In Vitro Effects of Cooking Methods on Digestibility of Lipids and Formation of Cholesterol Oxidation Products in Pork

PubMed Central

Moon, Sung Sil

2014-01-01

This study investigated the effects of cooking methods on the digestibility of lipids and formation of cholesterol oxidation products (COPs) in pork, during in vitro human digestion. Pork patties were cooked using four different methods (oven cooking, pan frying, boiling, and microwaving), to an internal temperature of approximately 85℃. The digestibility of pork patties were then evaluated, using the in vitro human digestion model that simulated the composition (pH, minerals, surfaceactive components, and enzymes) of digestive juices in the human mouth, stomach, and small intestine. The total lipid digestibility was higher after microwave cooking, whereas pan-frying resulted in lower in vitro digestibility, compared to the other cooking methods. The microwaving method followed by in vitro digestion also showed significantly higher content of free fatty acids and thiobarbituric acid reactive substances (TBARS), compared to the other cooking methods; whereas, the pan frying and boiling methods showed the lowest. Cholesterol content was not significantly different among the cooked samples before, and after in vitro human digestion. The formation of COPs was significantly higher in the microwave-treated pork samples, compared to those cooked by the other methods, which was consistent with the trend for lipid peroxidation (TBARS). We propose that from the point of view of COPs formation and lipid oxidation, the pan-frying or boiling methods would be useful. PMID:26761168

Effect of dietary lignocellulose on ileal and total tract digestibility of fat and fatty acids in broiler chickens.

PubMed

Bogusławska-Tryk, M; Piotrowska, A; Szymeczko, R; Burlikowska, K

2016-12-01

The study was conducted to determine the effect of a lignocellulose supplemented diet on apparent ileal and total tract digestibility of fat and fatty acids (FA) in broiler chickens. A total of 48 21-day-old male Ross 308 chickens were divided into four treatment groups (n = 12) with six replicates per treatment. From 21 to 42 days of age, the broilers were fed experimental diets varied in the amount of lignocellulose: 0%, 0.25%, 0.5% and 1%. Total excreta were gathered during the last 3 days of the feeding trial and digesta was collected from the ileum at 42 days of the bird age. Digestibility was determined by the indicator method. The ether extract content in diet/digesta/excreta was determined by the gravimetric method, and fatty acid methyl esters were analysed by gas chromatography-mass spectrometry. Fat digestibility measured to the end of the small intestine and in the whole gastrointestinal tract in birds was high and exceeded 90% and 87% respectively. Addition of lignocellulose (1%) increased (p < 0.05) ileal fat digestibility but had no significant effect on total tract fat digestion. Absorption of total fatty acids (TFA) as well as myristic (C14:0), palmitoleic (C16:1) and α-linolenic (C18:3n-3) acids, estimated by both methods, was significantly higher in birds fed the diets supplemented with lignocellulose, especially at a dose of 1%. Total tract absorption of some dietary polyunsaturated fatty acids (PUFA) (C20:2, C20:4n-6) was significantly lower from diet supplemented with 0.5% and 0.25% lignocellulose. There was observed a decrease in apparent digestibility of fat and most examined fatty acids, when measured between terminal ileum and total gastrointestinal tract. The results suggest that lignocellulose can affect digestion and FA absorption in broilers but, as the effect of lignocellulose was not studied previously, further investigations are necessary to confirm the results of the present experiment. Journal of Animal Physiology and Animal

Effects of antinutritional factors on protein digestibility and amino acid availability in foods.

PubMed

Gilani, G Sarwar; Cockell, Kevin A; Sepehr, Estatira

2005-01-01

Digestibility of protein in traditional diets from developing countries such as India, Guatemala, and Brazil is considerably lower compared to that of protein in typical North American diets (54-78 versus 88-94%). The presence of less digestible protein fractions, high levels of insoluble fiber, and high concentrations of antinutritional factors in the diets of developing countries, which are based on less refined cereals and grain legumes as major sources of protein, are responsible for poor digestibility of protein. The effects of the presence of some of the important antinutritional factors on protein and amino digestibilities of food and feed products are reviewed in this chapter. Food and feed products may contain a number of antinutritional factors that may adversely affect protein digestibility and amino acid availability. Antinutritional factors may occur naturally, such as glucosinolates in mustard and rapeseed protein products, trypsin inhibitors and hemagglutinins in legumes, tannins in legumes and cereals, phytates in cereals and oilseeds, and gossypol in cottonseed protein products. Antinutritional factors may also be formed during heat/alkaline processing of protein products, yielding Maillard compounds, oxidized forms of sulfur amino acids, D-amino acids, and lysinoalanine (LAL, an unnatural amino acid derivative). The presence of high levels of dietary trypsin inhibitors from soybeans, kidney beans, or other grain legumes can cause substantial reductions in protein and amino acid digestibilities (up to 50%) in rats and pigs. Similarly, the presence of high levels of tannins in cereals, such as sorghum, and grain legumes, such as fababean (Vicia faba L.), can result in significantly reduced protein and amino acid digestibilities (up to 23%) in rats, poultry, and pigs. Studies involving phytase supplementation of production rations for swine or poultry have provided indirect evidence that normally encountered levels of phytates in cereals and legumes

In vitro digestion with bile acids enhances the bioaccessibility of kale polyphenols.

PubMed

Yang, Isabelle; Jayaprakasha, Guddarangavvanahally K; Patil, Bhimanagouda

2018-02-21

Kale (Brassica oleracea) is a leafy green vegetable belonging to the Brassicaceae family, and kale leaves have large amounts of dietary fiber and polyphenolics. Dietary fiber can bind bile acids, thus potentially decreasing cholesterol levels; however, whether the polyphenols from kale contribute to in vitro bile acid binding capacity remains unclear. In the present study, kale was extracted with hexane, acetone, and MeOH : water and the dried extracts, as well as the fiber-rich residue, were tested for their bile acid binding capacity. The fiber-rich residue bound total bile acids in amounts equivalent to that bound by raw kale. The lyophilized acetone extract bound significantly more glycochenodeoxycholate and glycodeoxycholate and less of other bile acids. To test whether bile acid binding enhanced the bioaccessibility of polyphenolic compounds from kale, we used ultra-performance liquid chromatography coupled with electrospray ionization/quadrupole-time-of-flight mass spectrometry to identify chemical constituents and measure their bioaccessibility in an in vitro digestion reaction. This identified 36 phenolic compounds in kale, including 18 kaempferol derivatives, 13 quercetin derivatives, 4 sinapoyl derivatives, and one caffeoylquinic acid. The bioaccessibility of these phenolics was significantly higher (69.4%) in digestions with bile acids. Moreover, bile acids enhanced the bioaccessibility of quercetin by 25 times: only 2.7% of quercetin derivatives were bioaccessible in the digestion without bile acids, but with bile acids, their accessibility increased to 69.5%. Bile acids increased the bioaccessibility of kaempferol from 37.7% to 69.2%. The extractability and biostability of total phenolics in the digested residue increased 1.8 fold in the digestions with bile acids. These results demonstrated the potential use of kale to improve human health.

Syntrophic acetate oxidation in two-phase (acid-methane) anaerobic digesters.

PubMed

Shimada, T; Morgenroth, E; Tandukar, M; Pavlostathis, S G; Smith, A; Raskin, L; Kilian, R E

2011-01-01

The microbial processes involved in two-phase anaerobic digestion were investigated by operating a laboratory-scale acid-phase (AP) reactor and analyzing two full-scale, two-phase anaerobic digesters operated under mesophilic (35 °C) conditions. The digesters received a blend of primary sludge and waste activated sludge (WAS). Methane levels of 20% in the laboratory-scale reactor indicated the presence of methanogenic activity in the AP. A phylogenetic analysis of an archaeal 16S rRNA gene clone library of one of the full-scale AP digesters showed that 82% and 5% of the clones were affiliated with the orders Methanobacteriales and Methanosarcinales, respectively. These results indicate that substantial levels of aceticlastic methanogens (order Methanosarcinales) were not maintained at the low solids retention times and acidic conditions (pH 5.2-5.5) of the AP, and that methanogenesis was carried out by hydrogen-utilizing methanogens of the order Methanobacteriales. Approximately 43, 31, and 9% of the archaeal clones from the methanogenic phase (MP) digester were affiliated with the orders Methanosarcinales, Methanomicrobiales, and Methanobacteriales, respectively. A phylogenetic analysis of a bacterial 16S rRNA gene clone library suggested the presence of acetate-oxidizing bacteria (close relatives of Thermacetogenium phaeum, 'Syntrophaceticus schinkii,' and Clostridium ultunense). The high abundance of hydrogen consuming methanogens and the presence of known acetate-oxidizing bacteria suggest that acetate utilization by acetate oxidizing bacteria in syntrophic interaction with hydrogen-utilizing methanogens was an important pathway in the second-stage of the two-phase digestion, which was operated at high ammonium-N concentrations (1.0 and 1.4 g/L). A modified version of the IWA Anaerobic Digestion Model No. 1 (ADM1) with extensions for syntrophic acetate oxidation and weak-acid inhibition adequately described the dynamic profiles of volatile acid production

Gross and true ileal digestible amino acid contents of several animal body proteins and their hydrolysates.

PubMed

Cui, J; Chong, B; Rutherfurd, S M; Wilkinson, B; Singh, H; Moughan, P J

2013-07-01

Amino acid compositions of ovine muscle, ovine myofibrillar protein, ovine spleen, ovine liver, bovine blood plasma, bovine blood globulins and bovine serum albumin and the amino acid compositions and in vivo (laboratory rat) true ileal amino acid digestibilities of hydrolysates (sequential hydrolysis with Neutrase, Alcalase and Flavourzyme) of these protein sources were determined. True ileal amino acid digestibility differed (P<0.05) among the seven protein hydrolysates. The ovine myofibrillar protein and liver hydrolysates were the most digestible, with a mean true ileal digestibility across all amino acids of 99%. The least digestible protein hydrolysate was bovine serum albumin with a comparable mean true ileal digestibility of 93%. When the digestible amino acid contents were expressed as proportions relative to lysine, considerable differences, across the diverse protein sources, were found in the pattern of predicted absorbed amino acids. Copyright © 2013 Elsevier Ltd. All rights reserved.

Augmented digestion of lignocellulose by steam explosion, acid and alkaline pretreatment methods: a review.

PubMed

Singh, Joginder; Suhag, Meenakshi; Dhaka, Anil

2015-03-06

Lignocellulosic materials can be explored as one of the sustainable substrates for bioethanol production through microbial intervention as they are abundant, cheap and renewable. But at the same time, their recalcitrant structure makes the conversion process more cumbersome owing to their chemical composition which adversely affects the efficiency of bioethanol production. Therefore, the technical approaches to overcome recalcitrance of biomass feedstock has been developed to remove the barriers with the help of pretreatment methods which make cellulose more accessible to the hydrolytic enzymes, secreted by the microorganisms, for its conversion to glucose. Pretreatment of lignocellulosic biomass in cost effective manner is a major challenge to bioethanol technology research and development. Hence, in this review, we have discussed various aspects of three commonly used pretreatment methods, viz., steam explosion, acid and alkaline, applied on various lignocellulosic biomasses to augment their digestibility alongwith the challenges associated with their processing. Copyright © 2014 Elsevier Ltd. All rights reserved.

The 15N-leucine single-injection method allows for determining endogenous losses and true digestibility of amino acids in cecectomized roosters

PubMed Central

Hu, Rujiu; Li, Jing; Soomro, Rab Nawaz; Wang, Fei; Feng, Yan; Yang, Xiaojun

2017-01-01

This study was conducted to assess the influence of dietary protein content in poultry when using the 15N-leucine single-injection method to determine endogenous amino acid losses (EAALs) in poultry. Forty-eight cecectomized roosters (2.39 ± 0.23 kg) were randomly allocated to eight dietary treatments containing protein levels of 0, 3%, 6%, 9%, 12%, 15%, 18% and 21%. Each bird was precisely fed an experimental diet of 25 g/kg of body weight. After feeding, all roosters were subcutaneously injected with a 15N-leucine solution at a dose of 20 mg/kg of body weight. Blood was sampled 23 h after the injection, and excreta samples were continuously collected during the course of the 48-h experiment. The ratio of 15N-enrichment of leucine in crude mucin to free leucine in plasma ranged from 0.664 to 0.763 and remained relatively consistent (P > 0.05) across all treatments. The amino acid (AA) profiles of total endogenous AAs, except isoleucine, alanine, aspartic acid, cysteine, proline and serine, were not influenced (P > 0.05) by dietary protein contents. The predominant endogenous AAs in the excreta were glutamic acid, aspartic acid, threonine, serine and proline. The order of the relative proportions of these predominant AAs also remained relatively constant (P > 0.05). The endogenous losses of total AAs determined with the 15N-leucine single-injection method increased curvilinearly with the dietary protein contents. The true digestibility of most AAs and total AAs was independent of their respective dietary protein levels. Collectively, the 15N-leucine single-injection method is appropriate for determining EAALs and the true digestibility of AAs in poultry fed varying levels of protein-containing ingredients. PMID:29166671

The 15N-leucine single-injection method allows for determining endogenous losses and true digestibility of amino acids in cecectomized roosters.

PubMed

Hu, Rujiu; Li, Jing; Soomro, Rab Nawaz; Wang, Fei; Feng, Yan; Yang, Xiaojun; Yao, Junhu

2017-01-01

This study was conducted to assess the influence of dietary protein content in poultry when using the 15N-leucine single-injection method to determine endogenous amino acid losses (EAALs) in poultry. Forty-eight cecectomized roosters (2.39 ± 0.23 kg) were randomly allocated to eight dietary treatments containing protein levels of 0, 3%, 6%, 9%, 12%, 15%, 18% and 21%. Each bird was precisely fed an experimental diet of 25 g/kg of body weight. After feeding, all roosters were subcutaneously injected with a 15N-leucine solution at a dose of 20 mg/kg of body weight. Blood was sampled 23 h after the injection, and excreta samples were continuously collected during the course of the 48-h experiment. The ratio of 15N-enrichment of leucine in crude mucin to free leucine in plasma ranged from 0.664 to 0.763 and remained relatively consistent (P > 0.05) across all treatments. The amino acid (AA) profiles of total endogenous AAs, except isoleucine, alanine, aspartic acid, cysteine, proline and serine, were not influenced (P > 0.05) by dietary protein contents. The predominant endogenous AAs in the excreta were glutamic acid, aspartic acid, threonine, serine and proline. The order of the relative proportions of these predominant AAs also remained relatively constant (P > 0.05). The endogenous losses of total AAs determined with the 15N-leucine single-injection method increased curvilinearly with the dietary protein contents. The true digestibility of most AAs and total AAs was independent of their respective dietary protein levels. Collectively, the 15N-leucine single-injection method is appropriate for determining EAALs and the true digestibility of AAs in poultry fed varying levels of protein-containing ingredients.

Enhancing post aerobic digestion of full-scale anaerobically digested sludge using free nitrous acid pretreatment.

PubMed

Wang, Qilin; Zhou, Xu; Peng, Lai; Wang, Dongbo; Xie, Guo-Jun; Yuan, Zhiguo

2016-05-01

Post aerobic digestion of anaerobically digested sludge (ADS) has been extensively applied to the wastewater treatment plants to enhance sludge reduction. However, the degradation of ADS in the post aerobic digester itself is still limited. In this work, an innovative free nitrous acid (HNO2 or FNA)-based pretreatment approach is proposed to improve full-scale ADS degradation in post aerobic digester. The post aerobic digestion was conducted by using an activated sludge to aerobically digest ADS for 4 days. Degradations of the FNA-treated (treated at 1.0 and 2.0 mg N/L for 24 h) and untreated ADSs were then determined and compared. The ADS was degraded by 26% and 32%, respectively, in the 4-day post aerobic digestion period while being pretreated at 1.0 and 2.0 mg HNO2-N/L. In comparison, only 20% of the untreated ADS was degraded. Economic analysis demonstrated that the implementation of FNA pretreatment can be economically favourable or not depending on the sludge transport and disposal cost. Copyright © 2016 Elsevier Ltd. All rights reserved.

Relationship between body weight and level of fat supplementation on fatty acid digestion in feedlot cattle.

PubMed

Plascencia, A; Mendoza, G D; Vásquez, C; Zinn, R A

2003-11-01

Eight Holstein steers with cannulas in the rumen and proximal duodenum were used in a split-plot design experiment to evaluate the interaction of body weight (175 vs. 370 kg) and level of fat supplementation (0, 3, 6, and 9% yellow grease) on characteristics of digestion and feeding value of fat in finishing diets. Dry matter intake was restricted to 2% of BW. There were no interactions between BW and level of fat supplementation (P > 0.10) on ruminal or total-tract digestion. Level of supplemental fat decreased (linear, P < 0.01) ruminal digestion of OM and NDF, and increased (linear, P < 0.05) ruminal N efficiency. There were no treatment effects (P > 0.10) on postruminal digestion of OM, NDF, and N. There tended to be an interaction (P < 0.10) between BW and level of fat supplementation on postruminal starch digestion. Increasing level of fat supplementation increased postruminal digestion of starch in heavier steers but did not affect starch digestion in lighter steers. There were no interactions (P > 0.10) between BW and level of fat supplementation on postruminal fatty acid digestion. Increasing level of fat supplementation decreased (linear, P < 0.01) postruminal fatty acid digestion, which was due to a decreased (linear, P < 0.01) postruminal digestion of C16:0 and C18:0. Supplemental fat decreased (linear, P < 0.01) total-tract digestion of OM and NDF. The estimated NEm (Mcal/kg) of yellow grease averaged (linear, P < 0.01) 6.02, 5.70, and 5.06 for the 3, 6, and 9% of level supplementation, respectively. We conclude that intestinal fatty acid digestion (FAD, %) is a predictable function (r2 = 0.89; P < 0.01) of total fatty acid intake per unit body weight (FAI, g/kg BW): FAD = 87.560 - 8.591FAI. Depressions in fatty acid digestion with increasing level of intake were due primarily to decreased intestinal absorption of palmitic and stearic acid. Level of fatty acids intake did not appreciably affect intestinal absorption of unsaturated fatty acid. Changes

[Evaluation of the adjusted amino acid score by digestibility for estimating the protein quality and protein available in food and diets].

PubMed

Pak, N; Vera, G; Araya, H

1985-03-01

The purpose of the present study was to evaluate the amino acid score adjusted by digestibility to estimate protein quality and utilizable protein in foods and diets, considering net protein utilization (NPU) as a biological reference method. Ten foods of vegetable origin and ten of animal origin, as well as eight mixtures of foods of vegetable and animal origin were studied. When all the foods were considered, a positive (r = 0.83) and highly significant correlation (p less than 0.001) between NPU and the amino acid score adjusted by digestibility was found. When the foods were separated according to their origin, this correlation was positive only for the foods of vegetable origin (r = 0.93) and statistically significant (p less than 0.001). Also, only in those foods were similar values found between NPU and amino acid score adjusted by digestibility, as well as in utilizable protein estimated considering both methods. Caution is required to interpret protein quality and utilizable protein values of foods of animal origin and mixtures of foods of vegetable and animal origin when the amino acid score method adjusted by digestibility, or NPU, are utilized.

Comparative amino acid digestibility for broiler chickens and White Pekin ducks.

PubMed

Kong, C; Adeola, O

2013-09-01

A total of 608 three-week-old male broiler chickens and White Pekin ducks were used in a 5-d trial to compare ileal amino acid (AA) digestibility of soybean meal (SBM) and canola meal (CM) using the regression method. A corn-casein-cornstarch-based diet was mixed to contain 15% CP. Cornstarch was replaced with test ingredient (SBM or CM) to contain 18 or 21% of CP in 4 other diets. A nitrogen-free diet (NFD) was used for standardization of apparent digestibility. Birds received a standard starter diet (23% CP) from d 0 to 14 posthatch and then 6 experimental diets for 5 d. On d 19 posthatch, birds were asphyxiated with CO(2), and digesta from the distal section of ileum was collected. The ileal digestibility of AA from the test ingredients was assessed by multiple linear regression analysis using data on daily apparent ileal digestible AA and total AA intakes. The basal endogenous losses of N and all AA for ducks were significantly higher than those for broilers. For ileal AA digestibility by regression of apparent digestible AA intake against AA intake, there was a higher (P < 0.05) digestibility for Cys and Pro in ducks compared with broilers (P < 0.05). Within species, digestibility was not different between SBM and CM except for Lys of ducks, and Lys and Pro of broilers (P < 0.05). The results of this study showed that ducks have higher basal endogenous AA losses compared with broiler chickens as well as higher ileal Cys and Pro digestibility estimates derived from regression approach, indicating that data obtained from broilers should not be used to formulate diets for ducks.

Evaluation of the pepsin digestibility assay for predicting amino acid digestibility of meat and bone meals.

PubMed

Davis, T M; Parsons, C M; Utterback, P L; Kirstein, D

2015-05-01

Sixteen meat and bone meal (MBM) samples were obtained and selected from various company plants to provide a wide range in pepsin nitrogen digestibility values. Pepsin digestibility was determined using either 0.02 or 0.002% pepsin. Amino acid (AA) digestibility of the 16 MBM samples was then determined using a precision-fed cecectomized rooster assay. The 0.02% pepsin digestibility values were numerically higher than the 0.002% pepsin values. The values varied from 77 to 93% for 0.02% pepsin and from 67 to 91% for 0.002% pepsin. The rooster AA digestibility results showed a wide range of values among MBM samples mostly due to the 4 samples having lowest and highest AA digestibility. A precision-fed broiler chick ileal AA digestibility assay confirmed that there were large differences in AA digestibility among the MBM samples having the lowest and highest rooster digestibility values. Correlation analyses between pepsin and AA digestibility values showed that the correlation values (r) were highly significant (P < 0.0001) for all AA when all 16 MBM samples were included in the analysis. However, when the MBM samples with the 2 lowest and the 2 highest rooster digestibility values were not included in the correlation analyses, the correlation coefficient values (r) were generally very low and not significant (P > 0.05). The results indicated that the pepsin nitrogen digestibility assay is only useful for detecting large differences in AA digestibility among MBM. There also was no advantage for using 0.02 versus 0.002% pepsin. © 2015 Poultry Science Association Inc.

Binding of bile acids by pastry products containing bioactive substances during in vitro digestion.

PubMed

Dziedzic, Krzysztof; Górecka, Danuta; Szwengiel, Artur; Smoczyńska, Paulina; Czaczyk, Katarzyna; Komolka, Patrycja

2015-03-01

The modern day consumer tends to choose products with health enhancing properties, enriched in bioactive substances. One such bioactive food component is dietary fibre, which shows a number of physiological properties including the binding of bile acids. Dietary fibre should be contained in everyday, easily accessible food products. Therefore, the aim of this study was to determine sorption capacities of primary bile acid (cholic acid - CA) and secondary bile acids (deoxycholic - DCA and lithocholic acids - LCA) by muffins (BM) and cookies (BC) with bioactive substances and control muffins (CM) and cookies (CC) in two sections of the in vitro gastrointestinal tract. Variations in gut flora were also analysed in the process of in vitro digestion of pastry products in a bioreactor. Enzymes: pepsin, pancreatin and bile salts: cholic acid, deoxycholic acid and lithocholic acid were added to the culture. Faecal bacteria, isolated from human large intestine, were added in the section of large intestine. The influence of dietary fibre content in cookies and concentration of bile acids in two stages of digestion were analysed. Generally, pastry goods with bioactive substances were characterized by a higher content of total fibre compared with the control samples. These products also differ in the profile of dietary fibre fractions. Principal Component Analysis (PCA) showed that the bile acid profile after two stages of digestion depends on the quality and quantity of fibre. The bile acid profile after digestion of BM and BC forms one cluster, and with the CM and CC forms a separate cluster. High concentration of H (hemicellulose) is positively correlated with LCA (low binding effect) and negatively correlated with CA and DCA contents. The relative content of bile acids in the second stage of digestion was in some cases above the content in the control sample, particularly LCA. This means that the bacteria introduced in the 2nd stage of digestion synthesize the LCA.

Application of microwave digestion to the analysis of peat

USGS Publications Warehouse

Papp, C.S.E.; Fischer, L.B.

1987-01-01

A microwave digestion technique for the dissolution of peat is described and compared with a dry ashing method and a nitric - perchloric - hydrofluoric acid wet digestion. Peat samples with different organic matter contents were used and Ca, Mg, Fe, AI, Na, K, Mn, Zn, Cu and Li were determined by atomic absoprtion spectrometry. The results obtained using the three dissolution techniques were in good agreement. The microwave method has the advantage of digesting the samples in less than 2 h and uses less acid than the conventional wet digestion method. Keeping the volume of the acid mixture as small as possible minimises contamination and leads to lower blank values.

Effects of citric acid esterification on digestibility, structural and physicochemical properties of cassava starch.

PubMed

Mei, Ji-Qiang; Zhou, Da-Nian; Jin, Zheng-Yu; Xu, Xue-Ming; Chen, Han-Qing

2015-11-15

In this study, citric acid was used to react with cassava starch in order to compare the digestibility, structural and physicochemical properties of citrate starch samples. The results indicated that citric acid esterification treatment significantly increased the content of resistant starch (RS) in starch samples. The swelling power and solubility of citrate starch samples were lower than those of native starch. Compared with native starch, a new peak at 1724 cm(-1) was appeared in all citrate starch samples, and crystalline peaks of all starch citrates became much smaller or even disappeared. Differential scanning calorimetry results indicated that the endothermic peak of citrate starches gradually shrank or even disappeared. Moreover, the citrate starch gels exhibited better freeze-thaw stability. These results suggested that citric acid esterification induced structural changes in cassava starch significantly affected its digestibility and it could be a potential method for the preparation of RS with thermal stability. Copyright © 2015 Elsevier Ltd. All rights reserved.

In vitro digestibility of goat milk and kefir with a new standardised static digestion method (INFOGEST cost action) and bioactivities of the resultant peptides.

