to develop a DNA extraction method that accurate isolates DNA from complex host-associated microbiota. Given the multifactorial etiology of clinical mastitis and the diversified lifestyle of bacterial species harboring in milk, here four distinct milk sample fractions: raw whole milk, milk fat, casein-pellet, and casein-pellet + fat from healthy cows and cows with clinical mastitis, were subjected to bead-beating DNA extraction, followed by high-throughput sequencing. We aimed to identify the best approach for characterization of the milk microbiota and detection of mastitis pathogens (Klebsiella spp., Streptococcus spp. and Escherichia coli). DNA from each milk fraction tested was extracted by two commercial kits, which include physical, mechanical and chemical lysis; in total 280 DNA samples from 35 cows were analyzed. Milk-health-status were categorized into four groups (healthy group; E. coli-mastitis group; Klebsiella spp.-mastitis group; and Streptococcus spp.–mastitis group). Bacterial phyla and families were described for each milk-health-status group across milk sample fractions and DNA extraction kits. For the mastitis groups the relative abundance of f__Enterobacteriaceae and f__Streptococcaceae were compared to determine the efficacy of procedures in detecting the mastitis pathogens. The four milk fractions used allowed efficiently and uniformly detection of the causative agent of mastitis. Only 27% of the families detected in healthy milk were shared among the samples extracted from all fractions of milk samples; followed by 3, 4, and 12% for the samples from E. coli-mastitis, Klebsiella spp.-mastitis and Streptococcus spp-mastitis, respectively. However, the shared families comprised a mean relative abundance greater than 85%, regardless of milk-health-status, milk fraction and DNA isolation method. Taxonomic data at the family level showed that sequences from mastitis milk samples cultured positive for E. coli and Klebsiella spp. were predominantly affiliated with f__Enterobacteriaceae, while for Streptococcus spp. were dominated by f__Streptococcacea, followed by f__Pseudomonadaceae and f__Enterococcaceae. Microbial community analysis revealed that most of the microbial community composition corresponded to milk bacterial species irrespective of the DNA isolation method and milk fraction evaluated. PMID:29561873

Are fat acids of human milk impacted by pasteurization and freezing?

PubMed

Borgo, Luiz Antônio; Coelho Araújo, Wilma Maria; Conceição, Maria Hosana; Sabioni Resck, Inês; Mendonça, Márcio Antonio

2014-10-03

The Human Milk Bank undergo human milk to pasteurization, followed by storage in a freezer at -18° C for up to six months to thus keep available the stocks of this product in maternal and infant hospitals. The objective of this study was to evaluate the effects of processing on the lipid fraction of human milk. A sample of human milk was obtained from a donor and was subdivided into ten sub-samples that was subjected to the following treatments: LC = raw milk; T0 = milk after pasteurization; T30 = milk after pasteurization and freezing for 30 days; T60 = milk after pasteurization and freeze for 60 days, and so on every 30 days until T240 = milk after pasteurization and freezing for 240 days, with 3 repetitions for each treatment. Lipids were extracted, methylated and fatty acid profiles determined by gas chromatography. The fatty acids were characterized by nuclear magnetic resonance and functional groups were identified by infrared spectroscopy. There were variations in the concentration of fatty acids. For unsaturated fatty acids there was increasing trend in their concentrations. The IR and NMR analyze characterized and identified functional groups presents in fatty acids. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Traditional cheeses: rich and diverse microbiota with associated benefits.

PubMed

Montel, Marie-Christine; Buchin, Solange; Mallet, Adrien; Delbes-Paus, Céline; Vuitton, Dominique A; Desmasures, Nathalie; Berthier, Françoise

2014-05-02

The risks and benefits of traditional cheeses, mainly raw milk cheeses, are rarely set out objectively, whence the recurrent confused debate over their pros and cons. This review starts by emphasizing the particularities of the microbiota in traditional cheeses. It then describes the sensory, hygiene, and possible health benefits associated with traditional cheeses. The microbial diversity underlying the benefits of raw milk cheese depends on both the milk microbiota and on traditional practices, including inoculation practices. Traditional know-how from farming to cheese processing helps to maintain both the richness of the microbiota in individual cheeses and the diversity between cheeses throughout processing. All in all more than 400 species of lactic acid bacteria, Gram and catalase-positive bacteria, Gram-negative bacteria, yeasts and moulds have been detected in raw milk. This biodiversity decreases in cheese cores, where a small number of lactic acid bacteria species are numerically dominant, but persists on the cheese surfaces, which harbour numerous species of bacteria, yeasts and moulds. Diversity between cheeses is due particularly to wide variations in the dynamics of the same species in different cheeses. Flavour is more intense and rich in raw milk cheeses than in processed ones. This is mainly because an abundant native microbiota can express in raw milk cheeses, which is not the case in cheeses made from pasteurized or microfiltered milk. Compared to commercial strains, indigenous lactic acid bacteria isolated from milk/cheese, and surface bacteria and yeasts isolated from traditional brines, were associated with more complex volatile profiles and higher scores for some sensorial attributes. The ability of traditional cheeses to combat pathogens is related more to native antipathogenic strains or microbial consortia than to natural non-microbial inhibitor(s) from milk. Quite different native microbiota can protect against Listeria monocytogenes in cheeses (in both core and surface) and on the wooden surfaces of traditional equipment. The inhibition seems to be associated with their qualitative and quantitative composition rather than with their degree of diversity. The inhibitory mechanisms are not well elucidated. Both cross-sectional and cohort studies have evidenced a strong association of raw-milk consumption with protection against allergic/atopic diseases; further studies are needed to determine whether such association extends to traditional raw-milk cheese consumption. In the future, the use of meta-omics methods should help to decipher how traditional cheese ecosystems form and function, opening the way to new methods of risk-benefit management from farm to ripened cheese. Published by Elsevier B.V.

Destruction of Mycobacterium paratuberculosis, Salmonella spp., and Mycoplasma spp. in raw milk by a commercial on-farm high-temperature, short-time pasteurizer.

PubMed

Stabel, J R; Hurd, S; Calvente, L; Rosenbusch, R F

2004-07-01

The 2002 NAHM's Dairy Survey indicated that 87.2% of dairy farms in the United States feed waste milk to their neonatal calves. Although cost-effective, this practice can lead to increased calf morbidity and mortality due to ingestion of pathogenic agents. In an effort to reduce the risk of infection, dairy producers are implementing on-farm pasteurization of the waste milk as a control procedure before feeding the milk to calves. In the present study, the efficacy of a commercial high-temperature, short-time (HTST) on-farm pasteurizer unit to destroy Mycobacterium paratuberculosis, Salmonella enterica spp., and Mycoplasma spp. in raw milk was evaluated. Replicate experiments were run for 3 isolates of M. paratuberculosis, 3 serovars of Salmonella (derby, dublin, typhimurium); and 4 species of Mycoplasma (bovis, californicum, canadense, serogroup 7) at 2 different levels of experimental inoculation. In addition, HTST pasteurization experiments were performed on colostrum experimentally inoculated with M. paratuberculosis. After culture of the pasteurized milk samples, no viable M. paratuberculosis, Salmonella, or Mycoplasma were recovered, regardless of species, strain, or isolate. Pasteurization of colostrum was also effective in the destruction of M. paratuberculosis but resulted in an average 25% reduction in colostral immunoglobulin. These results suggest that HTST pasteurization is effective in generating a safer product to feed to young calves.

Fate of ivermectin residues in ewes' milk and derived products.

PubMed

Cerkvenik, Vesna; Perko, Bogdan; Rogelj, Irena; Doganoc, Darinka Z; Skubic, Valentin; Beek, Wim M J; Keukens, Henk J

2004-02-01

The fate of ivermectin (IVM) residues was studied throughout the processing of daily bulk milk from 30 ewes (taken up to 33 d following subcutaneous administration of 0.2 mg IVM/kg b.w.) in the following milk products: yoghurt made from raw and pasteurized milk; cheese after pressing; 30- and 60-day ripened cheese; and whey, secondary whey and whey proteins obtained after cheese-making (albumin cheese). The concentration of the H2B1a component of IVM was analysed in these dairy products using an HPLC method with fluorescence detection. The mean recovery of the method was, depending on the matrix, between 87 and 100%. Limits of detection in the order of only 0.1 microg H2B1a/kg of product were achieved. Maximum concentrations of IVM were detected mostly at 2 d after drug administration to the ewes. The highest concentration of IVM was found on day 2 in 60-day ripened cheese (96 microg H2B1a/kg cheese). Secondary whey was the matrix with the lowest concentration of IVM (<0.6 microg H2B1a/ kg). Residue levels fell below the limits of detection between day 5 (for secondary whey) and day 25 (for all cheese samples). In the matrices investigated, linear correlations between daily concentrations of IVM, milk fat and solid content were evident. During yoghurt production, fermentation and thermal stability of IVM was observed. During cheese production, approximately 35% of the IVM, present in the raw (bulk) milk samples, was lost. From the results it was concluded that the processing of ewes' milk did not eliminate the drug residues under investigation. The consequences of IVM in the human diet were discussed. Milk from treated animals should be excluded from production of fat products like cheese for longer after treatment with IVM than for lower fat products.

Aflatoxin M₁ in raw milk from different regions of São Paulo state--Brazil.

PubMed

Santili, Ana Beatriz Nappi; de Camargo, Adriano Costa; Nunes, Raquel de Syllos Rosa; da Gloria, Eduardo Micotti; Machado, Paulo Fernando; Cassoli, Laerte Dagher; Dias, Carlos Tadeu dos Santos; Calori-Domingues, Maria Antonia

2015-01-01

A total of 635 raw milk samples from 45 dairy farms, from three regions of São Paulo state - Brazil, were evaluated during 15 months for aflatoxin M1 (AFM1). AFM1 was determined by high performance liquid chromatograph with fluorescence detection. AFM1 was detected (>0.003 µg kg(-1)) in 72.9%, 56.3% and 27.5% of the samples from Bauru, Araçatuba and Vale do Paraíba regions, respectively. The mean AFM1 contamination considering all the samples was 0.021 µg kg(-1). Furthermore, the concentration of AFM1 was quite different among Bauru (0.038 µg kg(-1)), Araçatuba (0.017 µg kg(-1)) and Vale do Paraíba (<0.01 µg kg(-1)) regions. Only three samples (0.5%) had higher contamination than the tolerated limit in Brazil (0.50 µg kg(-1)) and 64 samples (10.1%) had a higher contamination than the maximum limit as set by the European Union (0.050 µg kg(-1)). The estimated AFM1 daily intake was 0.358 and 0.120 ng kg(-1) body weight per day for children and adults, respectively.

Effect of high-temperature, short-time (HTST) pasteurization on milk containing low numbers of Mycobacterium paratuberculosis.

PubMed

Grant, I R; Ball, H J; Rowe, M T

1998-02-01

The efficacy of high-temperature, short-time (HTST) pasteurization (72 degrees C/15 s) when low numbers (< or = 10(3) cfu ml-1) of Mycobacterium paratuberculosis are present in milk was investigated. Raw cows' milk spiked with Myco. paratuberculosis (10(3) cfu ml-1, 10(2) cfu ml-1, 10 cfu ml-1, and 10 cfu 50 ml-1) was subjected to HTST pasteurization using laboratory pasteurizing units. Ten bovine strains of Myco. paratuberculosis were tested in triplicate. Culture in BACTEC Middlebrook 12B radiometric medium detected acid-fast survivors in 14.8% and 10% of HTST-pasteurized milk samples at the 10(3) and 10(2) cfu ml-1 inoculum levels, respectively, whereas conventional culture on Herrold's egg yolk medium containing mycobactin J detected acid-fast survivors in only 3.7% and 6.7% of the same milk samples. IS900-based PCR confirmed that these acid-fast survivors were Myco. paratuberculosis. No viable Myco. paratuberculosis were isolated from HTST-pasteurized milk initially containing either 10 cfu ml-1 or 10 cfu 50 ml-1.

Detection of Toxoplasma gondii in raw caprine, ovine, buffalo, bovine, and camel milk using cell cultivation, cat bioassay, capture ELISA, and PCR methods in Iran.

PubMed

Dehkordi, Farhad Safarpoor; Borujeni, Mohammad Reza Haghighi; Rahimi, Ebrahim; Abdizadeh, Rahman

2013-02-01

This study was conducted to determine the presence of Toxoplasma gondii in animal milk samples in Iran. From a total of 395 dairy herds in three provinces of Iran, 66 bovine, 58 ovine, 54 caprine, 33 buffalo, and 30 camel herds were studied, and from these parts of Iran, 200 bovine, 185 ovine, 180 caprine, 164 buffalo, and 160 camel milk samples were collected from various seasons. Samples were tested for Toxoplasma gondii by cell line culture, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) technique. Only the results of cell line cultivation were confirmed by bioassay in cat. Results indicated that all herds were infected with Toxoplasma gondii. The culture method showed that 51 out of 889 milk samples (5.73%) were positive for Toxoplasma gondii, and all 51 positive culture results were positive with bioassay in cat. The Fars province had the highest prevalence of Toxoplasma gondii (6.84%). The ELISA test showed that 41 milk samples (4.61%) were positive for the presence of Toxoplasma gondii, while the PCR showed that 46 milk samples were positive for Toxoplasma gondii. The results showed higher sensitivity of PCR and higher specificity of ELISA. Caprine had the highest (10%) and camel had the lowest (3.12%) prevalence rate of parasite. The summer season had the highest (76.47%) but winter (3.92) had the lowest incidence of Toxoplasma gondii. This study is the first prevalence report of direct detection of Toxoplasma gondii in animal milk samples in Iran.

vacA Genotype Status of Helicobacter pylori Isolated from Foods with Animal Origin

PubMed Central

Saeidi, Elnaz

2016-01-01

According to controversial theories and results of studies, foods with animal origins play an important role in the transmission of H. pylori to human. The aim of this study was to determine the distribution of vacA genotypes of H. pylori, isolated from milk and meat samples of cow, sheep, goat, camel, and buffalo. Eight hundred and twenty raw milk and meat samples were collected from various parts of Iran. Samples were cultured and those found positive for H. pylori were analyzed for the presence of various genotypes of vacA gene. Out of 420 milk and 400 meat samples, 92 (21.90%) and 105 (26.25%) were positive for H. pylori, respectively. The most commonly detected genotypes in the vacA gene were s1a (86.80%), m1a (79.18%), s1b (69.54%), and m1b (63.45%) and detected combined genotypes were mostly m1as1a (68.52%), m1as1b (60.40%), m1bs1b (55.83%), and m1bs1a (53.29%). High presence of bacteria in the milk and meat samples of sheep represents that sheep may be the natural host of H. pylori. High presence of H. pylori strains in milk and meat samples similar to vacA genotypes in human being suggests that milk and meat samples could be the sources of bacteria for human. PMID:27088092

vacA Genotype Status of Helicobacter pylori Isolated from Foods with Animal Origin.

PubMed

Saeidi, Elnaz; Sheikhshahrokh, Amirhossein

2016-01-01

According to controversial theories and results of studies, foods with animal origins play an important role in the transmission of H. pylori to human. The aim of this study was to determine the distribution of vacA genotypes of H. pylori, isolated from milk and meat samples of cow, sheep, goat, camel, and buffalo. Eight hundred and twenty raw milk and meat samples were collected from various parts of Iran. Samples were cultured and those found positive for H. pylori were analyzed for the presence of various genotypes of vacA gene. Out of 420 milk and 400 meat samples, 92 (21.90%) and 105 (26.25%) were positive for H. pylori, respectively. The most commonly detected genotypes in the vacA gene were s1a (86.80%), m1a (79.18%), s1b (69.54%), and m1b (63.45%) and detected combined genotypes were mostly m1as1a (68.52%), m1as1b (60.40%), m1bs1b (55.83%), and m1bs1a (53.29%). High presence of bacteria in the milk and meat samples of sheep represents that sheep may be the natural host of H. pylori. High presence of H. pylori strains in milk and meat samples similar to vacA genotypes in human being suggests that milk and meat samples could be the sources of bacteria for human.

Presence of Escherichia coli O157, Salmonella spp., and Listeria monocytogenes in Raw Ovine Milk Destined for Cheese Production and Evaluation of the Equivalence Between the Analytical Methods Applied.

PubMed

Amagliani, Giulia; Petruzzelli, Annalisa; Carloni, Elisa; Tonucci, Franco; Foglini, Martina; Micci, Eleonora; Ricci, Mariagrazia; Di Lullo, Stefania; Rotundo, Luca; Brandi, Giorgio

2016-11-01

Italy is one of the main producers and exporters of cheese made from unpasteurized sheep milk. Since raw milk and its derived products are known sources of human infections, cheese produced from raw sheep milk could pose a microbiological threat to public health. Hence, the objectives of the study were: to characterize the potential risk of the presence of pathogens Escherichia coli O157, Listeria monocytogenes, and Salmonella in raw ovine milk destined for cheese production obtained from all the sheep farms (n = 24) in the Marches region (Central Italy) that directly transform raw milk into cheeses and to evaluate the equivalence between the analytical methods applied. A three-step molecular method (simultaneous culture enrichment, species-specific DNA magnetic isolation, and multiplex real-time polymerase chain reaction) was used for milk (n = 143) and cheese (n = 5) analysis over a 3-year period. L. monocytogenes was not detected on any of the farms, while E. coli O157 was found on three farms, although only using the molecular method. Four farms tested positive for Salmonella spp., and Salmonella enterica subsp. diarizonae serovar 61:k:1,5,7 was isolated in one of those cases. This information highlights the need to develop preventative measures to guarantee a high level of consumer safety for this specific product line, and the molecular method could be a time-saving and sensitive tool to be used in routine diagnosis.

Suitability of a new mixed-strain starter for manufacturing uncooked raw ewe's milk cheeses.

PubMed

Feutry, Fabienne; Torre, Paloma; Arana, Ines; Garcia, Susana; Pérez Elortondo, Francisco J; Berthier, Françoise

2016-06-01

Most raw milk Ossau-Iraty cheeses are currently manufactured on-farm using the same commercial streptococcal-lactococcal starter (S1). One way to enhance the microbial diversity that gives raw milk its advantages for cheese-making is to formulate new starters combining diverse, characterized strains. A new starter (OI) combining 6 raw milk strains of lactococci, recently isolated and characterized, was tested in parallel with the current starter by making 12 Ossau-Iraty raw milk cheeses at 3 farmhouses under the conditions prevailing at each farm. Compliance of the sensory characteristics with those expected by the Ossau-Iraty professionals, physicochemical parameters and coliforms were quantified at key manufacturing steps. The new starter OI gave cheeses having proper compliance but having lower compliance than the S1 cheeses under most manufacturing conditions, while managing coliform levels equally well as starter S1. This lower compliance relied more on the absence of Streptococcus thermophilus in starter OI, than on the nature of the lactoccocal strains present in starter OI. The study also shows that variations in 5 technological parameters during the first day of manufacture, within the range of values applied in the 3 farmhouses, are powerful tools for diversifying the scores for the sensory characteristics investigated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Selection of specific aptamer against enrofloxacin and fabrication of graphene oxide based label-free fluorescent assay.

PubMed

Dolati, Somayeh; Ramezani, Mohammad; Nabavinia, Maryam Sadat; Soheili, Vahid; Abnous, Khalil; Taghdisi, Seyed Mohammad

2018-05-15

Specific ssDNA aptamers for the antibiotic enrofloxacin (ENR) were isolated from an enriched nucleotide library by SELEX (Systematic Evolution of Ligands by EXponential enrichment) method with high binding affinity. After seven rounds, five aptamers were selected and identified. Apt58 with highest affinity and sensitivity (K d  = 14.19 nM) was employed to develop a label-free fluorescent biosensing approach based on aptamer, graphene oxide (GO) and native fluorescence of ENR for determination of ENR residue in raw milk samples. Under optimized experimental conditions, the linear range was from 5 nM to 250 nM and LOD was calculated to be 3.7 nM, and the recovery rate was between 94.1% and 108.5%. The integration of aptamer and GO in this bioassay provides a promising way for rapid, sensitive and cost-effective detection of ENR in real samples like raw milk. Copyright © 2018 Elsevier Inc. All rights reserved.

Fate of Mycobacterium avium subsp. paratuberculosis in Swiss hard and semihard cheese manufactured from raw milk.

PubMed

Spahr, U; Schafroth, K

2001-09-01

Raw milk was artificially contaminated with declumped cells of Mycobacterium avium subsp. paratuberculosis at a concentration of 10(4) to 10(5) CFU/ml and was used to manufacture model hard (Swiss Emmentaler) and semihard (Swiss Tisliter) cheese. Two different strains of M. avium subsp. paratuberculosis were tested, and for each strain, two model hard and semihard cheeses were produced. The survival of M. avium subsp. paratuberculosis cells was monitored over a ripening period of 120 days by plating out homogenized cheese samples onto 7H10-PANTA agar. In both the hard and the semihard cheeses, counts decreased steadily but slowly during cheese ripening. Nevertheless, viable cells could still be detected in 120-day cheese. D values were calculated at 27.8 days for hard and 45.5 days for semihard cheese. The most important factors responsible for the death of M. avium subsp. paratuberculosis in cheese were the temperatures applied during cheese manufacture and the low pH at the early stages of cheese ripening. Since the ripening period for these raw milk cheeses lasts at least 90 to 120 days, the D values found indicate that 10(3) to 10(4) cells of M. avium subsp. paratuberculosis per g will be inactivated.

Fate of Mycobacterium avium subsp. paratuberculosis in Swiss Hard and Semihard Cheese Manufactured from Raw Milk

PubMed Central

Spahr, U.; Schafroth, K.

2001-01-01

Raw milk was artificially contaminated with declumped cells of Mycobacterium avium subsp. paratuberculosis at a concentration of 104 to 105 CFU/ml and was used to manufacture model hard (Swiss Emmentaler) and semihard (Swiss Tisliter) cheese. Two different strains of M. avium subsp. paratuberculosis were tested, and for each strain, two model hard and semihard cheeses were produced. The survival of M. avium subsp. paratuberculosis cells was monitored over a ripening period of 120 days by plating out homogenized cheese samples onto 7H10-PANTA agar. In both the hard and the semihard cheeses, counts decreased steadily but slowly during cheese ripening. Nevertheless, viable cells could still be detected in 120-day cheese. D values were calculated at 27.8 days for hard and 45.5 days for semihard cheese. The most important factors responsible for the death of M. avium subsp. paratuberculosis in cheese were the temperatures applied during cheese manufacture and the low pH at the early stages of cheese ripening. Since the ripening period for these raw milk cheeses lasts at least 90 to 120 days, the D values found indicate that 103 to 104 cells of M. avium subsp. paratuberculosis per g will be inactivated. PMID:11526024

Characterization of lactococci isolated from milk produced in the Camembert region of Normandy.

PubMed

Desmasures, N; Mangin, I; Corroler, D; Guéguen, M

1998-12-01

Thirty-eight Lactococcus strains, isolated from raw milk produced in two dairy areas in Normandy, were identified at the phenotypic level. Only Lactococcus lactis strains with the lactis phenotype were found in the milk samples. Most strains fermented lactose (97%) and showed proteinase activity (76%). Isolates were characterized by RAPD technique and rRNA gene restriction analysis. More L. lactis strains with the lactis genotype were found in the first area, while L. lactis strains with the cremoris genotype predominated in the second area. RAPD was more efficient than rRNA gene restriction analysis in differentiating between strains with the subsp. lactis genotype. For L. lactis with the subsp. cremoris genotype, the second method gave a better result but there was poor discrimination between strains. Plasmid profiles were determined. Patterns ranged in size from 1.3 to 16.5 kbp, and 29 different profiles were found. Six groups of strains were determined, five of which were specific for the area of origin. It is suggested that the region of manufacture could influence organoleptic properties of cheeses because of different Lactococcus strains in the raw milk used for cheese making.

Evaluation of a GMP training of milkers in dairy goat farms in São Paulo, Brazil.

PubMed

Tavolaro, Paula; Oliveira, Carlos A F

2006-02-01

A good manufacturing practices (GMP) training course was applied for goat milkers and evaluated using microbiological analysis in milk before and after training. Milkers from three dairy goat farms located in São Paulo, Brazil, were submitted to a one-hour course on GMP and recommended guidelines for milking. Samples of raw milk were collected before and one to two months after training, and analysed for aerobic mesophilic, psychrotrophic, coliform, Staphylococcus aureus and Salmonella spp counts. Only mesophilic counts decreased (p < 0.05) after training in two of three farms studied. Although important to assess the overall quality of milk, microbiological parameters should not be used alone for the evaluation of GMP effectiveness for goat milkers.

Analysis of the influence of pasteurization, freezing/thawing, and offer processes on human milk's macronutrient concentrations.

PubMed

Vieira, Alan Araujo; Soares, Fernanda Valente Mendes; Pimenta, Hellen Porto; Abranches, Andrea Dunshee; Moreira, Maria Elisabeth Lopes

2011-08-01

The macronutrient concentrations of human milk could be influenced by the various processes used in human milk bank. To determine the effect of various process (Holder pasteurization, freezing and thawing and feeding method) on the macronutrient concentration of human milk. The samples of donated fresh human milk were studied before and after each process (Holder pasteurization, freezing and thawing and feeding method) until their delivery to newborn infants. Fifty-seven raw human milk samples were analyzed in the first step (pasteurization) and 228 in the offer step. Repeated measurements of protein, fat and lactose amounts were made in samples of human milk using an Infrared analyzer. The influence of repeated processes on the mean concentration of macronutrients in donor human milk was analyzed by repeated measurements ANOVA, using R statistical package. The most variable macronutrient concentration in the analyzed samples was fat (reduction of 59%). There was a significant reduction of fat and protein mean concentrations following pasteurization (5.5 and 3.9%, respectively). The speed at which the milk was thawed didn't cause a significant variation in the macronutrients concentrations. However, the continuous infusion delivery significantly reduced the fat concentration. When the influence of repeated processes was analyzed, the fat and protein concentrations varied significantly (reduction of 56.6% and 10.1% respectively) (P<0.05). Lactose didn't suffer significant reductions in all steps. The repeated processes that donor human milk is submitted before delivery to newborn infants cause a reduction in the fat and protein concentration. The magnitude of this decrease is higher on the fat concentration and it needs to be considered when this processed milk is used to feed preterm infants. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Longitudinal Study of Two Irish Dairy Herds: Low Numbers of Shiga Toxin-Producing Escherichia coli O157 and O26 Super-Shedders Identified.

PubMed

Murphy, Brenda P; McCabe, Evonne; Murphy, Mary; Buckley, James F; Crowley, Dan; Fanning, Séamus; Duffy, Geraldine

2016-01-01

A 12-month longitudinal study was undertaken on two dairy herds to ascertain the Shiga-toxin producing Escherichia coli (STEC) O157 and O26 shedding status of the animals and its impact (if any) on raw milk. Cattle are a recognized reservoir for these organisms with associated public health and environmental implications. Animals shedding E. coli O157 at >10,000 CFU/g of feces have been deemed super-shedders. There is a gap in the knowledge regarding super-shedding of other STEC serogroups. A cohort of 40 lactating cows from herds previously identified as positive for STEC in a national surveillance project were sampled every second month between August, 2013 and July, 2014. Metadata on any potential super-shedders was documented including, e.g., age of the animal, number of lactations and days in lactation, nutritional condition, somatic cell count and content of protein in milk to assess if any were associated with risk factors for super-shedding. Recto-anal mucosal swabs (RAMS), raw milk, milk filters, and water samples were procured for each herd. The swabs were examined for E. coli O157 and O26 using a quantitative real time PCR method. Counts (CFU swab -1 ) were obtained from a standard calibration curve that related real-time PCR cycle threshold ( C t ) values against the initial concentration of O157 or O26 in the samples. Results from Farm A: 305 animals were analyzed; 15 E. coli O157 (5%) were recovered, 13 were denoted STEC encoding either stx1 and/or stx2 virulence genes and 5 (2%) STEC O26 were recovered. One super-shedder was identified shedding STEC O26 ( stx1 &2). Farm B: 224 animals were analyzed; eight E. coli O157 (3.5%) were recovered (seven were STEC) and 9 (4%) STEC O26 were recovered. Three super-shedders were identified, one was shedding STEC O157 ( stx2 ) and two STEC O26 ( stx2 ). Three encoded the adhering and effacement gene ( eae) and one isolate additionally encoded the haemolysin gene ( hlyA ). All four super-shedders were only super-shedding once during the 1-year sampling period. The results of this study show, low numbers of super-shedders in the herds examined, with high numbers of low and medium shedding. Although four super-shedding animals were identified, no STEC O157 or O26 were recovered from any of the raw milk, milk filter, or water samples. The authors conclude that this study highlights the need for further surveillance to assess the potential for environmental contamination and food chain security.