PubMed

Nehir El, Sedef; Karakaya, Sibel; Simsek, Sebnem; Dupont, Didier; Menfaatli, Esra; Eker, Alper Tolga

2015-07-01

The hydrolysis degrees of goat milk and kefir during simulated gastrointestinal digestion and some bioactivities of the resulting peptides after fermentation and digestion were studied. A static in vitro digestion method by the COST FA1005 Action INFOGEST was used and goat milk and kefir were partially hydrolyzed during the gastric phase and had above 80% hydrolysis after duodenal digestion. There were no differences between the digestibility of goat milk and kefir (p > 0.05). Goat milk and kefir displayed about 7-fold antioxidant activity after digestion (p < 0.05). Fermentation showed no effect on the calcium-binding capacity of the samples (p > 0.05), however, after in vitro digestion calcium-binding capacity of the goat milk and kefir increased 2 and 5 fold, respectively (p < 0.05). Digested goat milk and kefir showed a higher dose-dependent inhibitory effect on α-amylase compared to undigested samples (p < 0.05). α-Glucosidase inhibitory activities and in vitro bile acid-binding capacities of the samples were not determined at the studied concentrations.

Determination of silica coating efficiency on metal particles using multiple digestion methods.

PubMed

Wang, Jun; Topham, Nathan; Wu, Chang-Yu

2011-10-15

Nano-sized metal particles, including both elemental and oxidized metals, have received significant interest due to their biotoxicity and presence in a wide range of industrial systems. A novel silica technology has been recently explored to minimize the biotoxicity of metal particles by encapsulating them with an amorphous silica shell. In this study, a method to determine silica coating efficiency on metal particles was developed. Metal particles with silica coating were generated using gas metal arc welding (GMAW) process with a silica precursor tetramethylsilane (TMS) added to the shielding gas. Microwave digestion and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) were employed to solubilize the metal content in the particles and analyze the concentration, respectively. Three acid mixtures were tested to acquire the appropriate digestion method targeting at metals and silica coating. Metal recovery efficiencies of different digestion methods were compared through analysis of spiked samples. HNO(3)/HF mixture was found to be a more aggressive digestion method for metal particles with silica coating. Aqua regia was able to effectively dissolve metal particles not trapped in the silica shell. Silica coating efficiencies were thus calculated based on the measured concentrations following digestion by HNO(3)/HF mixture and aqua regia. The results showed 14-39% of welding fume particles were encapsulated in silica coating under various conditions. This newly developed method could also be used to examine the silica coverage on particles of silica shell/metal core structure in other nanotechnology areas. Copyright © 2011 Elsevier B.V. All rights reserved.

Evaluation of digestion methods for analysis of trace metals in mammalian tissues and NIST 1577c.

PubMed

Binder, Grace A; Metcalf, Rainer; Atlas, Zachary; Daniel, Kenyon G

2018-02-15

Digestion techniques for ICP analysis have been poorly studied for biological samples. This report describes an optimized method for analysis of trace metals that can be used across a variety of sample types. Digestion methods were tested and optimized with the analysis of trace metals in cancerous as compared to normal tissue as the end goal. Anthropological, forensic, oncological and environmental research groups can employ this method reasonably cheaply and safely whilst still being able to compare between laboratories. We examined combined HNO 3 and H 2 O 2 digestion at 170 °C for human, porcine and bovine samples whether they are frozen, fresh or lyophilized powder. Little discrepancy is found between microwave digestion and PFA Teflon pressure vessels. The elements of interest (Cu, Zn, Fe and Ni) yielded consistently higher and more accurate values on standard reference material than samples heated to 75 °C or samples that utilized HNO 3 alone. Use of H 2 SO 4 does not improve homogeneity of the sample and lowers precision during ICP analysis. High temperature digestions (>165 °C) using a combination of HNO 3 and H 2 O 2 as outlined are proposed as a standard technique for all mammalian tissues, specifically, human tissues and yield greater than 300% higher values than samples digested at 75 °C regardless of the acid or acid combinations used. The proposed standardized technique is designed to accurately quantify potential discrepancies in metal loads between cancerous and healthy tissues and applies to numerous tissue studies requiring quick, effective and safe digestions. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of acid detergent fiber in hydrothermally pretreated sewage sludge on anaerobic digestion process

NASA Astrophysics Data System (ADS)

Takasaki, Rikiya; Yuan, Lee Chang; Kamahara, Hirotsugu; Atsuta, Youichi; Daimon, Hiroyuki

2017-10-01

Hydrothermal treatment is one of the pre-treatment method for anaerobic digestion. The application of hydrothermal treatment to sewage sludge of wastewater treatment plant has been succeeded to enhance the biogas production. The purpose of this study is to quantitatively clarify the effect of hydrothermal treatment on anaerobic digestion process focusing on acid detergent fiber (ADF) in sewage sludge, which is low biodegradability. The hydrothermal treatment experiment was carried out for 15 minutes between 160 °C and 200 °C respectively. The ADF content was decreased after hydrothermal treatment compared with untreated sludge. However, ADF content was increased when raising the treatment temperature from 160 °C to 200 °C. During batch anaerobic digestion experiment, untreated and treated sludge were examined for 10 days under 38 °C, and all samples were fed once based on volatile solids of samples. From batch anaerobic digestion experiment, as ADF content in sewage sludge increased, the total biogas production decreased. It was found that ADF content in sewage sludge influence on anaerobic digestion. Therefore, ADF could be one of the indicator to evaluate the effect of hydrothermal treatment to sewage sludge on anaerobic digestion.

Comparison of digestion methods for total elemental analysis of peat and separation of its organic and inorganic components

USGS Publications Warehouse

Papp, C.S.E.; Harms, T.F.

1985-01-01

In order to find the most efficient digestion method for the total elemental recovery in peat, ten samples were subjected to different techniques and analysed for Ca, Mg, Fe, AI, Na, K, Mn, P, Zn, Cu, Li, Cd, Co, Ni, Pb and Si using atomic-absorption spectrophotometry. The most satisfactory procedures were dry ashing followed by hydrofluoric acid treatment and wet digestion using a mixture of hot nitric, perchloric and hydrofluoric acids. The wet digestion offers the advantage of a single decomposition method for the determination of Ca, Mg, Fe, AI, K, Na, Mn, Cu, Li, Zn and P. An alkaline fusion technique was required for the determination of Si. Hydrogen peroxide was used to separate the peat into its organic and inorganic components, leading to the total recovery of the elements for both fractions.

The effect of microbial phytase on ileal phosphorus and amino acid digestibility in the broiler chicken.

PubMed

Rutherfurd, S M; Chung, T K; Moughan, P J

2002-09-01

1. The study aimed to assess the effect of a commercially available microbial phytase on phytate phosphorus and total phosphorus content at the terminal ileum as well as true ileal amino acid digestibility. 2. Five diets, each containing a different plant-based feedstuff, were supplemented with microbial phytase and fed, along with a non-supplemented corresponding diet, to 28-d-old broiler chickens, Chromic oxide was used as an indigestible marker. Ileal contents were collected and analysed, along with the diets, for total phosphorus, phytate phosphorus and amino acids. 3. Endogenous phosphorus determined at the terminal ileum was 272 +/- 108 mg/kg food dry matter (mean +/- SE). Endogenous ileal amino acid flows ranged from 58 +/- 10 mg/kg food dry matter for methionine to 568 +/- 47 mg/kg food dry matter for glutamic acid. 4. Supplementation with microbial phytase resulted in a significantly greater phytate P disappearance from the terminal ileum for rice bran (17% units), but not for soyabean meal, maize, wheat or rapeseed meal. Similarly total phosphorus digestibility was significantly (P < 0.05) higher when microbial phytase was added to the rice-bran-based diet but not for any of the other feedstuffs. 5. Amino acid digestibility was significantly greater in the presence of microbial phytase for all the amino acids examined in wheat, for several of the amino acids each in maize and rapeseed meal and for one amino acid in rice bran and soyabean meal. The average increase in amino acid digestibility for those amino acids affected, was 13, 6, 10, 7 and 12% units for wheat, maize, rapeseed meal, rice bran and soyabean meal, respectively. 6. It appears that microbial phytase improves phosphorus digestibility and amino acid digestibility for certain plant-based feedstuffs.

Prececal amino acid digestibility of soybean cake in fast- and slow-growing broiler chickens.

PubMed

Ganzer, C; Siegert, W; Kluth, H; Bennewitz, J; Rodehutscord, M

2017-08-01

The objective of the present study was to determine whether there are differences in prececal amino acid digestibility between commonly used slow- and fast-growing broiler strains when the regression approach is applied. ISA J-275 and Ross 308 were selected as common representatives of slow- and fast-growing broiler strains, respectively. The experimental diets with soybean cake at levels of 0, 100, and 200 g/kg were offered for ad libitum consumption between 22 and 29 d post-hatch. Titanium dioxide was used as an indigestible marker. Each treatment was tested with six pens comprising 10 birds each. Digesta samples were collected on a pen basis from the distal two-thirds of the intestine section between Meckel's diverticulum and 2 cm anterior to the ileocecal-colonic junction. The prececal amino acid digestibility of soybean cake was calculated by linear regression simultaneously for both strains. There was no significant interaction between broiler strain and inclusion level of soybean cake with respect to the prececal CP and amino acid digestibility of complete diets; there was a significant strain effect for 5 out of the 16 measured amino acids. The prececal CP and amino acid digestibility of soybean cake did not differ significantly between strains and was numerically almost identical. The results of the present study provide evidence of the transferability between broiler strains of prececal amino acid digestibility data, determined using the regression approach, thus improving the accuracy of diet formulation without drawbacks. © 2017 Poultry Science Association Inc.

Low-protein diets affect ileal amino acid digestibility and gene expression of digestive enzymes in growing and finishing pigs.

PubMed

He, Liuqin; Wu, Li; Xu, Zhiqi; Li, Tiejun; Yao, Kang; Cui, Zhijie; Yin, Yulong; Wu, Guoyao

2016-01-01

The objective of this study was to evaluate effects of dietary crude protein (CP) intake on ileal amino acid digestibilities and expression of genes for digestive enzymes in growing and finishing pigs. In Experiment 1, 18 growing pigs (average initial BW = 36.5 kg) were assigned randomly into one of three treatments (n = 6/treatment group) representing normal (18 % CP), low (15 % CP), and very low (12 % CP) protein intake. In Experiment 2, 18 finishing pigs (average initial BW = 62.3 kg) were allotted randomly into one of three treatments (n = 6/treatment group), representing normal (16 % CP), low (13 % CP) and very low (10 % CP) protein intake. In both experiments, diets with low and very low CP were supplemented with crystalline amino acids to achieve equal content of standardized ileal digestible Lys, Met, Thr, and Trp, and were provided to pigs ad libitum. Daily feed intake, BW, and feed/gain ratios were determined. At the end of each experiment, all pigs were slaughtered to collect pancreas, small-intestine samples, and terminal ileal chymes. Samples were used for determining expression of genes for digestive enzymes and ileal amino acid digestibilities. Growing pigs fed the 12 % CP and 15 % CP diets had lower final body weight (P < 0.01) and ADG (P < 0.0001) when compared with pigs fed the 18 % dietary CP diet. Growing pigs fed with the 12 % CP diet showed higher digestibilities for CP (P < 0.05), DM (P < 0.05), Lys (P < 0.0001), Met (P < 0.01), Cys (P < 0.01), Thr (P < 0.01), Trp (P < 0.05), Val (P < 0.05), Phe (P < 0.05), Ala (P < 0.05), Cys (P < 0.01), and Gly (P < 0.05) than those fed the 18 % CP diet. Finishing pigs fed the 16 % CP diet had a higher (P < 0.01) final body weight than those fed the 10 % CP diet. mRNA levels for digestive enzymes (trypsinogen, chymotrypsin B, and dipeptidases-II and III) differed among the three groups of pigs (P < 0.05), and no difference was noted in the genes expression between control group and lower CP group. These

Control of C/N ratio for butyric acid production from textile wastewater sludge by anaerobic digestion.

PubMed

Fu, Bo; Zhang, Jingjing; Fan, Jinfeng; Wang, Jin; Liu, He

2012-01-01

Increasing textile wastewaters and their biotreatment byproduct-waste activated sludge are serious pollution problems. Butyric acid production from textile wastewater sludge by anaerobic digestion at different C/N ratios was investigated. Adding starch to textile wastewater sludge with a C/N ratio of 30 increased the butyric acid concentration and percentage accounting for total volatile fatty acids (TVFAs) to 21.42 g/L and 81.5%, respectively, as compared with 21.42 g/L and 10.6% of textile wastewater sludge alone. The maximum butyric acid yield (0.45 g/g VS), conversion rate (0.74 g/g VS(digest)) and production rate (2.25 g/L d) was achieved at a C/N ratio of 30. The biological toxicity of textile wastewater sludge also significantly decreased after the anaerobic digestion. The study indicated that the anaerobic co-digestion of textile wastewater sludge and carbohydrate-rich waste with appropriate C/N ratio is possible for butyric acid production.

Inhibitory effect of chlorogenic acid on digestion of potato starch.

PubMed

Karim, Zida; Holmes, Melvin; Orfila, Caroline

2017-02-15

The effect of the chlorogenic acid isomer 5-O-caffeoylquinic acid (5-CQA) on digestion of potato starch by porcine pancreatic alpha amylase (PPAA) was investigated using isolated starch and cooked potato tuber as substrates. In vitro digestion was performed on five varieties of potato with varying phenolic content. Co- and pre-incubation of PPAA with 5-CQA significantly reduced PPAA activity in a dose dependent manner with an IC50 value of about 2mgmL(-1). Lineweaver-Burk plots indicated that 5-CQA exerts a mixed type inhibition as km increased and Vmax decreased. The total polyphenol content (TPC) of peeled tuber tissue ranged from 320.59 to 528.94mg 100g(-1)dry weight (DW) in raw tubers and 282.03-543.96mg 100g(-1)DW in cooked tubers. With the exception of Désirée, TPC and 5-CQA levels decreased after cooking. Principle component analysis indicated that digestibility is affected by multiple factors including phenolic, dry matter and starch content. Copyright © 2016 Elsevier Ltd. All rights reserved.

In vitro digestion of citric acid esters of mono- and diglycerides (CITREM) and CITREM-containing infant formula/emulsions.

PubMed

Amara, Sawsan; Patin, Amaury; Giuffrida, Francesca; Wooster, Tim J; Thakkar, Sagar K; Bénarouche, Anaïs; Poncin, Isabelle; Robert, Sylvie; Point, Vanessa; Molinari, Sacha; Gaussier, Hélène; Diomande, Sadia; Destaillats, Frédéric; Cruz-Hernandez, Cristina; Carrière, Frédéric

2014-07-25

CITREM is an emulsifier used in the food industry and contains citric acid esters of mono- and diglycerides (GCFE). It is generally recognized as safe but no publication on its digestibility under gastrointestinal conditions and impact on fat digestion was available. It was shown here that fatty acids are released from CITREM by gastric lipase, pancreatic lipase, pancreatic-lipase-related protein 2 and carboxyl ester hydrolase. A two-step in vitro digestion model mimicking lipolysis in the stomach and upper small intestine of term and preterm infants was then used to evaluate the digestibility of CITREM alone, CITREM-containing infant formula and fat emulsions, and isolated GCFE fractions. Overall, it was shown that fat digestion is not significantly changed by the presence of CITREM, and fatty acids contained in CITREM compounds are released to a large extent by lipases. Nevertheless, undigestible water-soluble compounds containing glycerol and citric acid units were identified, indicating that the ester bond between citric acid and glycerol is not fully hydrolyzed throughout the proposed digestion.

White clover fractions as protein source for monogastrics: dry matter digestibility and protein digestibility-corrected amino acid scores.

PubMed

Stødkilde, Lene; Damborg, Vinni K; Jørgensen, Henry; Laerke, Helle N; Jensen, Søren K

2018-05-01

The present study aimed to evaluate the use of white clover as an alternative protein source for monogastrics. White clover plant and leaves were processed using a screw-press resulting in a solid pulp and a juice from which protein was acid-precipitated. The chemical composition of all fractions was determined and digestibility of dry matter (DM) and protein was assessed in an experiment with growing rats. Protein concentrates were produced with crude protein (CP) contents of 451 g kg -1 and 530 g kg -1 DM for white clover plant and leaves, respectively, and a pulp with CP contents of 313 and 374 g kg -1 DM from plant and leaves, respectively. The amino acid composition ranged from 4.72 to 6.49 g per 16 g of nitrogen (N) for lysine, 1.82-2.6 g per 16 g N for methionine and cysteine, and 3.66-5.24 g per 16 g N for threonine. True faecal digestibility of protein varied from 0.81 to 0.88, whereas DM digestibility was in the range 0.72-0.80. Methionine and cysteine were found to be limiting in all fractions, regardless of the reference group used. A high digestibility of white clover protein was found irrespective of the physical fractionation. Together with a well-balanced amino acid composition, this makes white clover a promising protein source for monogastrics. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Detection and quantification of long chain fatty acids in liquid and solid samples and its relevance to understand anaerobic digestion of lipids.

PubMed

Neves, L; Pereira, M A; Mota, M; Alves, M M

2009-01-01

A method for long chain fatty acids (LCFA) extraction, identification and further quantification by gas chromatography was developed and its application to liquid and solid samples collected from anaerobic digesters was demonstrated. After validation, the usefulness of this method was demonstrated in a cow manure digester receiving pulses of an industrial effluent containing high lipid content. From the LCFA analysis data it was showed that the conversion of oleic acid, the main LCFA fed to the reactor, by the adapted biomass became faster and more effective along the successive pulses. Conversely, the accumulation of palmitic acid in the solid phase suggests that degradation of this LCFA, under these conditions, is less effective.

GFAAS determination of selenium in infant formulas using a microwave digestion method.

PubMed

Alegria, A; Barbera, R; Farré, R; Moreno, A

1994-01-01

A method for determining the selenium content of infant formulas is proposed. It includes wet digestion with nitric acid and hydrogen peroxide in medium pressure teflon bombs in a microwave oven and determination by graphite furnace atomic absorption spectrometry (GFAAS). The absence of interferences is checked. Values obtained for the limit of detection (19.4 ng/g), precision (RSD = 2.2%) and accuracy by analysis of a reference material show that the method is reliable.

Impact of antinutritional factors in food proteins on the digestibility of protein and the bioavailability of amino acids and on protein quality.

PubMed

Sarwar Gilani, G; Wu Xiao, Chao; Cockell, Kevin A

2012-08-01

significant reductions (up to 23 %) in protein and amino acid digestibility in rats, poultry, and pigs. Normally encountered levels of phytates in cereals and legumes can reduce protein and amino acid digestibility by up to 10 %. D-amino acids and LAL formed during alkaline/heat treatment of lactalbumin, casein, soya protein or wheat protein are poorly digestible (less than 40 %), and their presence can reduce protein digestibility by up to 28 % in rats and pigs, and can cause a drastic reduction (100 %) in protein quality, as measured by rat growth methods. The adverse effects of antinutritional factors on protein digestibility and protein quality have been reported to be more pronounced in elderly rats (20-months old) compared to young (5-weeks old) rats, suggesting the use of old rats as a model for assessing the protein digestibility of products intended for the elderly.

Prediction of the true digestible amino acid contents from the chemical composition of sorghum grain for poultry.

PubMed

Ebadi, M R; Sedghi, M; Golian, A; Ahmadi, H

2011-10-01

Accurate knowledge of true digestible amino acid (TDAA) contents of feedstuffs is necessary to accurately formulate poultry diets for profitable production. Several experimental approaches that are highly expensive and time consuming have been used to determine available amino acids. Prediction of the nutritive value of a feed ingredient from its chemical composition via regression methodology has been attempted for many years. The artificial neural network (ANN) model is a powerful method that may describe the relationship between digestible amino acid contents and chemical composition. Therefore, multiple linear regressions (MLR) and ANN models were developed for predicting the TDAA contents of sorghum grain based on chemical composition. A precision-fed assay trial using cecectomized roosters was performed to determine the TDAA contents in 48 sorghum samples from 12 sorghum varieties differing in chemical composition. The input variables for both MLR and ANN models were CP, ash, crude fiber, ether extract, and total phenols whereas the output variable was each individual TDAA for every sample. The results of this study revealed that it is possible to satisfactorily estimate the TDAA of sorghum grain through its chemical composition. The chemical composition of sorghum grain seems to highly influence the TDAA contents when considering components such as CP, crude fiber, ether extract, ash and total phenols. It is also possible to estimate the TDAA contents through multiple regression equations with reasonable accuracy depending on composition. However, a more satisfactory prediction may be achieved via ANN for all amino acids. The R(2) values for the ANN model corresponding to testing and training parameters showed a higher accuracy of prediction than equations established by the MLR method. In addition, the current data confirmed that chemical composition, often considered in total amino acid prediction, could be also a useful predictor of true digestible values

In vitro digestion and physicochemical characteristics of corn starch mixed with amino acid modified by low pressure treatment.

PubMed

Ji, Ying

2018-03-01

The digestibility and molecular structure of corn starch mixed with amino acid modified by low-pressure treatment (LPT) was investigated. Amino acid induced a significant increase in the slowly digestible starch (SDS) and decrease in the rapidly digestible starch (RDS) after LPT. The reason is the formation of ester bond between the molecular chains of amino acid and starch. Low pressure treatment altered greatly the morphology of corn starch mixed with or without amino acid. After LPT, less ordered Maltese and more granule fragments were observed for starch-amino acid complex. An increase in size distribution was obvious after LPT and the size distribution curves provided from a new variety. We found that higher enthalpy and relative crystallinity of the starch-amino acid complex were associated with a higher SDS content. It can be inferred that LPT had a greater impact on the digestion and structural characterization of corn starch mixed with amino acids. Copyright © 2017 Elsevier Ltd. All rights reserved.

Techniques for evaluating digestibility of energy, amino acids, phosphorus, and calcium in feed ingredients for pigs.

PubMed

Zhang, Fengrui; Adeola, Olayiwola

2017-12-01

Sound feed formulation is dependent upon precise evaluation of energy and nutrients values in feed ingredients. Hence the methodology to determine the digestibility of energy and nutrients in feedstuffs should be chosen carefully before conducting experiments. The direct and difference procedures are widely used to determine the digestibility of energy and nutrients in feedstuffs. The direct procedure is normally considered when the test feedstuff can be formulated as the sole source of the component of interest in the test diet. However, in some cases where test ingredients can only be formulated to replace a portion of the basal diet to provide the component of interest, the difference procedure can be applied to get equally robust values. Based on components of interest, ileal digesta or feces can be collected, and different sample collection processes can be used. For example, for amino acids (AA), to avoid the interference of fermentation in the hind gut, ileal digesta samples are collected to determine the ileal digestibility and simple T-cannula and index method are commonly used techniques for AA digestibility analysis. For energy, phosphorus, and calcium, normally fecal samples will be collected to determine the total tract digestibility, and therefore the total collection method is recommended to obtain more accurate estimates. Concerns with the use of apparent digestibility values include different estimated values from different inclusion level and non-additivity in mixtures of feed ingredients. These concerns can be overcome by using standardized digestibility, or true digestibility, by correcting endogenous losses of components from apparent digestibility values. In this review, methodologies used to determine energy and nutrients digestibility in pigs are discussed. It is suggested that the methodology should be carefully selected based on the component of interest, feed ingredients, and available experimental facilities.

Fatty acid profiles of in vitro digested processed milk

USDA-ARS?s Scientific Manuscript database

Digestion of milkfat releases some of the long-chain (18-carbon) fatty acids (FA) that can provide health benefits to the consumer, yet because they are found in small amounts and can be difficult to identify, there is limited information on the effects that common fluid milk processing may have on ...

[Simultaneous Determination of Sn and S in Methyltin Mercaptide by Microwave-Assisted Acid Digestion and ICP-OES].

PubMed

Chen, Qian; Wu, Xi; Hou, Xian-deng; Xu, Kai-lai

2015-09-01

Methyltin mercaptide is widely used as one of the best heat stabilizer in the polyvinylchloride (PVC) thermal processing due to its excellent stability, good transparency, high compatibility and weather resistance. The content of sulfur and tin significantly affects its quality and performance, so it is of great significance to develop an analytical method for the simultaneous determination of sulfur and tin. Inductively coupled plasma atomic emission spectrometry (ICP-OES) has been a powerful analytical tool for a myriad of complex samples owing to its advantages of the low detection limits, rapid and precise determinations over wide dynamic ranges, freedom from chemical inter-element interferences, the high sample throughput and above all, simultaneous multi-elements analysis. Microwave technique as a well-developed method for sample preparation can dramatically reduce the digestion time and the loss of volatile elements compared with the traditional open digestion. Hereby, a microwave-assisted acid digestion (MW-AAD) procedure followed by inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis was developed for the simultaneous determination of Sn and S in methyltin mercaptide. This method has the advantages of simplicity, rapidness, good accuracy, green and less use of samples. Parameters affecting the MW-AAD such as the digestion solution and digestion time were optimized by using a chemical analyzed reference sample (DX-181) to attain tin and sulfur quantitative recoveries. HNO3-HCl-HClO4 (v/v/v=9:3:1) and 10 min were the optimum digestion solution and digestion time, respectively. Under optimum conditions, the standard addition method and the standard calibration curve method were both been used to detect Sn and S in DX-181. There was no significant difference between two methods and the relative deviations to the chemical analysis values were both less than 2%. Additionally, the accuracy of the MW-AAD method was examined by analyzing

EPA Method 3135.2I: Cyanide, Total and Amenable in Aqueous and Solid Samples Automated Colorimetric With Manual Digestion

EPA Pesticide Factsheets

This method describes procedures for preparation and analysis of solid, water and wipe samples for detection and measurement of cyanide amendable to chlorination using acid digestion and spectrophotometry.

TOLERANCE TO AMINO ACID MIXTURES AND CASEIN DIGESTS GIVEN INTRAVENOUSLY

PubMed Central

Madden, S. C.; Woods, R. R.; Shull, F. W.; Remington, J. H.; Whipple, G. H.

1945-01-01

Several synthetic mixtures of natural and racemic crystalline amino acids suitable for the daily nitrogen requirement are tested in dogs for their tolerance upon intravenous injection. Certain mixtures of the ten essential amino acids plus non-essential amino acids exclusive of glutamic acid are accepted without any obvious sign of disturbance even at rates above 10 mg. nitrogen per kilo per minute for quantities greater than 300 mg. per kilo. One such mixture consists in parts per 100 of dl-threonine 7, dl-valine 15, l(-)-leucine 10.9, dl-isoleucine 9.9, l(+)-lysine· HCl·H2O 10.9, dl-tryptophane 3, dl-phenylalanine 9.9, dl-methionine 6, l(+)-histidine·HCl·H2O 5, l(+)-arginine-HCl 5, glycine 9.9, dl-α-alanine 4, dl-serine 2, l(-)-cystine 0.5, and l(-)-tyrosine 1. In addition other well tolerated mixtures included the prolines. When glutamic acid, natural or racemic, is included in similar mixtures vomiting reactions frequently occur at nitrogen rates above 4 mg. per kilo per minute. Vomiting almost always occurs on the first daily injection containing glutamic acid and usually on any subsequent injection containing more than 100 mg. glutamic acid per kilo unless given very slowly. Upon the addition of glycine certain mixtures of the ten essential amino acids show an improved tolerance. Two casein digests tested usually produced vomiting at injection rates above 2 mg. nitrogen per kilo per minute, probably because of their glutamic acid content. No serious reaction has ever occurrred to any mixture of amino acids or casein digest tested. Elimination of minor reactions such as vomiting appears possible and desirable for greater usefulness of these solutions in parenteral feeding. PMID:19871468

The function of digestive enzymes on Cu, Zn, and Pb release from soil in in vitro digestion tests.

PubMed

Li, Yi; Demisie, Walelign; Zhang, Ming-kui

2013-07-01

The bioaccessibility of soil heavy metals is the solubility of soil heavy metals in synthetic human digestive juice, which is usually determined using in vitro digestion test. To reveal the effects of digestive enzymes on soil heavy metals bioaccessibility, three representative in vitro digestion tests, Simple Bioaccessibility Extraction Test (SBET), Physiologically Based Extraction Test (PBET), and Simple Gastrointestinal Extraction Test (SGET), were chosen. The bioaccessibility of soil Cu, Zn, and Pb in each method were respectively evaluated with and without digestive enzymes, and the differences were compared. The results showed that the effects of digestive enzymes varied with different methods and elements. Because of digestive enzymes addition, the environmental change from acid gastric phase to neutral intestinal phase of PBET did not result in apparently decrease of the bioaccessibility of soil Cu. However, the solubility of soil Zn and Pb were pH-dependent. For SGET, when digestive enzymes were added, its results reflected more variations resulting from soil and element types. The impacts of digestive enzymes on heavy metal dissolution are mostly seen in the intestinal phase. Therefore, digestive enzyme addition is indispensable to the gastrointestinal digestion methods (PBET and SGET), while the pepsin addition is not important for the methods only comprised of gastric digestion (SBET).

Methods of ammonia removal in anaerobic digestion: a review.

PubMed

Krakat, Niclas; Demirel, Burak; Anjum, Reshma; Dietz, Donna

2017-10-01

The anaerobic digestion of substrates with high ammonia content has always been a bottleneck in the methanisation process of biomasses. Since microbial communities in anaerobic digesters are sensitive to free ammonia at certain conditions, the digestion of nitrogen-rich substrates such as livestock wastes may result in inhibition/toxicity eventually leading to process failures, unless appropriate engineering precautions are taken. There are many different options reported in literature to remove ammonia from anaerobic digesters to achieve a safe and stable process so that along with high methane yields, a good quality of effluents can also be obtained. Conventional techniques to remove ammonia include physical/chemical methods, immobilization and adaptation of microorganisms, while novel methods include ultrasonication, microwave, hollow fiber membranes and microbial fuel cell applications. This paper discusses conventional and novel methods of ammonia removal from anaerobic digesters using nitrogen-rich substrates, with particular focus on recent literature available about this topic.

Mechanisms and effects of arsanilic acid on antibiotic resistance genes and microbial communities during pig manure digestion.

PubMed

Sun, Wei; Qian, Xun; Gu, Jie; Wang, Xiao-Juan; Zhang, Li; Guo, Ai-Yun

2017-06-01

High concentrations of residual arsanilic acid occur in pig manure due to its use in feed to promote growth and control diseases. This study compared the effects of arsanilic acid at three concentrations (0, 325, and 650mg/kg dry pig manure) on the abundance of antibiotic resistance genes (ARGs) and the microbial community during anaerobic digestion. Addition of 650mg/kg arsanilic acid enhanced the absolute abundances of tetC, sul2, ermB, and gyrA more than twofold in the digestion product. Redundancy analysis indicated that the change in the microbial community structure was the main driver of variation in the ARGs profile. The As resistance gene arsC co-occurred with four ARGs and intI1, possibly causing the increase in ARGs under pressure by arsanilic acid. High arsanilic acid concentrations can increase the risk of ARGs occurring in anaerobic digestion products. The amount of arsanilic acid used as a feed additive should be controlled. Copyright © 2017. Published by Elsevier Ltd.

An in vitro digestion method adapted for carotenoids and carotenoid esters: moving forward towards standardization.

PubMed

Rodrigues, Daniele Bobrowski; Mariutti, Lilian Regina Barros; Mercadante, Adriana Zerlotti

2016-12-07

In vitro digestion methods are a useful approach to predict the bioaccessibility of food components and overcome some limitations or disadvantages associated with in vivo methodologies. Recently, the INFOGEST network published a static method of in vitro digestion with a proposal for assay standardization. The INFOGEST method is not specific for any food component; therefore, we aimed to adapt this method to assess the in vitro bioaccessibility of carotenoids and carotenoid esters in a model fruit (Byrsonima crassifolia). Two additional steps were coupled to the in vitro digestion procedure, centrifugation at 20 000g for the separation of the aqueous phase containing mixed micelles and exhaustive carotenoid extraction with an organic solvent. The effect of electrolytes, enzymes and bile acids on carotenoid micellarization and stability was also tested. The results were compared with those found with a simpler method that has already been used for carotenoid bioaccessibility analysis. These values were in the expected range for free carotenoids (5-29%), monoesters (9-26%) and diesters (4-28%). In general, the in vitro bioaccessibility of carotenoids assessed by the adapted INFOGEST method was significantly higher (p < 0.05) than those assessed by the simplest protocol, with or without the addition of simulated fluids. Although no trend was observed, differences in bioaccessibility values depended on the carotenoid form (free, monoester or diester), isomerization (Z/E) and the in vitro digestion protocol. To the best of our knowledge, it was the first time that a systematic identification of carotenoid esters by HPLC-DAD-MS/MS after in vitro digestion using the INFOGEST protocol was carried out.

Fast Startup of Semi-Pilot-Scale Anaerobic Digestion of Food Waste Acid Hydrolysate for Biogas Production.

PubMed

Huang, Chao; Zhao, Cheng; Guo, Hai-Jun; Wang, Can; Luo, Mu-Tan; Xiong, Lian; Li, Hai-Long; Chen, Xue-Fang; Chen, Xin-De

2017-12-27

In this study, a fast startup of semi-pilot-scale anaerobic digestion of food waste acid hydrolysate for biogas production was carried out for the first time. During the period of fast startup, more than 85% of chemical oxygen demand (COD) can be degraded, and even more than 90% of COD can be degraded during the later stage of anaerobic digestion. During this anaerobic digestion process, the biogas yield, the methane yield, and the CH 4 content in biogas were 0.542 ± 0.056 m 3 /kg COD consumption , 0.442 ± 0.053 m 3 /kg COD consumption , and 81.52 ± 3.05%, respectively, and these values were high and stable. Besides, the fermentation pH was very stable, in which no acidification was observed during the anaerobic digestion process (outlet pH was 7.26 ± 0.05 for the whole anaerobic digestion). Overall, the startup of this anaerobic digestion can be completed in a short period (the system can be stable 2 days after the substrate was pumped into the bioreactor), and anaerobic digestion of food waste acid hydrolysate is feasible and attractive for industrial treatment of food waste and biogas production.

Proximate composition, fatty acid analysis and protein digestibility-corrected amino acid score of three Mediterranean cephalopods.

PubMed

Zlatanos, Spiros; Laskaridis, Kostas; Feist, Christian; Sagredos, Angelos

2006-10-01

Proximate composition, fatty acid analysis and protein digestibility-corrected amino acid score (PDCAAS) in three commercially important cephalopods of the Mediterranean sea (cuttlefish, octopus and squid) were determined. The results of the proximate analysis showed that these species had very high protein:fat ratios similar to lean beef. Docosahexaenoic, palmitic and eicosipentaenoic acid were the most abundant fatty acids among analyzed species. The amount of n-3 fatty acids was higher than that of saturated, monounsaturated and n-6 fatty acids. Despite the fact that cephalopods contain small amounts of fat they were found quite rich in n-3 fatty acids. Finally, PDCAAS indicated that these organisms had a very good protein quality.

Digestibility marker and ileal amino acid digestibility in phytase-supplemented soybean or canola meals for growing pigs.

PubMed

Favero, A; Ragland, D; Vieira, S L; Owusu-Asiedu, A; Adeola, O

2014-12-01

Two experiments using soybean meal (SBM) or canola meal (CM) were conducted to investigate whether the choice of digestibility marker influenced the apparent ileal digestibility (AID) or standardized ileal digestibility (SID) of N and AA in diets supplemented with phytase. In each experiment, 18 barrows fitted with T-cannulas at the ileocecal junction were assigned to 3 diets consisting of a N-free diet to determine endogenous losses of N and AA, a semipurified diet (SBM in Exp. 1 or CM in Exp. 2), and the semipurified diet supplemented with phytase at 1,000 phytase units/kg. Three digestibility markers including acid-insoluble ash (AIA), chromic oxide (Cr2O3), and titanium dioxide (TiO2) were added to each diet at 3 g/kg. Each diet was fed for 7 d, consisting of a 5-d adjustment and a 2-d collection of ileal digesta. In both studies, basal ileal endogenous losses determined with Cr2O3 as a digestibility marker were lower (P<0.01) than with those determined with AIA or TiO2 digestibility markers. Using SBM as the protein source in Exp. 1, there was no interaction between phytase and digestibility marker on AID or SID of AA. The AID of N and AA in SBM using AIA as a digestibility marker tended to be lower (P<0.1) compared with Cr2O3 or TiO2 digestibility markers. Phytase supplementation increased (P<0.001) the AID of Ca and P. The use of AIA or Cr2O3 digestibility marker tended to be associated with lower (P<0.1) SID values compared with TiO2. Phytase did not affect the SID of N or any AA in SBM except for Met, for which there was an increase (P<0.05) with phytase supplementation. Using CM as the protein source in Exp. 2, there were significant interactions between digestibility marker and phytase. Phytase supplementation had effects (P<0.01) on AID or SID when Cr2O3 or TiO2 was used as the digestibility marker. With Cr2O3 or TiO2 as the digestibility marker in the CM diets, phytase supplementation increased (P<0.05) the SID of N and all AA (except Trp). There was

Low cost of gastric acid secretion during digestion in ball pythons.

PubMed

Nørgaard, Simon; Andreassen, Kim; Malte, Christian Lind; Enok, Sanne; Wang, Tobias

2016-04-01

Due to their large metabolic responses to digestion (specific dynamic action, SDA), snakes represent an interesting animal group to identify the underlying mechanisms for the postprandial rise in metabolism. The SDA response results from the energetic costs of many different processes ranging over prey handling, secretions by the digestive system, synthesis of enzymes, plasticity of most visceral organs, as well as protein synthesis and nitrogen excretion. The contribution of the individual mechanisms, however, remains elusive. Gastric acid secretion has been proposed to account for more than half of the SDA response, while other studies report much lower contributions of the gastric processes. To investigate the energetic cost of gastric acid secretion, ball pythons (Python regius) were fed meals with added amounts of bone meal (up to 25 g bone meal kg(-1) snake) to achieve a five-fold rise in the buffer capacity of the meals. Direct measurements within the stomach lumen showed similar reduction in gastric pH when buffer capacity was increased, but we found no effects on the rise in oxygen consumption over the first three days of digestion. There was, however, a slower return of oxygen consumption to resting baseline. We conclude that gastric acid secretion only contributes modestly to the SDA response and propose that post-absorptive processes, such as increased protein synthesis, are likely to underlie the SDA response. Copyright © 2016 Elsevier Inc. All rights reserved.

Polymorph-dependent titanium dioxide nanoparticle dissolution in acidic and alkali digestions

EPA Science Inventory

Multiple polymorphs (anatase, brookite and rutile) of titanium dioxide nanoparticles (TiO2-NPs) with variable structures were quantified in environmental matrices via microwave-based hydrofluoric (HF) and nitric (HNO3) mixed acid digestion and muffle furnace (MF)-based potassium ...

Methods to determine metabolizable energy and digestibility of feed ingredients in the domestic pigeon (Columba livia domestica).

PubMed

Sales, J; Janssens, G P J

2003-09-01

The influence of length of excreta collection period (1, 3, 6, 10, 14 d) and prefeeding protocol (7 d either individual feeding in collection cages or group feeding in housing cages) on AMEn, nitrogen retention (NR), and apparent DM, organic matter and ether extract digestibility of corn and peas were evaluated in domestic pigeons (Columba livia domestica). In addition, the use of internal markers [acid-insoluble ash (AIA) and acid detergent lignin (ADL)] to determine AMEn, NR, and apparent digestibility was compared with the method of measuring total feed input and excreta output. A quadratic (y = a + bx + cx2) trend in the CV for AMEn, NR, and apparent digestibility coefficients found over collection periods with corn presented evidence that excreta collection for a period of 3 d will produce a CV of 5% less than the minimum CV. Although no trend could be detected in CV for peas, a 3-d excreta collection period resulted in relatively low variation. Both AIA and ADL, when used as internal markers, resulted in AMEn, NR, and digestibility values below (P < 0.05) those obtained with total collection with corn. However, values between markers were comparable (P > 0.05) for all components evaluated. The ADL was unsuccessful as marker with peas. Group prefeeding of pigeons in housing cages resulted in lower feed intake, excreta output, NR, and apparent digestibility than when birds were adapted individually to collection cages. This study presents evidence that the method of measuring total feed intake and excreta output for a period of 3 d, with individual adaptation of birds to collection cages, resulted in the most reliable values for AMEn, NR, and apparent digestibility of DM, organic matter and ether extract of feed ingredients in pigeons.

Mineralogical basis for the interpretation of multi-element (ICP-AES), oxalic acid, and aqua regia partial digestions of stream sediments for reconnaissance exploration geochemistry

USGS Publications Warehouse

Church, S.E.; Mosier, E.L.; Motooka, J.M.

1987-01-01

We have applied partial digestion procedures, primarily oxalic acid and aqua regia leaches, to several regional geochemical reconnaissance studies carried out using Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) analytical methods. We have chosen to use these two acids because the oxalic acid primarily attacks those compounds formed during secondary geochemical processes, whereas aqua regia will digest the primary sulfide phases as well as secondary phases. Application of the partial digestion technique has proven superior to total digestion because the concentration of metals in hydromorphic compounds and the sulfides is enhanced relative to the metals bound in the unattacked silicate phases. The aqua regia digestion attacks and leaches metals from the mafic chain silicates and the phyllosilicates (coordination number of VI or more), yielding a characteristic geochemical signature, but does not leach appreciable metal from many other silicates. In order to interpret the results from these leach studies, we have initiated an investigation of a large suite of hand-picked mineral separates. The study includes analyses of about two hundred minerals representing the common rock-forming minerals as well as end-member compositions of various silicates, oxides, sulfides, carbonates, sulfates, and some vanadates, molybdates, tungstates, and phosphates. The objective of this study is to evaluate the effect of leaching by acids of particular lattice sites in specific mineral structures. ?? 1987.

Microwave acid digestion and preconcentration neutron activation analysis of biological and diet samples for iodine.

PubMed

Rao, R R; Chatt, A

1991-07-01

A simple preconcentration neutron activation analysis (PNAA) method has been developed for the determination of low levels of iodine in biological and nutritional materials. The method involves dissolution of the samples by microwave digestion in the presence of acids in closed Teflon bombs and preconcentration of total iodine, after reduction to iodide with hydrazine sulfate, by coprecipitation with bismuth sulfide. The effects of different factors such as acidity, time for complete precipitation, and concentrations of bismuth, sulfide, and diverse ions on the quantitative recovery of iodide have been studied. The absolute detection limit of the PNAA method is 5 ng of iodine. Precision of measurement, expressed in terms of relative standard deviation, is about 5% at 100 ppb and 10% at 20 ppb levels of iodine. The PNAA method has been applied to several biological reference materials and total diet samples.

Values for digestible indispensable amino acid scores (DIAAS) for some dairy and plant proteins may better describe protein quality than values calculated using the concept for protein digestibility-corrected amino acid scores (PDCAAS).

PubMed

Mathai, John K; Liu, Yanhong; Stein, Hans H

2017-02-01

An experiment was conducted to compare values for digestible indispensable amino acid scores (DIAAS) for four animal proteins and four plant proteins with values calculated as recommended for protein digestibility-corrected amino acid scores (PDCAAS), but determined in pigs instead of in rats. Values for standardised total tract digestibility (STTD) of crude protein (CP) and standardised ileal digestibility (SID) of amino acids (AA) were calculated for whey protein isolate (WPI), whey protein concentrate (WPC), milk protein concentrate (MPC), skimmed milk powder (SMP), pea protein concentrate (PPC), soya protein isolate (SPI), soya flour and whole-grain wheat. The PDCAAS-like values were calculated using the STTD of CP to estimate AA digestibility and values for DIAAS were calculated from values for SID of AA. Results indicated that values for SID of most indispensable AA in WPI, WPC and MPC were greater (P<0·05) than for SMP, PPC, SPI, soya flour and wheat. With the exception of arginine and tryptophan, the SID of all indispensable AA in SPI was greater (P<0·05) than in soya flour, and with the exception of threonine, the SID of all indispensable AA in wheat was less (P<0·05) than in all other ingredients. If the same scoring pattern for children between 6 and 36 months was used to calculate PDCAAS-like values and DIAAS, PDCAAS-like values were greater (P<0·05) than DIAAS values for SMP, PPC, SPI, soya flour and wheat indicating that PDCAAS-like values estimated in pigs may overestimate the quality of these proteins.

Acid and alkaline phosphatase localization in the digestive tract mucosa of the Hemisorubim platyrhynchos.

PubMed

Faccioli, Claudemir Kuhn; Chedid, Renata Alari; Mori, Ricardo Hideo; Amaral, Antônio Carlos do; Franceschini-Vicentini, Irene Bastos; Vicentini, Carlos Alberto

2016-09-01

This cytochemical study investigated the acid and alkaline phosphatase of the digestive tract of Hemisorubim platyrhynchos. Acid phosphatase was detected in the lining epithelium throughout the digestive tract, whereas alkaline phosphatase was only observed in the intestine. In the esophagus, an acid phosphatase reaction occurred in the apical cytoplasm of the epithelial cells and was related to epithelial protection and freeing of superficial cells for sloughing. Similar results were also observed in epithelial cells of gastric epithelium. In the gastric glands, acid phosphatase occurred in lysosomes of the oxynticopeptic cells acting in the macromolecule degradation for use as an energy source, whereas in the vesiculotubular system, its presence could be related to secretion processes. Furthermore, acid phosphatase in the intestine occurred in microvilli and lysosomes of the enterocytes and was correlated to absorption and intracellular digestion. However, no difference was reported among the regions of the intestine. However, alkaline phosphatase reaction revealed a large number of reaction dots in the anterior intestine, with the number decreasing toward the posterior intestine. This enzyme has been related to several functions, highlighting its role in the nutrient absorption primarily in the anterior intestine but also being essential in pH regulation because this is a carnivorous species with many gastric glands with secretions that could damage the intestine. Copyright © 2016 Elsevier GmbH. All rights reserved.

Potential impact of the digestible indispensable amino acid score as a measure of protein quality on dietary regulations and health

PubMed Central

Marinangeli, Christopher P F; House, James D

2017-01-01

Abstract Regulatory frameworks for protein content claims in Canada and the United States are underpinned by the protein efficiency ratio and protein digestibility-corrected amino acid score (PDCAAS), respectively, which are used to assess the protein quality of a given food. The digestible indispensable amino acid score (DIAAS) is a novel approach to measuring the protein quality of foods and is supported by the Food and Agriculture Organization of the United Nations. Methodological concerns about the PDCAAS are addressed by the DIAAS through introduction of the use of ileal amino acid digestibility coefficients and untruncated protein scores. However, before the DIAAS is widely adopted within regulatory frameworks, a comprehensive assessment is required. Accordingly, this review addresses the potential impact of the DIAAS on regulation, communication, and public health, as well as knowledge gaps, analytical challenges, and cost of implementation. A pragmatic approach to addressing protein quality is advocated by suggesting the use of conservative coefficients of digestibility that are derived from in vitro methods. Before adopting the DIAAS as a framework for supporting protein content claims, updated food-related regulations and policies should also be evaluated through a lens that anticipates the impact on consumer-facing nutrition communication, the adoption of dietary patterns that are nutritionally adequate, and a food value chain that fosters a spirit of food and nutritional innovation. PMID:28969364

Microwave-assisted digestion using nitric acid for heavy metals and sulfated ash testing in active pharmaceutical ingredients.

PubMed

Pluhácek, T; Hanzal, J; Hendrych, J; Milde, D

2016-04-01

The monitoring of inorganic impurities in active pharmaceutical ingredients plays a crucial role in the quality control of the pharmaceutical production. The heavy metals and residue on ignition/sulfated ash methods employing microwave-assisted digestion with concentrated nitric acid have been demonstrated as alternatives to inappropriate compendial methods recommended in United States Pharmacopoeia (USP) and European Pharmacopoeia (Ph. Eur.). The recoveries using the heavy metals method ranged between 89% and 122% for nearly all USP and Ph. Eur. restricted elements as well as the recoveries of sodium sulfate spikes were around 100% in all tested matrices. The proposed microwave-assisted digestion method allowed simultaneous decomposition of 15 different active pharmaceutical ingredients with sample weigh up to 1 g. The heavy metals and sulfated ash procedures were successfully applied to the determination of heavy metals and residue on ignition/sulfated ash content in mycophenolate mofetil, nicergoline and silymarin.

Disinhibition of excessive volatile fatty acids to improve the efficiency of autothermal thermophilic aerobic sludge digestion by chemical approach.

PubMed

Jin, Ningben; Jin, Bo; Zhu, Nanwen; Yuan, Haiping; Ruan, Jianbo

2015-01-01

In this study, we explored a chemical approach to eliminate inhibition of excessive volatile fatty acids (VFAs) in autothermal thermophilic aerobic digestion (ATAD). Ferric nitrate, ferric chloride, potassium nitrate and potassium chloride were employed to demonstrate the combined action of ferric ion and nitrate ion. Supplementation of ferric nitrate in the sludge digestion system resulted in reducing the concentration of Total VFAs (TVFA) by round 5000mg/L and more than 2000mg/L of acetic acid at the end of digestion. Lower TVFA concentration contributed to faster sludge stabilization rate and the VS removal of ferric nitrate dosed digester achieved 38.18% after 12days digestion which was 9days in advance compared with the stabilization time of sludge in digester without chemicals addition. Lower concentrations of NH4(+)-N and SCOD in supernatant while higher content of TP in digestion sludge were obtained in digester with ferric nitrate added. Copyright © 2014 Elsevier Ltd. All rights reserved.

Survival of lactic acid bacteria from fermented milks in an in vitro digestion model exploiting sequential incubation in human gastric and duodenum juice.

PubMed

Faye, T; Tamburello, A; Vegarud, G E; Skeie, S

2012-02-01

In the present study, the survival of 9 lactic acid bacteria (5 Lactococcus strains, 3 Lactobacillus strains, and 1 strain of Enterococcus hirae), was investigated in vitro under conditions similar to human digestion using human gastric and duodenal juices. The tolerance of the bacteria was also tested with traditional methods using acidic conditions and bile salts. The strains were subjected to a model digestive system comprising sequential incubation in human gastric and duodenal juices, in a 2-step digestion assay at 37°C, simulating the human upper gastrointestinal tract with human gastric juices at pH 2.5 and human duodenal juices at pH 7. The bacterial strains were tested either as washed cells from culture media or in fermented milk. The initial in vitro testing in acid and bile salts showed that Lactobacillus strains and the E. hirae strain displayed a significantly higher acid tolerance than the lactococci. The lactobacilli and the Enterococcus numbers increased, whereas the lactococci decreased at least 1 log during the bile salt treatment. The Lactobacillus strains showed the highest survival rate in the model digestive system when washed bacterial cultures were used with a minor log reduction, whereas the lactococci numbers were reduced by at least log 4. However, when using fermented milks in the model digestion system it was demonstrated that the Enterococcus strain and 2 strains of Lactococcus lactis ssp. cremoris benefited significantly from the presence of the fermented milk as food matrix, with log numbers >log 7 and 5, respectively, after digestion of the fermented milk. The analyses reported comprise a comprehensive in vitro testing regimen suitable for evaluation of the survival of candidate probiotic bacteria in human digestion as an initial prescreen to clinical trials. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of Digestion and Storage of Human Milk on Free Fatty Acid Concentration and Cytotoxicity

PubMed Central

Penn, Alexander H.; Altshuler, Angelina E.; Small, James W.; Taylor, Sharon F.; Dobkins, Karen R.; Schmid-Schönbein, Geert W.