Longitudinal Study of Two Irish Dairy Herds: Low Numbers of Shiga Toxin-Producing Escherichia coli O157 and O26 Super-Shedders Identified

PubMed Central

Murphy, Brenda P.; McCabe, Evonne; Murphy, Mary; Buckley, James F.; Crowley, Dan; Fanning, Séamus; Duffy, Geraldine

2016-01-01

A 12-month longitudinal study was undertaken on two dairy herds to ascertain the Shiga-toxin producing Escherichia coli (STEC) O157 and O26 shedding status of the animals and its impact (if any) on raw milk. Cattle are a recognized reservoir for these organisms with associated public health and environmental implications. Animals shedding E. coli O157 at >10,000 CFU/g of feces have been deemed super-shedders. There is a gap in the knowledge regarding super-shedding of other STEC serogroups. A cohort of 40 lactating cows from herds previously identified as positive for STEC in a national surveillance project were sampled every second month between August, 2013 and July, 2014. Metadata on any potential super-shedders was documented including, e.g., age of the animal, number of lactations and days in lactation, nutritional condition, somatic cell count and content of protein in milk to assess if any were associated with risk factors for super-shedding. Recto-anal mucosal swabs (RAMS), raw milk, milk filters, and water samples were procured for each herd. The swabs were examined for E. coli O157 and O26 using a quantitative real time PCR method. Counts (CFU swab-1) were obtained from a standard calibration curve that related real-time PCR cycle threshold (Ct) values against the initial concentration of O157 or O26 in the samples. Results from Farm A: 305 animals were analyzed; 15 E. coli O157 (5%) were recovered, 13 were denoted STEC encoding either stx1 and/or stx2 virulence genes and 5 (2%) STEC O26 were recovered. One super-shedder was identified shedding STEC O26 (stx1&2). Farm B: 224 animals were analyzed; eight E. coli O157 (3.5%) were recovered (seven were STEC) and 9 (4%) STEC O26 were recovered. Three super-shedders were identified, one was shedding STEC O157 (stx2) and two STEC O26 (stx2). Three encoded the adhering and effacement gene (eae) and one isolate additionally encoded the haemolysin gene (hlyA). All four super-shedders were only super-shedding once during the 1-year sampling period. The results of this study show, low numbers of super-shedders in the herds examined, with high numbers of low and medium shedding. Although four super-shedding animals were identified, no STEC O157 or O26 were recovered from any of the raw milk, milk filter, or water samples. The authors conclude that this study highlights the need for further surveillance to assess the potential for environmental contamination and food chain security. PMID:27917164

Rapid determination of ampicillin in bovine milk by liquid chromatography with fluorescence detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ang, C.Y.W.; Luo, Wenhong

1997-01-01

A rapid and sensitive liquid chromatographic (LC) method was developed for the determination of ampicillin residues in raw bovine milk, processed skim milk, and pasteurized, homogenized whole milk with vitamin D. Milk samples were deproteinized with trichloroacetic acid (TCA) and acetonictrile. After centrifugation, the clear supernatant was reacted with formaldehyde and TCA under heat. The major fluorescent derivative of ampicillin was then determined by reversed-phase LC with fluorescence detection. Average recoveries of ampicillin fortified at 5, 10, and 20 ppb (ng/mL) were all >85% with coefficients of variation <10%. Limits of detection ranged from 0.31 to 0.51 ppb and limitsmore » of quantitation, from 0.66 to 1.2 ppb. After appropriate validation, this method should be suitable for rapid analysis of milk for ampicillin residues at the tolerance level of 10 ppb. 16 refs., 4 figs., 3 tabs.« less

Enhanced creaming of milk fat globules in milk emulsions by the application of ultrasound and detection by means of optical methods.

PubMed

Juliano, P; Kutter, A; Cheng, L J; Swiergon, P; Mawson, R; Augustin, M A

2011-09-01

The effects of application of ultrasonic waves to recombined milk emulsions (3.5% fat, 7% total solids) and raw milk on fat destabilization and creaming were examined. Coarse and fine recombined emulsions (D[4,3]=9.3 μm and 2.7 μm, respectively) and raw milk (D[4,3]=4.9 μm) were subjected to ultrasound for 5 min at 35°C and 400 kHz or 1.6 MHz (using a single transducer) or 400 kHz (where the emulsion was sandwiched between two transducers). Creaming, as calculated from Turbiscan measurements, was more evident in the coarse recombined emulsion and raw milk compared to that of the recombined fine emulsion. Micrographs confirmed that there was flocculation and coalescence in creamed layer of emulsion. Coalescence was confirmed by particle size measurement. These results imply that ultrasound has potential to pre-dispose fat particles in milk emulsions to creaming in standing wave systems and in systems with inhomogeneous sound distributions. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Short communication: culture-independent detection of lactic Acid bacteria bacteriocin genes in two traditional slovenian raw milk cheeses and their microbial consortia.

PubMed

Trmcić, A; Obermajer, T; Rogelj, I; Bogovic Matijasić, B

2008-12-01

Two Slovenian traditional raw milk cheeses, Tolminc (from cows' milk) and Kraski (from ewes' milk), were examined for the presence of 19 lactic acid bacteria bacteriocin genes by PCR analysis of total DNA extracts from 9 cheeses and from consortia of strains isolated from these cheeses. Eleven bacteriocin genes were detected in at least one cheese or consortium, or from both. Different cheeses or consortia contained 3 to 9 bacteriocin determinants. Plantaricin A gene determinants were found in all cheese and consortia DNA extracts. Genes for enterocins A, B, P, L50A, and L50B, and the bacteriocin cytolysin were commonly detected, as were genes for nisin. These results indicate that bacteriocinogenic strains of Lactobacillus, Enterococcus, and Lactococcus genera with protective potential are common members of indigenous microbiota of raw milk cheeses, which can be a good source of new protective strains.

Applicability of Screening Tests for Oxytetracycline in the Milk of Three Breeds of Goats.

PubMed

Attaie, Rahmat; Bsharat, Mohammed; Mora-Gutierrez, Adela

2016-06-01

Antibiotics are widely used in animal husbandry, and the presence of antibiotic residues in milk is a health hazard. The objectives of this study were to determine residual amounts of oxytetracycline in the milk of three breeds of goats using high-pressure liquid chromatography (HPLC) analysis and screening tests. It was also essential to explore the safe withdrawal period of oxytetracycline in lactating goats and examine the applicability of Charm ROSA and SNAP screening tests. The qualitative results of these tests were compared with the quantitative results of the HPLC method. Fifteen milking does, five each from the Alpine, LaMancha, and Nubian breeds, were selected from the herd at Prairie View A&M University. Milk samples containing antibiotic residues were deproteinized by HCl and acetonitrile, and then oxytetracycline was extracted from the supernatant. The residues of oxytetracycline in goat's milk up to 110 h after injection were qualitatively detected using the Charm ROSA test. Similarly, the SNAP test detected the antibiotic residues in milk up to 110 h after treatment. The HPLC results indicated that oxytetracycline residues in milk from Alpine goats were below the tolerance level (300 ng/ml) 82 h after drug treatment (72 h for LaManchas, 58 h for Nubians); however, the results of the screening tests would indicate longer withdrawal periods for milk from the breeds of goats studied, which would result in economic losses to goat's milk producers. The results of this study also indicated that oxytetracycline was not stable in raw goat's milk at refrigeration temperature or during pasteurization and that the concentrations decreased significantly. Commercial goat's milk is usually exposed to several hours of refrigeration and then to pasteurization. The results of this study indicated that, if oxytetracycline was present in raw goat's milk, the concentration would decrease significantly before it was marketed.

MiRNA Analysis by Quantitative PCR in Preterm Human Breast Milk Reveals Daily Fluctuations of hsa-miR-16-5p.

PubMed

Floris, Ilaria; Billard, Hélène; Boquien, Clair-Yves; Joram-Gauvard, Evelyne; Simon, Laure; Legrand, Arnaud; Boscher, Cécile; Rozé, Jean-Christophe; Bolaños-Jiménez, Francisco; Kaeffer, Bertrand

2015-01-01

Human breast milk is an extremely dynamic fluid containing many biologically-active components which change throughout the feeding period and throughout the day. We designed a miRNA assay on minimized amounts of raw milk obtained from mothers of preterm infants. We investigated changes in miRNA expression within month 2 of lactation and then over the course of 24 hours. Analyses were performed on pooled breast milk, made by combining samples collected at different clock times from the same mother donor, along with time series collected over 24 hours from four unsynchronized mothers. Whole milk, lipids or skim milk fractions were processed and analyzed by qPCR. We measured hsa-miR-16-5p, hsa-miR-21-5p, hsa-miR-146-5p, and hsa-let-7a, d and g (all -5p). Stability of miRNA endogenous controls was evaluated using RefFinder, a web tool integrating geNorm, Normfinder, BestKeeper and the comparative ΔΔCt method. MiR-21 and miR-16 were stably expressed in whole milk collected within month 2 of lactation from four mothers. Analysis of lipids and skim milk revealed that miR-146b and let-7d were better references in both fractions. Time series (5H-23H) allowed the identification of a set of three endogenous reference genes (hsa-let-7d, hsa-let-7g and miR-146b) to normalize raw quantification cycle (Cq) data. We identified a daily oscillation of miR-16-5p. Our assay allows exploring miRNA levels of breast milk from mother with preterm baby collected in time series over 48-72 hours.

Public health significance of antimicrobial-resistant gram-negative bacteria in raw bulk tank milk.

PubMed

Straley, B A; Donaldson, S C; Hedge, N V; Sawant, A A; Srinivasan, V; Oliver, S P; Jayarao, B M

2006-01-01

The dairy farm environment and animals on the farm serve as important reservoirs of pathogenic and commensal bacteria that could potentially gain access to milk in the bulk tank via several pathways. Pathogenic gram-negative bacteria can gain access to bulk tank milk from infected mammary glands, contaminated udders and milking machines, and/or from the dairy farm environment. Contaminated raw milk when consumed by humans or fed to animals on the farm can result in gastroenteric infections in humans and animals and also provide an opportunity for organisms to colonize the farm environment. This scenario becomes much more complicated when pathogenic bacteria such as Salmonella, Shiga toxin-producing Escherichia coli, and commensal gram-negative enteric bacteria encode for antimicrobial resistance determinants. In recent years, the role of commensal bacteria as reservoirs of genetic determinants for antimicrobial resistance has come under closer scrutiny. Commensal bacteria in bulk tank milk can be a significant reservoir of antimicrobial determinants. Raw milk consumption can result in exposure to antimicrobial-resistant commensal gram-negative bacteria. This paper examines the prevalence and role of commensal gram-negative enteric bacteria in bulk tank milk and their public health significance.

[Investigation of gestagenic effect of raw drone milk in rats].

PubMed

Seres, Adrienn; Ducza, Eszter; Gáspár, Róbert

2014-01-01

Numerous honeybee products are used in traditional medicine. The best-known honeybee products are the honey, the propolis and the royal jelly. Drone milk is a relatively little-known honeybee product. Although, drone milk is traditionally used to treat infertility and to promote vitality in both men and women in certain countries, the literature furnishes no information concerning effects of the drone milk. The oestrogenic and androgenic effects of drone milk have recently been reported in rats and the effective compounds have also been identified. The aim of this study was to determine the putative gestagenic effect of raw drone milk in rats. Maintenance of pregnancy assays revealed that drone milk was able to increase the number of surviving fetuses. This results suggested some gestagenic effects. This effect was confirmed by RT-PCR and Western blot methods in which the mRNA and protein expressions of gestagen-dependent CRLR (Calcitonin Receptor-Like Receptor) peptide were determined. To determine the efficacy of gestagenic effect of drone milk, spironolactone (weak gestagen compound) was used. The combination of drone milk and spironolactone showed more potent gestagenic effect. These results lead us to suppose that raw drone milk shows weak gestagenic effect and this effect can be increased by another weak gestagen. Further studies are required to clarify the gestagenic mechanisms of action of drone milk.

Consumers' behavior in quantitative microbial risk assessment for pathogens in raw milk: Incorporation of the likelihood of consumption as a function of storage time and temperature.

PubMed

Crotta, Matteo; Paterlini, Franco; Rizzi, Rita; Guitian, Javier

2016-02-01

Foodborne disease as a result of raw milk consumption is an increasing concern in Western countries. Quantitative microbial risk assessment models have been used to estimate the risk of illness due to different pathogens in raw milk. In these models, the duration and temperature of storage before consumption have a critical influence in the final outcome of the simulations and are usually described and modeled as independent distributions in the consumer phase module. We hypothesize that this assumption can result in the computation, during simulations, of extreme scenarios that ultimately lead to an overestimation of the risk. In this study, a sensorial analysis was conducted to replicate consumers' behavior. The results of the analysis were used to establish, by means of a logistic model, the relationship between time-temperature combinations and the probability that a serving of raw milk is actually consumed. To assess our hypothesis, 2 recently published quantitative microbial risk assessment models quantifying the risks of listeriosis and salmonellosis related to the consumption of raw milk were implemented. First, the default settings described in the publications were kept; second, the likelihood of consumption as a function of the length and temperature of storage was included. When results were compared, the density of computed extreme scenarios decreased significantly in the modified model; consequently, the probability of illness and the expected number of cases per year also decreased. Reductions of 11.6 and 12.7% in the proportion of computed scenarios in which a contaminated milk serving was consumed were observed for the first and the second study, respectively. Our results confirm that overlooking the time-temperature dependency may yield to an important overestimation of the risk. Furthermore, we provide estimates of this dependency that could easily be implemented in future quantitative microbial risk assessment models of raw milk pathogens. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The Microbiology of Traditional Hard and Semihard Cooked Mountain Cheeses.

PubMed

Beuvier, Eric; Duboz, Gabriel

2013-10-01

Traditional cheeses originate from complex systems that confer on them specific sensory characteristics. These characteristics are linked to various factors of biodiversity such as animal feed, the use of raw milk and its indigenous microflora, the cheese technology, and the ripening conditions, all in conjunction with the knowledge of the cheesemaker and affineur. In Europe, particularly in France, the preservation of traditional cheesemaking processes, some of which have protected designation of origin, is vital for the farming and food industry in certain regions. Among these cheeses, some are made in the Alps or Jura Mountains, including Comté, Beaufort, Abondance, and Emmental, which are made from raw milk. The principle of hard or semihard cooked cheese, produced in the Alps and Jura Mountains, was to make a product during the summer-a period during which the animals feed more and milk production is high-with a shelf life of several months that could be consumed in winter. Today, these traditional cheeses are produced according to a specific approach combining science and tradition in order to better understand and preserve the elements that contribute to the distinctiveness of these cheeses. To address this complex problem, a global approach to the role of the raw milk microflora in the final quality of cheeses was initially chosen. The modifications resulting from the elimination of the raw milk microflora, either by pasteurization or by microfiltration, to the biochemistry of the ripening process and ultimately the sensory quality of the cheeses were evaluated. This approach was achieved mainly with experimental hard cooked cheeses. Other types of traditional cheese made with raw and pasteurized milk are also considered when necessary. Besides the native raw milk microflora, traditional lactic starters (natural or wild starters) also participate in the development of the characteristics of traditional hard and semihard cooked mountain cheeses. After an initial description, their roles are described, mainly for Comté.

Prevalence, pathogenic capability, virulence genes, biofilm formation, and antibiotic resistance of Listeria in goat and sheep milk confirms need of hygienic milking conditions.

PubMed

Osman, Kamelia M; Zolnikov, Tara Rava; Samir, Ahmed; Orabi, Ahmed

2014-01-01

Goat and sheep milk is consumed by human populations throughout the world; as a result, it has been proposed as an alternative, nutrient-rich milk to feed infants allergic to cow's milk. Unfortunately, potentially harmful bacteria have not been thoroughly tested in goat or sheep milk. Listeria monocytogenes is a harmful bacterium that causes adverse health effects if ingested by humans. The purpose of this study was to estimate the prevalence and characterize the phenotype, genotype, virulence factors, biofilm formation, and antibiopotential of Listeria isolated from the milk of goat and sheep. Udder milk samples were collected from 107 goats and 102 sheep and screened for mastitis using the California mastitis test (CMT). Samples were then examined for the presence of pathogenic Listeria spp; if detected, the isolation of pathogenic Listeria (L. monocytogenes and Listeria ivanovii) was completed using isolation and identification techniques recommended by the International Organization for Standards (ISO 11290-1, 1996), in addition to serological, in vitro and in vivo pathogenicity tests. The isolates were subjected to PCR assay for virulence associated genes (hlyA, plcA, actA, and iap). Pathogenic Listeria spp. were isolated from 5·6% of goat and 3·9% sheep milk samples, with 33·3 and 25% of these selected samples respectively containing L. monocytogenes. The results of this study provide evidence of the low-likelihood of contamination leading to the presence of L. monocytogenes in raw goat and sheep milk; however, this study also confirmed a strong in vitro ability for biofilm formation and pathogenic capability of L. monocytogenes if discovered in the milk. L. monocytogenes may be present in goat and sheep milk and in order to reduce the exposure, hygienic milking conditions must be employed for the milk to be considered a safe alternative for human consumption.

Prevalence, pathogenic capability, virulence genes, biofilm formation, and antibiotic resistance of Listeria in goat and sheep milk confirms need of hygienic milking conditions

PubMed Central

Osman, Kamelia M; Zolnikov, Tara Rava; Samir, Ahmed; Orabi, Ahmed

2014-01-01

Goat and sheep milk is consumed by human populations throughout the world; as a result, it has been proposed as an alternative, nutrient-rich milk to feed infants allergic to cow’s milk. Unfortunately, potentially harmful bacteria have not been thoroughly tested in goat or sheep milk. Listeria monocytogenes is a harmful bacterium that causes adverse health effects if ingested by humans. The purpose of this study was to estimate the prevalence and characterize the phenotype, genotype, virulence factors, biofilm formation, and antibiopotential of Listeria isolated from the milk of goat and sheep. Udder milk samples were collected from 107 goats and 102 sheep and screened for mastitis using the California mastitis test (CMT). Samples were then examined for the presence of pathogenic Listeria spp; if detected, the isolation of pathogenic Listeria (L. monocytogenes and Listeria ivanovii) was completed using isolation and identification techniques recommended by the International Organization for Standards (ISO 11290-1, 1996), in addition to serological, in vitro and in vivo pathogenicity tests. The isolates were subjected to PCR assay for virulence associated genes (hlyA, plcA, actA, and iap). Pathogenic Listeria spp. were isolated from 5.6% of goat and 3.9% sheep milk samples, with 33.3 and 25% of these selected samples respectively containing L. monocytogenes. The results of this study provide evidence of the low-likelihood of contamination leading to the presence of L. monocytogenes in raw goat and sheep milk; however, this study also confirmed a strong in vitro ability for biofilm formation and pathogenic capability of L. monocytogenes if discovered in the milk. L. monocytogenes may be present in goat and sheep milk and in order to reduce the exposure, hygienic milking conditions must be employed for the milk to be considered a safe alternative for human consumption. PMID:24548157

Nutritional and hygienic quality of raw milk in the mid-northern region of Algeria: correlations and risk factors.

PubMed

Adjlane-Kaouche, Soumeya; Benhacine, Rafik; Ghozlane, Faiçal; Mati, Abderrahmane

2014-01-01

This paper aims to study the overall quality of raw milk in the mid-northern region of Algeria. The analysis results showed a decrease in the average temperature for the delivery of 1,54°C with P<0.001. However, no significant variation (P>0.05) was observed in almost all the physical and nutritional parameters studied (pH, fat content, and protein content) between M1 and M2. The average contamination by total mesophilic aerobic bacteria (TMAB), coliforms, yeasts, molds, and different pathogens in samples taken at M1 showed significant changes at M2. This was confirmed by the decrease of reduction time of methylene blue (RTMB), about 54%. The variation was described as follows: (P>0.05) for yeasts and (P<0.05) for molds in M1 and M2, (P<0.05) for TMAB in M1, and (P<0.001) for TC, FC, and TMAB in M2. The analysis for the detection of Salmonella spp. showed no contamination in all samples tested, while antibiotic residues were detected in 35% of milks delivered. In conclusion, several risk factors have been identified in this study, namely, the effect of the season and the distance between the farm and the dairy unit.

Nutritional and Hygienic Quality of Raw Milk in the Mid-Northern Region of Algeria: Correlations and Risk Factors

PubMed Central

Adjlane-Kaouche, Soumeya; Benhacine, Rafik; Ghozlane, Faiçal; Mati, Abderrahmane

2014-01-01

This paper aims to study the overall quality of raw milk in the mid-northern region of Algeria. The analysis results showed a decrease in the average temperature for the delivery of 1,54°C with P<0.001. However, no significant variation (P>0.05) was observed in almost all the physical and nutritional parameters studied (pH, fat content, and protein content) between M1 and M2. The average contamination by total mesophilic aerobic bacteria (TMAB), coliforms, yeasts, molds, and different pathogens in samples taken at M1 showed significant changes at M2. This was confirmed by the decrease of reduction time of methylene blue (RTMB), about 54%. The variation was described as follows: (P>0.05) for yeasts and (P<0.05) for molds in M1 and M2, (P<0.05) for TMAB in M1, and (P<0.001) for TC, FC, and TMAB in M2. The analysis for the detection of Salmonella spp. showed no contamination in all samples tested, while antibiotic residues were detected in 35% of milks delivered. In conclusion, several risk factors have been identified in this study, namely, the effect of the season and the distance between the farm and the dairy unit. PMID:25374932

Chemical characterization of milk after treatment with thermal (HTST and UHT) and nonthermal (turbulent flow ultraviolet) processing technologies.

PubMed

Cappozzo, Jack C; Koutchma, Tatiana; Barnes, Gail

2015-08-01

As a result of growing interest to nonthermal processing of milk, the purpose of this study was to characterize the chemical changes in raw milk composition after exposure to a new nonthermal turbulent flow UV process, conventional thermal pasteurization process (high-temperature, short-time; HTST), and their combinations, and compare those changes with commercially UHT-treated milk. Raw milk was exposed to UV light in turbulent flow at a flow rate of 4,000L/h and applied doses of 1,045 and 2,090 J/L, HTST pasteurization, and HTST in combination with UV (before or after the UV). Unprocessed raw milk, HTST-treated milk, and UHT-treated milk were the control to the milk processed with the continuous turbulent flow UV treatment. The chemical characterization included component analysis and fatty acid composition (with emphasis on conjugated linoleic acid) and analysis for vitamin D and A and volatile components. Lipid oxidation, which is an indicator to oxidative rancidity, was evaluated by free fatty acid analysis, and the volatile components (extracted organic fraction) by gas chromatography-mass spectrometry to obtain mass spectral profile. These analyses were done over a 14-d period (initially after treatment and at 7 and 14 d) because of the extended shelf-life requirement for milk. The effect of UV light on proteins (i.e., casein or lactalbumin) was evaluated qualitatively by sodium dodecyl sulfate-PAGE. The milk or liquid soluble fraction was analyzed by sodium dodecyl sulfate-PAGE for changes in the protein profile. From this study, it appears that continuous turbulent flow UV processing, whether used as a single process or in combination with HTST did not cause any statistically significant chemical changes when compared with raw milk with regard to the proximate analysis (total fat, protein, moisture, or ash), the fatty acid profile, lipid oxidation with respect to volatile analysis, or protein profile. A 56% loss of vitamin D and a 95% loss of vitamin A content was noted after 7 d from the continuous turbulent flow UV processing, but this loss was equally comparable to that found with traditional thermal processing, such as HTST and UHT. Chemical characterization of milk showed that turbulent flow UV light technology can be considered as alternative nonthermal treatment of pasteurized milk and raw milk to extend shelf life. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

[Evaluation of the bacteriologic quality of breast milk in a neonatology service in Belgium].

PubMed

Vervoort, A; Delsat, L; Pieltain, C; De Halleux, V; Carpentier, M; Rigo, J

2007-03-01

Many studies demonstrated that human milk is the recommended source of enteral nutrition in preterm infants providing several benefits with regards to feeding tolerance, immunity and cognitive development However, neurological immaturity and associated clinical conditions prevent them from suckling effectively. Therefore, mother's milk must be expressed, stored and transported to the neonatal unit and could be contaminated. The microbiological quality of human milk was evaluated on each donation to the neonatal intensive care unit of the University of Liege, Belgium from November 1, 2003 to January 31, 2005. In all, 5842 samples from 176 mothers were included in the study. Samples were classified according to the exclusive presence of coagulase negative Staphylococcus and their number (less or more than 104 germs per ml) or to contamination with pathogens. More than 50% of analyzed milks had to be pasteurized (46%; >104 coagulase negative Staphylococcus per ml) or to be discarded (7% pathogen contamination). The incidence of pasteurisation tends to increase during the summer, suggesting a seasonal influence. Maternal profiles were established longitudinally. Among the 60 mothers whose at least one sample had pathogen contamination, 27% had a contamination occurring only during a few days, but 73% had more than 50% of their samples discarded. This study suggest the need to promote the use and the financial support of intrahospital human milk bank units to support the safe use of raw and pasteurised human milk in preterm infants.

Outbreak of staphylococcal food poisoning among children and staff at a Swiss boarding school due to soft cheese made from raw milk.

PubMed

Johler, Sophia; Weder, Delphine; Bridy, Claude; Huguenin, Marie-Claude; Robert, Luce; Hummerjohann, Jörg; Stephan, Roger

2015-05-01

On October 1, 2014, children and staff members at a Swiss boarding school consumed Tomme, a soft cheese produced from raw cow milk. Within the following 7h, all 14 persons who ingested the cheese fell ill, including 10 children and 4 staff members. Symptoms included abdominal pain and violent vomiting, followed by severe diarrhea and fever. We aim to present this food poisoning outbreak and characterize the causative agent. The duration of the incubation period was dependent of the age of the patient: 2.5h in children under 10 yr of age, 3.5h in older children and teenagers, and 7h in adults. The soft cheese exhibited low levels of staphylococcal enterotoxin (SE) A (>6ng of SEA/g of cheese) and high levels of staphylococcal enterotoxin D (>200ng of SED/g of cheese). Counts of 10(7) cfu of coagulase-positive staphylococci per gram of cheese were detected, with 3 different Staphylococcus aureus strains being present at levels >10(6) cfu/g. The 3 strains were characterized using spa typing and a DNA microarray. An enterotoxin-producing strain exhibiting sea and sed was identified as the source of the outbreak. The strain was assigned to spa type tbl 3555 and clonal complex 8, and it exhibited genetic criteria consistent with the characteristics of a genotype B strain. This genotype comprises bovine Staph. aureus strains exclusively associated with very high within-herd prevalence of mastitis and has been described as a major contaminant in Swiss raw milk cheese. It is therefore highly likely that the raw milk used for Tomme production was heavily contaminated with Staph. aureus and that levels further increased due to growth of the organism and physical concentration effects during the cheese-making process. Only a few staphylococcal food poisoning outbreaks involving raw milk products have been described. Still, in view of this outbreak and the possible occurrence of other foodborne pathogens in bovine milk, consumption of raw milk and soft cheese produced from raw milk constitutes a health risk, particularly when young children or other members of sensitive populations are involved. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Study of dielectric properties of adulterated milk concentration and freshness

NASA Astrophysics Data System (ADS)

Jitendra Murthy, V.; Sai Kiranmai, N.; Kumar, Sanjeev

2017-08-01

The knowledge of dielectric properties may hold a potential to develop a new technique for quality evaluation of milk. The dielectric properties of water diluted cow’s milk with milk concentration from 70 percent to 100 percent stored during 36hour storage at 22°C and 144 hour at 5°C were measured at room temperature for frequencies ranging from 10 to 4500 MHz and at low, high & at microwave frequencies using X band bench and open-ended coaxial-line probe technology, along with electrical conductivity. The raw milk had the lowest dielectric constant (ɛ‧) when the frequency was higher than about 20M.Hz, and had the highest loss (ɛ″) or decepation factor tan (δ) at each frequency. The penetration depth (dp) increased with decreasing frequency, water content and storage time, which was large enough to detect dielectric properties changes in milk samples and provide large scale RF pasteurization processes. The loss factor can be an indicator in predicting milk concentration and freshness.

Optimized enrichment for the detection of Escherichia coli O26 in French raw milk cheeses.

PubMed

Savoye, F; Rozand, C; Bouvier, M; Gleizal, A; Thevenot, D

2011-06-01

Our main objective was to optimize the enrichment of Escherichia coli O26 in raw milk cheeses for their subsequent detection with a new automated immunological method. Ten enrichment broths were tested for the detection of E. coli O26. Two categories of experimentally inoculated raw milk cheeses, semi-hard uncooked cheese and 'Camembert' type cheese, were initially used to investigate the relative efficacy of the different enrichments. The enrichments that were considered optimal for the growth of E. coli O26 in these cheeses were then challenged with other types of raw milk cheeses. Buffered peptone water supplemented with cefixim-tellurite and acriflavin was shown to optimize the growth of E. coli O26 artificially inoculated in the cheeses tested. Despite the low inoculum level (1-10 CFU per 25 g) in the cheeses, E. coli O26 counts reached at least 5.10(4) CFU ml(-1) after 24-h incubation at 41.5 °C in this medium. All the experimentally inoculated cheeses were found positive by the immunological method in the enrichment broth selected. Optimized E. coli O26 enrichment and rapid detection constitute the first steps of a complete procedure that could be used in routine to detect E. coli O26 in raw milk cheeses. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

Metabolic profile modifications in milk after enrofloxacin administration studied by liquid chromatography coupled with high resolution mass spectrometry.