2014-01-01

Objectives Fat is digested in the intestine into free fatty acids (FFAs), which are detergents and therefore toxic to cells at micromolar concentration. The mucosal barrier protects cells in the adult intestine, but this barrier may not be fully developed in premature infants. Lipase-digested infant formula, but not fresh human milk, has elevated FFAs and is cytotoxic to intestinal cells, and therefore could contribute to intestinal injury in necrotizing enterocolitis (NEC). But even infants exclusively fed breast milk may develop NEC. Our objective was to determine if stored milk and milk from donor milk banks (DM) could also become cytotoxic, especially after digestion. Methods We exposed cultured rat intestinal epithelial cells or human neutrophils to DM and milk collected fresh and stored at 4 or −20 °C for up to 12 weeks and then treated for 2 hours (37°C) with 0.1 or 1 mg/ml pancreatic lipase and/or trypsin and chymotrypsin. Results DM and milk stored 3 days (at 4 or −20 °C) and then digested were cytotoxic. Storage at −20 °C for 8 and 12 weeks resulted in an additional increase in cytotoxicity. Protease digestion decreased, but did not eliminate cell death. Conclusions Current storage practices may allow milk to become cytotoxic and contribute to intestinal damage in NEC. PMID:24840512

The effect of chaya (Cnidoscolus aconitifolius) leaf meal and of exogenous enzymes on amino acid digestibility in broilers.

PubMed

Sarmiento-Franco, L; McNab, J M; Pearson, A; Belmar-Casso, R

2003-07-01

1. The apparent ileal nitrogen (N) and amino acid digestibilities in chaya leaf meal (CLM) (Cnidoscolus aconitifolius) with added enzymes, and the same variables in diets containing different amounts of CLM were studied in chickens. 2. In the first experiment pectinase, beta-glucanase, and pectinase + beta-glucanase were added to CLM. In the second experiment, there were three diets based on maize and soybean: 0, 150 and 250 g/kg CLM. 3. Pectinase significantly increased both lysine and overall amino acid digestibilities in CLM. 4. In experiment 2, the amino acid digestibility in birds fed on CLM250 was lower than that from birds fed on either control or CLM150. Only the digestibilities of alanine, arginine and proline were lower in birds fed on CLM150 than in those fed on the control diet. Nitrogen digestibility was lower in birds fed on the CLM250 diet than on either control or CLM150 diets. These findings were attributed to the increasing concentration of fibre with increasing dietary CLM.

Urea free and more efficient sample preparation method for mass spectrometry based protein identification via combining the formic acid-assisted chemical cleavage and trypsin digestion.

PubMed

Wu, Shuaibin; Yang, Kaiguang; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

2011-10-30

A formic acid (FA)-assisted sample preparation method was presented for protein identification via mass spectrometry (MS). Detailedly, an aqueous solution containing 2% FA and dithiothreitol was selected to perform protein denaturation, aspartic acid (D) sites cleavage and disulfide linkages reduction simultaneously at 108°C for 2h. Subsequently, FA wiped off via vacuum concentration. Finally, iodoacetamide (IAA) alkylation and trypsin digestion could be performed ordinally. A series of model proteins (BSA, β-lactoglobulin and apo-Transferrin) were treated respectively using such method, followed by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) analysis. The identified peptide number was increased by ∼ 80% in comparison with the conventional urea-assisted sample preparation method. Moreover, BSA identification was achieved efficiently down to femtomole (25 ± 0 sequence coverage and 16 ± 1 peptides) via such method. In contrast, there were not peptides identified confidently via the urea-assisted method before desalination via the C18 zip tip. The absence of urea in this sample preparation method was an advantage for the more favorable digestion and MALDI-TOF MS analysis. The performances of two methods for the real sample (rat liver proteome) were also compared, followed by a nanoflow reversed-phase liquid chromatography with electrospray ionization tandem mass spectrometry system analysis. As a result, 1335 ± 43 peptides were identified confidently (false discovery rate <1%) via FA-assisted method, corresponding to 295 ± 12 proteins (of top match=1 and requiring 2 unique peptides at least). In contrast, there were only 1107 ± 16 peptides (corresponding to 231 ± 10 proteins) obtained from the conventional urea-assisted method. It was serving as a more efficient protein sample preparation method for researching specific proteomes better, and providing assistance to develop other proteomics analysis methods

Nucleic Acid Detection Methods

DOEpatents

Smith, Cassandra L.; Yaar, Ron; Szafranski, Przemyslaw; Cantor, Charles R.

1998-05-19

The invention relates to methods for rapidly determining the sequence and/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3'-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be easily distinguish from nuclease uncleaved heteroduplexes by differential labeling. Probes and target can be differentially labeled with detectable labels. Matched target can be detected by cleaving resulting loops from the hybridized target and creating free 3-hydroxyl groups. These groups are recognized and extended by polymerases added into the reaction system which also adds or releases one label into solution. Analysis of the resulting products using either solid phase or solution. These methods can be used to detect characteristic nucleic acid sequences, to determine target sequence and to screen for genetic defects and disorders. Assays can be conducted on solid surfaces allowing for multiple reactions to be conducted in parallel and, if desired, automated.

Nucleic acid detection methods

DOEpatents

Smith, C.L.; Yaar, R.; Szafranski, P.; Cantor, C.R.

1998-05-19

The invention relates to methods for rapidly determining the sequence and/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3{prime}-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be easily distinguish from nuclease uncleaved heteroduplexes by differential labeling. Probes and target can be differentially labeled with detectable labels. Matched target can be detected by cleaving resulting loops from the hybridized target and creating free 3-hydroxyl groups. These groups are recognized and extended by polymerases added into the reaction system which also adds or releases one label into solution. Analysis of the resulting products using either solid phase or solution. These methods can be used to detect characteristic nucleic acid sequences, to determine target sequence and to screen for genetic defects and disorders. Assays can be conducted on solid surfaces allowing for multiple reactions to be conducted in parallel and, if desired, automated. 18 figs.

STATISTICAL VALIDATION OF SULFATE QUANTIFICATION METHODS USED FOR ANALYSIS OF ACID MINE DRAINAGE

EPA Science Inventory

Turbidimetric method (TM), ion chromatography (IC) and inductively coupled plasma atomic emission spectrometry (ICP-AES) with and without acid digestion have been compared and validated for the determination of sulfate in mining wastewater. Analytical methods were chosen to compa...

β-Lactoglobulin-linoleate complexes: In vitro digestion and the role of protein in fatty acid uptake.

PubMed

Le Maux, Solène; Brodkorb, André; Croguennec, Thomas; Hennessy, Alan A; Bouhallab, Saïd; Giblin, Linda

2013-07-01

The dairy protein β-lactoglobulin (BLG) is known to bind fatty acids such as the salt of the essential longchain fatty acid linoleic acid (cis,cis-9,12-octadecadienoic acid, n-6, 18:2). The aim of the current study was to investigate how bovine BLG-linoleate complexes, of various stoichiometry, affect the enzymatic digestion of BLG and the intracellular transport of linoleate into enterocyte-like monolayers. Duodenal and gastric digestions of the complexes indicated that BLG was hydrolyzed more rapidly when complexed with linoleate. Digested as well as undigested BLG-linoleate complexes reduced intracellular linoleate transport as compared with free linoleate. To investigate whether enteroendocrine cells perceive linoleate differently when part of a complex, the ability of linoleate to increase production or secretion of the enteroendocrine satiety hormone, cholecystokinin, was measured. Cholecystokinin mRNA levels were different when linoleate was presented to the cells alone or as part of a protein complex. In conclusion, understanding interactions between linoleate and BLG could help to formulate foods with targeted fatty acid bioaccessibility and, therefore, aid in the development of food matrices with optimal bioactive efficacy. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Does the commonly used pH-stat method with back titration really quantify the enzymatic digestibility of lipid drug delivery systems? A case study on solid lipid nanoparticles (SLN).

PubMed

Heider, Martha; Hause, Gerd; Mäder, Karsten

2016-12-01

Enzymatic digestion of lipid drug carriers is very important. Commonly, pancreatin induced formation of fatty acids is monitored by the pH-stat method, which provides a fast, but unspecific readout. However, according to the literature, the pKa values of long chain fatty acids are strongly dependent on the local environment and might vary between 4.2 and 10.15. The high pKa values would lead to an incomplete detection of the lipid digestion and false results. In order to investigate these issues in more detail, we produced cetyl palmitate solid lipid nanoparticles (CP-SLN) stabilized with poloxamer 188 or polysorbate 80. The digestion of CP-SLN was investigated by two different and independent readouts. A HPTLC assay was used in addition to the pH-stat method (with or without back titration). An incomplete digestion of CP-SLN was observed with all methods. Partial digestion of polysorbate 80 contributed to the formation of fatty acids. Depending on the investigated system and the experimental conditions (FaSSIF or FeSSIF) the results of both readout methods were comparable or not. For example, in FeSSIF conditions, the values detected by HPTLC were roughly twice as high as the pH-stat results. Our findings on solid lipids agree with data from Helbig et al. on lipid emulsions, where a gas chromatography method detected much higher values than the pH-stat assay (Food Hydrocoll. 28 (2012) 10-19). The results of our pH-stat experiments with back titration at different pH values showed increased values for fatty acids from pH 7.5 to pH 10. The values obtained by back titration at high pH values (pH 9 or higher) did exceed the digestion values measured by HPTLC. Therefore, we conclude that the pH-stat method might give the same results as more specific reference methods, but it might also both under- (without back titration) or overestimate (with back titration) the enzymatic digestion of lipid drug delivery systems. A further outcome of our study was the proof that

Amino acid digestibility of different rye genotypes in caecectomised laying hens.

PubMed

Zuber, Tobias; Miedaner, Thomas; Rosenfelder, Pia; Rodehutscord, Markus

2016-12-01

This study investigated the variability of amino acid (AA) digestibility of rye grains in laying hens. Relationships between AA digestibility and physical properties (thousand seed weight, test weight, falling number, and extract viscoelasticity), chemical composition (proximate nutrients, non-starch polysaccharides, AA, minerals, and inositol phosphates), gross energy concentration, and in vitro solubility of nitrogen (N) of the grains were also examined. Twenty rye genotypes were grown under standardised agronomic and environmental conditions as part of a collaborative research project known as "GrainUp". Each genotype was added to a basal diet at 500 g/kg at the expense of maize starch to produce 20 rye diets. The experimental design comprised four Latin Squares (6 × 6) distributed over two runs, resulting in 12 experimental periods. Caecectomised laying hens (LSL-Classic) were individually kept in metabolism cages. Excreta were collected quantitatively for 4 d, and AA digestibility of the rye genotypes was determined using a regression approach. The digestibility of AA was generally low but varied significantly among the 20 rye genotypes, especially for Lys (digestibility range 35-59%), Met (57-75%), Thr (34-54%), and Trp (36-71%). Nevertheless, physical and chemical characteristics as well as the in vitro solubility of N correlated in only a few cases with AA digestibility. Multiple linear regression was used to calculate equations to predict AA digestibility based on the analysed characteristics. However, their explanatory power, as judged by the adjusted R(2), was not sufficiently precise for practical application (below 0.6 for most AA). In conclusion, the AA digestibility of rye grain is generally low and varies significantly between crop genotypes. Equations based on its physical and chemical characteristics are not sufficiently precise to be useful for feed formulation.

Microbial release of ferulic and p-coumaric acids from forages and their digestibility in lactating cows fed total mixed rations with different forage combinations.

PubMed

Cao, Bin-Bin; Jin, Xin; Yang, Hong-Jian; Li, Sheng-Li; Jiang, Lin-Shu

2016-01-30

Ferulic acid (FA) and p-coumaric acid (PCA) are widely distributed in graminaceous plant cell walls. This study investigated the in vitro and in vivo digestibility of ester-linked FA (FAest) and PCA (PCAest) in lactating dairy cows. Regarding corn stover, ensiled corn stover, whole corn silage, Chinese wild ryegrass and alfalfa hay with different phenolic acid profiles, the in vitro rumen digestibility of forage FAest and PCAest was negatively correlated with the ether-linked FA content and original PCA/FA ratio in the forages. The concentration of both phenolic acids in culture fluids was low after a 72 h incubation, and the mixed rumen microorganisms metabolized nearly all phenolic acids released into the culture fluids. FAest digestibility in the whole digestive tract was negatively correlated with dietary PCA/FA ratio, but a converse result occurred with dietary PCAest digestibility. The digestibility in either the rumen or the whole digestive tract was greater for FAest than for PCAest. Forage PCAest in comparison with FAest is not easily digested in either the rumen or the whole digestive tract, and they were negatively affected by forage FAeth content and lignification extent indicated by the original dietary PCA/FA ratio. © 2015 Society of Chemical Industry.

Optimization of microwave digestion for mercury determination in marine biological samples by cold vapour atomic absorption spectrometry.

PubMed

Cardellicchio, Nicola; Di Leo, Antonella; Giandomenico, Santina; Santoro, Stefania

2006-01-01

Optimization of acid digestion method for mercury determination in marine biological samples (dolphin liver, fish and mussel tissues) using a closed vessel microwave sample preparation is presented. Five digestion procedures with different acid mixtures were investigated: the best results were obtained when the microwave-assisted digestion was based on sample dissolution with HNO3-H2SO4-K2Cr2O7 mixture. A comparison between microwave digestion and conventional reflux digestion shows there are considerable losses of mercury in the open digestion system. The microwave digestion method has been tested satisfactorily using two certified reference materials. Analytical results show a good agreement with certified values. The microwave digestion proved to be a reliable and rapid method for decomposition of biological samples in mercury determination.

Determination of total lead in lipstick: development and validation of a microwave-assisted digestion, inductively coupled plasma-mass spectrometric method.

PubMed

Hepp, Nancy M; Mindak, William R; Cheng, John

2009-01-01

Recent reports describing the presence of lead (Pb) in lipsticks have suggested that, under ordinary use, the potential amount of Pb exposure is harmful. To permit independent assessment of the Pb contamination, a method for determining total Pb in lipstick using microwave-assisted digestion and analysis employing inductively coupled plasma-mass spectrometry (ICP-MS) was developed and validated. Since lipsticks may contain fats, oils, pigments, dyes, and minerals, several reference materials (RM) were analyzed, including coal, wear metals in oil, organic Pb in oil, milk powder, and estuarine sediment. With the exception of the RM with mineral content (estuarine sediment), complete recovery of Pb from the RMs was obtained by simple nitric acid (HNO(3)) digestion. Complete recovery of Pb from estuarine sediment was achieved only when hydrofluoric acid (HF) was added to the digestion mix, followed by treatment with excess boric acid (H(3)BO(3)) to neutralize the HF and to dissolve insoluble fluorides. Commercial lipsticks were tested for total Pb by the validated method. The detection limit was estimated to be 0.04 microg Pb/g. The average value obtained for the lipsticks was 1.07 microg/g. Undigested material was present in some lipstick digests when only HNO(3) was used, and generally lower Pb values were obtained. All of the Pb levels found by the U.S. Food and Drug Administration (FDA) were within the range the agency would expect to find in lipsticks formulated with permitted color additives and other ingredients prepared under good manufacturing practice (GMP) conditions. This method will be useful for the FDA and industry in helping to ensure the safety of cosmetic products.

[Comparison of two nucleic acid extraction methods for norovirus in oysters].

PubMed

Yuan, Qiao; Li, Hui; Deng, Xiaoling; Mo, Yanling; Fang, Ling; Ke, Changwen

2013-04-01

To explore a convenient and effective method for norovirus nucleic acid extraction from oysters suitable for long-term viral surveillance. Two methods, namely method A (glycine washing and polyethylene glycol precipitation of the virus followed by silica gel centrifugal column) and method B (protease K digestion followed by application of paramagnetic silicon) were compared for their performance in norovirus nucleic acid extraction from oysters. Real-time RT-PCR was used to detect norovirus in naturally infected oysters and in oysters with induced infection. The two methods yielded comparable positive detection rates for the samples, but the recovery rate of the virus was higher with method B than with method A. Method B is a more convenient and rapid method for norovirus nucleic acid extraction from oysters and suitable for long-term surveillance of norovirus.

Effect of acid hydrolysis on morphology, structure and digestion property of starch from Cynanchum auriculatum Royle ex Wight.

PubMed

Wang, Xingchi; Wen, Fanting; Zhang, Shurong; Shen, Ruru; Jiang, Wei; Liu, Jun

2017-03-01

Effect of acid hydrolysis on the morphology, structure and digestion property of starch from Cynanchum auriculatum Royle ex Wight was investigated in this study. The hydrolysis degree of C. auriculatum starch rapidly increased to 63.69% after 4days and reached 78.67% at the end of 9days. Morphology observation showed that the starch granules remained intact during the first 4days of hydrolysis. However, serious erosion phenomenon was observed after 5days and starch granules completely fell into pieces after 7days. During acid hydrolysis process, the crystal type of hydrolyzed starch changed from original C B -type to final A-type. Small-angle X-ray scattering patterns showed the semi-crystalline growth rings started to be hydrolyzed after 4days. The proportions of single helix and amorphous components as well as amylose content in starch gradually decreased, whereas the proportion of double helix components continuously increased during acid hydrolysis. However, the contents of rapidly digestible starch, slowly digestible starch and resistant starch were almost constant during acid hydrolysis process, indicating the in vitro digestion property of C. auriculatum starch was not affected by acid hydrolysis. Our results provided novel information on the inner structure of C. auriculatum starch granules. Copyright © 2017 Elsevier B.V. All rights reserved.

Anaerobic digestion of tuna waste for the production of volatile fatty acids.

PubMed

Bermúdez-Penabad, Noela; Kennes, Christian; Veiga, Maria C

2017-10-01

Fish canning industries generate a significant amount of solid waste that can be digested anaerobically into volatile fatty acids (VFA). The aim of this research was to study the effect of various pHs, ranging from 5.0 to 10.0, and percentage of total solids on the anaerobic digestion of tuna waste into VFA, both in batch assays and continuous reactor. The production of VFA was affected by pH and was significantly higher under alkaline conditions. At pH 8.0, the VFA production reached 30,611mgCOD/L. The VFA mainly consisted of acetic, propionic, n-butyric and i-valeric acids. Acetic acid was the main product at all the pHs tested. In terms of total solids (TS) the best results were obtained with 2.5% total solids, reaching 0.73gCOD VFA /gCOD waste . At higher TS concentrations (5 and 8% TS) lower yields were reached probably due to inhibition at high VFA concentration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of calcium on fatty acid bioaccessibility during in vitro digestion of Cheddar-type cheeses prepared with different milk fat fractions.

PubMed

Ayala-Bribiesca, Erik; Turgeon, Sylvie L; Britten, Michel

2017-04-01

Calcium plays an important role in intestinal lipid digestion by increasing the lipolysis rate, but also limits fatty acid bioaccessibility by producing insoluble Ca soaps with long-chain fatty acids at intestinal pH conditions. The aim of this study was to better understand the effect of Ca on the bioaccessibility of milk fat from Cheddar-type cheeses. Three anhydrous milk fats (AMF) with different fatty acid profiles (olein, stearin, or control AMF) were used to prepare Cheddar-type cheeses, which were then enriched or not with Ca using CaCl 2 during the salting step. The cheeses were digested in vitro, and their disintegration and lipolysis rates were monitored during the process. At the end of digestion, lipids were extracted under neutral and acidic pH conditions to compare free fatty acids under intestinal conditions in relation to total fatty acids released during the digestion process. The cheeses prepared with the stearin (the AMF with the highest ratio of long-chain fatty acids) were more resistant to disintegration than the other cheeses, owing to the high melting temperature of that AMF. The Ca-enriched cheeses had faster lipolysis rates than the regular Ca cheeses. Chromatographic analysis of the digestion products showed that Ca interacted with long-chain fatty acids, producing Ca soaps, whereas no interaction with shorter fatty acids was detected. Although higher Ca levels resulted in faster lipolysis rates, driven by the depletion of reaction products as Ca soaps, such insoluble compounds are expected to reduce the bioavailability of fatty acids by hindering their absorption. These effects on lipid digestion and absorption are of interest for the design of food matrices for the controlled release of fat-soluble nutrients or bioactive molecules. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Intestinal digestibility of long-chain fatty acids in lactating dairy cows: A meta-analysis and meta-regression.

PubMed

Boerman, J P; Firkins, J L; St-Pierre, N R; Lock, A L

2015-12-01

The objective of this analysis was to examine the intestinal digestibility of individual long-chain fatty acids (FA) in lactating dairy cows. Available data were collated from 15 publications containing 61 treatments, which reported total and individual FA duodenal flows and calculations of intestinal digestibility. All studies involved lactating dairy cows, and estimates of digestibility were based on measurements either between the duodenum and ileum (18 treatments) or between the duodenum and feces (43 treatments). Fatty acid digestibility was calculated for C16:0, C18:0, C18:1 (cis and trans isomers), C18:2, and C18:3. Digestibility of C18:0 was lower than for C18:1 and C18:3, with no difference in digestibility between saturated FA (C16:0 and C18:0). We weighted the studies by the reciprocal of the variance to generate best-fit equations to predict individual FA digestibility based on duodenal flow of FA and dietary independent variables. The flow of C18:0 negatively affected the digestibility of C18:0 and was also included in the best-fit equations for all other 18-carbon FA using duodenal flow characteristics. The type of fat supplemented had an effect on digestibility of individual FA, with whole seeds having reduced digestibility. Our meta-analysis results showed minimal differences in the digestibility of individual FA. However, C18:0 flow through the duodenum had a negative effect on the digestibility of several individual FA, with the largest negative effect on C18:0 digestibility. The mechanisms that reduce C18:0 absorption at high concentrations are unknown and warrant further investigation. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The effect of drying method temperature, collection method, and marker type on apparent ileal amino acid digestibility in 21-day-old broilers fed corn-soybean meal-barley based diet.

PubMed

Olojede, O C; Ford, M J; Jacob, J P; Ao, T; Pescatore, A J; Adedokun, S A

2018-06-01

For accurate estimation of nutrient digestibility, an ideal drying and sampling method is required to preserve the quality of the digesta. A standard corn-soybean meal (corn-SBM) broiler starter diet was fed from d 0 to 10 before birds were placed on the experimental diets until d 21. One hundred and sixty-eight male Cobb 500 broiler chicks were used to evaluate the effect of two drying methods (freeze-dryer vs. forced air-oven) and two drying temperatures (40 vs. 55°C) (Exp 1), while ninety-six chicks were used to evaluate the effect of flushing and squeezing as well as marker types (titanium vs. chromium) on apparent ileal DM, N, Ca, P, and AA digestibility (Exp 2). There were seven (Exp 1) or eight (Exp 2) replicate cages per treatment with 6 birds/cage. Digesta from the distal two thirds of the ileum was obtained from birds following euthanasia on d 21 by squeezing (Exp 1) and squeezing or flushing (Exp 2). Samples collected were stored in the freezer at -20°C until they were either freeze-dried (FD) or oven-dried (OD) at 40 or 55°C. There were no interactions between the drying methods and drying temperatures (Exp 1) on apparent ileal DM, N, and AA digestibility. Met had the highest (92.3%) while Cys had the lowest (73.8%) digestibility value. In Exp 2, no interaction between sampling methods and marker types was observed. The effect of sampling methods was not significant except for Arg and Met where squeezing resulted in higher (P < 0.05) digestibility values. Furthermore, apparent ileal His, Ile, Cys, Ser, and Tyr digestibility tended to be higher (P < 0.1) in squeezed digesta compared to the flushed digesta. Results from these studies showed that OD ileal digesta at 40 or 55°C had no negative effect on apparent ileal AA digestibility. Likewise, marker type did not influence apparent ileal AA digestibility values.

Accumulation of propionic acid during consecutive batch anaerobic digestion of commercial food waste.

PubMed

Capson-Tojo, Gabriel; Ruiz, Diane; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Bernet, Nicolas; Delgenès, Jean-Philippe; Escudié, Renaud

2017-12-01

The objective of this study was to test three different alternatives to mitigate the destabilizing effect of accumulation of ammonia and volatile fatty acids during food waste anaerobic digestion. The three options tested (low temperature, co-digestion with paper waste and trace elements addition) were compared using consecutive batch reactors. Although methane was produced efficiently (∼500ml CH 4 gVS -1 ; 16l CH 4 lreactor -1 ), the concentrations of propionic acid increased gradually (up to 21.6gl -1 ). This caused lag phases in the methane production and eventually led to acidification at high substrate loads. The addition of trace elements improved the kinetics and allowed higher substrate loads, but could not avoid propionate accumulation. Here, it is shown for the first time that addition of activated carbon, trace elements and dilution can favor propionic acid consumption after its accumulation. These promising options should be optimized to prevent propionate accumulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Developing a vacuum thermal stripping - acid absorption process for ammonia recovery from anaerobic digester effluent.

PubMed

Ukwuani, Anayo T; Tao, Wendong

2016-12-01

To prevent acetoclastic methanogens from ammonia inhibition in anaerobic digestion of protein-rich substrates, ammonia needs to be removed or recovered from digestate. This paper presents an innovative ammonia recovery process that couples vacuum thermal stripping with acid absorption. Ammonia is stripped out of digestate boiling at a temperature below the normal boiling point due to vacuum. Stripped ammonia is absorbed to a sulfuric acid solution, forming ammonium sulfate crystals as a marketable product. Three common types of digestate were found to have boiling point temperature-vacuum curves similar to water. Seven combinations of boiling temperature and vacuum (50 °C 16.6 kPa, 58 °C 20.0 kPa, 65 °C 25.1 kPa, 70 °C 33.6 kPa, 80 °C 54.0 kPa, 90 °C 74.2 kPa, and 100 °C 101.3 kPa) were tested for batch stripping of ammonia in dairy manure digestate. 93.3-99.9% of ammonia was stripped in 3 h. The Lewis-Whitman model fitted ammonia stripping process well. Ammonia mass transfer coefficient was significantly higher at boiling temperature 65-100 °C and vacuum pressure 25.1-101.3 kPa than 50-58 °C and 16.6-20.0 kPa. The low ammonia saturation concentrations (0-24 mg N/L) suggested a large driving force to strip ammonia. The optimum boiling point temperature - vacuum pressure for ammonia recovery in a recirculation line of a mesophilic digester was 65 °C and 25.1 kPa, at which the ammonia mass transfer coefficient was as high as 37.3 mm/h. Installation of a demister and liquid trap could avoid negative effects of higher stripping temperature and stronger vacuum on formation of ammonium sulfate crystals. Pilot tests demonstrated that high-purity ammonium sulfate crystals could be produced by controlling sulfuric acid content and maintaining acid solution saturated with ammonium sulfate. Although volatile organic compounds such as cyclohexene were found in the final acid solutions, no volatile organic compounds were found in the recovered

Comparative ileal amino acid digestibility of distillers' grains for growing pigs.