PubMed

Junza, A; Saurina, J; Barrón, D; Minguillón, C

2016-08-19

High resolution accurate mass spectrometry (HRMS) operating in full scan MS mode was used in the search and identification of metabolites in raw milk from cows medicated with enrofloxacin. Data consisting of m/z features were taken throughout the entire chromatogram of milk samples from medicated animals and were compared with blank samples. Twenty six different compounds were identified. Some of them were attributed to structures related to enrofloxacin while others were dipeptides or tripeptides. Additionally, enrofloxacin was administered in a controlled treatment for three days. Milk was collected daily from the first day of treatment and until four days after in the search for the identified compounds. The obtained data were chemometrically treated by Principal Component Analysis. Samples were classified by this method into three different groups corresponding to days 1-2, day 3 and days 4-7 considering the different concentration profile evolution of metabolites during the days studied. Tentative metabolic pathways were designed to rationalize the presence of the newly identified compounds. Copyright © 2016 Elsevier B.V. All rights reserved.

Colorimetric method for the detection of melamine using in-situ formed silver nanoparticles via tannic acid

NASA Astrophysics Data System (ADS)

Alam, Md. Fazle; Laskar, Amaj Ahmed; Ahmed, Shahbaz; Shaida, Mohd. Azfar; Younus, Hina

2017-08-01

Melamine toxicity has recently attracted worldwide attention as it causes renal failure and the death of humans and animals. Therefore, developing a simple, fast and sensitive method for the routine detection of melamine is the need of the hour. Herein, we have developed a selective colorimetric method for the detection of melamine in milk samples based upon in-situ formation of silver nanoparticles (AgNPs) via tannic acid. The AgNPs thus formed were characterized by UV-Visible spectrophotometer, transmission electron microscope (TEM), zetasizer and dynamic light scattering (DLS). The AgNPs were used to detect melamine under in vitro condition and in raw milk spiked with melamine. Under optimal conditions, melamine could be selectively detected in vitro within the concentration range of 0.05-1.4 μM with a limit of detection (LOD) of 0.01 μM, which is lower than the strictest melamine safety requirement of 1 ppm. In spiked raw milk, the recovery percentage range was 99.5-106.5% for liquid milk and 98.5-105.5% for powdered milk. The present method shows extreme selectivity with no significant interference with other substances like urea, glucose, glycine, ascorbic acid etc. This assay method does not utilize organic cosolvents, enzymatic reactions, light sensitive dye molecules and sophisticated instrumentation, thereby overcoming some of the limitations of the other conventional methods.

Use of donor milk in the neonatal intensive care unit.

PubMed

de Halleux, Virginie; Pieltain, Catherine; Senterre, Thibault; Rigo, Jacques

2017-02-01

Own mother's milk is the first choice in feeding preterm infants and provides multiple short- and long-term benefits. When it is unavailable, donor human milk is recommended as the first alternative. Donor milk undergoes processing (i.e. pasteurization) to reduce bacteriological and viral contaminants but influences its bioactive properties with potentially fewer benefits than raw milk. However, there is no clinical evidence of health benefit of raw compared to pasteurized human milk, and donor milk maintains documented advantages compared to formula. Nutrient content of donor and own mother's milk fails to meet the requirements of preterm infants. Adequate fortification is necessary to provide optimal growth. There are significant challenges in providing donor milk for premature infants; therefore, specific clinical guidelines for human milk banks and donor milk use in the neonatal intensive care unit should be applied and research should focus on innovative solutions to process human milk while preserving its immunological and nutritional components. In addition, milk banks are not the only instrument to collect, process and store donor milk but represent an excellent tool for breastfeeding promotion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genetic variation in vitamin B-12 content of bovine milk and its association with SNP along the bovine genome.

PubMed

Rutten, Marc J M; Bouwman, Aniek C; Sprong, R Corinne; van Arendonk, Johan A M; Visker, Marleen H P W

2013-01-01

Vitamin B-12 (also called cobalamin) is essential for human health and current intake levels of vitamin B-12 are considered to be too low. Natural enrichment of the vitamin B-12 content in milk, an important dietary source of vitamin B-12, may help to increase vitamin B-12 intake. Natural enrichment of the milk vitamin B-12 content could be achieved through genetic selection, provided there is genetic variation between cows with respect to the vitamin B-12 content in their milk. A substantial amount of genetic variation in vitamin B-12 content was detected among raw milk samples of 544 first-lactation Dutch Holstein Friesian cows. The presence of genetic variation between animals in vitamin B-12 content in milk indicates that the genotype of the cow affects the amount of vitamin B-12 that ends up in her milk and, consequently, that the average milk vitamin B-12 content of the cow population can be increased by genetic selection. A genome-wide association study revealed significant association between 68 SNP and vitamin B-12 content in raw milk of 487 first-lactation Dutch Holstein Friesian cows. This knowledge facilitates genetic selection for milk vitamin B-12 content. It also contributes to the understanding of the biological mechanism responsible for the observed genetic variation in vitamin B-12 content in milk. None of the 68 significantly associated SNP were in or near known candidate genes involved in transport of vitamin B-12 through the gastrointestinal tract, uptake by ileum epithelial cells, export from ileal cells, transport through the blood, uptake from the blood, intracellular processing, or reabsorption by the kidneys. Probably, associations relate to genes involved in alternative pathways of well-studied processes or to genes involved in less well-studied processes such as ruminal production of vitamin B-12 or secretion of vitamin B-12 by the mammary gland.

Biodiversity and growth dynamics of lactic acid bacteria in artisanal PDO Ossau-Iraty cheeses made from raw ewe's milk with different starters.

PubMed

Feutry, Fabienne; Oneca, María; Berthier, Françoise; Torre, Paloma

2012-02-01

The biodiversity and growth dynamics of Lactic Acid Bacteria (LAB) in farm-house Ossau-Iraty cheeses were investigated from vat milk to 180 days of ripening in six independent batches made from six raw ewe's milks using five typical cheese-making methods. Commercial starter S1 was used for three batches, starter S1 combined with S2 for one batch and no starter for two batches. Up to ten LAB species from five genera and up to two strains per species were identified per milk; up to eleven species from five genera and up to three strains per species were identified per cheese. Lactococcus lactis, Lactobacillus paracasei, Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, and Leuconostoc mesenteroides were detected in all cheeses. Lactococci reached the highest counts irrespective of the milk and starter used. Lactococci and enterococci increased during manufacture, and mesophilic lactobacilli increased during ripening. Strain and species numbers, the percentage of isolates originating from the raw milk, maximum counts of each genus/species and time for reaching them, all varied according to whether or not a starter was used and the composition of the starter. The genotypes of strains within species varied according to the raw milk used. This generated distinct LAB microbiotas throughout manufacture and ripening that will certainly impact on the characteristics of the ripened cheeses. Copyright © 2011 Elsevier Ltd. All rights reserved.

Development of a qPCR direct detection method for Listeria monocytogenes in milk

USDA-ARS?s Scientific Manuscript database

There is a growing movement among consumers in the US and Europe towards minimally processed foods, including raw milk and dairy products. This trend significantly increases exposure to dairy-borne pathogens and indicates a need for rapid, sensitive screening tests for raw dairy products to reduce ...

Immunomodulatory potential of a brewers' spent grain protein hydrolysate incorporated into low-fat milk following in vitro gastrointestinal digestion.

PubMed

Crowley, Damian; O'Callaghan, Yvonne; McCarthy, Aoife; Connolly, Alan; Piggott, Charles O; FitzGerald, Richard J; O'Brien, Nora M

2015-01-01

Brewers' spent grain (BSG) protein rich fraction was previously hydrolysed using Alcalase (U) and three additional fractions were prepared by membrane fractionation; a 5-kDa retentate (U > 5), a 5-kDa permeate (U < 5) and a 3-kDa permeate (U < 3). In the present study, these fractions were added to milk, subjected to simulated gastrointestinal digestion (SGID) and their anti-inflammatory potential was investigated. The digestates caused a significant reduction (p < 0.05) in interleukin-6 (IL-6) production in Concanavalin-A (ConA)-stimulated Jurkat T cells. The samples did not significantly alter the production of IL-6 in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. IL-2 and interferon-γ (IFN-γ) production in stimulated Jurkat T cells and IL-1β and tumor necrosis factor-α (TNF-α) production in stimulated RAW 264.7 cells were not affected in the presence of the digestates. Results show that a SGID milk product supplemented with BSG hydrolysate and its associated ultrafiltered fractions can confer anti-inflammatory effects in Jurkat T cells.

Rapid Diagnostic Device for Subclinical Mastitis Based on Electrochemical Detection of Superoxide Produced from Neutrophils in Fresh Milk

NASA Astrophysics Data System (ADS)

Okada, Kohei; Fukuda, Junji; Suzuki, Hiroaki

Electrochemical microdevices were fabricated to identify mastitic cows based on the increased number of neutrophils in raw milk. Because neutrophils produce superoxide (O2·-), the amount of O2·- can be used as an early indicator for subclinical mastitis. In the microdevices, O2·- was detected on a gold electrode using superoxide dismutase immobilized via a self-assembled monolayer of cysteine. In a preliminary test using xanthine oxidase to produce O2·-, one of the devices detected the production and rapid extinction of O2·-. When neutrophils obtained from a mastitic cow were concentrated by centrifugation and introduced into the device, a current increase distinctly different from the background was observed. Furthermore, a micropillar structure was fabricated on the gold electrode to trap and collect neutrophils, thereby facilitating the concentration of these cells around the electrode. The measured current clearly depended on the number of neutrophils in raw milk samples, demonstrating the applicability of the device for rapid diagnosis of subclinical mastitis.

Invited review: Microbial evolution in raw-milk, long-ripened cheeses produced using undefined natural whey starters.

PubMed

Gatti, Monica; Bottari, Benedetta; Lazzi, Camilla; Neviani, Erasmo; Mucchetti, Germano

2014-02-01

The robustness of the starter culture during cheese fermentation is enhanced by the presence of a rich consortium of microbes. Natural starters are consortia of microbes undoubtedly richer than selected starters. Among natural starters, natural whey starters (NWS) are the most common cultures currently used to produce different varieties of cheeses. Undefined NWS are typically used for Italian cooked, long-ripened, extra-hard, raw milk cheeses, such as Parmigiano Reggiano and Grana Padano. Together with raw milk microbiota, NWS are responsible for most cheese characteristics. The microbial ecology of these 2 cheese varieties is based on a complex interaction among starter lactic acid bacteria (SLAB) and nonstarter lactic acid bacteria (NSLAB), which are characterized by their different abilities to grow in a changing substrate. This review aims to summarize the latest findings on Parmigiano Reggiano and Grana Padano to better understand the dynamics of SLAB, which mainly arise from NWS, and NSLAB, which mainly arise from raw milk, and their possible role in determining the characteristics of these cheeses. The review is presented in 4 main sections. The first summarizes the main microbiological and chemical properties of the ripened cheese as determined by cheese-making process variables, as these variables may affect microbial growth. The second describes the microbiota of raw milk as affected by specific milk treatments, from milking to the filling of the cheese milk vat. The third describes the microbiota of NWS, and the fourth reviews the knowledge available on microbial dynamics from curd to ripened cheese. As the dynamics and functionality of complex undefined NWS is one of the most important areas of focus in current food microbiology research, this review may serve as a good starting point for implementing future studies on microbial diversity and functionality of undefined cheese starter cultures. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Residue behavior of organochlorine pesticides during the production process of yogurt and cheese.

PubMed

Duan, Jing; Cheng, Zheng; Bi, Jiawei; Xu, Yangguang

2018-04-15

The presence of organochlorine pesticides (OCPs) in dairy products can lead to human exposure. This study investigated the behavior of OCP residues in milk during yogurt and cheese production. Gas chromatography with electron-capture detection (GC-ECD) was used to detect α-hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), γ-HCH, g-chlordane, and α-chlordane in fresh milk, yogurt, and cheese. The results showed that fermentation reduced the residual concentration of OCPs in yogurt, with processing factors (PFs) ranging from 0.42 to 0.64. The reductions in residue levels during fermentation were due to the activity of the starter. The cheese making process increased the residual concentration of OCPs in cheese compared to raw milk, with PFs ranging from 2.37 to 4.93. Additionally, milk, yogurt, and cheese samples were purchased from local markets and OCP levels were analyzed. The target OCPs ranged from ND to 16.50 μg/kg in these samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of Hygiene and Safety Criteria in the Production of a Traditional Piedmont Cheese.

PubMed

Astegiano, Sara; Bellio, Alberto; Adriano, Daniela; Bianchi, Daniela Manila; Gallina, Silvia; Gorlier, Alessandra; Gramaglia, Monica; Lombardi, Giampiero; Macori, Guerrino; Zuccon, Fabio; Decastelli, Lucia

2014-08-28

Traditional products and related processes must be safe to protect consumers' health. The aim of this study was to evaluate microbiological criteria of a traditional Piedmont cheese, made by two different cheese producers (A and B). Three batches of each cheese were considered. The following seven samples of each batch were collected: raw milk, milk at 38°C, curd, cheese at 7, 30, 60, 90 days of ripening. During cheese making process, training activities dealing with food safety were conducted. Analyses regarding food safety and process hygiene criteria were set up according to the EC Regulation 2073/2005. Other microbiological and chemical-physical analyses [lactic streptococci, lactobacilli, pH and water activity (A w )] were performed as well. Shiga-toxin Escherichia coli , aflatoxin M1 and antimicrobial substances were considered only for raw milk. All samples resulted negative for food safety criteria; Enterobacteriaceae , E.coli and coagulase-positive staphylococci (CPS) were high in the first phase of cheese production, however they decreased at the end of ripening. A high level of CPS in milk was found in producer A, likewise in some cheese samples a count of >5 Log CFU/g was reached; staphylococcal enterotoxins resulted negative. The pH and A w values decreased during the cheese ripening period. The competition between lactic flora and potential pathogen microorganisms and decreasing of pH and A w are considered positive factors in order to ensure safety of dairy products. Moreover, training activities play a crucial role to manage critical points and perform corrective action. Responsible application of good manufacturing practices are considered key factors to obtain a high hygienic level in dairy products.

Assessment of the prevalence of Mycobacterium avium subsp. paratuberculosis in commercially pasteurized milk.

PubMed

Cerf, O; Griffiths, M; Aziza, F

2007-01-01

Conflicting laboratory-acquired data have been published about the heat resistance of Mycobacterium avium subsp. paratuberculosis (MAP), the cause of the deadly paratuberculosis (Johne's disease) of ruminants. Results of surveys of the presence of MAP in industrially pasteurized milk from several countries are conflicting also. This paper critically reviews the available data on the heat resistance of MAP and, based on these studies, a quantitative model describing the probability of finding MAP in pasteurized milk under the conditions prevailing in industrialized countries was derived using Monte Carlo simulation. The simulation assesses the probability of detecting MAP in 50-mL samples of pasteurized milk as lower than 1%. Hypotheses are presented to explain why higher frequencies were found by some authors; these included improper pasteurization and cross-contamination in the analytical laboratory. Hypotheses implicating a high rate of inter- and intraherd prevalence of paratuberculosis or heavy contamination of raw milk by feces were rejected.

A comprehensive dairy valorization model.

PubMed

Banaszewska, A; Cruijssen, F; van der Vorst, J G A J; Claassen, G D H; Kampman, J L

2013-02-01

Dairy processors face numerous challenges resulting from both unsteady dairy markets and some specific characteristics of dairy supply chains. To maintain a competitive position on the market, companies must look beyond standard solutions currently used in practice. This paper presents a comprehensive dairy valorization model that serves as a decision support tool for mid-term allocation of raw milk to end products and production planning. The developed model was used to identify the optimal product portfolio composition. The model allocates raw milk to the most profitable dairy products while accounting for important constraints (i.e., recipes, composition variations, dairy production interdependencies, seasonality, demand, supply, capacities, and transportation flows). The inclusion of all relevant constraints and the ease of understanding dairy production dynamics make the model comprehensive. The developed model was tested at the international dairy processor FrieslandCampina (Amersfoort, the Netherlands). The structure of the model and its output were discussed in multiple sessions with and approved by relevant FrieslandCampina employees. The elements included in the model were considered necessary to optimally valorize raw milk. To illustrate the comprehensiveness and functionality of the model, we analyzed the effect of seasonality on milk valorization. A large difference in profit and a shift in the allocation of milk showed that seasonality has a considerable impact on the valorization of raw milk. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Prevalence of Listeria monocytogenes in Idiazabal cheese.

PubMed

Arrese, E; Arroyo-Izaga, M

2012-01-01

Raw-milk cheese has been identified in risk assessment as a food of greater concern to public health due to listeriosis. To determine the prevalence and levels of Listeria monocytogenes in semi-hard Idiazabal cheese manufactured by different producers in the Basque Country at consumer level. A total of 51 Idiazabal cheese samples were obtained from 10 separate retail establishments, chosen by stratified random sampling. Samples were tested using the official standard ISO procedure 11290-1 for detection and enumeration methods. All cheese samples tested negative for L. monocytogenes. However, 9.8% tested positive for Listeria spp., different from L. monocytogenes. Positive samples came from two brands, two were natural and three were smoked. The presence of Listeria spss. suggests that the cheese making process and the hygiene whether at milking or during cheese making could be insufficient.

Light scattering and transmission measurement using digital imaging for online analysis of constituents in milk

NASA Astrophysics Data System (ADS)

Jain, Pranay; Sarma, Sanjay E.

2015-05-01

Milk is an emulsion of fat globules and casein micelles dispersed in an aqueous medium with dissolved lactose, whey proteins and minerals. Quantification of constituents in milk is important in various stages of the dairy supply chain for proper process control and quality assurance. In field-level applications, spectrophotometric analysis is an economical option due to the low-cost of silicon photodetectors, sensitive to UV/Vis radiation with wavelengths between 300 - 1100 nm. Both absorption and scattering are witnessed as incident UV/Vis radiation interacts with dissolved and dispersed constituents in milk. These effects can in turn be used to characterize the chemical and physical composition of a milk sample. However, in order to simplify analysis, most existing instrument require dilution of samples to avoid effects of multiple scattering. The sample preparation steps are usually expensive, prone to human errors and unsuitable for field-level and online analysis. This paper introduces a novel digital imaging based method of online spectrophotometric measurements on raw milk without any sample preparation. Multiple LEDs of different emission spectra are used as discrete light sources and a digital CMOS camera is used as an image sensor. The extinction characteristic of samples is derived from captured images. The dependence of multiple scattering on power of incident radiation is exploited to quantify scattering. The method has been validated with experiments for response with varying fat concentrations and fat globule sizes. Despite of the presence of multiple scattering, the method is able to unequivocally quantify extinction of incident radiation and relate it to the fat concentrations and globule sizes of samples.

Short communication: jenny milk as an inhibitor of late blowing in cheese: a preliminary report.

PubMed

Cosentino, C; Paolino, R; Freschi, P; Calluso, A M

2013-06-01

Late blowing on semihard and hard cheese may have an important economic effect on dairy production. Many studies have attempted to prevent this defect by physical treatment, the use of additives, and the use of bacteriocins. In this paper, we look at the effect of jenny milk as an inhibitor of blowing caused by clostridia and coliforms in ewe cheese making. Bulk ewe and jenny milk samples were collected in the morning by mechanical milking and were refrigerated at 4°C. On the collected samples, the count of somatic cells, coliforms, Clostridium butyricum, and Escherichia coli were determined. The bulk raw milk was divided in two 45-L vats: vat 1 was used as a control, whereas 0.5L of jenny milk was added to vat 2. Four semihard cheeses, weighing about 2 kg each, were made from each vat. Cheese making was replicated twice. After a ripening period of 60 d, the count of coliforms and of C. butyricum was determined. In the treated group, a significant inhibition of coliform bacteria was observed. The addition of jenny milk in cheese making may prove to be a useful and innovative approach for the inhibition of spore-forming clostridia strains. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

[Study on national active monitoring for food borne pathogens and antimicrobial resistance in China 2001].

PubMed

Wang, Maoqi; Ran, Lu; Wang, Zhutian; Li, Zhigang

2004-01-01

To survey food borne pathogens and antimicrobial resistance in China. A total of 4034 samples of foods (raw meats, raw milk, cooked meats, ice cream, yoghurt, aquatic product and vegetable) were examined for the presence of Escherichia coli O157:H7 Salmonella spp and Listeria monocytogens by national active foodborne pathogens surveillance system. The samples were obtained from 11 provinces in 2001. Approximate 5.50% of the all samples yielded 3 pathogenes, whereas Escherichia coli O157:H7 (0.82%), Salmonella servoars (3.32%) and Listeria monocytogens (1.29%). The most heavy contamination by three food borne pathogens are in raw meat (12.96%). Top seven serotype of the 137 Salmonella isolates are S. derby, S. agona, S. enteritidis, S. reading, S. anatum. S. muenster, S. typhimurium. Serotypes and antibiotic resistance patterns of Salmonella isolates are different in 11 provinces. E. coli O157:H7 strains that are isolated from raw meat and cooked meat have VT2, eae, Hly genes. Salmonella and E. coli strains of multidrug resistance were isolated and identified.

Prevalence, identification of virulence factors, O-serogroups and antibiotic resistance properties of Shiga-toxin producing Escherichia coli strains isolated from raw milk and traditional dairy products.

PubMed

Ranjbar, Reza; Safarpoor Dehkordi, Farhad; Sakhaei Shahreza, Mohammad Hossein; Rahimi, Ebrahim

2018-01-01

Shiga-toxigenic Escherichia coli strains are one of the most important foodborne bacteria with an emergence of antibiotic resistance. Foodborne STEC strains are mainly associated with presence of certain virulence factors and O-seogroups. The present investigation was done to study the distribution of virulence factors, O-serogroups and antibiotic resistance properties of Shiga-toxigenic Escherichia coli isolated from milk and dairy products. Six-hundred samples were randomly collected and immediately transferred to laboratory. All samples were cultured and E. coli strains were isolated. STEC strains were identified based on the presence of putative virulence factors and subtypes. STEC isolates were subjected to multiplex PCR and disk diffusion methods. One-hundred and eighty-one out of 600 samples (30.16%) harbored E. coli . Prevalence of STEC strains was 10.66%. O157 (43.75%) and O26 (37.50%) were the most frequently identified serogroups. Aac(3)-IV (100%), CITM (96.87%) and tetA (76.56%) were the most commonly detected antibiotic resistance genes. STEC strains had the highest prevalence of resistance against ampicillin (100%), gentamicin (100%) and tetracycline (96.87%). Kashk and dough were negative for presence of E. coli strains. High prevalence of resistant-O157 strains and simultaneous presence of multiple virulence factors pose an important public health problem regarding the consumption of raw milk and dairy products.

Isolation and detection of Listeria monocytogenes in poultry meat by standard culture methods and PCR

NASA Astrophysics Data System (ADS)

Kureljušić, J.; Rokvić, N.; Jezdimirović, N.; Kureljušić, B.; Pisinov, B.; Karabasil, N.

2017-09-01

Listeria is the genus of a bacteria found in soil and water and some animals, including poultry and cattle. It can be present in raw milk and food made from raw milk. It can also live in food processing plants and contaminate a variety of processed meats. Microscopically, Listeria species appear as small, Gram-positive rods, which are sometimes arranged in short chains. In direct smears, they can be coccoid, so they can be mistaken for streptococci. Longer cells can resemble corynebacteria. Flagella are produced at room temperature but not at 37°C. Haemolytic activity on blood agar has been used as a marker to distinguish Listeria monocytogenes among other Listeria species, but it is not an absolutely definitive criterion. Further biochemical characterization is necessary to distinguish between the different Listeria species. The objective of this study was to detect, isolate and identify Listeria monocytogenes from poultry meat. Within a period of six months from January to June 2017, a total of 15 samples were collected. Three samples were positive for the presence of Listeria monocytogenes. Biochemical and microbiological tests as well as PCR technique using specific primers were used to confirm L. Monocytogenes in the samples.

Effects of raw milk and starter feed on intake and body composition of Holstein × Gyr male calves up to 64 days of age.

PubMed

Silva, A L; Marcondes, M I; Detmann, E; Machado, F S; Valadares Filho, S C; Trece, A S; Dijkstra, J

2015-04-01

The objective was to evaluate the effect of supplying different levels of raw milk, alone or in combination, with access to a starter feed, on the intake, digestibility, daily gain, N balance, and body composition of Holstein × Gyr crossbred suckling calves until 64 d of age. Thirty-nine male calves aged 4 d with an average initial live weight of 36 ± 1.0 kg were used. Five calves were defined as a reference group and slaughtered at 4 d of age to estimate the initial body composition of the animals. The other calves were distributed according to a completely randomized design in a 3 × 2 factorial arrangement consisting of 3 levels of milk (2, 4, or 8 L/d) and 2 levels of starter feed (presence or absence in diet). At 15 and 45 d of age, 4 animals from each treatment were subjected to digestibility trials with total collection of feces and urine and sampling of feeds. At 64 d of age, all animals were slaughtered and their body tissues were sampled for analyses. Total dry matter and nutrient intake increased linearly and starter intake decreased linearly in response to the supply of increasing amounts of milk. The digestibility coefficient of organic matter was not affected by the inclusion of starter feed and increased linearly as milk supply was elevated. Daily gain was greater at increased milk supply levels and also greater when starter was supplied, without any interaction between milk supply level and the presence or absence of starter. Fecal N excretion and N retention were higher in the animals fed starter feed. Fecal N excretion was not affected by milk levels, whereas N retention was affected. Body protein and ash contents decreased linearly according to increased milk allowance. In contrast, fat body content increased linearly according to milk supply. The presence of starter feed in the diet was responsible for the increased body fat content, but had no effect on protein or ash content. In conclusion, weight gain and N retention in calves up to 64 d of age increased with milk supply. Ad libitum access to starter further increased weight gain and N retention and no interaction with milk allowance level occurred. However, greater levels of milk are also associated with reduced starter feed intake, in addition to increased body fat content. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

[Determination of fat, protein and DM in raw milk by portable short-wave near infrared spectrometer].

PubMed

Li, Xiao-yun; Wang, Jia-hua; Huang, Ya-wei; Han, Dong-hai

2011-03-01

Near infrared diffuse reflectance spectroscopy calibrations of fat, protein and DM in raw milk were studied with partial least-squares (PLS) regression using portable short-wave near infrared spectrometer. The results indicated that good calibrations of fat and DM were found, the correlation coefficients were all 0.98, the RMSEC were 0.187 and 0.217, RMSEP were 0.187 and 0.296, the RPDs were 5.02 and 3.20 respectively; the calibration of protein needed to be improved but can be used for practice, the correlation coefficient was 0.95, RMSEC was 0.105, RMSEP was 0.120, and RPD was 2.60. Furthermore, the measuring accuracy was improved by analyzing the correction relation of fat and DM in raw milk This study will probably provide a new on-site method for nondestructive and rapid measurement of milk.

Isotopic ratio analysis of cattle tail hair: A potential tool in building the database for cow milk geographical traceability.

PubMed

Behkami, Shima; Zain, Sharifuddin Md; Gholami, Mehrdad; Bakirdere, Sezgin

2017-02-15

The potential for the isotopic ratio analysis of cattle tail hair in determining the geographical origin of raw cow milk in Peninsular Malaysia had been investigated in this research using exploratory visualization. A significant positive correlation (p<0.0001) (n=54) was noticed between δ(13)C and δ(15)N in milk with that of hair which indicated that these matrices could be used in tracing the geographical origin of animal produce and tissues, and there is a possibility that hair could be used as a substitute in building the database for the geographical traceability of milk. It was also observed that both hair and milk isotopic ratio correlations exhibited separation between the northern and southern regions. The accuracy of using isotopic ratio in determining geographical discrimination had been clearly demonstrated when several commercial milk samples from the same regions under the study were correctly assigned to the appropriate geographical clusters. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Results of mycologic studies of donated breast milk].

PubMed

Blaschke-Hellmessen, R; Henker, J; Futschik, M

1991-03-01

From 1968 to 1989 altogether 37,000 specimens of donated and collected mother's milk were mycologically examined by means of a liquid medium (twofold concentrated Raulin solution). The yearly incidence of Candida albicans varied between 8.5 and 5.2%. 25% respectively 14.8% of the donors (n = 60 respectively 813) had delivered milk to the human milk bank which was contaminated by Candida albicans. The mother's milk was primarily contaminated by the donor's own suckling baby. 92.3% of these infants were infected with Candida albicans in the mouth and/or rectum and/or on the skin. Candida albicans was also detected in 46.2% on the nipples of the mothers. It is recommended to transport donated mother's milk at temperatures of 4-8 degrees C and to store the milk at -20 degrees C until the mycological examination is finished to exclude samples contaminated by Candida albicans. Judging our experience donated human milk to be fed in raw state should be regularly controlled mycologically. If the donated milk contains Candida albicans, the donation of milk should be interrupted and an antifungal treatment of the donor and her baby should be performed.

Distribution of animal drugs among curd, whey, and milk protein fractions in spiked skim milk and whey

USDA-ARS?s Scientific Manuscript database

It is important to understand the partitioning of drugs in processed milk and milk products, when drugs are present in raw milk, in order to estimate the potential consumer exposure. Radioisotopically labelled erythromycin, ivermectin, ketoprofen, oxytetracycline, penicillin G, sulfadimethoxine, and...

Examining trust factors in online food risk information: The case of unpasteurized or 'raw' milk.

PubMed

Sillence, Elizabeth; Hardy, Claire; Medeiros, Lydia C; LeJeune, Jeffrey T

2016-04-01

The internet has become an increasingly important way of communicating with consumers about food risk information. However, relatively little is known about how consumers evaluate and come to trust the information they encounter online. Using the example of unpasteurized or raw milk this paper presents two studies exploring the trust factors associated with online information about the risks and benefits of raw milk consumption. In the first study, eye-tracking data was collected from 33 pasteurised milk consumers whilst they viewed six different milk related websites. A descriptive analysis of the eye-tracking data was conducted to explore viewing patterns. Reports revealed the importance of images as a way of capturing initial attention and foregrounding other features and highlighted the significance of introductory text within a homepage. In the second, qualitative study, 41 consumers, some of whom drank raw milk, viewed a selection of milk related websites before participating in either a group discussion or interview. Seventeen of the participants also took part in a follow up telephone interview 2 weeks later. The qualitative data supports the importance of good design whilst noting that balance, authorship agenda, the nature of evidence and personal relevance were also key factors affecting consumers trust judgements. The results of both studies provide support for a staged approach to online trust in which consumers engage in a more rapid, heuristic assessment of a site before moving on to a more in-depth evaluation of the information available. Findings are discussed in relation to the development of trustworthy online food safety resources. Copyright © 2016 Elsevier Ltd. All rights reserved.

From milk to diet: feed recognition for milk authenticity.

PubMed

Ponzoni, E; Gianì, S; Mastromauro, F; Breviario, D

2009-11-01

The presence of plastidial DNA fragments of plant origin in animal milk samples has been confirmed. An experimental plan was arranged with 4 groups of goats, each provided with a different monophytic diet: 3 fresh forages (oats, ryegrass, and X-triticosecale) and one 2-wk-old silage (X-triticosecale). Feed-derived rubisco (ribulose bisphosphate carboxylase, rbcL) DNA fragments were detected in 100% of the analyzed goat milk samples, and the nucleotide sequence of the PCR-amplified fragments was found to be 100% identical to the corresponding fragments amplified from the plant species consumed in the diet. Two additional chloroplast-based molecular markers were used to set up an assay for distinctiveness, conveniently based on a simple PCR. In one case, differences in single nucleotides occurring within the gene encoding for plant maturase K (matK) were exploited. In the other, plant species recognition was based on the difference in the length of the intron present within the transfer RNA leucine (trnL) gene. The presence of plastidial plant DNA, ascertained by the PCR-based amplification of the rbcL fragment, was also assessed in raw cow milk samples collected directly from stock farms or taken from milk sold on the commercial market. In this case, the nucleotide sequence of the amplified DNA fragments reflected the multiple forages present in the diet fed to the animals.

The milk delivery chain and presence of Brucella spp. antibodies in bulk milk in Uganda.

PubMed

Rock, Kim Toeroek; Mugizi, Denis Rwabiita; Ståhl, Karl; Magnusson, Ulf; Boqvist, Sofia

2016-06-01

This study examined the influence of informal milk delivery chains on the risk of human exposure to Brucella spp. through milk consumption in two regions of Uganda (Gulu and Soroti Districts). The work involved describing milk delivery chains, investigating brucellosis awareness amongst milk deliverers and determining the presence of Brucella spp. antibodies in cattle milk on delivery to primary collection points (boiling points and dairies). Milk samples (n = 331) were collected from deliverers at primary collection points and from street vendors at point of sale and analysed using indirect enzyme-linked immunosorbent assay (I-ELISA). A written questionnaire was used to collect data from deliverers (n = 279) on their milk delivery chains and their brucellosis awareness. The most common delivery points in Gulu District were small dairies and in Soroti District boiling points. The presence of Brucella spp. antibodies in milk samples was higher in Soroti (40 %) than in Gulu (11 %) (P < 0.0001). There are possible public health risk consequences of this finding as 42 % of deliverers in Soroti District reported drinking raw milk, compared with 15 % in Gulu District (P < 0.0001). Awareness of brucellosis was low, with 70 % of all milk deliverers reporting not having heard of the disease or the bacterium. Application of quality controls for milk (colour and odour) along the delivery chain varied depending upon supply and demand. This study provides evidence of the diversity of informal milk markets in low-income countries and of the potential public health risks of consuming unpasteurised milk. These results can be useful to those planning interventions to reduce brucellosis.

A 100-Year Review: The production of fluid (market) milk.

PubMed

Barbano, David M

2017-12-01

During the first 100 years of the Journal of Dairy Science, dairy foods and dairy production dairy scientists have partnered to publish new data and research results that have fostered the development of new knowledge. This knowledge has been the underpinning of both the commercial development of the fluid milk processing industry and regulations and marketing policies for the benefit of dairy farmers, processors, and consumers. During the first 50 years, most of the focus was on producing and delivering high-quality raw milk to factories and improving the shelf life of pasteurized fluid milk. During the second 50 years, raw milk quality was further improved through the use of milk quality payment incentives. Due to changing demographics and lifestyle, whole fluid milk consumption declined and processing technologies were developed to increase the range of fluid milk products (skim and low-fat milks, flavored milks, lactose-reduced milk, long-shelf-life milks, and milks with higher protein and calcium contents) offered to the consumer. In addition, technology to produce specialty high-protein sports beverages was developed, which expanded the milk-based beverage offerings to the consumer. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Detection and genotyping of Toxoplasma gondii DNA in the blood and milk of naturally infected donkeys (Equus asinus).

PubMed

Mancianti, Francesca; Nardoni, Simona; Papini, Roberto; Mugnaini, Linda; Martini, Mina; Altomonte, Iolanda; Salari, Federica; D'Ascenzi, Carlo; Dubey, Jitender P

2014-04-03

Toxoplasma gondii is a worldwide zoonotic protozoan. Consumption of raw milk from infected animals is considered a risk factor for acquiring toxoplasmosis in humans. Recently, donkey milk has been indicated for therapeutic and nutritional purposes and T. gondii infection is common in donkeys. The purpose of the present paper was to detect the presence of parasite DNA in milk of T. gondii positive donkeys. Antibodies to T. gondii were found in 11 out of 44 healthy lactating donkeys by IFAT. T. gondii DNA was detected by PCR in blood of 6 and milk of 3 seropositive jennies. Results of limited RFLP-PCR genotyping indicated the presence of T. gondii genotype II or III, commonly found in Europe. The occurrence of T. gondii DNA in milk suggests that the consumption of raw milk from seropositive donkeys could be a potential source of human infection.

Rapid detection methods for viable Mycobacterium avium subspecies paratuberculosis in milk and cheese.

PubMed

Botsaris, George; Slana, Iva; Liapi, Maria; Dodd, Christine; Economides, Constantinos; Rees, Catherine; Pavlik, Ivo

2010-07-31

Mycobacterium avium subsp. paratuberculosis (MAP) may have a role in the development of Crohn's disease in humans via the consumption of contaminated milk and milk products. Detection of MAP from milk and dairy products has been reported from countries on the European continent, Argentina, the UK and Australia. In this study three different methods (quantitative real time PCR, combined phage IS900 PCR and conventional cultivation) were used to detect the presence of MAP in bulk tank milk (BTM) and cheese originating from sheep, goat and mixed milks from farms and products in Cyprus. During the first survey the presence of MAP was detected in 63 (28.6%) of cows' BTM samples by quantitative real time PCR. A second survey of BTM used a new combined phage IS900 PCR assay, and in this case MAP was detected in 50 (22.2%) samples showing a good level of agreement by both methods. None of the herds tested were known to be affected by Johne's disease and the presence of viable MAP was confirmed by conventional culture in only two cases of cows BTM. This suggests that either rapid method used is more sensitive than the conventional culture when testing raw milk samples for MAP. The two isolates recovered from BTM were identified by IS1311 PCR REA as cattle and sheep strains, respectively. In contrast when cheese samples were tested, MAP DNA was detected by quantitative real time PCR in seven (25.0%) samples (n=28). However no viable MAP was detected when either the combined phage IS900 PCR or conventional culture methods were used. Copyright 2010 Elsevier B.V. All rights reserved.

40 CFR 180.6 - Pesticide tolerances regarding milk, eggs, meat, and/or poultry; statement of policy.

Code of Federal Regulations, 2010 CFR

2010-07-01

... residues in or on raw agricultural commodities, consideration is always given to possible residues of those pesticide chemicals or their conversion products entering the diet of man through the ingestion of milk... finite residues will actually be incurred in these foods from feed use of the raw agricultural commodity...

40 CFR 180.6 - Pesticide tolerances regarding milk, eggs, meat, and/or poultry; statement of policy.

Code of Federal Regulations, 2011 CFR

2011-07-01

... residues in or on raw agricultural commodities, consideration is always given to possible residues of those pesticide chemicals or their conversion products entering the diet of man through the ingestion of milk... finite residues will actually be incurred in these foods from feed use of the raw agricultural commodity...

A cluster of two human cases of tick-borne encephalitis (TBE) transmitted by unpasteurised goat milk and cheese in Germany, May 2016.

PubMed

Brockmann, S O; Oehme, R; Buckenmaier, T; Beer, M; Jeffery-Smith, A; Spannenkrebs, M; Haag-Milz, S; Wagner-Wiening, C; Schlegel, C; Fritz, J; Zange, S; Bestehorn, M; Lindau, A; Hoffmann, D; Tiberi, S; Mackenstedt, U; Dobler, G

2018-04-01

In May 2016, two cases of tick-borne encephalitis (TBE) were confirmed by serology (positive IgM and IgG antibodies against TBE virus (TBEV) in serum), with a possible link to raw milk and cheese from a goat farm in a region in Baden-Württemberg, Germany not previously known as TBE-endemic. The outbreak investigation identified 32 consumers of goat dairy products (29 consumers, one farm employee, two owners) of whom none had IgM antibodies against TBEV 3-8 weeks after consumption. Of the 27 notified TBE cases in the State, none reported consumption of raw goat milk or cheese from the suspected farm. Five of 22 cheese samples from 18 different batches were RT-qPCR-positive for TBEV -genome, and two of the five samples were confirmed by virus isolation, indicating viability of TBEV in the cheese. Nine of the 45 goats had neutralising TBEV antibodies, two of them with a high titre indicating recent infection. One of 412 Ixodes ricinus was RT-qPCR-positive, and sequencing of the E gene from nucleic acid extracted from the tick confirmed TBEV. Phylogenetic analyses of tick and cheese isolates showed 100% amino acid homology in the E gene and a close relation to TBEV strains from Switzerland and Austria.

Molecular approaches to analysing the microbial composition of raw milk and raw milk cheese.

PubMed

Quigley, Lisa; O'Sullivan, Orla; Beresford, Tom P; Ross, R Paul; Fitzgerald, Gerald F; Cotter, Paul D

2011-11-01

The availability and application of culture-independent tools that enable a detailed investigation of the microbiota and microbial biodiversity of food systems has had a major impact on food microbiology. This review focuses on the application of DNA-based technologies, such as denaturing gradient gel electrophoresis (DGGE), temporal temperature gradient gel electrophoresis (TTGE), single stranded conformation polymorphisms (SSCP), the polymerase chain reaction (PCR) and others, to investigate the diversity, dynamics and identity of microbes in dairy products from raw milk. Here, we will highlight the benefits associated with culture-independent methods which include enhanced sensitivity, rapidity and the detection of microorganisms not previously associated with such products. Copyright © 2011 Elsevier B.V. All rights reserved.

Concentrations of 17beta-estradiol in Holstein whole milk.

PubMed

Pape-Zambito, D A; Magliaro, A L; Kensinger, R S

2007-07-01

Some individuals have expressed concern about estrogens in food because of their potential to promote growth of estrogen-sensitive human cancer cells. Researchers have reported concentrations of estrogen in milk but few whole milk samples have been analyzed. Because estrogen associates with the fat phase of milk, the analysis of whole milk is an important consideration. The objectives of this study, therefore, were to quantify 17beta-estradiol (E2) in whole milk from dairy cows and to determine whether E2 concentrations in milk from cows in the second half of pregnancy were greater than that in milk from cows in the first half of pregnancy or in nonpregnant cows. Milk samples and weights were collected during a single morning milking from 206 Holstein cows. Triplicate samples were collected and 2 samples were analyzed for fat, protein, lactose, and somatic cell counts (SCC); 1 sample was homogenized and analyzed for E2. The homogenized whole milk (3 mL) was extracted twice with ethyl acetate and once with methanol. The extract was reconstituted in benzene:methanol (9:1, vol/vol) and run over a Sephadex LH-20 column to separate E2 from cholesterol and estrone before quantification using radioimmunoassay. Cows were classified as not pregnant (NP, n = 138), early pregnant (EP, 1 to 140 d pregnant, n = 47), or midpregnant (MP, 141 to 210 d pregnant, n = 21) at the time of milk sampling based on herd health records. Mean E2 concentration in whole milk was 1.4 +/- 0.2 pg/mL and ranged from nondetectable to 22.9 pg/mL. Milk E2 concentrations averaged 1.3, 0.9, and 3.0 pg/mL for NP, EP, and MP cows, respectively. Milk E2 concentrations for MP cows were greater and differed from those of NP and EP cows. Milk composition was normal for a Holstein herd in that log SCC values and percentages of fat, protein, and lactose averaged 4.9, 3.5, 3.1, and 4.8, respectively. Estradiol concentration was significantly correlated (r = 0.20) with percentage fat in milk. Mean milk yield was 18.9 +/- 0.6 kg for the morning milking. The mean E2 mass accumulated in the morning milk was 23.2 +/- 3.4 ng/cow. Likewise, using the overall mean concentration for E2 in milk, the mean E2 mass in 237 mL (8 fluid ounces) of raw whole milk was 330 pg. The quantity of E2 in whole milk, therefore, is low and is unlikely to pose a health risk for humans.

An outbreak of tuberculosis affecting cattle and people on an Irish dairy farm, following the consumption of raw milk

PubMed Central

2009-01-01

Bovine tuberculosis is an ongoing problem in Ireland, and herd incidence has remained at approximately 5% for some years. Spillover of infection from cattle to people remains an ever-present possibility, given the ongoing pool of infection in the Irish cattle population. This paper describes an outbreak of tuberculosis affecting cattle and people on a dairy farm in southeastern Ireland following the consumption of milk from a seven-year-old cow with tuberculous mastitis. Twenty-five of 28 calves born during autumn 2004 and spring 2005 were subsequently identified as TB reactors, and five of six family members were positive on the Mantoux test. During 2005, milk from this cow had mainly been used to feed calves, and was added only occasionally to the bulk tank. Therefore, the calves each received infected milk on an almost continuous basis between birth and weaning. The family collected milk from the bulk milk tank, and consumed it without pasteurisation. This case highlights the risks associated with the consumption of raw milk. In this family, TB has had a very significant impact on the health of two young children. These risks are well recognised, and relevant information for farmers is available. It is of concern, therefore, that raw milk consumption remains prevalent on Irish farms. New strategies are needed, in partnership with industry, to address this important issue. Keywords: bovine tuberculosis, Ireland, mastitis, milk, Mycobacterium bovis, pasteurisation, TB, zoonosis PMID:21851735

MiRNA Analysis by Quantitative PCR in Preterm Human Breast Milk Reveals Daily Fluctuations of hsa-miR-16-5p

PubMed Central

Floris, Ilaria; Billard, Hélène; Boquien, Clair-Yves; Joram-Gauvard, Evelyne; Simon, Laure; Legrand, Arnaud; Boscher, Cécile; Rozé, Jean-Christophe; Bolaños-Jiménez, Francisco; Kaeffer, Bertrand

2015-01-01

Background and Aims Human breast milk is an extremely dynamic fluid containing many biologically-active components which change throughout the feeding period and throughout the day. We designed a miRNA assay on minimized amounts of raw milk obtained from mothers of preterm infants. We investigated changes in miRNA expression within month 2 of lactation and then over the course of 24 hours. Materials and Methods Analyses were performed on pooled breast milk, made by combining samples collected at different clock times from the same mother donor, along with time series collected over 24 hours from four unsynchronized mothers. Whole milk, lipids or skim milk fractions were processed and analyzed by qPCR. We measured hsa-miR-16-5p, hsa-miR-21-5p, hsa-miR-146-5p, and hsa-let-7a, d and g (all -5p). Stability of miRNA endogenous controls was evaluated using RefFinder, a web tool integrating geNorm, Normfinder, BestKeeper and the comparative ΔΔCt method. Results MiR-21 and miR-16 were stably expressed in whole milk collected within month 2 of lactation from four mothers. Analysis of lipids and skim milk revealed that miR-146b and let-7d were better references in both fractions. Time series (5H-23H) allowed the identification of a set of three endogenous reference genes (hsa-let-7d, hsa-let-7g and miR-146b) to normalize raw quantification cycle (Cq) data. We identified a daily oscillation of miR-16-5p. Perspectives Our assay allows exploring miRNA levels of breast milk from mother with preterm baby collected in time series over 48–72 hours. PMID:26474056

Effects of management practices on yield and quality of milk from smallholder dairy units in urban and peri-urban Morogoro, Tanzania.

PubMed

Gillah, Kejeri A; Kifaro, George C; Madsen, Jorgen

2014-10-01

A longitudinal study design was used to assess the management, chemical composition of cows' milk and quantify the microbial load of raw milk produced at farm level. Data were collected between December 2010 and September 2011 in Morogoro municipality. Milk samples were collected once every month and analysed for butter fat (BF), crude protein (CP), total solids (TS) and solids non-fat (SNF). Total bacterial count (TBC) and coliform counts (CC) were normalized by log transformation. The average milk yield was 7.0 l/day and was not influenced by feeding systems and breeds. Dairy cows owned by people who had no regular income produced more milk than government employees and retired officers. Means of BF, TS, SNF and CP were similar in different feeding systems. Wet season had significantly higher TBC (5.9 log10 cfu/ml) and CC (2.4 log10 cfu/ml) but feeding systems had no effect. Stocking density influenced TBC but not CC. It can be concluded that dairy cows produced low milk yield and its quality was poor.

7 CFR 58.936 - Milk.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Milk. 58.936 Section 58.936 Agriculture Regulations of... Official Identification § 58.936 Milk. To process and package evaporated and condensed milk of ultra... Shield the raw incoming milk shall meet the requirements as outlined in §§ 58.132 through 58.136. Unless...

7 CFR 58.936 - Milk.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Milk. 58.936 Section 58.936 Agriculture Regulations of... Official Identification § 58.936 Milk. To process and package evaporated and condensed milk of ultra... Shield the raw incoming milk shall meet the requirements as outlined in §§ 58.132 through 58.136. Unless...

7 CFR 58.627 - Milk and dairy products.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Milk and dairy products. 58.627 Section 58.627... Material § 58.627 Milk and dairy products. To produce ice cream and related products the raw milk and cream... commingled milk and cream meeting the bacteriological requirements of No. 1 shall be used. ...

7 CFR 58.627 - Milk and dairy products.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Milk and dairy products. 58.627 Section 58.627... Material § 58.627 Milk and dairy products. To produce ice cream and related products the raw milk and cream... commingled milk and cream meeting the bacteriological requirements of No. 1 shall be used. ...

7 CFR 58.936 - Milk.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Milk. 58.936 Section 58.936 Agriculture Regulations of... Official Identification § 58.936 Milk. To process and package evaporated and condensed milk of ultra... Shield the raw incoming milk shall meet the requirements as outlined in §§ 58.132 through 58.136. Unless...

7 CFR 58.627 - Milk and dairy products.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Milk and dairy products. 58.627 Section 58.627... Material § 58.627 Milk and dairy products. To produce ice cream and related products the raw milk and cream... commingled milk and cream meeting the bacteriological requirements of No. 1 shall be used. ...

7 CFR 58.627 - Milk and dairy products.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Milk and dairy products. 58.627 Section 58.627... Material § 58.627 Milk and dairy products. To produce ice cream and related products the raw milk and cream... commingled milk and cream meeting the bacteriological requirements of No. 1 shall be used. ...

7 CFR 58.627 - Milk and dairy products.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Milk and dairy products. 58.627 Section 58.627... Material § 58.627 Milk and dairy products. To produce ice cream and related products the raw milk and cream... commingled milk and cream meeting the bacteriological requirements of No. 1 shall be used. ...

7 CFR 58.936 - Milk.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Milk. 58.936 Section 58.936 Agriculture Regulations of... Official Identification § 58.936 Milk. To process and package evaporated and condensed milk of ultra... Shield the raw incoming milk shall meet the requirements as outlined in §§ 58.132 through 58.136. Unless...

7 CFR 58.936 - Milk.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Milk. 58.936 Section 58.936 Agriculture Regulations of... Official Identification § 58.936 Milk. To process and package evaporated and condensed milk of ultra... Shield the raw incoming milk shall meet the requirements as outlined in §§ 58.132 through 58.136. Unless...

Collecting and banking human milk: to heat or not to heat?

PubMed

Björkstén, B; Burman, L G; De Château, P; Fredrikzon, B; Gothefors, L; Hernell, O

1980-09-20

Data on human breast milk and its handling when fed to babies who cannot be breast-fed were reviewed to determine whether the method of processing and storage affected the properties of the milk. Breast milk is normally contaminated by potential pathogens, which seem to produce no ill effects, but it also contains antimicrobial properties which protect against infection. The evidence suggests that pasteurisation not only eliminates pathogenic bacteria but also damages bacteriostatic mechanisms, so making the milk more susceptible to later contamination. Pasteurisation also affects the nutritional properties of milk. Freezing has little effect on milk proteins, while a study on the effect of refrigeration showed that there was little bacterial growth at temperatures below 8 degrees C. Several years' experience of feeding donated raw milk to newborn infants has confirmed that it produces no ill effects. These findings suggest that pasteurisation of donated breastmilk is unnecessary, and it is not recommended, while the decision whether or not to freeze the milk may be made on practical grounds. Raw breast milk can be safely stored at 4-6 degrees C for 72 hours.

Thermal inactivation of foot-and-mouth disease virus in milk using high-temperature, short-time pasteurization.

PubMed

Tomasula, P M; Kozempel, M F; Konstance, R P; Gregg, D; Boettcher, S; Baxt, B; Rodriguez, L L

2007-07-01

Previous studies of laboratory simulation of high temperature, short time pasteurization (HTST) to eliminate foot-and-mouth disease virus (FMDV) in milk have shown that the virus is not completely inactivated at the legal pasteurization minimum (71.7 degrees C/15 s) but is inactivated in a flow apparatus at 148 degrees C with holding times of 2 to 3 s. It was the intent of this study to determine whether HTST pasteurization conducted in a continuous-flow pasteurizer that simulates commercial operation would enhance FMDV inactivation in milk. Cows were inoculated in the mammary gland with the field strain of FMDV (01/UK). Infected raw whole milk and 2% milk were then pasteurized using an Arm-field pilot-scale, continuous-flow HTST pasteurizer equipped with a plate-and-frame heat exchanger and a holding tube. The milk samples, containing FMDV at levels of up to 10(4) plaque-forming units/mL, were pasteurized at temperatures ranging from 72 to 95 degrees C at holding times of either 18.6 or 36 s. Pasteurization decreased virus infectivity by 4 log10 to undetectable levels in tissue culture. However, residual infectivity was still detectable for selected pasteurized milk samples, as shown by intramuscular and intradermal inoculation of milk into naïve steers. Although HTST pasteurization did not completely inactivate viral infectivity in whole and 2% milk, possibly because a fraction of the virus was protected by the milk fat and the casein proteins, it greatly reduced the risk of natural transmission of FMDV by milk.

Effects of two different domestic boiling practices on the allergenicity of cow's milk proteins.

PubMed

Lamberti, Cristina; Baro, Cristina; Giribaldi, Marzia; Napolitano, Lorenzo; Cavallarin, Laura; Giuffrida, Maria Gabriella

2018-04-01

The sale of raw drinking milk through automatic dispensers is permitted in some EU member states, but consumers are usually advised to boil the milk before consumption. The present study has been conducted to evaluate the effects of two common domestic boiling techniques on the proteins of raw milk and, in particular, on their potential allergenicity. Native one-dimensional electrophoresis, N-terminal amino acid sequencing and immunoblotting have been used to characterize the protein pattern and to evaluate the possible changes in the allergenic properties of the processed milk. The main result of this investigation is that heating induces the aggregation of β-lactoglobulin in higher-molecular-weight products, while caseins seem to be more resistant to the treatments. β-Lactoglobulin aggregates have been found to be non-immunoreactive with the sera of subjects suffering from cow's milk protein allergy. Domestic boiling modifies the milk protein profile, causing a minor reduction in milk allergenicity. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Fermentation Results in Quantitative Changes in Milk-Derived Exosomes and Different Effects on Cell Growth and Survival.

PubMed

Yu, Siran; Zhao, Zhehao; Sun, Liming; Li, Ping

2017-02-15

The discovery of microRNAs encapsulated in milk-derived exosomes has revealed stability under extreme conditions reflecting the protection of membranes. We attempted to determine the variations in nanoparticles derived from milk after fermentation, and provide evidence to determine the effects of these exosomes on cells with potential bioactivity. Using scanning electron microscopy and dynamic light scattering, we compared the morphology and particle size distribution of exosomes from yogurt fermented with three different combinations of strains with those from raw milk. The protein content of the exosome was significantly reduced in fermented milk. The cycle threshold showed that the expression of miR-29b and miR-21 was relatively high in raw milk, indicating a loss of microRNA after fermentation. Milk-derived exosomes could promote cell growth and activate the mitogen-activated protein kinase pathway. These findings demonstrated biological functions in milk exosomes and provided new insight into the nutrient composition of dairy products.

The complex microbiota of raw milk.

PubMed

Quigley, Lisa; O'Sullivan, Orla; Stanton, Catherine; Beresford, Tom P; Ross, R Paul; Fitzgerald, Gerald F; Cotter, Paul D

2013-09-01

Here, we review what is known about the microorganisms present in raw milk, including milk from cows, sheep, goats and humans. Milk, due to its high nutritional content, can support a rich microbiota. These microorganisms enter milk from a variety of sources and, once in milk, can play a number of roles, such as facilitating dairy fermentations (e.g. Lactococcus, Lactobacillus, Streptococcus, Propionibacterium and fungal populations), causing spoilage (e.g. Pseudomonas, Clostridium, Bacillus and other spore-forming or thermoduric microorganisms), promoting health (e.g. lactobacilli and bifidobacteria) or causing disease (e.g. Listeria, Salmonella, Escherichia coli, Campylobacter and mycotoxin-producing fungi). There is also concern that the presence of antibiotic residues in milk leads to the development of resistance, particularly among pathogenic bacteria. Here, we comprehensively review these topics, while comparing the approaches, both culture-dependent and culture-independent, which can be taken to investigate the microbial composition of milk. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Genetic variation among Staphylococcus aureus strains from Norwegian bulk milk.

PubMed

Jørgensen, H J; Mørk, T; Caugant, D A; Kearns, A; Rørvik, L M

2005-12-01

Strains of Staphylococcus aureus obtained from bovine (n = 117) and caprine (n = 114) bulk milk were characterized and compared with S. aureus strains from raw-milk products (n = 27), bovine mastitis specimens (n = 9), and human blood cultures (n = 39). All isolates were typed by pulsed-field gel electrophoresis (PFGE). In addition, subsets of isolates were characterized using multilocus sequence typing (MLST), multiplex PCR (m-PCR) for genes encoding nine of the staphylococcal enterotoxins (SE), and the cloverleaf method for penicillin resistance. A variety of genotypes were observed, and greater genetic diversity was found among bovine than caprine bulk milk isolates. Certain genotypes, with a wide geographic distribution, were common to bovine and caprine bulk milk and may represent ruminant-specialized S. aureus. Isolates with genotypes indistinguishable from those of strains from ruminant mastitis were frequently found in bulk milk, and strains with genotypes indistinguishable from those from bulk milk were observed in raw-milk products. This indicates that S. aureus from infected udders may contaminate bulk milk and, subsequently, raw-milk products. Human blood culture isolates were diverse and differed from isolates from other sources. Genotyping by PFGE, MLST, and m-PCR for SE genes largely corresponded. In general, isolates with indistinguishable PFGE banding patterns had the same SE gene profile and isolates with identical SE gene profiles were placed together in PFGE clusters. Phylogenetic analyses agreed with the division of MLST sequence types into clonal complexes, and isolates within the same clonal complex had the same SE gene profile. Furthermore, isolates within PFGE clusters generally belonged to the same clonal complex.