PubMed

Adeola, Olayiwola; Ragland, Darryl

2016-12-01

The objective of the experiment reported here was to investigate and compare the amino acid (AA) digestibility of distillers' dried grains (DDG), distillers' dried grains with solubles (DDGS), high protein distillers' dried grains (HP-DDG), and high protein distillers' dried grains with solubles (HP-DDGS) in growing pigs. Five semi-purified diets consisting of DDG, DDGS, HP-DDG, HP-DDGS, and nitrogen-free diet (NFD) were fed to pigs fitted with simple T-cannula for 5 observations per diet. Endogenous losses of AA at the terminal ileum of pigs that received the NFD were used to calculate standardized ileal digestibility (SID) of AA from apparent ileal digestibility (AID) of AA. The AID of Lys in DDGS was lower ( P  < 0.05) than that in DDG, which was also lower ( P  < 0.05) than that in HP-DDG. There were no differences in AID of Met among DDG, DDGS and HP-DDGS, but was greater ( P  < 0.05) in HP-DDG than in DDG or DDGS. The AID of Thr in HP-DDG was greater ( P  < 0.05) than that in DDGS but not different from that in DDG or HP-DDGS. The branched-chain AA Ile and Leu had greater ( P  < 0.05) AID in HP-DDG than in DDG, DDGS or HP-DDGS, and there was no difference among DDG, DDGS, and HP-DDGS. The AID of Trp in DDG and DDGS or HP-DDG and HP-DDGS were not different, but the AID of Trp in HP-DDGS was greater ( P  < 0.05) than that of DDGS. The greatest SID of the indispensable AA was in HP-DDG. Except for Arg and Lys in which DDG had greater ( P  < 0.05) digestibility, there was no difference between DDG and DDGS in the SID of the indispensable AA. The SID of Lys in DDG was greater ( P  < 0.05) than that of DDGS but there was no difference between that of DDG and HP-DDGS. Only His, Ile, and Met had lower ( P  < 0.05) SID in HP-DDGS than HP-DDG within the indispensable AA. The SID of Ala, Asp, Cys, Glu, Gly, Ser and Tyr were lower ( P  < 0.05) in DDGS than in HP-DDG. There SID of dispensable AA in DDG was not different from that of HP-DDGS. The

Low temperature vapor phase digestion of graphite

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

Pierce, Robert A.

2017-04-18

A method for digestion and gasification of graphite for removal from an underlying surface is described. The method can be utilized to remove graphite remnants of a formation process from the formed metal piece in a cleaning process. The method can be particularly beneficial in cleaning castings formed with graphite molding materials. The method can utilize vaporous nitric acid (HNO.sub.3) or vaporous HNO.sub.3 with air/oxygen to digest the graphite at conditions that can avoid damage to the underlying surface.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; in-bottle acid digestion of whole-water samples

USGS Publications Warehouse

Hoffman, G.L.; Fishman, M. J.; Garbarino, J.R.

1996-01-01

Water samples for trace-metal determinations routinely have been prepared in open laboratories. For example, the U.S. Geological Survey method I-3485-85 (Extraction Procedure, for Water- Suspended Sediment) is performed in a laboratory hood on a laboratory bench without any special precautions to control airborne contamination. This method tends to be contamination prone for several trace metals primarily because the samples are transferred, acidified, digested, and filtered in an open laboratory environment. To reduce trace-metal contamination of digested water samples, procedures were established that rely on minimizing sample-transfer steps and using a class-100 clean bench during sample filtration. This new procedure involves the following steps: 1. The sample is acidified with HCl directly in the original water-sample bottle. 2. The water-sample bottle with the cap secured is heated in a laboratory oven. 3. The digestate is filtered in a class-100 laminar-flow clean bench. The exact conditions used (that is, oven temperature, time of heating, and filtration methods) for this digestion procedure are described. Comparisons between the previous U.S Geological Survey open-beaker method I-3485-85 and the new in-bottle procedure for synthetic and field-collected water samples are given. When the new procedure is used, blank concentrations for most trace metals determined are reduced significantly.

The Effect of Acid Pre-Treatment using Acetic Acid and Nitric Acid in The Production of Biogas from Rice Husk during Solid State Anaerobic Digestion (SS-AD)

NASA Astrophysics Data System (ADS)

Nugraha, Winardi Dwi; Syafrudin; Keumala, Cut Fadhila; Matin, Hasfi Hawali Abdul; Budiyono

2018-02-01

Pretreatment during biogas production aims to assist in degradation of lignin contained in the rice husk. In this study, pretreatment which is used are acid and biological pretreatment. Acid pretreatment was performed using acetic acid and nitric acid with a variety levels of 3% and 5%. While biological pretreatment as a control variable. Acid pretreatment was conducted by soaking the rice straw for 24 hours with acid variation. The study was conducted using Solid State Anaerobic Digestion (SS-AD) with 21% TS. Biogas production was measured using water displacement method every two days for 60 days at room temperature conditions. The results showed that acid pretreatment gave an effect on the production of biogas yield. The yield of the biogas produced by pretreatment of acetic acid of 5% and 3% was 43.28 and 45.86 ml/gr.TS. While the results without pretreatment biogas yield was 29.51 ml/gr.TS. The results yield biogas produced by pretreatment using nitric acid of 5% and 3% was 12.14 ml/gr.TS and 21.85 ml/gr.TS. Results biogas yield with acetic acid pretreatment was better than the biogas yield results with nitric acid pretreatment.

Application of Methanobrevibacter acididurans in anaerobic digestion.

PubMed

Savant, D V; Ranade, D R

2004-01-01

To operate anaerobic digesters successfully under acidic conditions, hydrogen utilizing methanogens which can grow efficiently at low pH and tolerate high volatile fatty acids (VFA) are desirable. An acid tolerant hydrogenotrophic methanogen viz. Methanobrevibacter acididurans isolated from slurry of an anaerobic digester running on alcohol distillery wastewater has been described earlier by this lab. This organism could grow optimally at pH 6.0. In the experiments reported herein, M. acididurans showed better methanogenesis under acidic conditions with high VFA, particularly acetate, than Methanobacterium bryantii, a common hydrogenotrophic inhabitant of anaerobic digesters. Addition of M. acididurans culture to digesting slurry of acidogenic as well as methanogenic digesters running on distillery wastewater showed increase in methane production and decrease in accumulation of volatile fatty acids. The results proved the feasibility of application of M. acididurans in anaerobic digesters.

Nutrient digestibility and milk production responses to increasing levels of palmitic acid supplementation vary in cows receiving diets with or without whole cottonseed.

PubMed

Rico, J E; de Souza, J; Allen, M S; Lock, A L

2017-01-01

Our study evaluated the dose-dependent effects of a palmitic acid-enriched supplement in basal diets with or without the inclusion of whole cottonseed on nutrient digestibility and production responses of dairy cows. Sixteen Holstein cows (149 ± 56 days in milk) were used in a split plot Latin square design experiment. Cows were blocked by 3.5% fat-corrected milk (FCM) and allocated to a main plot receiving either a basal diet with soyhulls (SH, = 8) or a basal diet with whole cottonseed (CS, = 8) that was fed throughout the experiment. A palmitic acid-enriched supplement (PA 88.5% C16:0) was fed at 0, 0.75, 1.50, or 2.25% of ration DM in a replicated 4 × 4 Latin Square design within each basal diet group. Periods were 14 d with the final 4 d used for data collection. PA dose increased milk fat content linearly, and cubically affected yields of milk fat and 3.5% FCM. The PA dose did not affect milk protein and lactose contents, BW, and BCS, but tended to increase yields of milk, milk protein, and milk lactose. Also, PA dose reduced DMI and 16-carbon fatty acid digestibility quadratically, and increased 18-carbon fatty acid digestibility quadratically. There were no effects of basal diet on the yield of milk or milk components, but DMI tended to decrease in CS compared with SH, increasing feed efficiency (3.5% FCM/DMI). Compared with SH, CS diets increased yield of preformed milk fatty acids and 16-carbon fatty acid digestibility, and tended to decrease 18-carbon fatty acid digestibility. We observed basal diet × PA dose interactions for yields of milk and milk protein and for 16-carbon and total fatty acid digestibility, as well as tendency for yields of milk fat and 3.5% FCM. Also, there was a tendency for an interaction between basal diet and PA dose for NDF digestibility, which increased more for CS with increasing PA than for SH. PA dose linearly decreased digestibility of total fatty acids in SH diets but did not affect it in CS diets Results demonstrate

[Improved device and method for determination of protein digestibility in vitro].

PubMed

Lipatov, N N; Iudina, S B; Lisitsyn, A B

1994-01-01

The ten-cells device for modelling of ferment hydrolysis of food proteins by acid basic proteases of human alimentary canal is described. The new procedure for the calculation of quantitative characteristic of proteins digestion "in vitro" is presented.

Excretion and detection of SARS coronavirus and its nucleic acid from digestive system

PubMed Central

Wang, Xin-Wei; Li, Jin-Song; Guo, Ting-Kai; Zhen, Bei; Kong, Qing-Xin; Yi, Bin; Li, Zhong; Song, Nong; Jin, Min; Wu, Xiao-Ming; Xiao, Wen-Jun; Zhu, Xiu-Mei; Gu, Chang-Qing; Yin, Jing; Wei, Wei; Yao, Wei; Liu, Chao; Li, Jian-Feng; Ou, Guo-Rong; Wang, Min-Nian; Fang, Tong-Yu; Wang, Gui-Jie; Qiu, Yao-Hui; Wu, Huai-Huan; Chao, Fu-Huan; Li, Jun-Wen

2005-01-01

AIM: To study whether severe acute respiratory syndrome coronavirus (SARS-CoV) could be excreted from digestive system. METHODS: Cell culture and semi-nested RT-PCR were used to detect SARS-CoV and its RNA from 21 stool and urine samples, and a kind of electropositive filter media particles was used to concentrate the virus in 10 sewage samples from two hospitals receiving SARS patients in Beijing in China. RESULTS: It was demonstrated that there was no live SARS-CoV in all samples collected, but the RNA of SARS-CoV could be detected in seven stool samples from SARS patients with any one of the symptoms of fever, malaise, cough, or dyspnea, in 10 sewage samples before disinfection and 3 samples after disinfection from the two hospitals. The RNA could not be detected in urine and stool samples from patients recovered from SARS. CONCLUSION: Nucleic acid of SARS-CoV can be excreted through the stool of patients into sewage system, and the possibility of SARS-CoV transmitting through digestive system cannot be excluded. PMID:16038039

Developing a multipoint titration method with a variable dose implementation for anaerobic digestion monitoring.

PubMed

Salonen, K; Leisola, M; Eerikäinen, T

2009-01-01

Determination of metabolites from an anaerobic digester with an acid base titration is considered as superior method for many reasons. This paper describes a practical at line compatible multipoint titration method. The titration procedure was improved by speed and data quality. A simple and novel control algorithm for estimating a variable titrant dose was derived for this purpose. This non-linear PI-controller like algorithm does not require any preliminary information from sample. Performance of this controller is superior compared to traditional linear PI-controllers. In addition, simplification for presenting polyprotic acids as a sum of multiple monoprotic acids is introduced along with a mathematical error examination. A method for inclusion of the ionic strength effect with stepwise iteration is shown. The titration model is presented with matrix notations enabling simple computation of all concentration estimates. All methods and algorithms are illustrated in the experimental part. A linear correlation better than 0.999 was obtained for both acetate and phosphate used as model compounds with slopes of 0.98 and 1.00 and average standard deviations of 0.6% and 0.8%, respectively. Furthermore, insensitivity of the presented method for overlapping buffer capacity curves was shown.

Relationship between in vitro assays and standardized ileal amino acid digestibility of animal protein meals in broilers.

PubMed

Rochell, S J; Kuhlers, D L; Dozier, W A

2013-01-01

Two identical trials were conducted to determine the relationship of a novel digestive enzyme assay, Poultry Complete IDEA (PC IDEA), and the pepsin digestibility assay with standardized ileal amino acid digestibility (SIAAD) of 20 animal protein meals (APM) fed to broilers from 25 to 30 d of age. Animal protein meals included 10 meat and bone meals (MBM) consisting of bovine, porcine, or mixed bovine and porcine raw materials (BP), and 10 animal protein blends containing animal proteins from various species. Treatments consisted of 20 semi-purified diets containing 1 APM as the sole source of dietary amino acids (AA), and 1 N-free diet to determine endogenous ileal AA flow. With the exception of the N-free diet, diets were formulated to contain 20% CP. In each trial, 756 Ross × Ross 708 male broilers were housed in battery cages and randomly assigned to 21 dietary treatments on d 25 (12 birds per cage; 3 replicate cages), and ileal digesta were collected on d 30 for determination of SIAAD. Pepsin digestibility and PC IDEA were determined for APM samples from each experimental diet (3 replicates per trial; 6 total replicates). Pepsin digestibility and PC IDEA were both correlated (P < 0.001) with SIAAD for each AA. Multiple linear regression of PC IDEA and pepsin digestibility on SIAAD resulted in the following equations: % Lys SIAAD = [-9.65 + (0.38 × % PC IDEA predicted Lys digestibility) + (0.69 × % pepsin digestibility)], % Met SIAAD = [-35.95 + (0.62 × % PC IDEA predicted Met digestibility) + (0.75 × % pepsin digestibility)], % Thr SIAAD = [-77.5 + (0.39 × % PC IDEA predicted Thr digestibility) + (1.37 × % pepsin digestibility)]. Values of R(2) were 0.46, 0.47, and 0.55 for Lys, Met, and Thr, respectively. The relatively low R(2) values may have been due to the limited range in SIAAD observed for the 20 APM, and additional data on APM varying in SIAAD are needed.

Cleaner production of citric acid by recycling its extraction wastewater treated with anaerobic digestion and electrodialysis in an integrated citric acid-methane production process.

PubMed

Xu, Jian; Su, Xian-Feng; Bao, Jia-Wei; Chen, Yang-Qiu; Zhang, Hong-Jian; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

2015-01-01

To solve the pollution problem of extraction wastewater in citric acid production, an integrated citric acid-methane production process was proposed. Extraction wastewater was treated through anaerobic digestion and the anaerobic digestion effluent (ADE) was recycled for the next batch of citric acid fermentation, thus eliminating wastewater discharge and reducing water consumption. Excessive Na(+) contained in ADE could significantly inhibit citric acid fermentation in recycling and was removed by electrodialysis in this paper. Electrodialysis performance was improved after pretreatment of ADE with air stripping and activated carbon adsorption to remove precipitable metal ions and pigments. Moreover, the concentrate water was recycled and mixed with feed to improve the water recovery rate above 95% in electrodialysis treatment, while the dilute water was collected for citric acid fermentation. The removal rate of Na(+) in ADE was above 95% and the citric acid production was even higher than that with tap water. Copyright © 2015 Elsevier Ltd. All rights reserved.

Starch digestibility: past, present, and future.

PubMed

Bello-Perez, Luis A; Flores-Silva, Pamela C; Agama-Acevedo, Edith; Tovar, Juscelino

2018-02-10

In the last century, starch present in foods was considered to be completely digested. However, during the 1980s, studies on starch digestion started to show that besides digestible starch, which could be rapidly or slowly hydrolysed, there was a variable fraction that resisted hydrolysis by digestive enzymes. That fraction was named resistant starch (RS) and it encompasses those forms of starch that are not accessible to human digestive enzymes but can be fermented by the colonic microbiota, producing short-chain fatty acids. RS has been classified into five types, depending on the mechanism governing its resistance to enzymatic hydrolysis. Early research on RS was focused on the methods to determine its content in foods and its physiological effects, including fermentability in the large intestine. Later on, due to the interest of the food industry, methods to increase the RS content of isolated starches were developed. Nowadays, the influence of RS on the gut microbiota is a relevant research topic owing to its potential health-related benefits. This review summarizes over 30 years of investigation on starch digestibility, its relationship with human health, the methods to produce RS and its impact on the microbiome. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Estimating Apparent Nutrient Digestibility of Diets Containing Leucaena leucocephala or Moringa oleifera Leaf Meals for Growing Rabbits by Two Methods

PubMed Central

Safwat, A. M.; Sarmiento-Franco, L.; Santos-Ricalde, R. H.; Nieves, D.; Sandoval-Castro, C. A.

2015-01-01

This study aimed to evaluate the nutrient digestibility of growing rabbits fed diets with different levels of either Leucaena leucocephala (LLM) or Moringa oleifera (MOLM) leaf meals and also to compare total collection and TiO2 marker methods for estimating digestibility. A total of 30 California growing rabbits (1.81±0.19 kg live weight on average) were randomly distributed into five experimental groups of six rabbits each and were housed in individual cages. The groups were control, 30% LLM, 40% LLM, 30% MOLM, and 40% MOLM. All groups received pelleted diets for two weeks; diets also contained 4 g/kg titanium dioxide as dietary marker. Daily feed intake was recorded during the whole experimental period and total feces were collected daily and weighed individually during four days. The results showed that there were no difference (p>0.05) in feed, dry matter (DM), organic matter (OM), crude protein (CP), digestible energy, and crude fiber (CF) intake between the control group and the other experimental groups. The apparent digestibility values of DM, OM, CP, CF, acid detergent fiber, and gross energy were the highest for control group (p = 0.001), meanwhile MOLM diets had generally higher nutrient digestibility coefficients than LLM diets. Increasing the inclusion level of leaf meal in the diet from 30% to 40% improved the digestibility of CF from 45.02% to 51.69% for LLM and from 48.11% to 55.89% for MOLM. Similar results for apparent nutrient digestibility coefficients were obtained when either total collection or indigestible marker method was used. In conclusion, the digestibility of MOLM containing diets were better than LLM diets, furthermore TiO2 as an external marker could be used as a simple, practical and reliable method to estimate nutrients digestibility in rabbit diets. PMID:26104524

Estimating Apparent Nutrient Digestibility of Diets Containing Leucaena leucocephala or Moringa oleifera Leaf Meals for Growing Rabbits by Two Methods.

PubMed

Safwat, A M; Sarmiento-Franco, L; Santos-Ricalde, R H; Nieves, D; Sandoval-Castro, C A

2015-08-01

This study aimed to evaluate the nutrient digestibility of growing rabbits fed diets with different levels of either Leucaena leucocephala (LLM) or Moringa oleifera (MOLM) leaf meals and also to compare total collection and TiO2 marker methods for estimating digestibility. A total of 30 California growing rabbits (1.81±0.19 kg live weight on average) were randomly distributed into five experimental groups of six rabbits each and were housed in individual cages. The groups were control, 30% LLM, 40% LLM, 30% MOLM, and 40% MOLM. All groups received pelleted diets for two weeks; diets also contained 4 g/kg titanium dioxide as dietary marker. Daily feed intake was recorded during the whole experimental period and total feces were collected daily and weighed individually during four days. The results showed that there were no difference (p>0.05) in feed, dry matter (DM), organic matter (OM), crude protein (CP), digestible energy, and crude fiber (CF) intake between the control group and the other experimental groups. The apparent digestibility values of DM, OM, CP, CF, acid detergent fiber, and gross energy were the highest for control group (p = 0.001), meanwhile MOLM diets had generally higher nutrient digestibility coefficients than LLM diets. Increasing the inclusion level of leaf meal in the diet from 30% to 40% improved the digestibility of CF from 45.02% to 51.69% for LLM and from 48.11% to 55.89% for MOLM. Similar results for apparent nutrient digestibility coefficients were obtained when either total collection or indigestible marker method was used. In conclusion, the digestibility of MOLM containing diets were better than LLM diets, furthermore TiO2 as an external marker could be used as a simple, practical and reliable method to estimate nutrients digestibility in rabbit diets.

Methods for producing extracted and digested products from pretreated lignocellulosic biomass

DOEpatents

Chundawat, Shishir; Sousa, Leonardo Da Costa; Cheh, Albert M.; Balan; , Venkatesh; Dale, Bruce

2017-05-16

Methods for producing extracted and digested products from pretreated lignocellulosic biomass are provided. The methods include converting native cellulose I.sub..beta. to cellulose III.sub.I by pretreating the lignocellulosic biomass with liquid ammonia under certain conditions, and performing extracting or digesting steps on the pretreated/converted lignocellulosic biomass.

Production of citric acid using its extraction wastewater treated by anaerobic digestion and ion exchange in an integrated citric acid-methane fermentation process.

PubMed

Xu, Jian; Chen, Yang-Qiu; Zhang, Hong-Jian; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

2014-08-01

In order to solve the problem of extraction wastewater pollution in citric acid industry, an integrated citric acid-methane fermentation process is proposed in this study. Extraction wastewater was treated by mesophilic anaerobic digestion and then used to make mash for the next batch of citric acid fermentation. The recycling process was done for seven batches. Citric acid production (82.4 g/L on average) decreased by 34.1 % in the recycling batches (2nd-7th) compared with the first batch. And the residual reducing sugar exceeded 40 g/L on average in the recycling batches. Pigment substances, acetic acid, ammonium, and metal ions in anaerobic digestion effluent (ADE) were considered to be the inhibitors, and their effects on the fermentation were studied. Results indicated that ammonium, Na(+) and K(+) in the ADE significantly inhibited citric acid fermentation. Therefore, the ADE was treated by acidic cation exchange resin prior to reuse to make mash for citric acid fermentation. The recycling process was performed for ten batches, and citric acid productions in the recycling batches were 126.6 g/L on average, increasing by 1.7 % compared with the first batch. This process could eliminate extraction wastewater discharge and reduce water resource consumption.

Ileal Amino Acid Digestibility of Broken Rice Fed to Postweaned Piglets with or without Multicarbohydrase and Phytase Supplementation.

PubMed

Dadalt, J C; Gallardo, C; Polycarpo, G V; Budiño, F E L; Rogiewicz, A; Berto, D A; Trindade Neto, M A

2016-10-01

Most of amino acid (AA) digestibility values for feed ingredients are obtained using pigs cannulated in the distal ileum. The ileal-cannulated pig model uses pigs older than six weeks due to difficulties related to implanting the T-cannula in distal ileum of younger pigs and complications during the post-surgical recovery. However, to properly formulate the diet of weaned pigs, the nutritive value of feed ingredients should be determined with younger pigs. Thus, 25 weaned pigs were used to determine the apparent total tract digestibility (ATTD) of nutrients, energy, and apparent ileal digestibility (AID) and standardized ileal digestibility (SID) ileal AA digestibility of broken rice (BR), with or without multicarbohydrase (MC) and phytase (Phy) supplementation. Piglets were weaned at 23 d of age and individually housed in digestibility cages until 45 d of age. The trial consisted of 7 d of adaptation to the experimental diets and 3 d of excreta (feces and urine) collection. Ileal digesta was collected at slaughter (about 6 weeks of age). A completely randomized experimental design was used to determine the effects of MC and Phy. Reference diets (RD, 5% casein) was replaced by 30% of BR with or without MC, Phy, or MC+Phy. The RD was used to quantify endogenous AA losses. BR with Phy supplied had increased the ATTD of dry matter (p<0.05) and SID of histidine (p = 0.05), arginine, leucine, lysine, valine, alanine, and proline (p<0.05). BR with MC had been increased digestible energy and protein and SID for histidine (p<0.05). There was no interaction between Phy and MC on the BR nutrient digestibilities. Standardized amino acid digestibilities of BR, without enzymes, were lower than those values reported in the literature. The MC and Phy improved the digestibility of some nutrients and energy of BR in post-weaned piglet diets.

Structure and function of the digestive system of solen grandis dunker

NASA Astrophysics Data System (ADS)

Sheng, Xiuzhen; Zhan, Wenbin; Ren, Sulian

2003-10-01

Structure and function of the digestive system of a bivalve mollusc, Solen grandis, were studied using light microscopy and histochemical methods. The wall of digestive tube consists of four layers: the mucosal epithelium, connective tissue, muscular and fibrosa or serosa (only in the portion of rectum) from the inner to the outer. The ciliated columnar epithelial cells, dispersed by cup-shaped mucous cells, rest on a thin base membrane. There are abundant blood spaces in connective tissue layer. The digestive diverticula are composed of multi-branched duct and digestive tubules. The digestive tubules are lined with digestive and basophilic secretory cells, and surrounded by a layer of smooth muscle fibers and connective tissues. Activities of acid and alkaline phosphatases, esterase and lipase are detected in the digestive cells, and the epithelia of stomach and intestine, suggesting that these cells are capable of intracellular digesting of food materials and absorbing. Besides, acid phosphatase and esterase activities are present in the posterior portion of esophagus. Phagocytes are abundant in blood spaces and the lumens of stomach and intestine, containing brown granules derived from the engulfed food materials. The present work indicates that phagocytes play important roles in ingestion and digestion of food materials, which is supported as well by the activities of acid phosphatase, esterase and lipase detected in blood spaces.

Nucleic acids digestion by enzymes in the stomach of snakehead (Channa argus) and banded grouper (Epinephelus awoara).

PubMed

Liu, Yu; Zhang, Yanfang; Jiang, Wei; Wang, Jing; Pan, Xiaoming; Wu, Wei; Cao, Minjie; Dong, Ping; Liang, Xingguo

2017-02-01

Dietary nucleic acids (NAs) were important nutrients. However, the digestion of NAs in stomach has not been studied. In this study, the digestion of NAs by enzymes from fish stomach was investigated. The snakehead pepsins (SP) which were the main enzymes in stomach were extracted and purified. The purity of SP was evaluated by SDS-PAGE and HPLC. The snakehead pepsin 2 (SP2) which was the main component in the extracts was used for investigating the protein and NAs digestion activity. SP2 could digest NAs, including λ DNA and salmon sperm DNA. Interestingly, the digestion could be inhibited by treatment of alkaline solution at pH 8.0 and pepstatin A, and the digestion could happen either in the presence or absence of hemoglobin (Hb) and BSA as the protein substrates. Similarly, the stomach enzymes of banded grouper also showed the NAs digestion activity. NAs could be digested by the stomach enzymes of snakehead and banded grouper. It may be helpful for understanding both animal nutrition and NAs metabolic pathway.

Foaming phenomenon in bench-scale anaerobic digesters.