Genetic Variation among Staphylococcus aureus Strains from Norwegian Bulk Milk

PubMed Central

Jørgensen, H. J.; Mørk, T.; Caugant, D. A.; Kearns, A.; Rørvik, L. M.

2005-01-01

Strains of Staphylococcus aureus obtained from bovine (n = 117) and caprine (n = 114) bulk milk were characterized and compared with S. aureus strains from raw-milk products (n = 27), bovine mastitis specimens (n = 9), and human blood cultures (n = 39). All isolates were typed by pulsed-field gel electrophoresis (PFGE). In addition, subsets of isolates were characterized using multilocus sequence typing (MLST), multiplex PCR (m-PCR) for genes encoding nine of the staphylococcal enterotoxins (SE), and the cloverleaf method for penicillin resistance. A variety of genotypes were observed, and greater genetic diversity was found among bovine than caprine bulk milk isolates. Certain genotypes, with a wide geographic distribution, were common to bovine and caprine bulk milk and may represent ruminant-specialized S. aureus. Isolates with genotypes indistinguishable from those of strains from ruminant mastitis were frequently found in bulk milk, and strains with genotypes indistinguishable from those from bulk milk were observed in raw-milk products. This indicates that S. aureus from infected udders may contaminate bulk milk and, subsequently, raw-milk products. Human blood culture isolates were diverse and differed from isolates from other sources. Genotyping by PFGE, MLST, and m-PCR for SE genes largely corresponded. In general, isolates with indistinguishable PFGE banding patterns had the same SE gene profile and isolates with identical SE gene profiles were placed together in PFGE clusters. Phylogenetic analyses agreed with the division of MLST sequence types into clonal complexes, and isolates within the same clonal complex had the same SE gene profile. Furthermore, isolates within PFGE clusters generally belonged to the same clonal complex. PMID:16332822

Molecular Typing and Antimicrobial Susceptibility of Staphylococcus aureus Strains Isolated from Raw Milk, Cheese, Minced Meat, and Chicken Meat Samples

PubMed Central

Karagöz, Alper

2017-01-01

The objectives of this study were: i) to detect the presence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in raw milk, cheese, beef minced meat, and chicken meat samples; ii) to evaluate the antimicrobial susceptibility of the isolates; and iii) to determine clonal relation among the isolates by using pulsed-field gel electrophoresis (PFGE) method. Therefore, a total of 160 food samples were randomly collected between August 2014 and May 2015 in Hatay province, located in the southern Turkey. Twenty (12.5%) of the samples were found to be contaminated with S. aureus. A total of 40 isolates from the 20 positive samples were confirmed to be S. aureus by multiplex PCR based on 16S rRNA and nuc gene. The mec A gene was not detected in any of the S. aureus strains. In the present study, 39 out of 40 (97.5%) isolates were found to be resistant to one or more antibiotics. All of isolates were susceptible to gentamicin, oxacillin, and vancomycin. The highest resistance rate was detected in penicillin (95%) and ampicillin (92.5%), followed by tetracycline (30%), erythromycin (20%), ciprofloxacin (12.5%). Nine major patterns were determined by PFGE. In 6 of these patterns, thirty-six strains (90%) had identical PFGE profiles. PMID:28515641

7 CFR 58.518 - Milk.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Milk. 58.518 Section 58.518 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....518 Milk. The selection of raw milk for cottage cheese shall be in accordance with §§ 58.132 through...

7 CFR 58.932 - Milk.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Milk. 58.932 Section 58.932 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....932 Milk. The raw milk shall meet the requirements as outlined in §§ 58.132 through 58.138. Unless...

7 CFR 58.518 - Milk.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Milk. 58.518 Section 58.518 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....518 Milk. The selection of raw milk for cottage cheese shall be in accordance with §§ 58.132 through...

7 CFR 58.518 - Milk.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Milk. 58.518 Section 58.518 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....518 Milk. The selection of raw milk for cottage cheese shall be in accordance with §§ 58.132 through...

7 CFR 58.232 - Milk.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 3 2012-01-01 2012-01-01 false Milk. 58.232 Section 58.232 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....232 Milk. Raw milk shall meet the requirements as outlined in §§ 58.132 through 58.138 and, unless...

7 CFR 58.932 - Milk.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Milk. 58.932 Section 58.932 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....932 Milk. The raw milk shall meet the requirements as outlined in §§ 58.132 through 58.138. Unless...

7 CFR 58.932 - Milk.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Milk. 58.932 Section 58.932 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....932 Milk. The raw milk shall meet the requirements as outlined in §§ 58.132 through 58.138. Unless...

7 CFR 58.232 - Milk.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 3 2013-01-01 2013-01-01 false Milk. 58.232 Section 58.232 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....232 Milk. Raw milk shall meet the requirements as outlined in §§ 58.132 through 58.138 and, unless...

7 CFR 58.232 - Milk.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Milk. 58.232 Section 58.232 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....232 Milk. Raw milk shall meet the requirements as outlined in §§ 58.132 through 58.138 and, unless...

7 CFR 58.932 - Milk.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Milk. 58.932 Section 58.932 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....932 Milk. The raw milk shall meet the requirements as outlined in §§ 58.132 through 58.138. Unless...

7 CFR 58.518 - Milk.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Milk. 58.518 Section 58.518 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....518 Milk. The selection of raw milk for cottage cheese shall be in accordance with §§ 58.132 through...

7 CFR 58.932 - Milk.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Milk. 58.932 Section 58.932 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....932 Milk. The raw milk shall meet the requirements as outlined in §§ 58.132 through 58.138. Unless...

7 CFR 58.518 - Milk.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Milk. 58.518 Section 58.518 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....518 Milk. The selection of raw milk for cottage cheese shall be in accordance with §§ 58.132 through...

Non-imported brucellosis outbreak from unpasteurized raw milk in Moroccan immigrants in Spain

PubMed Central

RAMOS, J. M.; BERNAL, E.; ESGUEVILLAS, T.; LOPEZ-GARCIA, P.; GAZTAMBIDE, M. S.; GUTIERREZ, F.

2008-01-01

SUMMARY Nine cases of brucellosis were identified in the city of Elche (Comunidad Valenciana, Spain) in two families of Moroccan immigrants. All of the patients had drunk unpasteurized raw milk from goats. Brucella melitensis biovar 3 was identified in clinical specimens. Preventive measures for brucellosis should be implemented among immigrant populations in Spain. PMID:18205974

Resident lactic acid bacteria in raw milk Canestrato Pugliese cheese.

PubMed

Aquilanti, L; Dell'Aquila, L; Zannini, E; Zocchetti, A; Clementi, F

2006-08-01

Investigation of the autochthonous lactic acid bacteria (LAB) population of the raw milk protected designation of origin Canestrato Pugliese cheese using phenotypic and genotypic methodologies. Thirty phenotypic assays and three molecular techniques (restriction fragment length polymorphism, partial sequencing of the 16S rRNA gene and recA multiplex PCR assay) were applied to the identification of 304 isolates from raw milk Canestrato Pugliese cheese. As a result, 168 of 207 isolates identified were ascribed to genus Enterococcus, 25 to Lactobacillus, 13 to Lactococcus and one to Leuconostoc. More in details among the lactobacilli, the species Lactobacillus brevis and Lactobacillus plantarum were predominant, including 13 and 10 isolates respectively, whereas among the lactococci, Lactococcus lactis subsp.cremoris [corrected] was the species more frequently detected (seven isolates). Except for the enterococci, phenotypic tests were not reliable enough for the identification of the isolates, if not combined to the genotype-based molecular techniques. The polyphasic approach utilized allowed 10 different LAB species to be detected; thus suggesting the appreciable LAB diversity of the autochthonous microbial population of the Canestrato Pugliese cheese. A comprehensive study of the resident raw milk Canestrato Pugliese cheese microbial population has been undertaken.

Rapid method for quantification of nine sulfonamides in bovine milk using HPLC/MS/MS and without using SPE.

PubMed

Nebot, Carolina; Regal, Patricia; Miranda, Jose Manuel; Fente, Cristina; Cepeda, Alberto

2013-12-01

Sulfonamides are antimicrobial agents widely employed in animal production and their residues in food could be an important risk to human health. In the dairy industry, large quantities of milk are monitored daily for the presence of sulfonamides. A simple and low-cost extraction protocol followed by a liquid chromatographic-tandem mass spectrometry method was developed for the simultaneous detection of nine sulfonamides in whole milk. The method was validated at the maximum residue limits established by European legislation. The limits of quantification obtained for most sulfonamides were between 12.5 and 25 μg kg(-1), detection capabilities ranged from 116 to 145 μg kg(-1), and recoveries, at 100 μg kg(-1), were greater than 89±12.5%. The method was employed to analyse 100 raw whole bovine milk samples collected from dairy farms in the northwest region of Spain. All of the samples were found to be compliant, but two were positive; one for sulfadiazine and the other for sulfamethoxipyridazine. Copyright © 2013 Elsevier Ltd. All rights reserved.

Estimating the impact of somatic cell count on the value of milk utilising parameters obtained from the published literature.

PubMed

Geary, Una; Lopez-Villalobos, Nicolas; O'Brien, Bernadette; Garrick, Dorian J; Shalloo, Laurence

2014-05-01

The impact of mastitis on milk value per litre independent of the effect of mastitis on milk volume, was quantified for Ireland using a meta-analysis and a processing sector model. Changes in raw milk composition, cheese processing and composition associated with increased bulk milk somatic cell count (BMSCC) were incorporated into the model. Processing costs and market values were representative of current industry values. It was assumed that as BMSCC increased (i) milk fat and milk protein increased and milk lactose decreased, (ii) fat and protein recoveries decreased, (iii) cheese protein decreased and cheese moisture increased. Five BMSCC categories were examined from ⩽100 000 to >400 000 cells/ml. The analysis showed that as BMSCC increased the production quantities reduced. An increase in BMSCC from 100 000 to >400 000 cells/ml saw a reduction in net revenue of 3·2% per annum (€51·3 million) which corresponded to a reduction in the value of raw milk of €0·0096 cents/l.

Multiclass methods for the analysis of antibiotic residues in milk by liquid chromatography coupled to mass spectrometry: A review.

PubMed

Rossi, Rosanna; Saluti, Giorgio; Moretti, Simone; Diamanti, Irene; Giusepponi, Danilo; Galarini, Roberta

2018-02-01

Milk is an important and beneficial food from a nutritional point of view, being an indispensable source of high quality proteins. Furthermore, it is a raw material for many dairy products, such as yoghurt, cheese, cream etc. Before reaching consumers, milk goes through production, processing and circulation. Each step involves potentially unsafe factors, such as chemical contamination that can affect milk quality. Antibiotics are widely used in veterinary medicine for dry cow therapy and mastitis treatment in lactating cows, which can cause the presence of antimicrobial residues in milk. In order to ensure consumers' safety, milk is analyzed to make sure that the fixed Maximum Residue Limits (MRLs) for antibiotics are not exceeded. Multiclass methods can monitor more drug classes through a single analysis, so they are faster, less time-consuming and cheaper than traditional methods (single-class); this aspect is particularly important for milk, which is a highly perishable food. Nevertheless, multiclass methods for veterinary drug residues in foodstuffs are real analytical challenges. This article reviews the major multiclass methods published for the determination of antibiotic residues in milk by liquid chromatography coupled to mass spectrometry, with a special focus on sample preparation approaches.

Extrahuman Epidemiology of Acinetobacter baumannii in Lebanon

PubMed Central

Rafei, Rayane; Hamze, Monzer; Pailhoriès, Hélène; Eveillard, Matthieu; Marsollier, Laurent; Joly-Guillou, Marie-Laure; Dabboussi, Fouad

2015-01-01

The presence of Acinetobacter baumannii outside hospitals is still a controversial issue. The objective of our study was to explore the extrahospital epidemiology of A. baumannii in Lebanon. From February 2012 to October 2013, a total of 73 water samples, 51 soil samples, 37 raw cow milk samples, 50 cow meat samples, 7 raw cheese samples, and 379 animal samples were analyzed by cultural methods for the presence of A. baumannii. Species identification was performed by rpoB gene sequencing. Antibiotic susceptibility was investigated, and the A. baumannii population was studied by two genotyping approaches: multilocus sequence typing (MLST) and blaOXA-51 sequence-based typing (SBT). A. baumannii was detected in 6.9% of water samples, 2.7% of milk samples, 8.0% of meat samples, 14.3% of cheese samples, and 7.7% of animal samples. All isolates showed a susceptible phenotype against most of the antibiotics tested and lacked carbapenemase-encoding genes, except one that harbored a blaOXA-143 gene. MLST analysis revealed the presence of 36 sequence types (STs), among which 24 were novel STs reported for the first time in this study. blaOXA-51 SBT showed the presence of 34 variants, among which 21 were novel and all were isolated from animal origins. Finally, 30 isolates had new partial rpoB sequences and were considered putative new Acinetobacter species. In conclusion, animals can be a potential reservoir for A. baumannii and the dissemination of new emerging carbapenemases. The roles of the novel animal clones identified in community-acquired infections should be investigated. PMID:25616788

Iodine in raw and pasteurized milk of dairy cows fed different amounts of potassium iodide.

PubMed

Norouzian, M A

2011-02-01

Relation between iodine (I) intake by lactating Holstein cows and iodine concentrations in raw and pasteurized milk were investigated. Four treatment groups with eight cows assigned to each treatment were fed a basal diet containing 0.534 mg I/kg alone or supplemented with potassium iodide at 2.5, 5 or 7.5 mg/kg in 7-week period. Iodine concentrations in raw milk increased with each increase in dietary I from 162.2 ng/ml for basal diet to 534.5, 559.8 and 607.5 ng/ml when 2.5, 5 and 7.5 mg/kg was fed as potassium iodide (P < 0.05). This trend was found for blood plasma and urine iodine concentration. Iodine supplementation had no significant effect on thyroidal hormones. high-temperature short-time (HTST) pasteurization process reduced I concentration. The mean iodine content found in the milk prior to heating processing was 466.0 ± 205.0 ng/ml, whereas for the processed milk this level was 349.5 ± 172.8 ng/ml. It was concluded that iodine supplementation above of NRC recommendation (0.5 mg/kg diet DM) resulted in significant increases in iodine concentrations in milk, although the effect of heating in HTST pasteurization process on iodine concentration was not negligible.

A novel approach for the efficient extraction of silybin from milk thistle fruits.

PubMed

Tan, Caihong; Xu, Xianrong; Shang, Yaqi; Fu, Xianli; Xia, Guohua; Yang, Huan

2014-10-01

Milk Thistle fruit is an important herb popularly consumed worldwide for a very long time. Silybin is the main bioactive constituent of the herb, and it has been approved by US Food and Drug Administration (FDA) as a medicine to treat liver diseases. Presently, using conventional technology, the meal of Milk Thistle fruit is used as the raw material to extract silybin. To investigate the necessity of detaching husk from kernel of the herb and also to propose a novel approach to enhance the extraction technology in pharmaceutical practices. The husk of Milk Thistle fruit was detached from the kernel of the herb using an automatic huller specially designed for this application. The husk and the meal of Milk Thistle fruit was subsequently refluxed, separately, with production rate of silybin as index for comparison of their extraction effect. The highest production rate was achieved under optimized condition. The husk was extracted 2 times (3 hrs each) using ethyl acetate, and the ratio of solvent to raw material was 8:1. The extract was allowed to be crystallized out. The separation of kernel from the husk of Milk Thistle fruit and using only the husk as raw material can largely enhance the extraction of silybin.

Multiclass method for the determination of 62 antibiotics in milk.

PubMed

Moretti, Simone; Cruciani, Gabriele; Romanelli, Sara; Rossi, Rosanna; Saluti, Giorgio; Galarini, Roberta

2016-09-01

A multiclass method for screening and confirmatory analysis of antimicrobial residues in milk has been developed and validated. Sixty-two antibiotics belonging to ten different drug families (amphenicols, cephalosporins, lincosamides, macrolides, penicillin, pleuromutilins, quinolones, rifamycins, sulfonamides and tetracyclines) have been included. After the addition of an aqueous solution of EDTA, the milk samples were extracted twice with acetonitrile, evaporated and dissolved in ammonium acetate. After centrifugation, 10 µl were analysed using LC-Q-Orbitrap operating in positive electrospray ionization mode. The method was validated in bovine milk in the range 2-150 µg kg(-1) for all antibiotics; for four compounds with maximum residue limits higher than 100 µg kg(-1) , the validation interval has been extended until 333 µg kg(-1) . The estimated performance characteristics were satisfactory complying with the requirements of Commission Decision 2002/657/EC. Good accuracies were obtained also taking advantage from the versatility of the hybrid mass analyser. Identification criteria were achieved verifying the mass accuracy and ion ratio of two ions, including the pseudomolecular one, where possible. Finally, the developed procedure was applied to 13 real cases of suspect milk samples (microbiological assay) confirming the presence of one or more antibiotics, although frequently, the maximum residue limits were not exceeded. The availability of rapid multiclass confirmatory methods can avoid wastes of suspect, but compliant, raw milk samples. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Occurrence of Perfluorooctanoic Acid and Perfluorooctane Sulfonate in Milk and Yogurt and Their Risk Assessment.

PubMed

Xing, Zhenni; Lu, Jianjiang; Liu, Zilong; Li, Shanman; Wang, Gehui; Wang, Xiaolong

2016-10-21

Although perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been identified in milk and dairy products in many regions, knowledge on their occurrence in Xinjiang (China) is rare. This study was conducted to measure the levels of PFOA and PFOS in milk and yogurt from Xinjiang and to investigate the average daily intake (ADI) of these two compounds. PFOA and PFOS levels were analyzed using ultrasonic extraction with methanol and solid-phase extraction followed by liquid chromatography-mass spectrometry. Retail milk and yogurt samples present higher detection rates (39.6% and 48.1%) and mean concentrations (24.5 and 31.8 ng/L) of PFOS than those of PFOA (33.0% and 37.0%; 16.2 and 22.6 ng/L, respectively). For raw milk samples, only PFOS was detected. The differences in the levels of the two compounds between samples from the north and south regions were observed, and northern regions showed higher pollution levels than southern regions. On the basis of the retail milk measurements and consumption data, the ADIs of PFOA and PFOS for Xinjiang adults were calculated to be 0.0211 and 0.0318 ng/kg/day, respectively. Furthermore, the estimated intakes of PFOA and PFOS varied among different groupings (age, area, gender, and race) and increased with increasing age. Relevant hazard ratios were found to be far less than 1.0, and this finding suggested that no imminent health damages were produced by PFOA and PFOS intake via milk and yogurt consumption in the Xinjiang population.

Occurrence of Perfluorooctanoic Acid and Perfluorooctane Sulfonate in Milk and Yogurt and Their Risk Assessment

PubMed Central

Xing, Zhenni; Lu, Jianjiang; Liu, Zilong; Li, Shanman; Wang, Gehui; Wang, Xiaolong

2016-01-01

Although perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been identified in milk and dairy products in many regions, knowledge on their occurrence in Xinjiang (China) is rare. This study was conducted to measure the levels of PFOA and PFOS in milk and yogurt from Xinjiang and to investigate the average daily intake (ADI) of these two compounds. PFOA and PFOS levels were analyzed using ultrasonic extraction with methanol and solid-phase extraction followed by liquid chromatography–mass spectrometry. Retail milk and yogurt samples present higher detection rates (39.6% and 48.1%) and mean concentrations (24.5 and 31.8 ng/L) of PFOS than those of PFOA (33.0% and 37.0%; 16.2 and 22.6 ng/L, respectively). For raw milk samples, only PFOS was detected. The differences in the levels of the two compounds between samples from the north and south regions were observed, and northern regions showed higher pollution levels than southern regions. On the basis of the retail milk measurements and consumption data, the ADIs of PFOA and PFOS for Xinjiang adults were calculated to be 0.0211 and 0.0318 ng/kg/day, respectively. Furthermore, the estimated intakes of PFOA and PFOS varied among different groupings (age, area, gender, and race) and increased with increasing age. Relevant hazard ratios were found to be far less than 1.0, and this finding suggested that no imminent health damages were produced by PFOA and PFOS intake via milk and yogurt consumption in the Xinjiang population. PMID:27775680

Microbial diversity in raw milk and traditional fermented dairy products (Hurood cheese and Jueke) from Inner Mongolia, China.

PubMed

Gao, M L; Hou, H M; Teng, X X; Zhu, Y L; Hao, H S; Zhang, G L

2017-03-08

Hurood cheese (HC) and Jueke (Jk) are 2 traditional fermented dairy products produced from raw milk (RM) in the Inner Mongolia region of China. They have a long history of production and consumption. The microbial compositions of RM, HC, and Jk vary greatly, and are influenced by their geographical origins and unique processing methods. In this study, 2 batches of RM, HC, and Jk samples were collected (April and August 2015) from the Zhenglan Banner, a region located in the southern part of Inner Mongolian belonging to the Xilingol league prefecture. The bacterial and fungal diversities of the samples were determined by 16S rRNA and 18S rRNA gene sequence analysis, respectively. A total of 112 bacterial and 30 fungal sequences were identified, with Firmicutes and Ascomycota being the predominant phyla for bacteria and fungi, respectively. Lactococcus and Lactobacillus were identified as the main bacterial genera, whereas Kluyveromyces was the predominant fungus identified in the 3 dairy products. Different bacterial and fungal compositions were observed in RM, HC, and Jk samples collected at different times. These results suggested that time of production may be an important factor influencing the microbial diversity present in RM, HC, and Jk.

Prevalence and Comparing of Some Microbiological Properties, Somatic Cell Count and Antibiotic Residue of Organic and Conventional Raw Milk Produced in Turkey

PubMed Central

Şengül, Mustafa; Erkaya, Tuba; Aksakal, Vecihi

2017-01-01

The aim of this study was to investigate the effects of production systems and milk collection periods on the somatic cell count (SCC), some microbiological properties, total aerobic mesophilic bacteria (TAMB), coliform, Staphylococcus aureus (S. aureus), yeast and mould) and antibiotic residue of milk; in Turkey. Milk samples were collected from 9 conventional farms and 9 organic farms during one year time, at six different months (December 2013 to October 2014), and all farms were selected from the same geographical locations. All organically managed farms had organic production certificates given by the Republic of Turkey Ministry of Food, Agriculture and Livestock. The count of TAMB, coliform, and coagulase positive S. aureus were affected by production systems at the level of p<0.01; yeast and mold, and somatic cell count (SCC) were affected at the level of p<0.05. But, differences according to months were statistically significant only on TAMB (p<0.01) and coliform (p<0.05) counts. The general means of TAMB, coliform and yeast and mould counts of the organic milk (OM) were significantly lower (p<0.05), while the general means of SCC and coagulase positive S. aureus count of the OM was significantly higher (p<0.05) compared to conventional milk (CM). Antibiotic residue was determined in one of the CM sample and in two of the OM samples. Our study is the first research that compared conventional and organic milk in Turkey. This study indicated that the microbiological quality of OM was the higher in terms of TAMB, coliform and yeast and mould, whereas was the lower in relation to SCC and coagulase positive S. aureus counts. But, the quality of both milk types should be improved. PMID:28515650

Evaluation the virulence of Mycobacterium bovis isolated from milk samples through histopathological study in laboratory animals.

PubMed

Al-Saqur, I M; Al-Thwani, A N; Al-Attar, I M; Al-Mashhadani, M S

2016-12-01

Mycobacterium bovis has a broad host range, and it is the principal agent responsible for tuberculosis (TB) in bovine, domestic and wild mammals. M. bovis also infects human, causing zoonotic TB through ingestion, inhalation and, less frequently by contact with mucous membranes and broken skin. Zoonotic TB was formerly an endemic disease, usually transmitted to man by consumption of raw cow's milk. It is indistinguishable clinically or pathologically from TB caused by M. tuberculosis. The aims of this study were, to isolate and identified M. bovis from raw milk samples by different methods, and evaluate the virulence of M. bovis in laboratory animals (Rabbit). To conduct the study, ninety three cow's milk samples were collected from farms around Baghdad governorate. The decontamination of milk samples was firstly carried out, then samples were subjected to routine tests which include, direct smear for Ziehl Neelsen acid fast stain, culture, each sample was cultured on Lowenstein Jensen media with Sodium pyruvite (All cultures incubated on 37°C for 4-10weeks with continuous observation), and biochemical testes as Nitrate reduction test, Niacin paper strip test and pyrazinamidase test, were employed to diagnose and identified the bacteria. Beside molecular assay was used to confirm the identification of the isolates by Polymerase Chain Reaction (PCR) using specific primers for M. bovis. The virulence of these isolates were investigated through inoculate it in group of laboratory animals consist of 8 rabbit in addition to other group of 4 animals as control (inoculate with Phosphate Buffer Saline). The animals were scarified after 6weeks of inoculation, post- mortem examination was carried out, smears were taken from lesions, and tissue samples were collected from lymph nodes and different organs. The results revealed five isolates of M. bovis in direct smear by acid fast Ziehl-Neelsen stain, while eight isolates observed by culture, the colonies appeared with characteristic feature of cream color, rough, and with irregular edge. The molecular assay using PCR technique confirmed the diagnosis of eight positive isolates in smears and culture. The virulence of these isolates were investigated through the pathological effects appeared in inoculated rabbit which showed lesions scattered mainly in lymph nodes and different organs as lung, liver, spleen and kidney when compared with control group which were naive. Beside the infiltration of mononuclear cells in the internal organs particularly in the lungs. The result of histopathological examination clarified the virulence of M. bovis isolates, and its impact on tissue and organs of the rabbit. Our study conclude the presence of M. bovis isolates in milk in high percentage pause important source of tuberculosis infection for human being. Copyright © 2016.

Analysis of Processed Foods Containing Oils and Fats by Time of Flight Mass Spectrometry with an APCI Direct Probe.

PubMed

Ito, Shihomi; Chikasou, Masato; Inohana, Shuichi; Fujita, Kazuhiro

2016-01-01

Discriminating vegetable oils and animal and milk fats by infrared absorption spectroscopy is difficult due to similarities in their spectral patterns. Therefore, a rapid and simple method for analyzing vegetable oils, animal fats, and milk fats using TOF/MS with an APCI direct probe ion source was developed. This method enabled discrimination of these oils and fats based on mass spectra and detailed analyses of the ions derived from sterols, even in samples consisting of only a few milligrams. Analyses of the mass spectra of processed foods containing oils and milk fats, such as butter, cheese, and chocolate, enabled confirmation of the raw material origin based on specific ions derived from the oils and fats used to produce the final product.

Invited review: Anti-adhesive properties of bovine oligosaccharides and bovine milk fat globule membrane-associated glycoconjugates against bacterial food enteropathogens.

PubMed

Douëllou, T; Montel, M C; Thevenot Sergentet, D

2017-05-01

The prevalence of the main raw milk and raw milk-derived dairy product enteropathogens (Campylobacter, Shiga toxin-producing Escherichia coli, Listeria, and Salmonella) is higher than the number of epidemiological cases related to ingesting these foodstuffs. Bovine milk oligosaccharides and milk fat globule membrane (MFGM)-linked glycoconjugates interact with foodborne enteropathogens to inhibit their adhesion to intestinal cells and tissues. This review examines the main mechanisms and strategies used by enteropathogens to adhere to their target, details the anti-adhesive properties of MFGM against enteropathogens and enterotoxins, assesses the integrity of bacteria-MFGM complexes during dairy product manufacture and digestion, and discusses the potential for using these macromolecules and glycoconjugates in foods for public health. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Short communication: A comparison of biofilm development on stainless steel and modified-surface plate heat exchangers during a 17-h milk pasteurization run.

PubMed

Jindal, Shivali; Anand, Sanjeev; Metzger, Lloyd; Amamcharla, Jayendra

2018-04-01

Flow of milk through the plate heat exchanger (PHE) results in denaturation of proteins, resulting in fouling. This also accelerates bacterial adhesion on the PHE surface, eventually leading to the development of biofilms. During prolonged processing, these biofilms result in shedding of bacteria and cross-contaminate the milk being processed, thereby limiting the duration of production runs. Altering the surface properties of PHE, such as surface energy and hydrophobicity, could be an effective approach to reduce biofouling. This study was conducted to compare the extent of biofouling on native stainless steel (SS) and modified-surface [Ni-P-polytetrafluoroethylene (PTFE)] PHE during the pasteurization of raw milk for an uninterrupted processing run of 17 h. For microbial studies, raw and pasteurized milk samples were aseptically collected from inlets and outlets of both PHE at various time intervals to examine shedding of bacteria in the milk. At the end of the run, 3M quick swabs (3M, St. Paul, MN) and ATP swabs (Charm Sciences Inc., Lawrence, MA) were used to sample plates from different sections of the pasteurizers (regeneration, heating, and cooling) for biofilm screening and to estimate the efficiency of cleaning in place, respectively. The data were tested for ANOVA, and means were compared. Modified PHE experienced lower mesophilic and thermophilic bacterial attachment and biofilm formation (average log 1.0 and 0.99 cfu/cm 2 , respectively) in the regenerative section of the pasteurizer compared with SS PHE (average log 1.49 and 1.47, respectively). Similarly, higher relative light units were observed for SS PHE compared with the modified PHE, illustrating the presence of more organic matter on the surface of SS PHE at the end of the run. In addition, at h 17, milk collected from the outlet of SS PHE showed plate counts of 5.44 cfu/cm 2 , which were significantly higher than those for pasteurized milk collected from modified PHE (4.12 log cfu/cm 2 ). This provided further evidence in favor of the modified PHE achieving better microbial quality of pasteurized milk in long process runs. Moreover, because cleaning SS PHE involves an acid treatment step, whereas an alkali treatment step is sufficient for the modified-surface PHE, use of the latter is both cost and time effective, making it a better surface for thermal processing of milk and other fluid dairy products. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Volatile sulphur compounds in UHT milk.

PubMed

Al-Attabi, Z; D'Arcy, B R; Deeth, H C

2009-01-01

Several volatile sulphur compounds have been detected in raw and processed milk. These are hydrogen sulphide, methanethiol, carbonyl sulphide, dimethyl sulphide, carbon disulphide, dimethyl disulphide, dimethyl trisulphide, dimethyl sulphoxide, and dimethyl sulphone. Many of these increase in milk during heat processing and are associated with the cooked flavor of heat-treated milks, particularly UHT and sterilized milk. Several researchers have attempted to explain the origin of these volatiles in both raw and processed milk, and how to reduce the associated cooked flavor that has a negative impact on consumer acceptability of processed milk. These compounds are difficult to detect and analyze due to their high volatility, sensitivity to oxidation and heat, and in some cases, their very low concentrations. However, methods of detection and quantification have improved in recent years. Pre-concentration methods such as solid phase microextraction (SPME) together with gas chromatography equipped with sulphur-selective detectors now enable low concentrations of these compounds to be analyzed. In this review, methods of extraction and analyzes of these volatile sulphur compounds are compared, and their occurrence in milk is reviewed.

In vivo digestion of bovine milk fat globules: effect of processing and interfacial structural changes. I. Gastric digestion.

PubMed

Gallier, Sophie; Cui, Jack; Olson, Trent D; Rutherfurd, Shane M; Ye, Aiqian; Moughan, Paul J; Singh, Harjinder

2013-12-01

The aim was to study the in vivo gastric digestion of fat globules in bovine cream from raw, pasteurised or pasteurised and homogenised milk. Fasted rats were gavaged once and chyme samples were collected after 30, 120 and 180 min post-gavage. Proteins from raw (RC) and pasteurised (PC) creams appeared to be digested faster and to a greater extent. Free fatty acids (FAs) increased throughout the 3h postprandial period. Short and medium chain FAs were released more rapidly than long chain FAs which were hydrolysed to a greater degree from PC. The size of the fat globules of all creams increased in the stomach. Protein aggregates were observed in pasteurised and homogenised cream chyme. Protrusions, probably caused by the accumulation of insoluble lipolytic products, appeared at the surface of the globules in RC and PC chyme. Overall, PC proteins and lipids appeared to be digested to a greater extent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Seroprevalence and risk factors associated with brucellosis as a professional hazard in Pakistan.

PubMed

Ali, Shahzad; Ali, Qurban; Neubauer, Heinrich; Melzer, Falk; Elschner, Mandy; Khan, Iahtasham; Abatih, Emmanuel Nji; Ullah, Nemat; Irfan, Muhammad; Akhter, Shamim

2013-06-01

The present study was conducted to determine the seroprevalence and identify risk factors associated with brucellosis in humans at high risk in the Potohar plateau of northeastern Pakistan. A total of 262 serum samples were collected from persons of different occupational groups: veterinary personnel, milkers, abattoir workers, livestock farmers, and others (drivers, security guards, housewives). Data related to gender, age, occupation, contact with animals, brucellosis-related symptoms, consumption of raw milk, and geographical region were collected. The Rose Bengal plate test and the serum agglutination test were performed to determine the seroprevalence of brucellosis. The overall seroprevalence was found to be 6.9% (95% confidence interval [CI]: 4.1, 10.6). Real-time polymerase chain reaction assay showed that all cases were affected by Brucella abortus. Individuals who consumed raw milk had higher odds of brucellosis seropositivity. This is the first report of human brucellosis related to B. abortus in high-risk professionals from Pakistan by the combined use of serological and molecular methods.

Tetracycline antibiotics transfer from contaminated milk to dairy products and the effect of the skimming step and pasteurisation process on residue concentrations.

PubMed

Gajda, Anna; Nowacka-Kozak, Ewelina; Gbylik-Sikorska, Malgorzata; Posyniak, Andrzej

2018-01-01

The presence of antibiotics in raw milk and milk derivatives poses a threat to human health and can negatively affect the dairy industry. Therefore, the main object of this study was to investigate the transfer of oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC) and doxycycline (DC) from raw, experimental milk contaminated with tetracyclines (TCs) to different dairy products: cream, butter, buttermilk, sour milk, whey, curd and cheese. Additionally the effect of the skimming process on TCs concentrations was tested, as well as the influence of low-temperature long-time pasteurisation. The analyses of TCs in milk and dairy products were performed by an LC-MS/MS method. In order to determine TCs residues in dairy products, an analytical method was developed with the same extraction step for all matrices. TCs molecules were inhomogenously distributed between the milk derivative fractions. The highest concentrations were determined in curd and cheese in the ranges 320-482 µg/kg and 280-561 µg/kg, respectively. Low levels of TCs in butter and whey were observed (11.8-41.2 µg/kg). TCs were found in sour milk (66.0-111 µg/kg), cream (85.0-115 µg/kg) and buttermilk (196-221 µg/kg) at much higher levels than in butter and whey, but lower than in curd and cheese. During the skimming process, the highest yield of cream was obtained after the raw milk was held at 2-8°C for 24 h. The differences in concentrations of TCs between whole milk and skimmed milk, expressed as percentages of recovery, were below 19% (recoveries in excess of 81%). The highest content was observed in milk and cream skimmed at 2-8°C. The degradation percentages for TCs during the pasteurisation process (63°C for 30 min) were below 19%.

Isolation and identification of bacterial pathogen from mastitis milk in Central Java Indonesia

NASA Astrophysics Data System (ADS)

Harjanti, D. W.; Ciptaningtyas, R.; Wahyono, F.; Setiatin, ET

2018-01-01

Mastitis is a multi-etiologic disease of the mammary gland characterized mainly by reduction in milk production and milk quality due to intramammary infection by pathogenic bacteria. Nearly 83% of lactating dairy cows in Indonesia are infected with mastitis in various inflammation degrees. This study was conducted to isolate and identify the pathogen in milk collected from mastitis-infected dairy cows. The study was carried out in ten smallholder dairy farms in Central Java Indonesia based on animal examination, California mastitis test, isolation bacterial pathogens, Gram staining, Catalase and Coagulase test, and identification of bacteria species using Vitek. Bacteriological examination of milk samples revealed 15 isolates where Streptococcus was predominant species (73.3%) and the coagulase negative Staphylococcus species was identified at the least bacteria (26.7%). The Streptococcus bacteria found were Streptococcus uberis (2 isolates), Streptococcus sanguinis(6 isolates), Streptococcus dysgalactiaessp dysgalactiae(1 isolate) , Streptococcus mitis (1 isolate) and Streptococcus agalactiae (1 isolate). The Staphylococcus isolates comprising of Staphylococcus simulans (1 isolate) and Staphylococcus chromogens (3 isolates). Contamination of raw milkwith pathogenic bacteria can cause outbreaks of human disease (milk borne disease). Thus, proper milk processing method that couldinhibit the growth or kill these pathogenic bacteria is important to ensure the safety of milk and milk products.

Effect of genetic and nongenetic factors on chemical composition of individual milk samples from dromedary camels (Camelus dromedarius) under intensive management.

PubMed

Nagy, P; Fábri, Zs N; Varga, L; Reiczigel, J; Juhász, J

2017-11-01

The aims of the present study were to monitor the changes in gross chemical composition of individual dromedary camel milk over a 5-yr period, to provide reference values, and to determine the effect of genetic and nongenetic factors influencing camel milk composition under intensive management. A total of 1,528 lactating dromedary camels were included in the study. Animals were fed a constant diet and were milked twice a day in a herringbone parlor. Milk samples were collected at monthly intervals using a sampling device and then fat, protein, lactose, total solids (TS), and solids-nonfat (SNF) concentrations of raw camel milk were determined with an automatic milk analyzer. For each milk sample, production parameters were recorded and quantities (grams) of milk constituents were calculated. The overall mean quantity and fat, protein, lactose, SNF, and TS concentrations of the morning milk were 4.0 kg, 2.58%, 2.95%, 4.19%, 8.08%, and 10.46%, respectively. Milk quantity showed a positive correlation with lactose and a negative correlation with all other components. Parity exerted a strong effect on all milk parameters. Primiparous dromedaries (n = 60) produced less milk with higher concentrations of components than did multiparous animals (n = 1,468). Milk composition varied among the 7 breeds tested, but none of the genotypes was found to be superior to the others in this respect. We detected a significant, yet small calf sex-biased difference in milk yield and composition. Stage of lactation and season strongly influenced milk yield and all milk components. We also found a significant interaction between month postpartum (mPP) and month of the year. The concentration of all milk components decreased from 1 to 5 mPP. Later, lactose concentration and quantity continued to decrease parallel with decreasing milk production. The concentration of other components showed a temporary increase in mid lactation, from 6 to 11 mPP, and in late lactation, from 18 to 23 mPP. Mean fat, protein, SNF, and TS concentrations showed a high seasonal variation (9.5 to 28.7%), with the lowest and highest values being measured during summer and winter, respectively. This seasonal variation was independent of nutrition and may reflect an endogenous circannual rhythm. We observed a noticeable variation among years. Dromedary camels could provide a useful in vivo model to study the homeorhetic regulation of mammary cell function by endogenous and environmental factors. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Short communication: Sensory profile of raw goat milk cheeses made with artisan kid rennet pastes from commercial-weight animals: alternative to farmhouse goat cheeses.

PubMed

Fresno, M; Álvarez, S; Díaz, E; Virto, M; de Renobales, M

2014-10-01

The loss of traditional kid rennet pastes in the Canary Islands (Spain), as in many other regions, is most likely due to the custom of using abomasa from very young animals killed below desirable commercial weight. In addition, the reasonable price of commercial rennets (CR) has resulted in the loss of typical sensory characteristics for most farmhouse raw goat milk cheeses, placing them at a disadvantage when local and international markets are full of different cheeses, often with aggressive marketing strategies. This paper analyzes the sensory characteristics of raw goat milk cheeses made with rennet pastes prepared from commercial kid abomasa in 2 ways: dried while full of ingested milk [full, commercial, artisan kid rennet (FCKR)], or dried after being emptied of ingested milk and refilled with raw goat milk [empty, commercial, artisan kid rennet (ECKR)]. This latter practice allows the use of empty abomasa, or abomasa with grass, soil, and so on. Sensory profiles of cheeses made with FCKR and ECKR rennets were compared with those made with CR by an expert panel (n=7). The FCKR and ECKR cheeses had similar sensory profiles. Although scores for FCKR cheeses were somewhat higher than for ECKR cheeses, they were in the range found for traditional cheeses made with rennet prepared with abomasa from very young animals. The sensory profile of CR cheeses was very different. Almost 90% of consumer panelists (n=90) preferred cheeses made with the experimental rennet pastes. These results demonstrate the possibility to prepare artisan rennet pastes from commercial-weight kids in an easy way for farmhouse cheese makers using local resources that would otherwise be destroyed in abattoirs. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

[The study of the contamination and the levels of Campylobacter spp. during the processing of selected types of foods].

PubMed

Efimochkina, N R; Bykova, I B; Stetsenko, V V; Minaeva, L P; Pichugina, T V; Markova, Yu M; Korotkevich, Yu V; Kozak, S S; Sheveleva, S A

2016-01-01

The purpose of the work was to study the nature of the Campylobacter spp. contamination during the processing of food products of plant and animal origin (raw poultry and beef meat, raw milk, leafy salads, sliced raw vegetables). In the study of 148 samples 50 strains of Campylobacter spp. (33.8%) were found. For the main phenotypic characteristics they were identified as C. jejuni spp. jejuni and C. jejuni spp. doylei (over 75%). The highest level of detection of campylobacteria (over 45%) was set for raw poultry, including the carcasses of chickens broilers, quails, turkeys and their semi-finished products. 19 of the 27 strains from poultry were identified as C. jejuni. Among the strains isolated from the environment, including swabs from equipment surfaces, 91% of the isolates were also presented by C. jejuni. It was found that the investigated foodstuffs were characterized by high levels of contamination with bacteria of the family Enterobacteriaceae, the content of which was comparable with the identified values of total viable bacteria (cfu). Salmonella was detected in 19% of the investigated poultry samples and in 14.3% of raw cow milk. In the study of swabs from surfaces of poultry processing equipment, the frequency of detection of Campylobacter strains was 38.7%, Salmonella - 12.9%. Most commonly Campylobacter and Salmonella were detected in the zones of primary processing of poultry: the frequency of isolation of Salmonella in slaughter corner was 25%, Campylobacter - 43%. When testing the swabs taken in the cooking zone of «fast food» restaurants Campylobacter and Salmonella were not detected. For studying the swabs from equipment surfaces and the environment for the presence of Campylobacter spp. a modified technique of sampling was developed. The method includes a comprehensive analysis in the test area with the use of three types of media for transportation and incubation of Campylobacter spp. (Preston broth with blood, Brucella broth, Cary-Blair medium), that increase the probability of detection of these pathogens.

Anti-Listeria bacteriocin-producing bacteria from raw ewe's milk in northern Greece.

PubMed

Chanos, P; Williams, D R

2011-03-01

The isolation and partial characterization of anti-Listeria bacteriocin producing strains present in milk from areas of northern Greece in view of their potential use as protective cultures in food fermentations. Three hundred and thirty-two isolates were obtained from milk samples intended for Feta cheese production and gathered from 40 individual producers in Northern Greece. Isolates with anti-Listeria activity were identified by multiplex PCR as Enterococcus faecium and grouped by (GTG)(5) -PCR. The genomes of the anti-Listeria isolates were examined for the presence of known enterocin genes and major virulence genes by means of specific PCR. At least three known enterocin encoding genes were present in the genome of each of the 17 isolates. None of the 17 isolates harboured any of the virulence genes tested for or exhibited haemolytic activity. Enterococcus faecium was the dominant anti-Listeria species in the milk samples. The isolates had the potential of multiple bacteriocin production and did not exhibit some important elements of virulence. Enterococci present in milk of this area of northern Greece may be partly responsible for the safety of Feta cheese and could be useful for the production of anti-Listeria protective cultures. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

The occurrence of noncoagulating milk and the association of bovine milk coagulation properties with genetic variants of the caseins in 3 Scandinavian dairy breeds.

PubMed

Poulsen, N A; Bertelsen, H P; Jensen, H B; Gustavsson, F; Glantz, M; Månsson, H Lindmark; Andrén, A; Paulsson, M; Bendixen, C; Buitenhuis, A J; Larsen, L B

2013-08-01

Substantial variation in milk coagulation properties has been observed among dairy cows. Consequently, raw milk from individual cows and breeds exhibits distinct coagulation capacities that potentially affect the technological properties and milk processing into cheese. This variation is largely influenced by protein composition, which is in turn affected by underlying genetic polymorphisms in the major milk proteins. In this study, we conducted a large screening on 3 major Scandinavian breeds to resolve the variation in milk coagulation traits and the frequency of milk with impaired coagulation properties (noncoagulation). In total, individual coagulation properties were measured on morning milk collected from 1,299 Danish Holstein (DH), Danish Jersey (DJ), and Swedish Red (SR) cows. The 3 breeds demonstrated notable interbreed differences in coagulation properties, with DJ cows exhibiting superior coagulation compared with the other 2 breeds. In addition, milk samples from 2% of DH and 16% of SR cows were classified as noncoagulating. Furthermore, the cows were genotyped for major genetic variants in the αS1- (CSN1S1), β- (CSN2), and κ-casein (CSN3) genes, revealing distinct differences in variant frequencies among breeds. Allele I of CSN2, which had not formerly been screened in such a high number of cows in these Scandinavian breeds, showed a frequency around 7% in DH and DJ, but was not detected in SR. Genetic polymorphisms were significantly associated with curd firming rate and rennet coagulation time. Thus, CSN1S1 C, CSN2 B, and CSN3 B positively affected milk coagulation, whereas CSN2 A(2), in particular, had a negative effect. In addition to the influence of individual casein genes, the effects of CSN1S1-CSN2-CSN3 composite genotypes were also examined, and revealed strong associations in all breeds, which more or less reflected the single gene results. Overall, milk coagulation is under the influence of additive genetic variation. Optimal milk for future cheese production can be ensured by monitoring the frequency of unfavorable variants and thus preventing an increase in the number of cows producing milk with impaired coagulation. Selective breeding for variants associated with superior milk coagulation can potentially increase raw milk quality and cheese yield in all 3 Scandinavian breeds. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Impact of processing on in vitro digestion of milk from grazing organic and confined conventional herds

USDA-ARS?s Scientific Manuscript database

Debate on differences between milk from grazing and non-grazing cows has not addressed the effects that standard processing may have on milk digestibility. In this study, raw milk from grazing organic (ORG) and non-grazing conventional (CONV) herds was adjusted to 0 and 3.25% fat and processed as fo...

Milk Fat Globules Hamper Adhesion of Enterohemorrhagic Escherichia coli to Enterocytes: In Vitro and in Vivo Evidence

PubMed Central

Douëllou, Thomas; Galia, Wessam; Kerangart, Stéphane; Marchal, Thierry; Milhau, Nadège; Bastien, Renaud; Bouvier, Marion; Buff, Samuel; Montel, Marie-Christine; Sergentet-Thevenot, Delphine

2018-01-01

Enterohemorrhagic Escherichia coli (EHEC; E. coli) are food-borne agents associated with gastroenteritis, enterocolitis, bloody diarrhea and the hemolytic-uremic syndrome (HUS). Bovine milk glycans have been shown to contain oligosaccharides which are similar to host epithelial cell receptors and can therefore prevent bacterial adhesion. This study aimed to describe interactions between EHEC O157:H7 EDL933 and O26:H11 21765 and milk fat globules (MFGs) in raw milk and raw milk cheese, and the impact of MFGs on EHEC strains adhesion to the intestinal tract in vitro and in vivo. Both EHEC serotypes clearly associated with native bovine MFGs and significantly limited their adhesion to a co-culture of intestinal cells. The presence of MFGs in raw milk cheese had two effects on the adhesion of both EHEC serotypes to the intestinal tracts of streptomycin-treated mice. First, it delayed and reduced EHEC excretion in mouse feces for both strains. Second, the prime implantation site for both EHEC strains was 6 cm more proximal in the intestinal tracts of mice fed with contaminated cheese containing less than 5% of fat than in those fed with contaminated cheese containing 40% of fat. Feeding mice with 40% fat cheese reduced the intestinal surface contaminated with EHEC and may therefore decrease severity of illness. PMID:29867855

Effect of a pre-treatment of milk with high pressure homogenization on yield as well as on microbiological, lipolytic and proteolytic patterns of "Pecorino" cheese.

PubMed

Vannini, Lucia; Patrignani, Francesca; Iucci, Luciana; Ndagijimana, Maurice; Vallicelli, Melania; Lanciotti, Rosalba; Guerzoni, Maria Elisabetta

2008-12-10

The principal aim of this work was to compare Pecorino cheeses obtained from ewes' milk previously subjected to high pressure homogenization (HPH) at 100 MPa with those produced from raw and heat treated ewes' milk. The HPH milk treatment induced a significant increase of the cheese yield and caused a reduction of enterococci, lactococci and yeasts in the curds. Enterococci cell loads remained at lower levels in cheeses obtained from HPH milk over the ripening period. Analyses of free fatty acids, Sodium Dodecil Sulphate (SDS)-PAGE profiles, Gas Chromatography-Mass Spectrometry-Solid Phase Microextraction (GC-MS-SPME) measurements of volatile compounds and sensory traits evidenced that the pressure treatment can be regarded also as a useful tool to differentiate products obtained from the same raw material. In fact such a milk treatment induced a marked lipolysis, an early proteolysis, a relevant modification of the volatile molecule profiles and sensory properties of Pecorino cheese.

Cryo-transmission electron tomography of native casein micelles from bovine milk

PubMed Central

Trejo, R.; Dokland, T.; Jurat-Fuentes, J.; Harte, F.

2013-01-01

Caseins are the principal protein components in milk and an important ingredient in the food industry. In liquid milk, caseins are found as micelles of casein proteins and colloidal calcium nanoclusters. Casein micelles were isolated from raw skim milk by size exclusion chromatography and suspended in milk protein-free serum produced by ultrafiltration (molecular weight cut-off of 3 kDa) of raw skim milk. The micelles were imaged by cryo-electron microscopy and subjected to tomographic reconstruction methods to visualize the 3-dimensional and internal organization of native casein micelles. This provided new insights into the internal architecture of the casein micelle that had not been apparent from prior cryo-transmission electron microscopy studies. This analysis demonstrated the presence of water-filled cavities (~20 to 30 nm in diameter), channels (diameter greater than ~5 nm), and several hundred high-density nanoclusters (6 to 12 nm in diameter) within the interior of the micelles. No spherical protein submicellar structures were observed. PMID:22118067

Physicochemical and Microbiological Properties of Yogurt-cheese Manufactured with Ultrafiltrated Cow's Milk and Soy Milk Blends

PubMed Central

Lee, Na-Kyoung; Mok, Bo Ram; Jeewanthi, Renda Kankanamge Chaturika; Yoon, Yoh Chang; Paik, Hyun-Dong

2015-01-01

The objective of this study was to develop yogurt-cheese using cow’s milk, ultrafiltrated cow’s milk, and soy milk. The addition of soy milk and ultrafiltrated milk increased the amount of protein in the yogurt-cheese. Yogurt-cheeses were made using cheese base using 10% and 20% soy milk with raw and ultrafiltrated cow’s milk, and stored at 4℃ during 2 wk. The yield of yogurt-cheeses made with added soy milk was decreased and the cutting point was delayed compared to yogurt-cheese made without soy milk. Yogurt-cheese made using ultrafiltrated cow’s milk showed the highest yield. However, yogurt-cheese made with added soy milk had higher protein content and titratable acidity than yogurt-cheese made using raw and ultrafiltrated cow’s milk. Fat and lactose contents in the yogurt-cheese made with added soy milk were lower. Yogurt-cheeses made with added soy milk contained several soy protein bands corresponding to the sizes of α2-, β-, and κ-casein band. Yogurt-cheese made with added soy milk had similar elasticity to yogurt-cheese made without soy milk but had lower cohesiveness. There was no significant difference in the number of lactic acid bacteria in the different cheeses, as all had over 8.0 Log CFU/g. Considering these data and the fact that proteins and fats of vegetable origin with high biological value were observed as well as unsaturated fats, yogurt-cheese made with added soy milk can be considered to be a functional food. PMID:26761829

Detection and characterisation of Complement protein activity in bovine milk by bactericidal sequestration assay.

PubMed

Maye, Susan; Stanton, Catherine; Fitzgerald, Gerald F; Kelly, Philip M

2015-08-01

While the Complement protein system in human milk is well characterised, there is little information on its presence and activity in bovine milk. Complement forms part of the innate immune system, hence the importance of its contribution during milk ingestion to the overall defences of the neonate. A bactericidal sequestration assay, featuring a Complement sensitive strain, Escherichia coli 0111, originally used to characterise Complement activity in human milk was successfully applied to freshly drawn bovine milk samples, thus, providing an opportunity to compare Complement activities in both human and bovine milks. Although not identical in response, the levels of Complement activity in bovine milk were found to be closely comparable with that of human milk. Differential counts of Esch. coli 0111 after 2 h incubation were 6.20 and 6.06 log CFU/ml, for raw bovine and human milks, respectively - the lower value representing a stronger Complement response. Exposing bovine milk to a range of thermal treatments e.g. 42, 45, 65, 72, 85 or 95 °C for 10 min, progressively inhibited Complement activity by increasing temperature, thus confirming the heat labile nature of this immune protein system. Low level Complement activity was found, however, in 65 and 72 °C heat treated samples and in retailed pasteurised milk which highlights the outer limit to which high temperature, short time (HTST) industrial thermal processes should be applied if retention of activity is a priority. Concentration of Complement in the fat phase was evident following cream separation, and this was also reflected in the further loss of activity recorded in low fat variants of retailed pasteurised milk. Laboratory-based churning of the cream during simulated buttermaking generated an aqueous (buttermilk) phase with higher levels of Complement activity than the fat phase, thus pointing to a likely association with the milk fat globule membrane (MFGM) layer.

Conjugated linolenic acid (CLnA), conjugated linoleic acid (CLA) and other biohydrogenation intermediates in plasma and milk fat of cows fed raw or extruded linseed.

PubMed

Akraim, F; Nicot, M C; Juaneda, P; Enjalbert, F

2007-07-01

Thirty lactating dairy cows were used in a 3 × 3 Latin-square design to investigate the effects of a raw or extruded blend of linseed and wheat bran (70:30) on plasma and milk fatty-acids (FA). Linseed diets, containing 16.6% linseed blend on a dry-matter basis, decreased milk yield and protein percentage. They decreased the proportions of FA with less than 18 carbons in plasma and milk and resulted in cis-9, cis-12, cis-15 18:3 proportions that were more than three and four times higher in plasma and milk, respectively, whereas cis-9, cis-12 18:2 proportions were decreased by 10-15%. The cis-9, trans-11, cis-15 18:3 isomer of conjugated linolenic acid was not detected in the milk of control cows, but was over 0.15% of total FA in the milk fat of linseed-supplemented cows. Similarly, linseed increased plasma and milk proportions of all biohydrogenation (BH) intermediates in plasma and milk, including the main isomer of conjugated linoleic acid cis-9, trans-11 18:2, except trans-4 18:1 and cis-11, trans-15 18:2 in plasma lipids. In milk fat, compared with raw linseed, extruded linseed further reduced 6:0-16:0 even-chain FA, did not significantly affect the proportions of 18:0, cis-9 18:1 and cis-9, cis-12 18:2, tended to increase cis-9, cis-12, cis-15 18:3, and resulted in an additional increase in the proportions of most BH intermediates. It was concluded that linseed addition can improve the proportion of conjugated linoleic and linolenic acids, and that extrusion further increases the proportions of intermediates of ruminal BH in milk fat.

Foodborne pathogens in milk and the dairy farm environment: food safety and public health implications.

PubMed

Oliver, S P; Jayarao, B M; Almeida, R A

2005-01-01

Milk and products derived from milk of dairy cows can harbor a variety of microorganisms and can be important sources of foodborne pathogens. The presence of foodborne pathogens in milk is due to direct contact with contaminated sources in the dairy farm environment and to excretion from the udder of an infected animal. Most milk is pasteurized, so why should the dairy industry be concerned about the microbial quality of bulk tank milk? There are several valid reasons, including (1) outbreaks of disease in humans have been traced to the consumption of unpasteurized milk and have also been traced back to pasteurized milk, (2) unpasteurized milk is consumed directly by dairy producers, farm employees, and their families, neighbors, and raw milk advocates, (3) unpasteurized milk is consumed directly by a large segment of the population via consumption of several types of cheeses manufactured from unpasteurized milk, (4) entry of foodborne pathogens via contaminated raw milk into dairy food processing plants can lead to persistence of these pathogens in biofilms, and subsequent contamination of processed milk products and exposure of consumers to pathogenic bacteria, (5) pasteurization may not destroy all foodborne pathogens in milk, and (6) inadequate or faulty pasteurization will not destroy all foodborne pathogens. Furthermore, pathogens such as Listeria monocytogenes can survive and thrive in post-pasteurization processing environments, thus leading to recontamination of dairy products. These pathways pose a risk to the consumer from direct exposure to foodborne pathogens present in unpasteurized dairy products as well as dairy products that become re-contaminated after pasteurization. The purpose of this communication is to review literature published on the prevalence of bacterial foodborne pathogens in milk and in the dairy environment, and to discuss public health and food safety issues associated with foodborne pathogens found in the dairy environment. Information presented supports the model in which the presence of pathogens depends on ingestion of contaminated feed followed by amplification in bovine hosts and fecal dissemination in the farm environment. The final outcome of this cycle is a constantly maintained reservoir of foodborne pathogens that can reach humans by direct contact, ingestion of raw contaminated milk or cheese, or contamination during the processing of milk products. Isolation of bacterial pathogens with similar biotypes from dairy farms and from outbreaks of human disease substantiates this hypothesis.