PubMed

Siebels, Amanda M; Long, Sharon C

2013-04-01

The Madison Metropolitan Sewerage District (The District) in Madison, Wisconsin has been experiencing seasonal foaming in their anaerobic biosolids digesters, which has occurred from mid-November to late June for the past few years. The exact cause(s) of foaming is unknown. Previous research findings are unclear as to whether applications of advanced anaerobic digestion processes reduce the foaming potential of digesters. The object of this study was to investigate how configurations of thermophilic and acid phase-thermophilic anaerobic digestion would affect foaming at the bench-scale level compared to single stage mesophilic digestion for The District. Bench-scale anaerobic digesters were fed with a 4 to 4.5% by dry weight of solids content blend of waste activated sludge (WAS) and primary sludge from The District. Foaming potential was monitored using Alka-Seltzer and aeration foaming tests. The bench-scale acid phase-thermophilic digester had a higher foaming potential than the bench-scale mesophilic digester. These results indicate that higher temperatures increase the foaming potential of the bench-scale anaerobic digesters. The bench-scale acid phase-thermophilic digesters had a greater percent (approximately 5 to 10%) volatile solids destruction and a greater percent (approximately 5 to 10%) total solids destruction when compared to the bench-scale mesophilic digester. Overall, for the full-scale foaming experienced by The District, it appears that adding an acid phase or switching to thermophilic digestion would not alleviate The District's foaming issues.

Current perspective on assessing site of digestion in ruminants.

PubMed

Merchen, N R; Elizalde, J C; Drackley, J K

1997-08-01

The site of nutrient digestion in the gastrointestinal tract of ruminants affects nutrient availability and the nature of digestive end-products supplied to the host animal. Methods to study site of digestion in vivo provide a tool to obtain data that enhance the ability to interpret or predict animal responses to some feeding practices. Examples are discussed for which site of digestion data provided insights that might not have been evident from other approaches. The use of site of digestion techniques may provide interpretation regarding digestion of N by ruminants different from those derived from measurement of total tract N digestion. Site of digestion measurements have been particularly important in studying effects of heat processing of protein sources and in understanding the nature of digestion of N in high-quality, fresh forages. Moreover, site of digestion techniques have been instrumental in interpreting the influences of supplemental fat sources on ruminal digestion and ruminal biohydrogenation and small intestinal digestion of long-chain fatty acids.

Acidic mammalian chitinase is a proteases-resistant glycosidase in mouse digestive system.

PubMed

Ohno, Misa; Kimura, Masahiro; Miyazaki, Haruko; Okawa, Kazuaki; Onuki, Riho; Nemoto, Chiyuki; Tabata, Eri; Wakita, Satoshi; Kashimura, Akinori; Sakaguchi, Masayoshi; Sugahara, Yasusato; Nukina, Nobuyuki; Bauer, Peter O; Oyama, Fumitaka

2016-11-24

Chitinases are enzymes that hydrolyze chitin, a polymer of β-1, 4-linked N-acetyl-D-glucosamine (GlcNAc). Chitin has long been considered as a source of dietary fiber that is not digested in the mammalian digestive system. Here, we provide evidence that acidic mammalian chitinase (AMCase) can function as a major digestive enzyme that constitutively degrades chitin substrates and produces (GlcNAc) 2 fragments in the mouse gastrointestinal environment. AMCase was resistant to endogenous pepsin C digestion and remained active in the mouse stomach extract at pH 2.0. The AMCase mRNA levels were much higher than those of four major gastric proteins and two housekeeping genes and comparable to the level of pepsinogen C in the mouse stomach tissues. Furthermore, AMCase was expressed in the gastric pepsinogen-synthesizing chief cells. The enzyme was also stable and active in the presence of trypsin and chymotrypsin at pH 7.6, where pepsin C was completely degraded. Mouse AMCase degraded polymeric colloidal and crystalline chitin substrates in the gastrointestinal environments in presence of the proteolytic enzymes. Thus, AMCase can function as a protease-resistant major glycosidase under the conditions of stomach and intestine and degrade chitin substrates to produce (GlcNAc) 2 , a source of carbon, nitrogen and energy.

Acidic mammalian chitinase is a proteases-resistant glycosidase in mouse digestive system

PubMed Central

Ohno, Misa; Kimura, Masahiro; Miyazaki, Haruko; Okawa, Kazuaki; Onuki, Riho; Nemoto, Chiyuki; Tabata, Eri; Wakita, Satoshi; Kashimura, Akinori; Sakaguchi, Masayoshi; Sugahara, Yasusato; Nukina, Nobuyuki; Bauer, Peter O.; Oyama, Fumitaka

2016-01-01

Chitinases are enzymes that hydrolyze chitin, a polymer of β-1, 4-linked N-acetyl-D-glucosamine (GlcNAc). Chitin has long been considered as a source of dietary fiber that is not digested in the mammalian digestive system. Here, we provide evidence that acidic mammalian chitinase (AMCase) can function as a major digestive enzyme that constitutively degrades chitin substrates and produces (GlcNAc)2 fragments in the mouse gastrointestinal environment. AMCase was resistant to endogenous pepsin C digestion and remained active in the mouse stomach extract at pH 2.0. The AMCase mRNA levels were much higher than those of four major gastric proteins and two housekeeping genes and comparable to the level of pepsinogen C in the mouse stomach tissues. Furthermore, AMCase was expressed in the gastric pepsinogen-synthesizing chief cells. The enzyme was also stable and active in the presence of trypsin and chymotrypsin at pH 7.6, where pepsin C was completely degraded. Mouse AMCase degraded polymeric colloidal and crystalline chitin substrates in the gastrointestinal environments in presence of the proteolytic enzymes. Thus, AMCase can function as a protease-resistant major glycosidase under the conditions of stomach and intestine and degrade chitin substrates to produce (GlcNAc)2, a source of carbon, nitrogen and energy. PMID:27883045

Effects of essential oils on performance, egg quality, nutrient digestibility and yolk fatty acid profile in laying hens.

PubMed

Ding, Xuemei; Yu, Yang; Su, Zhuowei; Zhang, Keying

2017-06-01

The study was conducted to investigate the effect of essential oils on performance, egg quality, nutrient digestibility and yolk fatty acid profile in laying hens. A total of 960 Lohmann laying hens aged 53 weeks were enrolled, under 4 different treatment diets supplemented with 0, 50, 100 and 150 mg/kg essential oils (Enviva EO, Dupont Nutrition Biosciences ApS, Denmark), respectively. Each treatment was replicated 8 times with 30 birds each. Birds were fed dietary treatment diets for 12 weeks (54 to 65 weeks). For data recording and analysis, a 12-week period was divided into 3 periods of 4 weeks' duration each: period 1 (54 to 57 weeks), period 2 (58 to 61 weeks), and period 3 (62 to 65 weeks). For the diet supplemented with Enviva EO, hen-day egg production and the feed conversion ratio (FCR) were significantly improved ( P  < 0.05) at weeks 58 to 61, and the eggshell thickness was significantly increased ( P  < 0.05) at week 65. However, egg production, egg weight, feed intake, FCR and other egg quality parameters (albumen height, Haugh unit, egg yolk color and eggshell strength) were not affected by the dietary treatment. In addition, compared with the control diet, protein digestibility in the 100 mg/kg Enviva EO treatment group was significantly increased ( P  < 0.05), and fat digestibility in the 100 and 150 mg/kg Enviva EO treatment groups was significantly decreased ( P  < 0.05), but Enviva EO had no effect on energy apparent digestibility. Saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) gradually decreased and polyunsaturated fatty acid (PUFA) increased with Enviva EO supplementation, but the difference was not significant. The data suggested that the supplementation of essential oils (Enviva EO) in laying hen diet did not show a significant positive effect on performance and yolk fatty acid composition but it tended to increase eggshell thickness and protein digestibility, especially at the dose of 50 mg/kg.

Digestive system development and study of acid and alkaline protease digestive capacities using biochemical and molecular approaches in totoaba (Totoaba macdonaldi) larvae.

PubMed

Galaviz, Mario A; López, Lus M; García Gasca, Alejandra; Álvarez González, Carlos Alfonso; True, Conal D; Gisbert, Enric

2015-10-01

The present study aimed to describe and understand the development of the digestive system in totoaba (Totoaba macdonaldi) larvae from hatching to 40 days post-hatch (dph) from morphological and functional perspectives. At hatch, the digestive system of totoaba was undifferentiated. The anus and the mouth opened at 4 and 5 dph, respectively. During exogenous feeding, development of the esophagus, pancreas, liver and intestine was observed with a complete differentiation of all digestive organs. Expression and activity of trypsin and chymotrypsin were observed as early as at 1 dph, and increments in their expression and activity coincided with changes in food items (live and compound diets) and morpho-physiological development of the accessory digestive glands. In contrast, pepsin was detected later during development, which includes the appearance of the gastric glands between 24 and 28 dph. One peak in gene expression was detected at 16 dph, few days before the initial development of the stomach at 20 dph. A second peak of pepsin expression was detected at day 35, followed by a peak of activity at day 40, coinciding with the change from live to artificial food. Totoaba larvae showed a fully morphologically developed digestive system between 24 and 28 dph, as demonstrated by histological observations. However, gene expression and activity of alkaline and acid proteases were detected earlier, indicating the functionality of the exocrine pancreas and stomach before the complete morphological development of the digestive organs. These results showed that integrative studies are needed to fully understand the development of the digestive system from a morphological and functional point of views, since the histological organization of digestive structures does not reflect their real functionality. These results indicate that the digestive system of totoaba develops rapidly during the first days post-hatch, especially for alkaline proteases, and the stomach

Different sources of omega-3 polyunsaturated fatty acids affects apparent digestibility, tissue deposition, and tissue oxidative stability in growing female rats

PubMed Central

2011-01-01

Background Numerous health benefits associated with increased omega-3 polyunsaturated fatty acid (n-3 PUFA) consumption has lead to an increasing variety of available n-3 PUFA sources. However, sources differ in the type, amount, and structural form of the n-3 PUFAs. Therefore, the objective of this study was to determine the effect of different sources of ω-3 PUFAs on digestibility, tissue deposition, eicosanoid metabolism, and oxidative stability. Methods Female Sprague-Dawley rats (age 28 d) were randomly assigned (n = 10/group) to be fed a high fat 12% (wt) diet consisting of either corn oil (CO) or n-3 PUFA rich flaxseed (FO), krill (KO), menhaden (MO), salmon (SO) or tuna (TO) oil for 8 weeks. Rats were individually housed in metabolic cages to determine fatty acid digestibility. Diet and tissue fatty acid composition was analyzed by gas chromatography and lipid classes using thin layer chromatography. Eicosanoid metabolism was determined by measuring urinary metabolites of 2-series prostaglandins (PGs) and thromoboxanes (TXBs) using enzyme immunoassays. Oxidative stability was assessed by measuring thiobarbituric acid reactive substances (TBARS) and total antioxidant capacity (TAC) using colorimetric assays. Gene expression of antioxidant defense enzymes was determined by real time quantitative polymerase chain reaction (RT-qPCR). Results Rats fed KO had significantly lower DHA digestibility and brain DHA incorporation than SO and TO-fed rats. Of the n-3 PUFA sources, rats fed SO and TO had the highest n-3 PUFAs digestibility and in turn, tissue accretion. Higher tissue n-3 LC-PUFAs had no significant effect on 2-series PG and TXB metabolites. Despite higher tissue n-3 LC-PUFA deposition, there was no increase in oxidation susceptibility indicated by no significant increase in TBARS or decrease in TAC and gene expression of antioxidant defense enzymes, in SO or TO-fed rats. Conclusions On the basis that the optimal n-3 PUFA sources should provide high

Psyllium husk fibre supplementation to soybean and coconut oil diets of humans: effect on fat digestibility and faecal fatty acid excretion.

PubMed

Ganji, V; Kies, C V

1994-08-01

The effects of psyllium fibre supplementation to polyunsaturated fatty acid rich soybean oil and saturated fatty acid rich coconut oil diets on fat digestibility and faecal fatty acid excretion were investigated in healthy humans. The study consisted of four 7-day experimental periods. Participants consumed soybean oil (SO), soybean oil plus psyllium fibre (20 g/day) (SO+PF), coconut oil (CO) and coconut oil plus psyllium fibre (20 g/day) (CO+PF) diets. Laboratory diet provided 30% calories from fat (20% from test oils and 10% from basal diet), 15% calories from protein and 55% calories from carbohydrate. Fat digestibility was significantly lower and faecal fat excretion was significantly higher with SO+PF diet than SO diet and with CO+PF diet than CO diet. Faecal excretion of myristic and lauric acids was not affected by test diets. Percent faecal palmitic acid excretion was significantly higher during psyllium supplementation periods. Higher faecal linoleic acid excretion was observed with soybean oil diets compared with coconut oil diets. Increased faecal fat loss, decreased fat digestibility and increased faecal palmitic acid excretion with psyllium supplementation may partly explain the hypocholesterolaemic action of psyllium fibre.

Analysis of fluorescently labeled glycosphingolipid-derived oligosaccharides following ceramide glycanase digestion and anthranilic acid labeling.

PubMed

Neville, David C A; Coquard, Virginie; Priestman, David A; te Vruchte, Danielle J M; Sillence, Daniel J; Dwek, Raymond A; Platt, Frances M; Butters, Terry D

2004-08-15

Interest in cellular glycosphingolipid (GSL) function has necessitated the development of a rapid and sensitive method to both analyze and characterize the full complement of structures present in various cells and tissues. An optimized method to characterize oligosaccharides released from glycosphingolipids following ceramide glycanase digestion has been developed. The procedure uses the fluorescent compound anthranilic acid (2-aminobenzoic acid; 2-AA) to label oligosaccharides prior to analysis using normal-phase high-performance liquid chromatography. The labeling procedure is rapid, selective, and easy to perform and is based on the published method of Anumula and Dhume [Glycobiology 8 (1998) 685], originally used to analyze N-linked oligosaccharides. It is less time consuming than a previously published 2-aminobenzamide labeling method [Anal. Biochem. 298 (2001) 207] for analyzing GSL-derived oligosaccharides, as the fluorescent labeling is performed on the enzyme reaction mixture. The purification of 2-AA-labeled products has been improved to ensure recovery of oligosaccharides containing one to four monosaccharide units, which was not previously possible using the Anumula and Dhume post-derivatization purification procedure. This new approach may also be used to analyze both N- and O-linked oligosaccharides.

Improved acid digestion of environmental and biological samples and coal for the determination of both arsenic and selenium by hydride generation

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

Huang, Z.

1994-12-31

Hydride generation (HG) is a good sample introduction technique for the determination of As and Se, and has been widely used in atomic spectrometry. Several instrumental developments have been made in the hydride-generation system, however, sample digestion (pretreatment) is still the critical step in the FIG determination of As and Se in solid and semi-solid samples. The general digestion procedure with mineral acids is not suitable for complete decomposition of refractory organic compounds of As and Se present in some organic-rich materials, and then does not allow for the measurement of both As and Se in most environmental and biologicalmore » samples by HG. In this work, some well-designed experiments on the wet digestion in open system have been done with a temperature controlled sand bath. The oxidation performances of some mixtures of mineral acids and salts in different combinations have been investigated and evaluated with environmental and biological samples. With the use of HNO{sub 3}/HClO{sub 4} mixing with either the high-boiling-point acids (H{sub 2}SO{sub 4}, H{sub 3}PO{sub 4}) or some mineral salts(Mg(NO{sub 3}){sub 2}, MgSO{sub 4}, Na{sub 2}SO{sub 4}, NaH{sub 2}PO{sub 4}), the complete mineralization of organoarsenic and organoselenium compounds in the samples can be readily achieved while a dewatered step is in the employ of the digestion program. An improved wet digestion procedure with HNO{sub 3}/HClO{sub 4}/H{sub 3}PO{sub 4}(or Mg(NO{sub 3}){sub 2}, or MgSO{sub 4}) was investigated and optimized for the determination of both As and Se in sediment, soil, coal, fish and plant materials by HG-AAS. This method has been evaluated by the analyses of CRMs, including PACS-1, BCSS-1, MESS-11 DORM-1. DOLT-1. NIST-1632b, BCR-40 and BCR-181 for both As and Se, and good agreements with the certified values were obtained.« less

New method for estimating digestion of Paracoccidioides brasiliensis by phagocytic cells in vitro.

PubMed Central

Goihman-Yahr, M; Essenfeld-Yahr, E; Albornoz, M C; Yarzábal, L; de Gómez, M H; San Martín, B; Ocanto, A; Convit, J

1979-01-01

We describe a method by which phagocytosis and digestion of Paracoccidioides brasiliensis yeast cells by polymorphonuclear leukocytes or other phagocytic cells may be estimated. Suspensions of P. brasiliensis in its yeastlike phase were sonicated, counted, and incubated with known numbers of peripheral blood polymorphonuclear leukocytes. At given intervals, cytocentrifuge droplets were stained by a variation of Papanicolaou's method. Stained preparations were examined with phase-contrast optics. Digested organisms showed total or partial disappearance of protoplasm. Green-stained cell walls resisted digestion. The proportion of digested cells as a function of time was estimated. Images PMID:90683

A comparison of techniques for preparing fish fillet for ICP-AES multielemental analysis and the microwave digestion of whole fish.

PubMed

Moeller, A; Ambrose, R F; Que Hee, S S

2001-01-01

Four catfish fillet homogenate treatments before multielemental metal analysis by simultaneous inductively coupled plasma/atomic emission spectroscopy were compared in triplicate. These treatments were: nitric acid wet-ashing by Parr bomb digestion; nitric acid wet-ashing by microwave digestion; tetramethylammonium hydroxide/nitric acid wet digestion; and dry-ashing. The tetramethylammonium hydroxide/nitric acid method was imprecise (coefficients of variation > 20%). The dry-ashing method was fast and sensitive but had low recoveries of 50% for spiked Pb and Al and was not as precise as the Parr bomb or microwave treatments. The Parr bomb method was the most precise method but was less sensitive than the microwave method which had nearly the same precision. The microwave method was then adapted to homogenates of small whole fish < or = 3 cm in length. The whole fish homogenate required more vigorous digestion conditions, and addition of more acid after the evaporative step because of the presence of less oxidizable and acid-soluble components than fillet. The whole fish homogenate was also more heterogeneous than catfish fillet. A quality assurance protocol to demonstrate homogenate uniformity is essential. The use of a non-specialized microwave oven system allowed precise results for fillet and whole fish homogenates.

Diagnosis of digestive functional disease by the statistics of continuous monitoring of esophageal acidity

NASA Astrophysics Data System (ADS)

Rivera Landa, Rogelio; Cardenas Cardenas, Eduardo; Fossion, Ruben; Pérez Zepeda, Mario Ulises

2014-11-01

Technological advances in the last few decennia allow the monitoring of many physiological observables in a continuous way, which in physics is called a "time series". The best studied physiological time series is that of the heart rhythm, which can be derived from an electrocardiogram (ECG). Studies have shown that a healthy heart is characterized by a complex time series and high heart rate variability (HRV). In adverse conditions, the cardiac time series degenerates towards randomness (as seen in, e.g., fibrillation) or rigidity (as seen in, e.g., ageing), both corresponding to a loss of HRV as described by, e.g., Golberger et. al [1]. Cardiac and digestive rhythms are regulated by the autonomous nervous system (ANS), that consists of two antagonistic branches, the orthosympathetic branch (ONS) that accelerates the cardiac rhythm but decelerates the digestive system, and the parasympathetic brand (PNS) that works in the opposite way. Because of this reason, one might expect that the statistics of gastro-esophageal time series, as described by Gardner et. al. [2,3], reflects the health state of the digestive system in a similar way as HRV in the cardiac case, described by Minocha et. al. In the present project, we apply statistical methods derived from HRV analysis to time series of esophageal acidity (24h pHmetry). The study is realized on data from a large patient population from the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Our focus is on patients with functional disease (symptoms but no anatomical damage). We find that traditional statistical approaches (e.g. Fourier spectral analysis) are unable to distinguish between different degenerations of the digestive system, such as gastric esophageal reflux disease (GERD) or functional gastrointestinal disorder (FGID).

Variability in amino acid digestibility of triticale grain from diverse genotypes as studied in cecectomized laying hens.

PubMed

Zuber, T; Maurer, H P; Möhring, J; Nautscher, N; Siegert, W; Rosenfelder, P; Rodehutscord, M

2016-12-01

Triticale, an anthropogenic hybrid grain, is increasing in importance as a feed grain for laying hens. However, our limited knowledge of its nutritional qualities and their impact on hen performance prevents optimization of its use. The present study investigated the digestibility of amino acids ( AA: ) in triticale grain in laying hens, and additionally examined relationships between AA digestibility and chemical and physical characteristics of the grain. Twenty genotypes of triticale were grown under standardized agronomic and environmental conditions and were characterized according to their physical properties (thousand-seed weight, test weight, falling number, extract viscoelasticity), chemical composition (proximate nutrients, non-starch polysaccharides, AA, minerals, inositol phosphates) and gross energy concentration. Additionally, the in vitro solubility of nitrogen was determined. The animal trial comprised 4 Latin Squares (6 × 6) distributed among 2 subsequent runs. Twelve cecectomized LSL-Classic hens were individually housed in metabolism cages and either fed a basal diet containing 500 g/kg cornstarch or one of 20 triticale diets, each replacing the cornstarch with one triticale genotype, for 8 d. During the last 4 d, feed intake was recorded and excreta were collected quantitatively. Amino acid digestibility of the triticale genotypes was calculated by linear regression. The digestibility of all AA differed significantly between the 20 genotypes, including Lys (digestibility range 68 to 80%), Met (77 to 86%), Thr (68 to 78%) and Trp (74 to 83%). However, AA digestibility only correlated with characteristics of the grain in few cases, without a consistent pattern among AA. Equations to predict AA digestibility based on the grain's physical and chemical characteristics were calculated by multiple linear regression. The explanatory power (adjusted R 2 ;) of these prediction equations was below 0.7 for most AA and thus not sufficiently precise to be

A new method of two-phase anaerobic digestion for fruit and vegetable waste treatment.

PubMed

Wu, Yuanyuan; Wang, Cuiping; Liu, Xiaoji; Ma, Hailing; Wu, Jing; Zuo, Jiane; Wang, Kaijun

2016-07-01

A novel method of two-phase anaerobic digestion where the acid reactor is operated at low pH 4.0 was proposed and investigated. A completely stirred tank acid reactor and an up-flow anaerobic sludge bed methane reactor were operated to examine the possibility of efficient degradation of lactate and to identify their optimal operating conditions. Lactate with an average concentration of 14.8g/L was the dominant fermentative product and Lactobacillus was the predominant microorganism in the acid reactor. The effluent from the acid reactor was efficiently degraded in the methane reactor and the average methane yield was 261.4ml/gCOD removed. Organisms of Methanosaeta were the predominant methanogen in granular sludge of methane reactor, however, after acclimation hydrogenotrophic methanogens enriched, which benefited for the conversion of lactate to acetate. The two-phase AD system exhibited a low hydraulic retention time of 3.56days and high methane yield of 348.5ml/g VS removed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determination of toxic elements in yerba mate by ICP-MS after diluted acid digestion under O2 pressure.

PubMed

Pardinho, Renan B; Dalla Vecchia, Paula; Mendes, Ana L G; Bizzi, Cezar A; Mello, Paola A; Duarte, Fabio A; Flores, Erico M M

2018-10-15

In this work, a procedure allowing effective digestion of a high mass of yerba mate (up to 1500 mg) using diluted HNO 3, in a system pressurized with oxygen, is proposed. Digests were suitable for direct analysis by ICP-MS, virtually free of interferences. Digestion was performed using 7 mol l -1 HNO 3 and 8 bar O 2 . The digestion efficiency was better than 92% and digests presented a relatively low acidity (<10 mmol HNO 3 ). The limit of quantification was 4.0, 1.0 and 1.0 ng g -1 for As, Cd and Pb, respectively. Under optimized conditions up to 1500 mg of sample were digested and no interferences were observed during analyses by ICP-MS, making this approach suitable for routine determination of As, Cd and Pb in yerba mate and also in agreement with the quality control requirements. Copyright © 2018 Elsevier Ltd. All rights reserved.

Bioaccessibility of hydroxycinnamic acids and antioxidant capacity from sorghum bran thermally processed during simulated in vitro gastrointestinal digestion.

PubMed

Salazar-López, Norma Julieta; González-Aguilar, Gustavo A; Rouzaud-Sández, Ofelia; Robles-Sánchez, Maribel

2018-06-01

Sorghum is a source of hydroxycinnamic acids (HCA), which have shown antioxidant, anti-inflammatory and anti-proliferative capacities. However, a high proportion of them have low bioaccessibility due the complex structural disposition of the plant's cell wall. The effects of boiling and extrusion processes on sorghum bran and their effects on the antioxidant capacity and bioaccessibility of HCA during simulated in vitro gastrointestinal digestion were investigated. The bioaccessibility of phenolic compounds was significantly higher in extruded sorghum bran (38.4%) than that obtained by boiling (29.5%). This is consistent with the increase of the antioxidant capacity after in vitro digestion. In contrast, a low bioaccessibility of pure monomeric HCA was observed when they were exposed to in vitro gastrointestinal digestion. There were significant bioaccessibility reductions of 36.8, 19.5, 13.5, 62.1% for caffeic, ρ-coumaric, ferulic and sinapic acids, respectively, when unproccessed sorghum bran was added. Although the bioaccessibility of monomeric HCA was low, the total phenolic compounds and antioxidant capacity increased during the digestion simulation due to the thermal processes of extrusion and boiling. Extrusion and boiling could be utilized to produce food based on sorghum bran with biological potential.

Ontogeny and distribution of alkaline and acid phosphatases in the digestive system of California halibut larvae (Paralichthys californicus).