Brucellosis in pregnant women from Pakistan: an observational study.

PubMed

Ali, Shahzad; Akhter, Shamim; Neubauer, Heinrich; Scherag, André; Kesselmeier, Miriam; Melzer, Falk; Khan, Iahtasham; El-Adawy, Hosny; Azam, Asima; Qadeer, Saima; Ali, Qurban

2016-09-02

Brucella species occasionally cause spontaneous human abortion. Brucella can be transmitted commonly through the ingestion of raw milk or milk products. The objective of this study was to determine the sero-prevalence of and to identify potential risk factors for brucellosis in pregnant women from Rawalpindi, Pakistan. We conducted a cross-sectional study at the Gynecology Outdoor Patient department of the Benazir Bhutto Hospital, Rawalpindi, Pakistan from March to June 2013. Data related to potential risk factors and clinical history was collected by individual interviews on the blood sampling day. The 429 serum samples collected were initially screened by Rose Bengal Plate Agglutination test for the detection of Brucella antibodies. We applied standard descriptive statistics and logistic regression analyses. Twenty five (5.8 %; 95 % confidence interval (CI): 3.8 % -8.5 %) serum samples were found to be seropositive. Brucellosis-related clinical symptoms were recorded in various seropositive cases. Animal contact, raw milk consumption, having an abortion history and the experience of an intrauterine fetal death were associated with seropositivity for brucellosis in univariate analyses (all p <0.05). In multiple logistic regression models only the contact with animals remained as independent and robust risk factor (odds ratio 5.21; 95 % CI: 1.88-13.75; p = 0.001) for seropositivity. Brucellosis is a serious threat for pregnant women and their unborn children in Pakistan. Pregnant women having brucellosis-related symptoms or previous history of abortions, miscarriages, intrauterine fetal death and other brucellosis-related manifestations should be screened for brucellosis - especially those exposed to animals given the increased risk - and medication should be administered according to state of the art.

[Microbiological assessment of the Gouda-type cheese-making process in a Venezuelan industry].

PubMed

Dáivila, Jacqueline; Reyes, Genara; Corzo, Otoniel

2006-03-01

The adoption of the Hazard Analysis and Critical Control Point (HACCP) system is necessary to assure the safety of the product in the cheese-making industry. The compliment of pre-requisite programs as Good Manufacture Practices (GMPs) and Sanitation Standard Operating Procedures (SSOPs) are required before the implementation of the HACCP plan. GMPs are the standards related to equipments, tools, personnel, etc. SSOPs are the procedures related to hygiene and sanitation of the plant and workers. The aim of this study was to assess the compliment of the pre-requisite programs and the microbiological conditions of the Gouda type cheese-making process in a Venezuelan processing plant before designing a HACCP plan. Samples were: (a) raw milk, pasteurized milk, curd and ripened cheese, (b) water, (c) environment of the production areas and ripening premises, (d) equipments before and after sanitation, (e) food handlers. Microbiological analyses were done according to COVENIN standards. This study showed that even though pasteurization process was effective to kill pathogen bacteria of the raw milk and the water was safe, however there are deficient manufacture practices in the hygiene as well as in sanitation of the plant and food handlers. Prerequisite programs (GMP-SSOP) of this industry need to be well established, controlled and evaluated.

Milk Contamination and Resistance to Processing Conditions Determine the Fate of Lactococcus lactis Bacteriophages in Dairies

PubMed Central

Madera, Carmen; Monjardín, Cristina; Suárez, Juan E.

2004-01-01

Milk contamination by phages, the susceptibility of the phages to pasteurization, and the high levels of resistance to phage infection of starter strains condition the evolution dynamics of phage populations in dairy environments. Approximately 10% (83 of 900) of raw milk samples contained phages of the quasi-species c2 (72%), 936 (24%), and P335 (4%). However, 936 phages were isolated from 20 of 24 (85%) whey samples, while c2 was detected in only one (4%) of these samples. This switch may have been due to the higher susceptibility of c2 to pasteurization (936-like phages were found to be approximately 35 times more resistant than c2 strains to treatment of contaminated milk in a plate heat exchanger at 72°C for 15 s). The restriction patterns of 936-like phages isolated from milk and whey were different, indicating that survival to pasteurization does not result in direct contamination of the dairy environment. The main alternative source of phages (commercial bacterial starters) does not appear to significantly contribute to phage contamination. Twenty-four strains isolated from nine starter formulations were generally resistant to phage infection, and very small progeny were generated upon induction of the lytic cycle of resident prophages. Thus, we postulate that a continuous supply of contaminated milk, followed by pasteurization, creates a factory environment rich in diverse 936 phage strains. This equilibrium would be broken if a particular starter strain turned out to be susceptible to infection by one of these 936-like phages, which, as a consequence, became prevalent. PMID:15574937

21 CFR 1210.22 - Form of tag.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) REGULATIONS... IMPORT MILK ACT Permit Control § 1210.22 Form of tag. Each container of milk or cream shipped or... form, bearing the required information in clear and legible type: Product (State whether raw milk...

21 CFR 1210.22 - Form of tag.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) REGULATIONS... IMPORT MILK ACT Permit Control § 1210.22 Form of tag. Each container of milk or cream shipped or... form, bearing the required information in clear and legible type: Product (State whether raw milk...

Prevalence, antimicrobial susceptibility, and molecular characterization of Staphylococcus aureus isolated from dairy herds in northern China.

PubMed

Liu, Huimin; Li, Songli; Meng, Lu; Dong, Lei; Zhao, Shengguo; Lan, Xinyi; Wang, Jiaqi; Zheng, Nan

2017-11-01

Staphylococcus aureus is one of the main pathogens involved in dairy cow mastitis. Monitoring of antibiotic use would prove useful to assess the risk of Staph. aureus in raw milk. The objective of this work was to investigate the prevalence of Staph. aureus strais isolated from raw milk in northern China, and to characterize antimicrobial susceptibility of these strains and their key virulence genes. In total, 195 raw milk samples were collected from 195 dairy farms located in 4 cities of northern China from May to September 2015. Out of 195 samples, 54 (27.7%) were positive for Staph. aureus. Among these 54 samples, 54 strains of Staph. aureus were isolated, and 16 strains were identified as methicillin-resistant Staph. aureus. The strains exhibited high percentages of resistance to penicillin G (85.2%), ampicillin (79.6%), and erythromycin (46.3%). Moreover, 72% of the strains showed resistance to more than one antimicrobial agent. Overall, 63% of penicillin-resistant strains possessed the blaZ gene, and 60% of the erythromycin-resistant strains possessed erm(A), erm(B), erm(C), msr(A), or msr(B) genes with 8 different gene patterns. All isolates resistant to gentamicin, kanamycin, and oxacillin carried the aac6'-aph2", ant(4')-Ia, and mecA genes, respectively. Two tet(M)-positive isolates carried specific genes of the Tn916-Tn1545 transposon. The most predominant virulence genes were sec, sea, and pvl, which encode staphylococcal enterotoxins (sec and sea) and Panton-Valentine leukocidin, respectively. Thirty-two isolates (59.2%) harbored one or more virulence genes. The majority of Staph. aureus strains were multidrug resistant and carried multiple virulence genes, which may pose a risk to public health. Our data indicated that antimicrobial resistance of Staph. aureus was prevalent in dairy herds in northern China, and that antibiotics, especially penicillin G and ampicillin, to treat mastitis caused by Staph. aureus should be used with caution in northern China. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of pasteurization on survival of Mycobacterium paratuberculosis in milk.

PubMed

Gao, A; Mutharia, L; Chen, S; Rahn, K; Odumeru, J

2002-12-01

Mycobacterium paratuberculosis (Mptb) is the causative agent of Johne's disease of ruminant animals including cattle, goats, and sheep. It has been suggested that this organism is associated with Crohn's disease in humans, and milk is a potential source of human exposure to this organism. A total of 18, including 7 regular batch and 11 high temperature short time (HTST) pasteurization experiments, were conducted in this study. Raw milk or ultra-high temperature pasteurized milk samples were spiked at levels of 10(3), 10(5), and 10(7) cfu of Mptb/ml. Escherichia coli and Mycobacterium bovis BCG strains at 10(7) cfu/ml were used as controls. Pasteurization experiments were conducted using time and temperature standards specified in the Canadian National Dairy Code: regular batch pasteurization method: 63 degrees C for 30 min, and HTST method: 72 degrees C for 15 s. The death curve of this organism was assessed at 63 degrees C. No survivors were detected after 15 min. Each spiked sample was cultured in Middlebrook 7H9 culture broth and Middlebrook 7H11 agar slants. Samples selected from 15 experiments were also subjected to BACTEC culture procedure. Survival of Mptb was confirmed by IS900-based PCR of colonies recovered on slants. No survivors were detected from any of the slants or broths corresponding to the seven regular batch pasteurization trials. Mptb survivors were detected in two of the 11 HTST experiments. One was by both slant and broth culture for the sample spiked to 10(7) cfu/ml of Mptb, while the other was detected by BACTEC for the sample spiked to 10(5) cfu/ml. These results indicate that Mptb may survive HTST pasteurization when present at > or = 10(5) cfu/ml in milk. A total of 710 retail milk samples collected from retail store and dairy plants in southwest Ontario were tested by nested IS900 PCR for the presence of Mptb. Fifteen percent of these samples (n = 110) were positive. However, no survivors were isolated from the broth and agar cultures of 44 PCR positive and 200 PCR negative retail milk samples. The lack of recovery of live Mptb from the retail milk samples tested may be due to either the absence of live Mptb in the retail milk samples tested or the presence of low number of viable Mptb which were undetected by the culture method used in this study.

Occurrence, genotyping, shiga toxin genes and associated risk factors of E. coli isolated from dairy farms, handlers and milk consumers.

PubMed

Awadallah, M A; Ahmed, H A; Merwad, A M; Selim, M A

2016-11-01

The objectives of the current study were to determine the occurrence and genotypes of E. coli in dairy farms, workers and milk consumers and to evaluate risk factors associated with contamination of milk in dairy farms. Molecular characterization of shiga toxin associated genes and enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) finger printing of E. coli from different sources were also studied. Paired milk samples and rectal swabs from 125 dairy cows, rectal swabs from 82 calves and hand swabs from 45 dairy workers from five dairy farms were collected. In addition, 100 stool samples from 70 diarrheic and 30 healthy humans were collected and examined for the presence of E. coli. E. coli was isolated from milk (22.4%), dairy cattle feces (33.6%), calf feces (35.4%), dairy worker hand swabs (11.1%) and stools of milk consumers (2%, from diarrheic patients only). Only stx1 was identified in seven of 12 E. coli O125 isolated from different sources. High genetic diversity was determined (Simpson's index of diversity, D = 1) and E. coli O125 isolates were classified into 12 distinct profiles, E1-E12. The dendrogram analysis showed that two main clusters were generated. Mastitis in dairy cows was considered a risk factor associated with contamination of the produced milk with E. coli. The isolation of E. coli from rectal swabs of dairy cows and calves poses a zoonotic risk through consumption of unpasteurized contaminated dairy milk. Educational awareness should be developed to address risks related to consumption of raw milk. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of high pressure processing on dispersive and aggregative properties of almond milk.

PubMed

Dhakal, Santosh; Giusti, M Monica; Balasubramaniam, V M

2016-08-01

A study was conducted to investigate the impact of high pressure (450 and 600 MPa at 30 °C) and thermal (72, 85 and 99 °C at 0.1 MPa) treatments on dispersive and aggregative characteristics of almond milk. Experiments were conducted using a kinetic pressure testing unit and water bath. Particle size distribution, microstructure, UV absorption spectra, pH and color changes of processed and unprocessed samples were analyzed. Raw almond milk represented the mono model particle size distribution with average particle diameters of 2 to 3 µm. Thermal or pressure treatment of almond milk shifted the particle size distribution towards right and increased particle size by five- to six-fold. Micrographs confirmed that both the treatments increased particle size due to aggregation of macromolecules. Pressure treatment produced relatively more and larger aggregates than those produced by heat treated samples. The apparent aggregation rate constant for 450 MPa and 600 MPa processed samples were k450MPa,30°C  = 0.0058 s(-1) and k600MPa,30°C  = 0.0095 s(-1) respectively. This study showed that dispersive and aggregative properties of high pressure and heat-treated almond milk were different due to differences in protein denaturation, particles coagulation and aggregates morphological characteristics. Knowledge gained from the study will help food processors to formulate novel plant-based beverages treated with high pressure. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Presence of PAHs in milk of industrial farms from Tizayuca, Hidalgo, Mexico.

PubMed

Gutiérrez, Rey; Vega, Salvador; Ortiz, Rutilio; Pérez, José Jesús; Schettino, Beatriz

2015-01-01

The objective of this study was to determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) in cow's milk from industrial farms that are located near an industrial park in Hidalgo, Mexico. It was found that the concentrations of PAHs in the raw milk of cattle from industrial farms have increased in recent years. Composite samples were collected between 2008 and 2010 and analysis carried out according to 8100 EPA procedures and analyzed by gas chromatography with FID detection. The results show that combustion PAHs were mostly Ace, Acy, and Fla (0.25, 0.32, and 0.22 µg g(-1), respectively). Diagnostic ratios were used to show that the probable sources were grass and fuel combustion. The sum of concentrations of 16 individual PAHs did not breach permissible levels in milk (25 µg g(-1) according to the United States EPA), indicating a limited health risk to animals and humans in the study area. The industrial park has adequate pollutant emission regulations.

Stool Culture

MedlinePlus

... with pathogenic bacteria, such as undercooked meat or raw eggs, or the same food that has made ... most frequently encountered sources include: Campylobacter – found in raw or undercooked poultry and unpasteurized milk; it is ...

A Novel Lactobacilli-Based Teat Disinfectant for Improving Bacterial Communities in the Milks of Cow Teats with Subclinical Mastitis

PubMed Central

Yu, Jie; Ren, Yan; Xi, XiaoXia; Huang, Weiqiang; Zhang, Heping

2017-01-01

Teat disinfection pre- and post-milking is important for the overall health and hygiene of dairy cows. The objective of this study was to evaluate the efficacy of a novel probiotic lactobacilli-based teat disinfectant based on changes in somatic cell count (SCC) and profiling of the bacterial community. A total of 69 raw milk samples were obtained from eleven Holstein-Friesian dairy cows over 12 days of teat dipping in China. Single molecule, real-time sequencing technology (SMRT) was employed to profile changes in the bacterial community during the cleaning protocol and to compare the efficacy of probiotic lactic acid bacteria (LAB) and commercial teat disinfectants. The SCC gradually decreased following the cleaning protocol and the SCC of the LAB group was slightly lower than that of the commercial disinfectant (CD) group. Our SMRT sequencing results indicate that raw milk from both the LAB and CD groups contained diverse microbial populations that changed over the course of the cleaning protocol. The relative abundances of some species were significantly changed during the cleaning process, which may explain the observed bacterial community differences. Collectively, these results suggest that the LAB disinfectant could reduce mastitis-associated bacteria and improve the microbial environment of the cow teat. It could be used as an alternative to chemical pre- and post-milking teat disinfectants to maintain healthy teats and udders. In addition, the Pacific Biosciences SMRT sequencing with the full-length 16S ribosomal RNA gene was shown to be a powerful tool for monitoring changes in the bacterial population during the cleaning protocol. PMID:29018412

40 CFR 180.1 - Definitions and interpretations.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... (d) Raw agricultural commodities include, among other things, fresh fruits, whether or not they have been washed and colored or otherwise treated in their unpeeled natural form; vegetables in their raw or... green salads, etc.; grains, nuts, eggs, raw milk, meats, and similar agricultural produce. It does not...

40 CFR 180.1 - Definitions and interpretations.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... (d) Raw agricultural commodities include, among other things, fresh fruits, whether or not they have been washed and colored or otherwise treated in their unpeeled natural form; vegetables in their raw or... green salads, etc.; grains, nuts, eggs, raw milk, meats, and similar agricultural produce. It does not...

Effect of cattle management practices on raw milk quality on farms operating in a two-stage dairy chain.

PubMed

Sraïri, M T; Benhouda, H; Kuper, M; Le Gal, P Y

2009-02-01

In many developing countries, milk production varies greatly according to farm size, cattle breed, and milking practices. However, production systems often are dominated by smallholder farms. Therefore, relatively small volumes of milk are delivered daily from numerous farms to intermediate cooperatives which supply industrial units. This paper argues that in such two-stage dairy chains, milk quality could be improved by focusing on farming practices rather than on the testing of individual deliveries. Indeed, it is difficult to analyze their quality due to technical, economic, and logistic limitations. The objective of this study is to link on-farm practices with milk chemical quality parameters (fat and protein) and hygienic quality criteria (Aerobic Plate Count, APC and Coliforms). Cattle management practices were monitored monthly over one year on 23 farms located on an irrigation scheme in Morocco. 276 milk samples were analyzed. The monthly variability of milk quality parameters was then characterized. Results show that average cow milk chemical parameters vary within a normal range. They remain primarily linked to the genetic type of cows, the lactation stage, and the conversion of feed concentrates' net energy into milk. Overall milk hygienic quality was poor (APC and Coliforms counts were 100 fold international norms), due essentially to a lack of hygiene and inadequate milking conditions (hands, udder, and teat washing, type of bucket used, dirtiness of cows...). It is suggested that a close monitoring of herd management practices may allow the indirect control of milk quality parameters, thereby avoiding costly analyses of numerous smallholder milk deliveries.

Effect of preservatives on the accuracy of mid-infrared milk component testing.

PubMed

Barbano, D M; Wojciechowski, K L; Lynch, J M

2010-12-01

Our objective was to determine the effect of commonly used milk preservatives on the accuracy of fat, protein, and lactose content determination in milk by mid-infrared (mid-IR) milk analysis. Two producer raw milks (Holstein and Jersey) and 2 pasteurized modified milks, 1 similar to Holstein milk and 1 similar to Jersey milk were used as the 4 different milk sources. Seven different milk preservative approaches (K(2)Cr(2)O(7) and 6 different bronopol-based preservatives) and a portion of unpreserved milk for each of the 4 different milks sources were tested for fat B, lactose, protein, and fat A. The experiment was replicated 3 times (28 d each) for a total of 84 d. Two mid-infrared (mid-IR) transmittance milk analyzers (an optical and a virtual filter instrument) were used. A large batch of pilot milk was prepared from pasteurized, homogenized, unpreserved whole milk, split into vials, quick frozen by immersion in liquid nitrogen, and transferred into a -80 °C freezer. Pilots were thawed and analyzed on each testing day during the study. Significant increases were observed in all uncorrected readings on the pilot milks over the 84 d of the study, but the increases were gradual and small on each instrument for all components. Results from the study were corrected for these changes. A significant difference in mid-IR fat A readings was observed, whereas no differences were detected for fat B, lactose, or protein between unpreserved and preserved milks containing 0.02% K(2)Cr(2)O(7.) Therefore, K(2)Cr(2)O(7) has little or no effect on mid-IR test results. All bronopol-based preservative approaches in this study differed in mid-IR test results compared with K(2)Cr(2)O(7)-preserved and unpreserved milks, with the largest effect on protein results. Mid-IR uncorrected readings increased with time of refrigerated storage at 4°C for all preservative approaches, with the largest increase for protein. The rate of increase in uncorrected readings with time of storage was always higher for raw milks than for pasteurized milks, and the stability of instrument zero was lower for raw milks than for pasteurized milks. The largest economic effect of a systematic bias caused by a preservative occurs when the milks used for calibration and routine testing for payment do not contain the same preservative or when calibration milks are preserved and milks for routine testing are unpreserved. These effects can create errors in payment for large dairy processing plants ranging from several hundred thousand to over a million dollars annually. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

InstantLabs Listeria monocytogenes food safety kit. Performance tested method 051304.

PubMed

Sharma, Neil; Bambusch, Lauren; Le, Thu; Morey, Amit

2014-01-01

The InstantLabs Listeria monocytogenes Food Safety Kit was validated against the International Organization for Standardization (ISO) reference method 11290-1 for the detection of Listeria monocytogenes and other Listeria species. The matrixes (stainless steel, sealed concrete, ice cream, whole milk, cheddar cheese, raw shrimp, hot dogs, deli turkey, and lettuce) were inoculated with approximately 1 CFU/test portion of L. monocytogenes to generate fractional positives (5-15) in 20 inoculated samples. Enrichments were also fractionally inoculated with L. grayii for side-by-side testing of the Listeria Species Food Safety Kit. Stainless steel and sealed concrete samples were validated using 4 x 4" and 1 x 1 " test areas, respectively, and enriched in Buffered Listeria Enrichment Broth (BLEB) at 35 +/- 1degreesC for 22-28 h. All food samples were tested at 25 g and enriched in BLEB at 35 +/- 1 degreesC for 24-28 h. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method performed as well as or better than the reference method for the detection of L. monocytogenes on stainless steel and sealed concrete and in ice cream, whole milk, cheddar cheese, raw shrimp, hot dogs, deli turkey, and lettuce. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 50 L. monocytogenes serovars and 30 non-L. monocytogenes species examined. The method was shown to be robust when the enrichment times, volumes for DNA extraction, and heat block times were varied.

ADSA Foundation Scholar Award: Trends in culture-independent methods for assessing dairy food quality and safety: emerging metagenomic tools.

PubMed

Yeung, Marie

2012-12-01

Enhancing the quality and safety of dairy food is critical to maintaining the competitiveness of dairy products in the food and beverage market and in reinforcing consumer confidence in the dairy industry. Raw milk quality has a significant effect on finished product quality. Several microbial groups found in raw milk have been shown to adversely affect the shelf life of pasteurized milk. Current microbiological criteria used to define milk quality are based primarily on culture-dependent methods, some of which are perceived to lack the desired sensitivity and specificity. To supplement traditional methods, culture-independent methods are increasingly being used to identify specific species or microbial groups, and to detect indicator genes or proteins in raw milk or dairy products. Some molecular subtyping techniques have been developed to track the transmission of microbes in dairy environments. The burgeoning "-omics" technologies offer new and exciting opportunities to enhance our understanding of food quality and safety in relation to microbes. Metagenomics has the potential to characterize microbial diversity, detect nonculturable microbes, and identify unique sequences or other factors associated with dairy product quality and safety. In this review, fluid milk will be used as the primary example to examine the adequacy and validity of conventional methods, the current trend of culture-independent methods, and the potential applications of metagenomics in dairy food research. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Multiple-Strain Approach and Probabilistic Modeling of Consumer Habits in Quantitative Microbial Risk Assessment: A Quantitative Assessment of Exposure to Staphylococcal Enterotoxin A in Raw Milk.

PubMed

Crotta, Matteo; Rizzi, Rita; Varisco, Giorgio; Daminelli, Paolo; Cunico, Elena Cosciani; Luini, Mario; Graber, Hans Ulrich; Paterlini, Franco; Guitian, Javier

2016-03-01

Quantitative microbial risk assessment (QMRA) models are extensively applied to inform management of a broad range of food safety risks. Inevitably, QMRA modeling involves an element of simplification of the biological process of interest. Two features that are frequently simplified or disregarded are the pathogenicity of multiple strains of a single pathogen and consumer behavior at the household level. In this study, we developed a QMRA model with a multiple-strain approach and a consumer phase module (CPM) based on uncertainty distributions fitted from field data. We modeled exposure to staphylococcal enterotoxin A in raw milk in Lombardy; a specific enterotoxin production module was thus included. The model is adaptable and could be used to assess the risk related to other pathogens in raw milk as well as other staphylococcal enterotoxins. The multiplestrain approach, implemented as a multinomial process, allowed the inclusion of variability and uncertainty with regard to pathogenicity at the bacterial level. Data from 301 questionnaires submitted to raw milk consumers were used to obtain uncertainty distributions for the CPM. The distributions were modeled to be easily updatable with further data or evidence. The sources of uncertainty due to the multiple-strain approach and the CPM were identified, and their impact on the output was assessed by comparing specific scenarios to the baseline. When the distributions reflecting the uncertainty in consumer behavior were fixed to the 95th percentile, the risk of exposure increased up to 160 times. This reflects the importance of taking into consideration the diversity of consumers' habits at the household level and the impact that the lack of knowledge about variables in the CPM can have on the final QMRA estimates. The multiple-strain approach lends itself to use in other food matrices besides raw milk and allows the model to better capture the complexity of the real world and to be capable of geographical specificity.

7 CFR 58.332 - Segregation of raw material.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Segregation of raw material. 58.332 Section 58.332 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.332 Segregation of raw material. The milk and cream received at the dairy plant shall meet...

7 CFR 58.332 - Segregation of raw material.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Segregation of raw material. 58.332 Section 58.332 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.332 Segregation of raw material. The milk and cream received at the dairy plant shall meet...

7 CFR 58.143 - Raw product storage.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Raw product storage. 58.143 Section 58.143 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.143 Raw product storage. (a) All milk shall be held and processed under conditions and at...

7 CFR 58.143 - Raw product storage.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Raw product storage. 58.143 Section 58.143 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.143 Raw product storage. (a) All milk shall be held and processed under conditions and at...

Heterogeneity of heat-resistant proteases from milk Pseudomonas species.

PubMed

Marchand, Sophie; Vandriesche, Gonzalez; Coorevits, An; Coudijzer, Katleen; De Jonghe, Valerie; Dewettinck, Koen; De Vos, Paul; Devreese, Bart; Heyndrickx, Marc; De Block, Jan

2009-07-31

Pseudomonas fragi, Pseudomonas lundensis and members of the Pseudomonas fluorescens group may spoil Ultra High Temperature (UHT) treated milk and dairy products, due to the production of heat-stable proteases in the cold chain of raw milk. Since the aprX gene codes for a heat-resistant protease in P. fluorescens, the presence of this gene has also been investigated in other members of the genus. For this purpose an aprX-screening PCR test has been developed. Twenty-nine representatives of important milk Pseudomonas species and thirty-five reference strains were screened. In 42 out of 55 investigated Pseudomonas strains, the aprX gene was detected, which proves the potential of the aprX-PCR test as a screening tool for potentially proteolytic Pseudomonas strains in milk samples. An extensive study of the obtained aprX-sequences on the DNA and the amino acid level, however, revealed a large heterogeneity within the investigated milk isolates. Although this heterogeneity sets limitations to a general detection method for all proteolytic Pseudomonas strains in milk, it offers a great potential for the development of a multiplex PCR screening test targeting individual aprX-genes. Furthermore, our data illustrated the potential use of the aprX gene as a taxonomic marker, which may help in resolving the current taxonomic deadlock in the P. fluorescens group.

Milk: an exosomal microRNA transmitter promoting thymic regulatory T cell maturation preventing the development of atopy?

PubMed

Melnik, Bodo C; John, Swen Malte; Schmitz, Gerd

2014-02-12

Epidemiological evidence confirmed that raw cow's milk consumption in the first year of life protects against the development of atopic diseases and increases the number of regulatory T-cells (Tregs). However, milk's atopy-protective mode of action remains elusive.This review supported by translational research proposes that milk-derived microRNAs (miRs) may represent the missing candidates that promote long-term lineage commitment of Tregs downregulating IL-4/Th2-mediated atopic sensitization and effector immune responses. Milk transfers exosomal miRs including the ancient miR-155, which is important for the development of the immune system and controls pivotal target genes involved in the regulation of FoxP3 expression, IL-4 signaling, immunoglobulin class switching to IgE and FcϵRI expression. Boiling of milk abolishes milk's exosomal miR-mediated bioactivity. Infant formula in comparison to human breast- or cow's milk is deficient in bioactive exosomal miRs that may impair FoxP3 expression. The boost of milk-mediated miR may induce pivotal immunoregulatory and epigenetic modifications required for long-term thymic Treg lineage commitment explaining the atopy-protective effect of raw cow's milk consumption.The presented concept offers a new option for the prevention of atopic diseases by the addition of physiological amounts of miR-155-enriched exosomes to infant formula for mothers incapable of breastfeeding.

Detection and genotyping of Toxoplasma gondii DNA in the blood and milk of naturally infected donkeys (Equus asinus)

USDA-ARS?s Scientific Manuscript database

Toxoplasma gondii is a worldwide zoonotic protozoan. Consumption of raw milk from infected animals is considered a risk factor for acquiring toxoplasmosis in humans. Recently, donkey milk has been indicated for therapeutic and nutritional purposes and T. gondii infection is common in donkeys. The pu...

Altered concentrate to forage ratio in cows ration enhanced bioproduction of specific size subpopulation of milk fat globules.

PubMed

Mesilati-Stahy, Ronit; Moallem, Uzi; Magen, Yogev; Argov-Argaman, Nurit

2015-07-15

The mechanism underlying the shift in milk-fat-globule (MFG) mean diameter upon changing the concentrate-to-forage ratio in dairy cow rations was investigated. Cows were fed high-concentrate low-forage (HCLF) or high-forage low-concentrate (LCHF) rations for 4 weeks. Mean diameter of MFG, determined in raw whole milk, was 0.4 μm larger in the LCHF-fed vs. HCLF-fed group. The main compositional differences between treatments were found in a specific MFG subgroup with the diameter of 3.3 μm (F1), with higher capric, lauric, myristic and lower oleic acid concentrations in HCLF vs. LCHF milk. Similarly, lipid concentration differences between treatments were only found in F1, with higher triglyceride and phosphatidylethanolamine, and lower sphingomyelin concentrations in LCHF vs. HCLF milk. The higher MFG mean diameter in whole raw LCHF milk might therefore be attributed to increased secretion of F1-group MFG, while fat content and composition in the other MFG size groups remains unchanged. Copyright © 2015 Elsevier Ltd. All rights reserved.

Using confocal laser scanning microscopy to probe the milk fat globule membrane and associated proteins.

PubMed

Gallier, Sophie; Gragson, Derek; Jiménez-Flores, Rafael; Everett, David

2010-04-14

The bovine milk fat globule membrane (MFGM) is an important, biologically relevant membrane due to its functional and health properties. Its composition has been thoroughly studied, but its structure, especially the lateral organization of its components, still remains unclear. We have used confocal laser scanning microscopy (CLSM) to investigate the surface structure of the MFGM in globules with different degrees of processing using two types of fluorescently labeled phospholipid probes and a protein dye. Using this technique, we have observed heterogeneities in the distribution of MFGM lipids and proteins relating to the processing and size of the globules. The effect of pretreating the milk (centrifugation, pasteurization-homogenization and churning) was studied by double-staining the surface of the milk fat globules, followed by observation using CLSM, and by determining the phospholipid profile of raw milk, raw cream, processed milk and buttermilk powder. Our findings agree with other techniques by showing that the composition of the MFGM changes with processing through the loss of phospholipids and the adsorption of caseins and whey proteins onto the surface.

Cryo-transmission electron tomography of native casein micelles from bovine milk.

PubMed

Trejo, R; Dokland, T; Jurat-Fuentes, J; Harte, F

2011-12-01

Caseins are the principal protein components in milk and an important ingredient in the food industry. In liquid milk, caseins are found as micelles of casein proteins and colloidal calcium nanoclusters. Casein micelles were isolated from raw skim milk by size exclusion chromatography and suspended in milk protein-free serum produced by ultrafiltration (molecular weight cut-off of 3 kDa) of raw skim milk. The micelles were imaged by cryo-electron microscopy and subjected to tomographic reconstruction methods to visualize the 3-dimensional and internal organization of native casein micelles. This provided new insights into the internal architecture of the casein micelle that had not been apparent from prior cryo-transmission electron microscopy studies. This analysis demonstrated the presence of water-filled cavities (∼20 to 30 nm in diameter), channels (diameter greater than ∼5 nm), and several hundred high-density nanoclusters (6 to 12 nm in diameter) within the interior of the micelles. No spherical protein submicellar structures were observed. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Ptaquiloside, the major carcinogen of bracken fern, in the pooled raw milk of healthy sheep and goats: an underestimated, global concern of food safety.

PubMed

Virgilio, Antonella; Sinisi, Annamaria; Russo, Valeria; Gerardo, Salvatore; Santoro, Adriano; Galeone, Aldo; Taglialatela-Scafati, Orazio; Roperto, Franco

2015-05-20

Bracken fern (Pteridium aquilinum) is a worldwide plant containing toxic substances, which represent an important chemical hazard for animals, including humans. Ptaquiloside, 1, a norsesquiterpenoid glucoside, is the major carcinogen of bracken detected in the food chain, particularly in the milk from farm animals. To date, ptaquiloside has been shown in the milk of cows feeding on a diet containing bracken fern. This is the first study that shows the systematic detection of ptaquiloside, 1, and reports its direct quantitation in pooled raw milk of healthy sheep and goats grazing on bracken. Ptaquiloside, 1, was detected by a sensitive method based on the chemical conversion of ptaquiloside, 1, into bromopterosine, 4, following gas chromatography-mass spectrometry (GC-MS) analysis. The presence of ptaquiloside, 1, possibly carcinogenic to humans, in the milk of healthy animals is an unknown potential health risk, thus representing a harmful and potential global concern of food safety.

Native fat globules of different sizes selected from raw milk: thermal and structural behavior.

PubMed

Michalski, Marie-Caroline; Ollivon, Michel; Briard, Valérie; Leconte, Nadine; Lopez, Christelle

2004-12-01

The aim of this study was to characterize differences in the thermal and structural behavior between different sized native milk fat globules. A novel microfiltration process permits the selection of native small fat globules (SFG, 1-3 microm) and large fat globules (LFG, >5 microm) in raw milk, that were analyzed by X-ray diffraction (XRD) coupled to differential scanning calorimetry (DSC). There were no major differences in triglyceride crystalline structures between SFG and LFG, after eliminating thermal history and the influence of cooling rates. The three main 3L and 2L crystalline structures appearing under slow cooling existed regardless of globule size. The supercooling increased for the SFG, mainly due to heterogeneous nucleation in winter milk, and also to compositional variations in spring milk. Differences appeared regarding stabilized crystalline forms at 20 degrees C and subsequent cooling: the SFG contained less 2L triglyceride structures than the LFG. These results can be important in dairy manufactures using tempering periods.

Dynamics of bacterial communities during manufacture and ripening of traditional Caciocavallo of Castelfranco cheese in relation to cows' feeding.

PubMed

Giello, Marina; La Storia, Antonietta; Masucci, Felicia; Di Francia, Antonio; Ercolini, Danilo; Villani, Francesco

2017-05-01

Traditional Caciocavallo of Castelfranco is a semi-hard "pasta-filata" cheese produced from raw cows' milk in Campania region. The aim of the present research is mainly focused on the study, by 16S rRNA gene pyrosequencing and viable counts, of the dynamics of bacterial communities during manufacture and ripening of traditional Caciocavallo cheese. Moreover, the possible correlation between cheese microbiota and cows' feeding based on silage or hay was also evaluated. In general, except for enterococci, the technological process significantly affected all the microbial groups. According to 16S rRNA, raw cows' milk was dominated by Streptococcus thermophilus, L. lactis and Pseudomonas sp. in hay cheese production, whereas Lactococcus lactis and Acinetobacter sp. dominated silage production. Differences in the taxonomic structure of the milk's microbiota within diet groups were not related to silage and hay cows' feeding. Moreover, S. thermophilus was the unique species that dominate from raw milks to fermented intermediates and cheese in both hay and silage cheese productions. Feeding and ripening time influenced significantly sensory characteristics of the cheeses. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antagonistic lactic acid bacteria isolated from goat milk and identification of a novel nisin variant Lactococcus lactis

PubMed Central

2014-01-01

Background The raw goat milk microbiota is considered a good source of novel bacteriocinogenic lactic acid bacteria (LAB) strains that can be exploited as an alternative for use as biopreservatives in foods. The constant demand for such alternative tools justifies studies that investigate the antimicrobial potential of such strains. Results The obtained data identified a predominance of Lactococcus and Enterococcus strains in raw goat milk microbiota with antimicrobial activity against Listeria monocytogenes ATCC 7644. Enzymatic assays confirmed the bacteriocinogenic nature of the antimicrobial substances produced by the isolated strains, and PCR reactions detected a variety of bacteriocin-related genes in their genomes. Rep-PCR identified broad genetic variability among the Enterococcus isolates, and close relations between the Lactococcus strains. The sequencing of PCR products from nis-positive Lactococcus allowed the identification of a predicted nisin variant not previously described and possessing a wide inhibitory spectrum. Conclusions Raw goat milk was confirmed as a good source of novel bacteriocinogenic LAB strains, having identified Lactococcus isolates possessing variations in their genomes that suggest the production of a nisin variant not yet described and with potential for use as biopreservatives in food due to its broad spectrum of action. PMID:24521354

A Preliminary Assessment of HTST Processing on Donkey Milk

PubMed Central

Antoniazzi, Sara; Gariglio, Gian Marco; Coscia, Alessandra; Bertino, Enrico; Cavallarin, Laura

2017-01-01

Due to increasing attention from consumers on non-bovine milk types, and to the increase in the number of small dairy donkey farms in Italy, farmers require more advanced and reliable processing devices, in order to guarantee a safe product of high quality. To this aim, a new small-scale High-Temperature Short-Time (HTST) pasteurizer (72 °C for 15 s), prototyped by the authors, was tested on donkey milk. The efficacy of the HTST device was tested on raw donkey milk microflora by enumeration of total aerobic bacteria, Enterobacteriaceae and Bacillus cereus. The biochemical quality was assessed by determining the protein profile by monodimensional electrophoresis and by measuring lysozyme activity. The HTST apparatus was able to reduce the total bacteria count, and to completely eradicate Enterobacteriaceae. Bacillus cereus, when present, was decreased with low efficiency. Changes in the protein profile were observed in milk pasteurized in accordance with both processes, although HTST seemed to limit casein degradation. Lysozyme activity was not substantially affected in comparison to raw donkey milk. In conclusion, a tailored small-volume HTST device could be safely applied to pasteurize donkey milk in on-farm pasteurization processes on small dairy donkey farms. PMID:29056708

A Preliminary Assessment of HTST Processing on Donkey Milk.

PubMed

Giribaldi, Marzia; Antoniazzi, Sara; Gariglio, Gian Marco; Coscia, Alessandra; Bertino, Enrico; Cavallarin, Laura

2017-10-09

Due to increasing attention from consumers on non-bovine milk types, and to the increase in the number of small dairy donkey farms in Italy, farmers require more advanced and reliable processing devices, in order to guarantee a safe product of high quality. To this aim, a new small-scale High-Temperature Short-Time (HTST) pasteurizer (72 °C for 15 s), prototyped by the authors, was tested on donkey milk. The efficacy of the HTST device was tested on raw donkey milk microflora by enumeration of total aerobic bacteria, Enterobacteriaceae and Bacillus cereus. The biochemical quality was assessed by determining the protein profile by monodimensional electrophoresis and by measuring lysozyme activity. The HTST apparatus was able to reduce the total bacteria count, and to completely eradicate Enterobacteriaceae. Bacillus cereus, when present, was decreased with low efficiency. Changes in the protein profile were observed in milk pasteurized in accordance with both processes, although HTST seemed to limit casein degradation. Lysozyme activity was not substantially affected in comparison to raw donkey milk. In conclusion, a tailored small-volume HTST device could be safely applied to pasteurize donkey milk in on-farm pasteurization processes on small dairy donkey farms.

Dynamics of bacterial communities during the ripening process of different Croatian cheese types derived from raw ewe's milk cheeses.

PubMed

Fuka, Mirna Mrkonjić; Wallisch, Stefanie; Engel, Marion; Welzl, Gerhard; Havranek, Jasmina; Schloter, Michael

2013-01-01

Microbial communities play an important role in cheese ripening and determine the flavor and taste of different cheese types to a large extent. However, under adverse conditions human pathogens may colonize cheese samples during ripening and may thus cause severe outbreaks of diarrhoea and other diseases. Therefore in the present study we investigated the bacterial community structure of three raw ewe's milk cheese types, which are produced without the application of starter cultures during ripening from two production sites based on fingerprinting in combination with next generation sequencing of 16S rRNA gene amplicons. Overall a surprisingly high diversity was found in the analyzed samples and overall up to 213 OTU97 could be assigned. 20 of the major OTUs were present in all samples and include mostly lactic acid bacteria (LAB), mainly Lactococcus, and Enterococcus species. Abundance and diversity of these genera differed to a large extent between the 3 investigated cheese types and in response to the ripening process. Also a large number of non LAB genera could be identified based on phylogenetic alignments including mainly Enterobacteriaceae and Staphylococcacae. Some species belonging to these two families could be clearly assigned to species which are known as potential human pathogens like Staphylococcus saprophyticus or Salmonella spp. However, during cheese ripening their abundance was reduced. The bacterial genera, namely Lactobacillus, Streptococcus, Leuconostoc, Bifidobacterium, Brevibacterium, Corynebacterium, Clostridium, Staphylococcus, Thermoanerobacterium, E. coli, Hafnia, Pseudomonas, Janthinobacterium, Petrotoga, Kosmotoga, Megasphaera, Macrococcus, Mannheimia, Aerococcus, Vagococcus, Weissella and Pediococcus were identified at a relative low level and only in selected samples. Overall the microbial composition of the used milk and the management of the production units determined the bacterial community composition for all cheese types to a large extend, also at the late time points of cheese ripening.

Dynamics of Bacterial Communities during the Ripening Process of Different Croatian Cheese Types Derived from Raw Ewe's Milk Cheeses

PubMed Central

Fuka, Mirna Mrkonjić; Wallisch, Stefanie; Engel, Marion; Welzl, Gerhard; Havranek, Jasmina; Schloter, Michael

2013-01-01

Microbial communities play an important role in cheese ripening and determine the flavor and taste of different cheese types to a large extent. However, under adverse conditions human pathogens may colonize cheese samples during ripening and may thus cause severe outbreaks of diarrhoea and other diseases. Therefore in the present study we investigated the bacterial community structure of three raw ewe's milk cheese types, which are produced without the application of starter cultures during ripening from two production sites based on fingerprinting in combination with next generation sequencing of 16S rRNA gene amplicons. Overall a surprisingly high diversity was found in the analyzed samples and overall up to 213 OTU97 could be assigned. 20 of the major OTUs were present in all samples and include mostly lactic acid bacteria (LAB), mainly Lactococcus, and Enterococcus species. Abundance and diversity of these genera differed to a large extent between the 3 investigated cheese types and in response to the ripening process. Also a large number of non LAB genera could be identified based on phylogenetic alignments including mainly Enterobacteriaceae and Staphylococcacae. Some species belonging to these two families could be clearly assigned to species which are known as potential human pathogens like Staphylococcus saprophyticus or Salmonella spp. However, during cheese ripening their abundance was reduced. The bacterial genera, namely Lactobacillus, Streptococcus, Leuconostoc, Bifidobacterium, Brevibacterium, Corynebacterium, Clostridium, Staphylococcus, Thermoanerobacterium, E. coli, Hafnia, Pseudomonas, Janthinobacterium, Petrotoga, Kosmotoga, Megasphaera, Macrococcus, Mannheimia, Aerococcus, Vagococcus, Weissella and Pediococcus were identified at a relative low level and only in selected samples. Overall the microbial composition of the used milk and the management of the production units determined the bacterial community composition for all cheese types to a large extend, also at the late time points of cheese ripening. PMID:24278315

Chemical decontamination with N-acetyl-L-cysteine-sodium hydroxide improves recovery of viable Mycobacterium avium subsp. paratuberculosis organisms from cultured milk.

PubMed

Bradner, L; Robbe-Austerman, S; Beitz, D C; Stabel, J R

2013-07-01

Mycobacterium avium subsp. paratuberculosis is shed into the milk and feces of cows with advanced Johne's disease, allowing the transmission of M. avium subsp. paratuberculosis between animals. The objective of this study was to formulate an optimized protocol for the isolation of M. avium subsp. paratuberculosis in milk. The parameters investigated included chemical decontamination with N-acetyl-l-cysteine-sodium hydroxide (NALC-NaOH), alone and in combination with antibiotics (vancomycin, amphotericin B, and nalidixic acid), and the efficacy of solid (Herrold's egg yolk medium [HEY]) and liquid (Bactec 12B and para-JEM) culture media. For each experiment, raw milk samples from a known noninfected cow were inoculated with 10(2) to 10(8) CFU/ml of live M. avium subsp. paratuberculosis organisms. The results indicate that an increased length of exposure to NALC-NaOH from 5 to 30 min and an increased concentration of NaOH from 0.5 to 2.0% did not affect the viability of M. avium subsp. paratuberculosis. Additional treatment of milk samples with the antibiotics following NALC-NaOH treatment decreased the recovery of viable M. avium subsp. paratuberculosis cells more than treatment with NALC-NaOH alone. The Bactec 12B medium was the superior medium of the three evaluated for the isolation of M. avium subsp. paratuberculosis from milk, as it achieved the lowest threshold of detection. The optimal conditions for NALC-NaOH decontamination were determined to be exposure to 1.50% NaOH for 15 min followed by culture in Bactec 12B medium. This study demonstrates that chemical decontamination with NALC-NaOH resulted in a greater recovery of viable M. avium subsp. paratuberculosis cells from milk than from samples treated with hexadecylpyridinium chloride (HPC). Therefore, it is important to optimize milk decontamination protocols to ensure that low concentrations of M. avium subsp. paratuberculosis can be detected.

Prevalence, antimicrobial susceptibility and molecular typing of Methicillin-Resistant Staphylococcus aureus (MRSA) in bulk tank milk from southern Italy.

PubMed

Parisi, A; Caruso, M; Normanno, G; Latorre, L; Sottili, R; Miccolupo, A; Fraccalvieri, R; Santagada, G

2016-09-01

This paper assesses the prevalence of MRSA in bulk tank milk (BTM) samples from southern Italy, and the relationship between the Coagulase Positive Staphylococci count (CPS) and MRSA prevalence. Of 486 BTM samples tested, 12 samples (2.5%) resulted positive for the presence of MRSA. Great genetic diversity was found among the isolates: ST1/t127 and t174/IVa, ST5/t688/V, ST8/t unknown/IVa/V, ST45/t015/IVa, ST71/t524/V, ST88/t786/Iva, ST398/t011 and t899/IVa/V and ST2781/t1730/V. All isolates were pvl-negative and icaA positive. The majority of strains (58%) carried the ses (sec, seh, seg, seo, sem and sen) genes. All tested strains resulted susceptible to amikacin, cephalotin, cloramphenicol, gentamycin, trimethoprim - sulfamethoxazole, tobramycin and vancomycin, and variably resistant to ampicillin, oxacillin and tetracycline. No statistical association between the CPS count and MRSA detection was found in the MRSA-positive samples. Although some of the spa-types and STs detected in our survey are known to cause human infections, raw milk from Italian herds in the considered area is not a common source of MRSA. Nonetheless, it is necessary to assess the risk of foodborne infection and the risk related to the handling of milk. Copyright © 2016 Elsevier Ltd. All rights reserved.

In Vivo Selection of Resistant E. coli after Ingestion of Milk with Added Drug Residues

PubMed Central

Pereira, Richard Van Vleck; Siler, Julie D.; Bicalho, Rodrigo Carvalho; Warnick, Lorin D.

2014-01-01

Antimicrobial resistance represents a major global threat to modern medicine. In vitro studies have shown that very low concentrations of drugs, as frequently identified in the environment, and in foods and water for human and animal consumption, can select for resistant bacteria. However, limited information is currently available on the in vivo impact of ingested drug residues. The objective of our study was to evaluate the effect of feeding preweaned calves milk containing antimicrobial drug residues (below the minimum inhibitory concentration), similar to concentrations detected in milk commonly fed to dairy calves, on selection of resistant fecal E. coli in calves from birth to weaning. At birth, thirty calves were randomly assigned to a controlled feeding trial where: 15 calves were fed raw milk with no drug residues (NR), and 15 calves were fed raw milk with drug residues (DR) by adding ceftiofur, penicillin, ampicillin, and oxytetracycline at final concentrations in the milk of 0.1, 0.005, 0.01, and 0.3 µg/ml, respectively. Fecal samples were rectally collected from each calf once a week starting at birth prior to the first feeding in the trial (pre-treatment) until 6 weeks of age. A significantly greater proportion of E. coli resistant to ampicillin, cefoxitin, ceftiofur, streptomycin and tetracycline was observed in DR calves when compared to NR calves. Additionally, isolates from DR calves had a significant decrease in susceptibility to ceftriaxone and ceftiofur when compared to isolates from NR calves. A greater proportion of E. coli isolates from calves in the DR group were resistant to 3 or more antimicrobial drugs when compared to calves in the ND group. These findings highlight the role that low concentrations of antimicrobial drugs have on the evolution and selection of resistance to multiple antimicrobial drugs in vivo. PMID:25506918

Extended-spectrum β-lactamase producing Enterobacteriaceae in bulk tank milk from German dairy farms.

PubMed

Odenthal, Sabrina; Akineden, Ömer; Usleber, Ewald

2016-12-05

Although the dairy farm environment is a known source of extended-spectrum β-lactamase (ESBL)-producing bacteria, surveillance data on ESBL in the milk production chain are still scarce. This study aimed at estimating the dimensions of the problem for public health and animal welfare by surveying ESBL-producing Enterobacteriaceae in raw bulk tank milk in Germany. Samples from 866 dairy farms, comprising about 1% of the total number of dairy farms in Germany, were first screened for presence of cefotaxime-resistant bacteria by selective enrichment. Suspect colonies were identified phenotypically and further characterized by biochemical and molecular methods, including analysis of resistance genes and clonal diversity in ESBL-producing isolates. Bulk tank milk from 82 (9.5%) farms yielded Enterobacteriaceae with confirmed ESBL-production. The most frequent ESBL-producing species was Escherichia coli (75.6%), followed by Citrobacter spp. (9.6%), Enterobacter cloacae (6.1%), and Klebsiella oxytoca (3.7%), a few isolates belonged to other species within the genera Hafnia, Raoutella and Serratia. The majority of isolates (95.1%) harbored the β-lactamase blaCTX-M gene, which has gained increased importance among ESBL-producing strains worldwide; the CTX-M group 1 was found to be the dominating (88.4%) phylogenetic group. All ESBL-positive Escherichia coli isolates were clonally heterogeneous, as determined by pulsed-field gel electrophoresis. The results from this survey demonstrate that ESBL-producing bacteria are distributed widely in the dairy farm environment in Germany. Therefore, raw milk is a potential source of exposure for the consumer, which is of increasing importance considering the trend of farmer-to-consumer direct marketing. Furthermore, dairy farm staff have an increased likelihood of exposure to ESBL-producing bacteria. Finally, ESBL-producing bacteria may also be transferred via waste milk to calves, thus further spreading antibiotic resistance in the farm environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Short communication: Characterization of methicillin-resistant Staphylococcus aureus isolated from raw milk fresh cheese in Colombia.

PubMed

Herrera, Fanny C; García-López, María-Luisa; Santos, Jesús A

2016-10-01

The aim of this study was the characterization of a collection of 8 methicillin-resistant Staphylococcus aureus (MRSA) isolates, obtained from samples of fresh cheese (Doble Crema) produced from raw cow milk in small dairies in Colombia. All the isolates harbored the mecA and Panton-Valentine leukocidin (PVL) genes, presented with SCCmec type IV, and belonged to multilocus sequence type 8 and spa type 024. Seven isolates presented 3 closely related pulsed-field gel electrophoresis profiles. Three of them carried the staphylococcal enterotoxin B gene. The isolates were resistant to cefoxitin, oxacillin, penicillin, and ampicillin and susceptible to all non-β-lactams antibiotics tested, with minimum inhibitory concentration values for oxacillin of 4 to 8mg/L. The isolates belonged to the community-acquired MRSA group, suggesting a human source of contamination. The risk of human infection by MRSA via contaminated foods is considered low, but contaminated food commodities can contribute to the worldwide dissemination of clones of community-acquired MRSA. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of homogenization and heat treatment on the behavior of protein and fat globules during gastric digestion of milk.

PubMed

Ye, Aiqian; Cui, Jian; Dalgleish, Douglas; Singh, Harjinder

2017-01-01

The effects of homogenization and heat treatment on the formation and the breakdown of clots during gastric digestion of whole milk were investigated using a human gastric simulator. Homogenization and heat treatment led to formation of coagula with fragmented and crumbled structures compared with the coagulum formed from raw whole milk, but a larger fraction of the protein and more fat globules were incorporated into the coagula induced by action of the milk-clotting enzyme pepsin. The fat globules in the whole milk appeared to be embedded in the clots as they formed. After formation of the clot, the greater numbers of pores in the structures of the clots formed with homogenized milk and heated whole milk led to greater rates of protein hydrolysis by pepsin, which resulted in faster release of fat globules from the clots into the digesta. Coalescence of fat globules occurred both in the digesta and within the protein clots no matter whether they were in homogenized or heated milk samples. The formation of clots with different structures and hence the changes in the rates of protein hydrolysis and the release of milk fat into the digesta in the stomach provide important information for understanding the gastric emptying of milk and the potential to use this knowledge to manipulate the bioavailability of fat and other fat-soluble nutrients in dairy products. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Yield of acid curd cheese produced from cow's milk from different lactation periods.

PubMed

Salamończyk, Ewa; Młynek, Krzysztof; Guliński, Piotr; Zawadzka, Wiesława

2017-01-01

Milk production intensification has led in many countries, including Poland, to increased milk yields per cow. A higher milk yield resulted in changes in cow productivity, including extended lactations. There is a paucity of information on the quality of milk harvested during the last months of lactations exceed- ing 10 months. Production capacity cheese (“cheese expenditure”) is an important parameter of providing   a recovery as much as the possible components of the milk processed are dry substances, which in turn af- fects the economics of production. The aim of the study was to determine the influence of the lactation period (from standard lactation; extended lactation phase) on the performance of the acid curd cheese. the relation- ship between total protein content and acidity of fresh milk collected in two separate periods of lactation on the yield of acid cheese was also evaluated. The study included 1384 samples of milk collected from Polish Holstein-Friesian cows, the Black-White variety. The basic chemical composition of fresh milk and acid-curd cheese produced in the laboratory were analyzed. The cheese milk yield was evaluated on the basis of the quantity of the re- sulting curd mass. According to our estimates, under laboratory conditions an average of 100 kg of milk per cow in population produced an estimated 20.1 kg of curd cheese. The basic chemical composition of raw milk, which was diverse in terms of the period of lactation, showed a higher dry matter, fat and protein content in milk acquired during the extension phase of lactation compared to the milk of standard lactation. It has been found that the lower titratable acidity of fresh milk appeared with a higher yield of cheese curd. This difference was between 1.76 kg (with milk from cows milked during the extended lactation phase) to 2.72 kg from 100 kg of cheese milk (milk with the standard lactation). Thus, the optimum level of titratable acidity of milk for cheese yield is 6.0–7.5°SH. Most samples with the highest yields of acid curd cheese (>20%) were obtained from the milk from collected in the period from day 306 till the end of lactation (60.54%).

Nutritional value of raw soybeans, extruded soybeans, roasted soybeans and tallow as fat sources in early lactating dairy cows.

PubMed

Amanlou, H; Maheri-Sis, N; Bassiri, S; Mirza-Aghazadeh, A; Salamatdust, R; Moosavi, A; Karimi, V

2012-01-01

Thirty multiparous Holstein cows (29.8 ± 4.01days in milk; 671.6 ± 31.47 kg of body weight) were used in a completely randomized design to compare nutritional value of four fat sources including tallow, raw soybeans, extruded soybeans and roasted soybeans for 8 weeks. Experimental diets were a control containing 27.4 % alfalfa silage, 22.5% corn silage, and 50.1% concentrate, and four diets with either tallow, raw soybean, extruded soybean, or roasted soybean added to provide 1.93% supplemental fat. Dry matter and NEL intakes were similar among treatments, while cows fed fat diets had significantly (P<0.05) high NEL intakes when compared to control with no fat. Supplemental fat, whether tallow or full fat soybeans increased milk production (1.89-2.45 kg/d; P<0.01) and FCM production (1.05-2.79; P<0.01). Milk fat yield and percentage of cows fed fat-supplemented diets were significantly (P<0.01 and P<0.05 respectively) higher than control. Between fat-supplemented diets, roasted soybean caused highest milk fat yield and extruded soybean caused lowest milk fat yield. There was no significant effect of supplemental fat on the milk protein and lactose content and yield. Feed efficiency of fat-supplemented diets was significantly (P<0.01) higher than control. Body weight, body weight change and BCS (body condition score) of cows, as well as energy balance and energy efficiency were similar between treatments. In conclusion, while there was no significant effect of fat sources on production response of cows, fat originating from heat-treated soybean help to minimize imported RUP (rumen undegradable protein) sources level as fish meal in comparison with tallow and raw soybean oil. In the Current study, there was no statistical significance among nutritional values of oil from extruded soybeans and roasted soybeans.