PubMed

Zacarias-Soto, Magali; Barón-Sevilla, Benjamín; Lazo, Juan P

2013-10-01

Studies aimed to assess the digestive physiology of marine fish larvae under culture conditions are important to further understand the functional characteristics and digestive capacities of the developing larvae. Most studies to date concentrate on intestinal lumen digestion and little attention to the absorption process. Thus, the objectives of this study were to histochemically detect and quantify some of the enzymes responsible for absorption and intracellular digestion of nutrients in the anterior and posterior intestine of California halibut larvae. Alkaline and acid phosphatases were detected from the first days post-hatch (dph). Alkaline phosphatase maintained a high level of activity during the first 20 dph in both intestinal regions. Thereafter, a clear intestinal regionalization of the activity was observed with the highest levels occurring in the anterior intestine. Acid phosphatase activity gradually increased in both intestinal regions during development, and a regionalization of the activity was not observed until late in development, once the ocular migration began. Highest levels were observed in the anterior intestine at the end of metamorphosis concomitant with the stomach development. The results from this study show some morphological and physiological changes are occurring during larval development and a clear regionalization of the absorption process as the larvae develops. These ontological changes must be considered in the elaboration of diets according to the digestive capacity of the larvae.

Standardized Ileal Amino Acid Digestibility of Commonly Used Feed Ingredients in Growing Broilers

PubMed Central

Ullah, Zafar; Ahmed, Gulraiz; Nisa, Mehr un; Sarwar, Muhammad

2016-01-01

This experiment was conducted to determine standardized ileal amino acid digestibility (SIAAD) of commonly used feed ingredients in poultry diets in Pakistan. These feed ingredients included corn, rice broken (RB), rice polishings (RP), wheat bran (WB), sunflower meal (SFM), cottonseed meal (CSM), guar meal (GM), soybean meal (SBM) from India and Argentine and fish meal (FM). The SIAAD of each ingredient was determined in triplicate using 21-days-old broilers. Day-old male broiler chicks (Hubbard× Hubbard) were reared on corn-SBM based diet from 1 to 13 days and thereafter birds were fed experimental diets from day 14 to 21. Each diet was fed to 36 birds kept in six replicate cages, each cage had six birds. In cereals, the SIAAD of corn’s amino acid (AA) (90.1%) was similar (p>0.05) to RB (89.0%). Isoleucine (97.8%) and lysine (96.9%) were highly digestible AA in corn and RB, respectively. Among cereal-by products, WB’s SIAAD (76.9%) was same (p>0.05) as RP (71.9%). Arginine from WB (82.5%) and RP (83.2%) was highly digestible. However, threonine in WB (72.7%) and leucine in RP (69.6%) were the lowest digestible AAs. In plant protein meals, AAs from Argentine-SBM (85.1%) and Indian-SBM (83.4%) had higher (p<0.5) SIAAD than other protein meals. However, SIAAD of SFM (77.1%) and CSM (71.7%) was intermediate while GM (60.3%) exhibited the lowest (p<0.05) SIAAD among all ingredients. Arginine from GM (76.9%), CSM (85.8%), SBM-India (89.5%) and SBM-Argentine (91.5%) was highly digestible from indispensable AAs. In SFM, methionine (91.4%) SIAAD was the greatest. The average SIAAD of FM was 77.6%. Alanine from FM had the highest (84.0%) but cysteine (62.8%) had the lowest SIAAD. In conclusion, cereals i.e. corn and RB had higher (p<0.05) SIAAD of the cereals by-products. The SIAAD of RP and WB was same (p>0.05). The SBM from plant protein meals had higher (p<0.05) SIAAD than other studied feed ingredients. However, the GM had the lowest (p<0.05) SIAAD among protein

Standardized Ileal Amino Acid Digestibility of Commonly Used Feed Ingredients in Growing Broilers.

PubMed

Ullah, Zafar; Ahmed, Gulraiz; Nisa, Mehr Un; Sarwar, Muhammad

2016-09-01

This experiment was conducted to determine standardized ileal amino acid digestibility (SIAAD) of commonly used feed ingredients in poultry diets in Pakistan. These feed ingredients included corn, rice broken (RB), rice polishings (RP), wheat bran (WB), sunflower meal (SFM), cottonseed meal (CSM), guar meal (GM), soybean meal (SBM) from India and Argentine and fish meal (FM). The SIAAD of each ingredient was determined in triplicate using 21-days-old broilers. Day-old male broiler chicks (Hubbard× Hubbard) were reared on corn-SBM based diet from 1 to 13 days and thereafter birds were fed experimental diets from day 14 to 21. Each diet was fed to 36 birds kept in six replicate cages, each cage had six birds. In cereals, the SIAAD of corn's amino acid (AA) (90.1%) was similar (p>0.05) to RB (89.0%). Isoleucine (97.8%) and lysine (96.9%) were highly digestible AA in corn and RB, respectively. Among cereal-by products, WB's SIAAD (76.9%) was same (p>0.05) as RP (71.9%). Arginine from WB (82.5%) and RP (83.2%) was highly digestible. However, threonine in WB (72.7%) and leucine in RP (69.6%) were the lowest digestible AAs. In plant protein meals, AAs from Argentine-SBM (85.1%) and Indian-SBM (83.4%) had higher (p<0.5) SIAAD than other protein meals. However, SIAAD of SFM (77.1%) and CSM (71.7%) was intermediate while GM (60.3%) exhibited the lowest (p<0.05) SIAAD among all ingredients. Arginine from GM (76.9%), CSM (85.8%), SBM-India (89.5%) and SBM-Argentine (91.5%) was highly digestible from indispensable AAs. In SFM, methionine (91.4%) SIAAD was the greatest. The average SIAAD of FM was 77.6%. Alanine from FM had the highest (84.0%) but cysteine (62.8%) had the lowest SIAAD. In conclusion, cereals i.e. corn and RB had higher (p<0.05) SIAAD of the cereals by-products. The SIAAD of RP and WB was same (p>0.05). The SBM from plant protein meals had higher (p<0.05) SIAAD than other studied feed ingredients. However, the GM had the lowest (p<0.05) SIAAD among protein meals.

A combination of acid lactase from Aspergillus oryzae and yogurt bacteria improves lactose digestion in lactose maldigesters synergistically: A randomized, controlled, double-blind cross-over trial.

PubMed

de Vrese, Michael; Laue, Christiane; Offick, Birte; Soeth, Edlyn; Repenning, Frauke; Thoß, Angelika; Schrezenmeir, Jürgen

2015-06-01

Lactose digestion can be improved in subjects with impaired or completely absent intestinal lactase activity by administration of lactase preparations and particularly of acid lactase, which is active in the stomach, or by yogurt containing live lactic acid bacteria. It is the question, if lactose digestion can be further enhanced by combining these two approaches. We investigated in a randomised, placebo-controlled, double-blind, 5-arm crossover study on 24 lactose malabsorbers with variable degrees of lactase deficiency if different lactase preparations and freeze-dried yogurt culture affect gastrointestinal lactose digestion after consuming moderate amounts of lactose (12.5 g) by assessing hydrogen exhalation over 6 h. Furthermore, symptoms of lactose intolerance (excess gas production, abdominal pain, diarrhoea or nausea) were assessed using validated questionnaires. All preparations increased lactose digestion and reduced peak hydrogen exhalation by -27% (yogurt), -29/-33% (3300/9000 FCC(1) ((1) One FCC hydrolyses about 5 or 1.7-2.5 mg lactose in aquous solution or in (artificial) chyme, respectively, according to the FCC-III method of the Committee on Codex Specifications, Food and Nutrition Board, National Research Council. Food Chemicals Codex, 3rd edition. Washington, DC, National Academy Press, 1981 It cannot precisely be defined how much lactose can be hydrolysed in vivo by the consumption of a certain number of FCC units.) units acid lactase from Aspergillus oryzae) or -46%, respectively (3300 FCC units lactase plus yogurt culture combined), as compared with placebo (p < 0.001, Friedman test). The combination preparation had not only the strongest effect, but also showed the lowest variance in H(2)-exhalation values (less malabsorbers with no reduction of H(2)-exhalation) Apart from this, both the higher dose lactase and the combination preparation significantly reduced the symptoms most closely associated with H(2)-exhalation, namely flatulences and

Protein-bound D-amino acids, and to a lesser extent lysinoalanine, decrease true ileal protein digestibility in minipigs as determined with (15)N-labeling.

PubMed

de Vrese, M; Frik, R; Roos, N; Hagemeister, H

2000-08-01

Heat and alkali treatment of food may increase the concentrations of protein-bound D-amino acids and cross-links such as lysinoalanine (LAL). To examine how protein treatment affects digestibility, purified test meals [total protein 150 g/kg dry matter (DM), 0.44 MJ/(kg BW(0.75). d)] were prepared, containing (g/kg DM) casein, 75; beta-lactoglobulin, 50; or wheat protein, 40. Each was (15)N-labeled. Test proteins were used either in their native form or after treatment for 6 or 24 h at 65 degrees C, pH 10.5-11.5. Each meal was fed to nine adult miniature pigs (twofold complete cross-classification). Chyme was collected continuously over 33 h postprandially via T-fistulas in the terminal ileum, and digestibilities of test proteins and individual L- and D-amino acids were calculated on the basis of recovery of (15)N and the respective amino acids in the chyme. Treatment of casein, beta-lactoglobulin or wheat protein for 24 h increased levels of D-amino acid residues. L-Asparagine and aspartate (L-Asx) were particularly susceptible; 14. 7 +/- 0.4, 11.7 +/- 0.2 and 11.0 +/- 0.9%, respectively, underwent racemization. LAL levels increased in parallel; 11.7 +/- 0.3, 13.6 +/- 0 and 14.8 +/- 0.0%, respectively, of total lysine was converted to LAL. At the same time, prececal protein digestibility was decreased by 13.4 +/- 2.3, 15.3 +/- 1.4 and 17.8 +/- 1.2% units, respectively (P < 0.05; mean +/- SEM, n = 9). Digestibility of individual L-amino acids decreased by 10-15%, but L-amino acids prone to peptic cleavage, such as L-phenylalanine and L-tyrosine, were not affected. Digestibilities of D-amino acids and LAL were approximately 35%. It seems that mainly D-amino acids, and to a lesser extent LAL, were responsible for lower digestibility by interfering with peptic cleavage.

In vivo digestion of bovine milk fat globules: effect of processing and interfacial structural changes. II. Upper digestive tract digestion.

PubMed

Gallier, Sophie; Zhu, Xiang Q; Rutherfurd, Shane M; Ye, Aiqian; Moughan, Paul J; Singh, Harjinder

2013-12-01

The aim of this research was to study the effect of milk processing on the in vivo upper digestive tract digestion of milk fat globules. Fasted rats were serially gavaged over a 5h period with cream from raw, pasteurised, or pasteurised and homogenised milk. Only a few intact dietary proteins and peptides were present in the small intestinal digesta. Significantly (P<0.05) more longer chain (C≥10) fatty acids were present in the digesta of rats gavaged with raw (448 mg g(-1) digesta dry matter (DDM)) and homogenised creams (528 mg g(-1) DDM), as compared to pasteurised and homogenised cream (249 mg g(-1) DDM). Microscopy techniques were used to investigate the structural changes during digestion. Liquid-crystalline lamellar phases surrounding the fat globules, fatty acid soap crystals and lipid-mucin interactions were evident in all small intestinal digesta. Overall, the pasteurised and homogenised cream appeared to be digested to a greater extent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of various fiber additions on lipid digestion during in vitro digestion of beef patties.

PubMed

Hur, S J; Lim, B O; Park, G B; Joo, S T

2009-01-01

The purpose of this study was to examine the effect of various fiber additions on lipid digestion during the in vitro digestion of beef patties. The control patties were prepared with 90.5% lean meat and 9.5% tallow. Treatments consisted of 90% lean meat with 9.5% tallow and either 0.5% cellulose, 0.5% chitosan, or 0.5% pectin. The beef patties were then passed through an in vitro digestion model that simulated the composition of the mouth, stomach, and small intestine juices. The change in structure and properties of the lipid droplets was monitored by laser scanning confocal fluorescence microscopy. In general, there was a decrease in lipid droplet diameter as the droplets moved from mouth to stomach to small intestine. The amount of free fatty acid dramatically increased after in vitro digestion in all beef patties. The amount of free fatty acid was, however, lower in beef patties containing chitosan and pectin than other beef patties after in vitro digestion. Beef patties containing various fibers had lower thiobarbituric acid-reactive substances (TBARS) values than samples with no fibers. Among the samples to which fibers were added, chitosan and pectin had lower TBARS than beef patties with cellulose. The cholesterol content decreased after in vitro digestion in all beef patties but was not different among the beef patties before and after in vitro digestion. These results enhance our understanding of the physicochemical and structural changes that occur to ground beef within the gastrointestinal tract.

Peracetic acid oxidation as an alternative pre-treatment for the anaerobic digestion of waste activated sludge.

PubMed

Appels, Lise; Van Assche, Ado; Willems, Kris; Degrève, Jan; Van Impe, Jan; Dewil, Raf

2011-03-01

Anaerobic digestion is generally considered to be an economic and environmentally friendly technology for treating waste activated sludge, but has some limitations, such as the time it takes for the sludge to be digested and also the ineffectiveness of degrading the solids. Various pre-treatment technologies have been suggested to overcome these limitations and to improve the biogas production rate by enhancing the hydrolysis of organic matter. This paper studies the use of peracetic acid for disintegrating sludge as a pre-treatment of anaerobic digestion. It has been proved that this treatment effectively leads to a solubilisation of organic material. A maximum increase in biogas production by 21% is achieved. High dosages of PAA lead to a decrease in biogas production. This is due to the inhibition of the anaerobic micro-organisms by the high VFA-concentrations. The evolution of the various VFAs during digestion is studied and the observed trends support this hypothesis. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effect of nitrogen fertilisation on the amino acid digestibility of different triticale genotypes in caecectomised laying hens.

PubMed

Siegert, Wolfgang; Boguhn, Jeannette; Maurer, Hans Peter; Weiss, Jochen; Zuber, Tobias; Möhring, Jens; Rodehutscord, Markus

2017-01-01

The influence of nitrogen fertilisation and genotype on the amino acid (AA) digestibility of triticale grain was investigated in caecectomised laying hens. Three genotypes, Grenado, EAW6002 and Lasko, were cultivated with and without nitrogen fertilisation at the end of the heading stage. The six triticale variants as well as a basal diet were each used to feed seven laying hens in a 7 × 7 Latin square design. Nitrogen fertilisation influenced the digestibility of Cys, Glu, Phe and Ser in some triticale genotypes and reduced Ala, Ile, Lys, Met and Val digestibility in all genotypes (P < 0.05). Nitrogen fertilisation increased the concentration of all AAs in the grain. Consequently, the concentration of digestible AAs in the grains was increased for most AAs upon nitrogen fertilisation. Overall, Lys had the lowest digestibility, whereas that of Glu and Pro was the highest. For the triticale genotypes, the level of AA digestibility was highest for EAW6002 followed by Lasko and Grenado, with significant differences (P < 0.05) between genotypes for some but not all AAs. The results indicated that the accuracy of the digestible AA supply for hen feeding might benefit from considering fertilisation and genotype-specific digestibility data in feed formulation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Chromic oxide and acid-insoluble ash as markers in digestibility studies with growing pigs and sows.

PubMed

Brestenský, M; Nitrayová, S; Heger, J; Patráš, P

2017-02-01

The results of three experiments, focused on the determination of endogenous ileal flow (EIF) of amino acids (AA) and nitrogen (N) (Exp. 1), apparent ileal digestibility (AID) of AA and N (Exp. 2), and apparent total tract digestibility (ATTD) of dry matter (DM), organic matter (OM), N, calcium (Ca) and phosphorus (P) (Exps. 2 and 3), were used to compare chromic oxide (Cr 2 O 3 ) and acid-insoluble ash (AIA) as digestibility markers. In Exps. 1 and 2, a total of six gilts fitted with T-cannula in terminal ileum, and in Exp. 3, a total of 24 pregnant sows were used. In Exps. 1 and 2, the pigs were assigned into four dietary treatments according to 4 × 6 crossover design (Exp. 1; diets with 0%, 4%, 8% and 12% of casein; Exp. 2 basal diet with different levels of phytase). In Exp. 3, the sows were assigned to four dietary treatments (basal diet with different levels of phytase) of six sows. In Exps. 1 and 2 ileal digesta and in Exps. 2 and 3 faeces were collected for the determination of EIF, AID and ATTD. Differences in EIF of AA determined by Cr 2 O 3 and AIA ranged (p ˃ 0.05) from -4.62 to 4.54%. The lowest EIF was for methionine and the greatest one for proline, determined by both markers. Apparent ileal digestibility determined by Cr 2 O 3 was slightly greater (p ˃ 0.05) in comparison with AIA. Differences ranged from 1.88% (Arg) to 7.08% (Gly). The greatest AID was for arginine and the lowest one for glycine, determined by both Cr 2 O 3 and AIA. Similarly for ATTD of DM, OM, N, Ca and P, there were no differences in digestibility determined by Cr 2 O 3 and AIA. Both, Cr 2 O 3 and AIA, are suitable and comparable markers for digestibility studies in pigs. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Long-term thermophilic mono-digestion of rendering wastes and co-digestion with potato pulp.

PubMed

Bayr, S; Ojanperä, M; Kaparaju, P; Rintala, J

2014-10-01

In this study, mono-digestion of rendering wastes and co-digestion of rendering wastes with potato pulp were studied for the first time in continuous stirred tank reactor (CSTR) experiments at 55°C. Rendering wastes have high protein and lipid contents and are considered good substrates for methane production. However, accumulation of digestion intermediate products viz., volatile fatty acids (VFAs), long chain fatty acids (LCFAs) and ammonia nitrogen (NH4-N and/or free NH3) can cause process imbalance during the digestion. Mono-digestion of rendering wastes at an organic loading rate (OLR) of 1.5 kg volatile solids (VS)/m(3)d and hydraulic retention time (HRT) of 50 d was unstable and resulted in methane yields of 450 dm(3)/kg VS(fed). On the other hand, co-digestion of rendering wastes with potato pulp (60% wet weight, WW) at the same OLR and HRT improved the process stability and increased methane yields (500-680 dm(3)/kg VS(fed)). Thus, it can be concluded that co-digestion of rendering wastes with potato pulp could improve the process stability and methane yields from these difficult to treat industrial waste materials. Copyright © 2014 Elsevier Ltd. All rights reserved.

Digestibility by lambs offered alfalfa hay treated with a propionic acid hay preservative and baled at different concentrations of moisture

USDA-ARS?s Scientific Manuscript database

Eighteen crossbred wether lambs (76.1 ± 8.18 lb initial BW) were used for a 2 period digestion study to evaluate the effect of hay preservative concentration (0, 0.56, or 0.98% buffered propionic acid) and hay moisture concentration at baling (19.6, 23.8, or 27.4% moisture) on digestibility of alfal...

Milk production and nutrient digestibility responses to increasing levels of stearic acid supplementation of dairy cows.

PubMed

Boerman, J P; de Souza, J; Lock, A L

2017-04-01

The objective of our study was to evaluate the dose-response effects of a stearic acid (C18:0)-enriched supplement on nutrient digestibility, production responses, and the maximum amount of C18:0 that can be incorporated into the milk fat of dairy cows. Multiparous Holstein cows (n = 32; 145 ± 66 d in milk) with a wide range in milk yield (30 to 70 kg/d) were blocked by milk yield and assigned to replicated 4 × 4 Latin squares. Treatments were diets supplemented with a C18:0-enriched supplement (SA; 93% C18:0) at 0, 0.80, 1.50, or 2.30% of diet dry matter (DM). Periods were 21 d with the final 5 d used for data and sample collection. Dry matter intake increased linearly as SA supplementation increased. Supplementation of SA had no effect on the yield of milk or milk components. Due to the increase in DM intake, SA linearly reduced the ratio of energy-corrected milk to DM intake. Supplementation of SA did not affect body weight. Increasing SA reduced digestibility of 16-carbon, 18-carbon, and total fatty acids (FA), with the reduction in digestibility of 18-carbon FA being approximately 30 percentage units from the 0.0 to 2.30% SA supplemented diets. Supplementation of SA linearly increased concentrations of preformed milk fatty acids (FA) but did not affect the yield of preformed milk FA. Yields of C18:0 plus cis-9 C18:1 were increased by SA supplementation; however, the increase from 0 to 2.3% SA was only 16 g/d. The concentration and yield of de novo and 16-carbon milk FA were unaffected by SA supplementation. In conclusion, increasing doses of SA decreased FA digestibility and had little effect on production parameters. Although SA increased the yield of C18:0 and cis-9 C18:1 in milk fat, it had no overall effect on milk fat yield. The lack of production responses to a C18:0-enriched fat supplement was most likely associated with the marked decrease in FA digestibility. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights

Effects of Coated Compound Proteases on Apparent Total Tract Digestibility of Nutrients and Apparent Ileal Digestibility of Amino Acids for Pigs.

PubMed

Pan, L; Zhao, P F; Yang, Z Y; Long, S F; Wang, H L; Tian, Q Y; Xu, Y T; Xu, X; Zhang, Z H; Piao, X S

2016-12-01

Two experiments were conducted to evaluate effects of coated compound proteases (CC protease) on apparent total tract digestibility (ATTD) of nitrogen (N) and energy, and apparent ileal digestibility (AID) of amino acids (AA) and nutrients in diets for pigs. In Exp. 1, 12 crossbred barrows (initial body weight: 20.14±1.71 kg) were housed in individual metabolism crates and allotted into 2 treatments with 6 piglets per treatment according to weight in a randomized complete block design. The 2 diets were corn-soybean meal basal diets with (0.2 g/kg) or without CC protease supplementation. The CC protease supplementation increased (p<0.05) the digestible and metabolizable N and energy values and the digestibility and retention rate of N in the diet. The ATTD of energy and nutrients had been improved (p<0.05) in the diet supplemented with CC protease. In Exp. 2, 12 crossbred barrows (initial body weight: 20.79±1.94 kg), fitted with T-cannulas at the distal ileum, were blocked by body weight into 2 groups with 6 pigs each. The diets were the same as those in Exp. 1. The CC protease increased (p<0.05) the AID of crude protein and some essential AA including arginine, isoleucine and leucine. The AID and ATTD of energy and nutrients had been improved (p<0.05) by supplemental CC protease, but the hindgut digestibility of nutrients was unaffected. Overall, the CC protease improved the ATTD of N and energy and AID of some indispensible AA and nutrients in the corn-soybean meal diet for pigs. Therefore, the CC protease supplement could improve the utilization of protein in the corn-soybean meal diet and thus contribute to lower N excretion to the environment.

Cooking Chicken Breast Reduces Dialyzable Iron Resulting from Digestion of Muscle Proteins

PubMed Central

Gokhale, Aditya S.; Mahoney, Raymond R.

2014-01-01

The purpose of this research was to study the effect of cooking chicken breast on the production of dialyzable iron (an in vitro indicator of bioavailable iron) from added ferric iron. Chicken breast muscle was cooked by boiling, baking, sautéing, or deep-frying. Cooked samples were mixed with ferric iron and either extracted with acid or digested with pepsin and pancreatin. Total and ferrous dialyzable iron was measured after extraction or digestion and compared to raw chicken samples. For uncooked samples, dialyzable iron was significantly enhanced after both extraction and digestion. All cooking methods led to markedly reduced levels of dialyzable iron both by extraction and digestion. In most cooked, digested samples dialyzable iron was no greater than the iron-only (no sample) control. Cooked samples showed lower levels of histidine and sulfhydryls but protein digestibility was not reduced, except for the sautéed sample. The results showed that, after cooking, little if any dialyzable iron results from digestion of muscle proteins. Our research indicates that, in cooked chicken, residual acid-extractable components are the most important source of dialyzable iron. PMID:26904627

Cooking Chicken Breast Reduces Dialyzable Iron Resulting from Digestion of Muscle Proteins.

PubMed

Gokhale, Aditya S; Mahoney, Raymond R

2014-01-01

The purpose of this research was to study the effect of cooking chicken breast on the production of dialyzable iron (an in vitro indicator of bioavailable iron) from added ferric iron. Chicken breast muscle was cooked by boiling, baking, sautéing, or deep-frying. Cooked samples were mixed with ferric iron and either extracted with acid or digested with pepsin and pancreatin. Total and ferrous dialyzable iron was measured after extraction or digestion and compared to raw chicken samples. For uncooked samples, dialyzable iron was significantly enhanced after both extraction and digestion. All cooking methods led to markedly reduced levels of dialyzable iron both by extraction and digestion. In most cooked, digested samples dialyzable iron was no greater than the iron-only (no sample) control. Cooked samples showed lower levels of histidine and sulfhydryls but protein digestibility was not reduced, except for the sautéed sample. The results showed that, after cooking, little if any dialyzable iron results from digestion of muscle proteins. Our research indicates that, in cooked chicken, residual acid-extractable components are the most important source of dialyzable iron.

Effect of digestion temperature and pH on treatment efficiency and evolution of volatile fatty acids during thermophilic aerobic digestion of model high strength agricultural waste.

PubMed

Ugwuanyi, J Obeta; Harvey, L M; McNeil, B

2005-04-01

Thermophilic aerobic digestion (TAD) of a model agricultural waste, potato peel slurry, at soluble chemical oxygen demand (COD) load equivalent to approximately 8.0 gl(-1), was carried out under batch conditions at 0.5 vvm aeration rate. Digestions were carried out at temperatures of 45, 50, 55, 60 and 65 degrees C (or left unregulated) without pH control to study the effect of digestion temperatures on TAD. The effects of digestion pH on the process were studied at pH 6.0, 7.0, 8.0, 9.0 and 9.5 (and in unregulated control) all at 55 degrees C. Except for digestion at 65 degrees C, which was inoculated extraneously using culture of Bacillus strearothermophilus all reactions were carried out using the populations indigenous to the waste. During digestion at different temperatures, the removal of soluble COD increased with temperature to reach a peak at 60 degrees C before declining slightly, removal of soluble solid (SS) followed similar pattern and reached peak at 65 degrees C being the highest temperature studied, while the degradation of TSS and TS (TSS + TS) decreased with an increase in temperature. Digestion at pH 7.0 was more efficient than at other pH values. Acetate was the predominant volatile fatty acid (VFA) in all the reactions and accounted for up to 90% of the total. Digestion at 60 degrees C led to the greatest accumulation of acetate, and this coincided with the period of highest oxygen uptake, and rapid consumption of soluble carbohydrate. Iso-valerate was also produced at all pH values. Digestion at 55 degrees C and also at pH 7.0 led to rapid and efficient processes with least accumulation of VFA and should be of interest in full-scale processes whenever it is practicable to regulate the digestion pH and temperature. The result of digestion at unregulated pH indicates that gradual adaptation may be used to achieve efficient treatment at elevated pH values. This would be of interest in full-scale processes where it is not practicable to tightly

In vitro digestion testing of lipid-based delivery systems: calcium ions combine with fatty acids liberated from triglyceride rich lipid solutions to form soaps and reduce the solubilization capacity of colloidal digestion products.

PubMed

Devraj, Ravi; Williams, Hywel D; Warren, Dallas B; Mullertz, Anette; Porter, Christopher J H; Pouton, Colin W

2013-01-30

In vitro digestion testing is of practical importance to predict the fate of drugs administered in lipid-based delivery systems. Calcium ions are often added to digestion media to increase the extent of digestion of long-chain triglycerides (LCTs), but the effects they have on phase behaviour of the products of digestion, and consequent drug solubilization, are not well understood. This study investigates the effect of calcium and bile salt concentrations on the rate and extent of in vitro digestion of soybean oil, as well as the solubilizing capacity of the digestion products for two poorly water-soluble drugs, fenofibrate and danazol. In the presence of higher concentrations of calcium ions, the solubilization capacities of the digests were reduced for both drugs. This effect is attributed to the formation of insoluble calcium soaps, visible as precipitates during the digestions. This reduces the availability of liberated fatty acids to form mixed micelles and vesicles, thereby reducing drug solubilization. The use of high calcium concentrations does indeed force in vitro digestion of LCTs but may overestimate the extent of drug precipitation that occurs within the intestinal lumen. Copyright © 2012 Elsevier B.V. All rights reserved.

Improvement of microwave-assisted digestion of milk powder with diluted nitric acid using oxygen as auxiliary reagent

NASA Astrophysics Data System (ADS)

Bizzi, Cezar A.; Barin, Juliano S.; Garcia, Edivaldo E.; Nóbrega, Joaquim A.; Dressler, Valderi L.; Flores, Erico M. M.

2011-05-01

The feasibility of using diluted HNO 3 solutions under oxygen pressure for decomposition of whole and non-fat milk powders and whey powder samples has been evaluated. Digestion efficiency was evaluated by determining the carbon content in solution (digests) and the determination of Ca, Cd, Cu, Fe, K, Mg, Mn, Mo, Na, Pb and Zn was performed by inductively coupled plasma optical emission spectrometry and Hg by chemical vapor generation coupled to inductively coupled plasma mass spectrometry. Samples (up to 500 mg) were digested using HNO 3 solutions (1 to 14 mol L - 1 ) and the effect of oxygen pressure was evaluated between 2.5 and 20 bar. It was possible to perform the digestion of 500 mg of milk powder using 2 mol L - 1 HNO 3 with oxygen pressure ranging from 7.5 to 20 bar with resultant carbon content in digests lower than 1700 mg L - 1 . Using optimized conditions, less than 0.86 mL of concentrated nitric acid (14 mol L - 1 ) was enough to digest 500 mg of sample. The accuracy was evaluated by determination of metal concentrations in certified reference materials, which presented an agreement better than 95% (Student's t test, P < 0.05) for all the analytes.

Expression pattern of peptide and amino acid genes in digestive tract of transporter juvenile turbot ( Scophthalmus maximus L.)

NASA Astrophysics Data System (ADS)

Xu, Dandan; He, Gen; Mai, Kangsen; Zhou, Huihui; Xu, Wei; Song, Fei

2016-04-01

Turbot ( Scophthalmus maximus L.), a carnivorous fish species with high dietary protein requirement, was chosen to examine the expression pattern of peptide and amino acid transporter genes along its digestive tract which was divided into six segments including stomach, pyloric caeca, rectum, and three equal parts of the remainder of the intestine. The results showed that the expression of two peptide and eleven amino acid transporters genes exhibited distinct patterns. Peptide transporter 1 (PepT1) was rich in proximal intestine while peptide transporter 2 (PepT2) was abundant in distal intestine. A number of neutral and cationic amino acid transporters expressed richly in whole intestine including B0-type amino acid transporter 1 (B0AT1), L-type amino acid transporter 2 (LAT2), T-type amino acid transporter 1 (TAT1), proton-coupled amino acid transporter 1 (PAT1), y+L-type amino acid transporter 1 (y+LAT1), and cationic amino acid transporter 2 (CAT2) while ASC amino acid transporter 2 (ASCT2), sodium-coupled neutral amino acid transporter 2 (SNAT2), and y+L-type amino acid transporter 2 (y+LAT2) abundantly expressed in stomach. In addition, system b0,+ transporters (rBAT and b0,+AT) existed richly in distal intestine. These findings comprehensively characterized the distribution of solute carrier family proteins, which revealed the relative importance of peptide and amino acid absorption through luminal membrane. Our findings are helpful to understand the mechanism of the utilization of dietary protein in fish with a short digestive tract.

Anaerobic sludge digestion with a biocatalytic additive. [Lactobacillus acidophilus

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

Ghosh, S.; Henry, M.P.; Fedde, P.A.

1982-01-01

Aimed at improving the process operating characteristics of anaerobic digestion for sludge stabilization and SNG production, this study evaluates the effects of a lactobacillus additive under normal, variable, and overload conditions. This whey fermentation product of an acid-tolerant strain of L. acidophilus fortified with CoCO/sub 3/, (NH/sub 4/)/sub 2/HPO/sub 4/, ferrous lactate, and lactic acid provides growth factors, metabolic intermediates, and enzymes needed for substrate degradation and cellular synthesis. Data indicate that the biochemical additive increases methane yield, gas production rate, and volatile solids reduction; decreases volatile acids accumulation; enhances the digester buffer capacity; and improves the fertilizer value andmore » dewatering characteristics of the digested residue. Digester capacities could be potentially doubled when the feed is so treated. Results of field tests with six full-scale digesters confirm observations made with bench-scale digesters.« less

Fates of Acid-Resistant and Non-Acid-Resistant Shiga Toxin-Producing Escherichia coli Strains in Ruminant Digestive Contents in the Absence and Presence of Probiotics ▿

PubMed Central

Chaucheyras-Durand, Frédérique; Faqir, Fahima; Ameilbonne, Aurélie; Rozand, Christine; Martin, Christine

2010-01-01

Healthy ruminants are the main reservoir of Shiga toxin-producing Escherichia coli (STEC). During their transit through the ruminant gastrointestinal tract, STEC encounters a number of acidic environments. As all STEC strains are not equally resistant to acidic conditions, the purpose of this study was to investigate whether acid resistance confers an ecological advantage to STEC strains in ruminant digestive contents and whether acid resistance mechanisms are induced in the rumen compartment. We found that acid-resistant STEC survived at higher rates during prolonged incubation in rumen fluid than acid-sensitive STEC and that they resisted the highly acidic conditions of the abomasum fluid, whereas acid-sensitive strains were killed. However, transit through the rumen contents allowed acid-sensitive strains to survive in the abomasum fluid at levels similar to those of acid-resistant STEC. The acid resistance status of the strains had little influence on STEC growth in jejunal and cecal contents. Supplementation with the probiotic Saccharomyces cerevisiae CNCM I-1077 or Lactobacillus acidophilus BT-1386 led to killing of all of the strains tested during prolonged incubation in the rumen contents, but it did not have any influence in the other digestive compartments. In addition, S. cerevisiae did not limit the induction of acid resistance in the rumen fluid. Our results indicate that the rumen compartment could be a relevant target for intervention strategies that could both limit STEC survival and eliminate induction of acid resistance mechanisms in order to decrease the number of viable STEC cells reaching the hindgut and thus STEC shedding and food contamination. PMID:19948865

Evaluation of the 5 and 8 pH point titration methods for monitoring anaerobic digesters treating solid waste.

PubMed

Vannecke, T P W; Lampens, D R A; Ekama, G A; Volcke, E I P

2015-01-01

Simple titration methods certainly deserve consideration for on-site routine monitoring of volatile fatty acid (VFA) concentration and alkalinity during anaerobic digestion (AD), because of their simplicity, speed and cost-effectiveness. In this study, the 5 and 8 pH point titration methods for measuring the VFA concentration and carbonate system alkalinity (H2CO3*-alkalinity) were assessed and compared. For this purpose, synthetic solutions with known H2CO3*-alkalinity and VFA concentration as well as samples from anaerobic digesters treating three different kind of solid wastes were analysed. The results of these two related titration methods were verified with photometric and high-pressure liquid chromatography measurements. It was shown that photometric measurements lead to overestimations of the VFA concentration in the case of coloured samples. In contrast, the 5 pH point titration method provides an accurate estimation of the VFA concentration, clearly corresponding with the true value. Concerning the H2CO3*-alkalinity, the most accurate and precise estimations, showing very similar results for repeated measurements, were obtained using the 8 pH point titration. Overall, it was concluded that the 5 pH point titration method is the preferred method for the practical monitoring of AD of solid wastes due to its robustness, cost efficiency and user-friendliness.

Effect of partitioning the nonfiber carbohydrate fraction and neutral detergent fiber method on digestibility of carbohydrates by dairy cows.

PubMed

Tebbe, A W; Faulkner, M J; Weiss, W P

2017-08-01

Many nutrition models rely on summative equations to estimate feed and diet energy concentrations. These models partition feed into nutrient fractions and multiply the fractions by their estimated true digestibility, and the digestible mass provided by each fraction is then summed and converted to an energy value. Nonfiber carbohydrate (NFC) is used in many models. Although it behaves as a nutritionally uniform fraction, it is a heterogeneous mixture of components. To reduce the heterogeneity, we partitioned NFC into starch and residual organic matter (ROM), which is calculated as 100 - CP - LCFA - ash - starch - NDF, where crude protein (CP), long-chain fatty acids (LCFA), ash, starch, and neutral detergent fiber (NDF) are a percentage of DM. However, the true digestibility of ROM is unknown, and because NDF is contaminated with both ash and CP, those components are subtracted twice. The effect of ash and CP contamination of NDF on in vivo digestibility of NDF and ROM was evaluated using data from 2 total-collection digestibility experiments using lactating dairy cows. Digestibility of NDF was greater when it was corrected for ash and CP than without correction. Conversely, ROM apparent digestibility decreased when NDF was corrected for contamination. Although correcting for contamination statistically increased NDF digestibility, the effect was small; the average increase was 3.4%. The decrease in ROM digestibility was 7.4%. True digestibility of ROM is needed to incorporate ROM into summative equations. Data from multiple digestibility experiments (38 diets) using dairy cows were collated, and ROM concentrations were regressed on concentration of digestible ROM (ROM was calculated without adjusting for ash and CP contamination). The estimated true digestibility coefficient of ROM was 0.96 (SE = 0.021), and metabolic fecal ROM was 3.43 g/100 g of dry matter intake (SE = 0.30). Using a smaller data set (7 diets), estimated true digestibility of ROM when calculated

A method to directly measure maximum volume of fish stomachs or digestive tracts

USGS Publications Warehouse

Burley, C.C.; Vigg, S.

1989-01-01

A new method for measuring maximum stomach or digestive tract volume of fish incorporates air injection at constant pressure with water displacement to measure directly the internal volume of a stomach or analogous structure. The method was tested with coho salmon, Oncorhynchus kisutch (Walbaum), which has a true stomach, and northern squawfish, Ptychocheilus oregonensis(Richardson), which has a modified foregut as a functional analogue. Both species were collected during July-October 1987 from the Columbia River, U.S.A. Relationships between fish weight (= volume) and maximum volume of the digestive organ were best fitted for coho salmon by an allometric model and for northern squawfish by an exponential model. Least squares regression analysis of individual measurements showed less variability in the volume of coho salmon stomachs (R2= 0.85) than in the total digestive tracts (R2= 0.55) and foreguts (R2= 0.61) of northern squawfish, relative to fish size. Compared to previous methods, the new technique has the advantage of accurately measuring the internal volume of a wide range of digestive organ shapes and sizes.

Ontogenetic changes in digestive enzyme activities and the amino acid profile of starry flounder Platichthys stellatus

NASA Astrophysics Data System (ADS)

Song, Zhidong; Wang, Jiying; Qiao, Hongjin; Li, Peiyu; Zhang, Limin; Xia, Bin

2016-09-01

Ontogenetic changes in digestive enzyme activities and the amino acid (AA) profile of starry flounder, Platichthys stellatus, were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements. Larvae were collected at the egg stage and 0, 2, 4, 7, 12, 17, 24 days after hatching (DAH) for analysis. Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH. Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH. Pepsin activity increased sharply beginning 17 DAH. Lipase activity increased significantly 4 DAH and increased progressively with larval growth. Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease. High free amino acid (FAA) content was detected in starry flounder eggs (110.72 mg/g dry weight). Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae. Most FAAs (except lysine and methionine) decreased >50% in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae. Changes in the protein amino acid (PAA) profile were much milder than those observed for FAAs. Most PAAs increased gradually during larval development, except lysine and phenylalanine. The percentages of free threonine, valine, isoleucine, and leucine decreased until the end of the trial, whereas the protein forms of these four AAs followed the opposite trend. A comparison of the essential AA composition of live food (rotifers, Artemia nauplii, and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA. These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food. Moreover, the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.

Influence of feed provisioning prior to digesta sampling on precaecal amino acid digestibility in broiler chickens.

PubMed

Siegert, Wolfgang; Ganzer, Christian; Kluth, Holger; Rodehutscord, Markus

2018-06-01

A regression approach was applied to determine the influence of feed provisioning prior to digesta sampling on precaecal (pc) amino acid (AA) digestibility in broiler chickens. Soybean meal was used as an example test ingredient. Five feed-provisioning protocols were investigated, four with restricted provision and one with ad libitum provision. When provision was restricted, feed was provided for 30 min after a withdrawal period of 12 h. Digesta were sampled 1, 2, 4 and 6 h after feeding commenced. A diet containing 300 g maize starch/kg was prepared. Half or all the maize starch was replaced with soybean meal in two other diets. Average pc digestibility of all determined AA in the soybean meal was 86% for the 4 and 6-h protocols and 66% and 60% for the 2 and 1-h protocols, respectively. Average pc AA digestibility of soybean meal was 76% for ad libitum feed provision. Feed provisioning also influenced the determined variance. Variance in digestibility ranked in magnitude 1 h > ad libitum > 2 h > 6 h > 4 h for all AA. Owing to the considerable influence of feed-provisioning protocols found in this study, comparisons of pc AA digestibility between studies applying different protocols prior to digesta sampling must be treated with caution. Digestibility experiments aimed at providing estimates for practical feed formulation should use feed-provisioning procedures similar to those used in practice.

An Evaluation of Partial Digestion Protocols for the Extraction and Measurement of Trace Metals of Environmental Concern in Marine and Estuarine Sediments

NASA Astrophysics Data System (ADS)

Winters, S. J.; Krahforst, C.; Sherman, L.; Kehm, K.

2013-12-01

As part of a broad study of the fate and transport of trace metals in estuarine sediments (Krahforst et al., 2013), the efficacy of commonly-used partial digestion protocols, including ISO 11466 (treatment with aqua regia), EPA 3050B (nitric acid followed by H2O2) and a modified rock digestion method ('RD' method- H2O2 followed by nitric), were evaluated for two NIST SRM materials, marine sediment 2702 and estuarine sediment 1646a. Unlike so-called total sediment digestions, the methods studied in this work do not employ hydrofluoric acid and are thought to leave silicates substantially or wholly intact. These methods can in principle compliment studies based on total digestions by providing information about trace metals in phases that are potentially more labile in the marine environment. Samples were digested in ~150 mg aliquots. Application of ISO 11466 and EPA 3050B followed published protocols except that digestions were carried out in trace-metal clean 15 mL capped Teflon vessels in an Al block digester and, at the end of the procedure, the supernatant was decanted from undigested material following repeated centrifugation in 2% nitric acid. Digested solutions were analyzed for Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Ag, Cd, Sn and Pb content by ICPMS. All elements were analyzed in collision reaction cell mode to minimize isobaric interferences, except Cd and Ag, which were analyzed in standard mode. Instrument performance was monitored in-run by analyzing the SRM 1643e and several quality-check standards. Two repeated digestions of SRM 2702 and SRM 1646a using EPA 3050B produced identical yields, within the standard deviation of repeated analyses (0 - 5%), for all analyzed elements except Cu, which varied by 30% for SRM 2702. The same was true for ISO 11466, although the standard deviation of repeated analyses for this digestion series tended to be larger (< ~15%). The RD method, which consists of pre-treatment with H2O2 followed by repeated treatments with

Thermal treatment of electronic waste in a fluidised bed and chemical digestion of solid products.

PubMed

Woynarowska, Amelia; Żukowski, Witold; Żelazny, Sylwester

2016-07-01

The article presents the results of e-waste thermal treatment in a fluidised bed reactor and solid products digestion under acidic conditions. During the processes, measurements of carbon monoxide, carbon dioxide, volatile organic compounds, nitrogen oxides, sulphur dioxide, hydrogen chloride, hydrogen bromide, hydrogen cyanide, ammonia, phenol, aliphatic and aromatic hydrocarbons, hydrogen fluoride and phosgene were carried out. Several digestion tests of the solid residue in sulphuric acid (VI) at 25 °C-65 °C, for 55 min-24 h were conducted. In each case, the dilution method was used, i.e. preliminary digestion in concentrated sulphuric acid (VI) (95%) for 40 min, and then dilution to expected concentrations (30%-50%). Most preferred results were obtained using sulphuric acid (VI) with a target concentration of 40% at 65 °C, where the leaching degrees were 76.56% for copper, 71.67% for iron, 91.89% for zinc and 97.40% for tin. The time necessary to effectively carry out the digestion process was 220 min. © The Author(s) 2016.

Metabolizable energy, nitrogen balance, and ileal digestibility of amino acids in quality protein maize for pigs

PubMed Central

2014-01-01

Background To compare the nutritional value and digestibility of five quality protein maize (QPM) hybrids to that of white and yellow maize, two experiments were carried out in growing pigs. In experiment 1, the energy metabolizability and the nitrogen balance of growing pigs fed one of five QPM hybrid diets were compared against those of pigs fed white or yellow maize. In experiment 2, the apparent and standardized ileal digestibility (AID and SID, respectively) of proteins and amino acids from the five QPM hybrids were compared against those obtained from pigs fed white and yellow maize. In both experiments, the comparisons were conducted using contrasts. Results The dry matter and nitrogen intakes were higher in the pigs fed the QPM hybrids (P < 0.05) than in the pigs fed white or yellow maize. Energy digestibility (P < 0.001) and metabolizability (P < 0.01) were higher in the pigs fed the white and yellow maize diets than in those fed the QPM diets. The AID of lysine was higher (P < 0.01) in the QPM diets than in the white and yellow maize. The AIDs of leucine, isoleucine, valine, phenylalanine, and methionine were lower in the QPM diets than those of maize (white and yellow) (all P < 0.05). Maize (white and yellow) had greater SIDs of leucine, isoleucine, valine, phenylalanine, glutamic acid, serine, alanine, tyrosine, and proline (P < 0.05). Conclusions Based on these results, it was concluded that QPM had a lower metabolizable energy content and a higher amount of digestible lysine than normal maize. PMID:25045520

Comparison of four USEPA digestion methods for trace metal analysis using certified and Florida soils

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

Chen, M.; Ma, L.Q.

1998-11-01

It is critical to compare existing sample digestion methods for evaluating soil contamination and remediation. USEPA Methods 3050, 3051, 3051a, and 3052 were used to digest standard reference materials and representative Florida surface soils. Fifteen trace metals (Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, and Za), and six macro elements (Al, Ca, Fe, K, Mg, and P) were analyzed. Precise analysis was achieved for all elements except for Cd, Mo, Se, and Sb in NIST SRMs 2704 and 2709 by USEPA Methods 3050 and 3051, and for all elements except for As, Mo,more » Sb, and Se in NIST SRM 2711 by USEPA Method 3052. No significant differences were observed for the three NIST SRMs between the microwave-assisted USEPA Methods 3051 and 3051A and the conventional USEPA Method 3050 Methods 3051 and 3051a and the conventional USEPA Method 3050 except for Hg, Sb, and Se. USEPA Method 3051a provided comparable values for NIST SRMs certified using USEPA Method 3050. However, for method correlation coefficients and elemental recoveries in 40 Florida surface soils, USEPA Method 3051a was an overall better alternative for Method 3050 than was Method 3051. Among the four digestion methods, the microwave-assisted USEPA Method 3052 achieved satisfactory recoveries for all elements except As and Mg using NIST SRM 2711. This total-total digestion method provided greater recoveries for 12 elements Ag, Be, Cr, Fe, K, Mn, Mo, Ni, Pb, Sb, Se, and Zn, but lower recoveries for Mg in Florida soils than did the total-recoverable digestion methods.« less

[Acidophilic methanogens and their applications in anaerobic digestion].

PubMed

Guo, Xiao-Hui; Wu, Wei-Xiang; Han, Zhi-Ying; Shi, De-Zhi

2011-02-01

Methanogens play an important role in global carbon cycle. There exists a range of unknown methanogenic archaea in acidic peat lands, among which, acidophilic methanogens have attracted increasing research interests because of their special metabolic characteristics. To introduce acidophilic methanogens in the anaerobic digestion process of high concentration organic wastes or waste water could essentially overcome the inhibition of acid accumulation on the methanogens and help reduce the operation cost, broadening the industrial application of anaerobic bio-treatment technology. In this paper, we reviewed the recent researches on acidophilic methanogens, with the focus on enrichment and isolation methods, physiological and biochemical characters, metabolic characteristics, and application of molecular biology. The potential applications of acidophilic methanogens in anaerobic digestion process were analyzed and proposed, and the directions for further researches were suggested.

Identification and characterization of isomeric N-glycans of human alfa-acid-glycoprotein by stable isotope labelling and ZIC-HILIC-MS in combination with exoglycosidase digestion.

PubMed

Mancera-Arteu, Montserrat; Giménez, Estela; Barbosa, José; Sanz-Nebot, Victòria

2016-10-12

In this study, a ZIC-HILIC-MS methodology for the analysis of N-glycan isomers was optimized to obtain greater detection sensitivity and thus identify more glycan structures in hAGP. In a second step, this method was combined with glycan reductive isotope labelling (GRIL) through [(12)C6]/[(13)C6]-aniline and exoglycosidase digestion to characterize the different glycan isomers. The GRIL method allows the peak areas resulting from two different labelled samples to be compared, since neither retention time shifts nor variations in the ionization of glycans between these samples are obtained. First, sialic acid linkage assignations were performed for most hAGP glycan isomers with α2-3 sialidase digestion. Bi-, tri- and tetraantennary glycan isomers with different terminal sialic acid linkages to galactose (α2-3 or α2-6) were assigned, and the potential of this technique for the structural characterization of isobaric isomers was therefore demonstrated. Furthermore, fucose linkage isomers of hAGP glycans were also characterized using this isotope-labelling approach in combination with α1-3,4 fucosidase and β1-4 galactosidase digestion. α1-3 antennary fucoses and α1-6 core fucosylation were detected in hAGP fucosylated glycans. These established methodologies can be extremely useful for patho-glycomic studies to characterize glycoproteins of biomedical interest and find novel glycan isomers that could be used as biomarkers in cancer research. Copyright © 2016 Elsevier B.V. All rights reserved.

[Effect of Ce3+ on volatile fatty acid concentrations during anaerobic granular sludge digestion].

PubMed

Liang, Rui; Xia, Qing; Ding, Li-Li; Shi, Xiao-Lei; Zhao, Ming-Yu; Ren, Hong-Qiang

2009-04-15

Batch experiments were conducted to investigate the effect of Ce3+ on volatile fatty acid(VFA) concentrations by anaerobic granular sludge digestion using D-Glucose and acetic sodium as substrate in the state of stabilization and restart-up. Results show that when the concentration of Ce3+ is lower than 1 mg/L, VFA concentration decreases, which suggests the transformation of butyric acid to acetic acid and acetic acid to methane is promoted. When the concentration of Ce3+ is 1-10 mg/L, the bacterial activity decreases and decomposition of the acetic acid and butyric acid becomes more difficult compared with the control. Adding Ce3+ brings little change in the constitution of VFA: 96% of VFA is acetic acid and butyric acid, while the propionic acid accounts for less than 3%. With the acetic sodium as the sole carbon and energy source, adding 0.05 mg/L Ce3+ could accelerate acetate degradation. After being conserved for 4 months, the activity of the Ce-containing anaerobic granular sludge is higher than that of the Ce-free sludge. The present of Ce contributes to the restart-up of anaerobic reactors.

Method for producing labeled single-stranded nucleic acid probes

DOEpatents

Dunn, John J.; Quesada, Mark A.; Randesi, Matthew

1999-10-19

Disclosed is a method for the introduction of unidirectional deletions in a cloned DNA segment. More specifically, the method comprises providing a recombinant DNA construct comprising a DNA segment of interest inserted in a cloning vector, the cloning vector having an f1 endonuclease recognition sequence adjacent to the insertion site of the DNA segment of interest. The recombinant DNA construct is then contacted with the protein pII encoded by gene II of phage f1 thereby generating a single-stranded nick. The nicked DNA is then contacted with E. coli Exonuclease III thereby expanding the single-stranded nick into a single-stranded gap. The single-stranded gapped DNA is then contacted with a single-strand-specific endonuclease thereby producing a linearized DNA molecule containing a double-stranded deletion corresponding in size to the single-stranded gap. The DNA treated in this manner is then incubated with DNA ligase under conditions appropriate for ligation. Also disclosed is a method for producing single-stranded DNA probes. In this embodiment, single-stranded gapped DNA, produced as described above, is contacted with a DNA polymerase in the presence of labeled nucleotides to fill in the gap. This DNA is then linearized by digestion with a restriction enzyme which cuts outside the DNA segment of interest. The product of this digestion is then denatured to produce a labeled single-stranded nucleic acid probe.

Bioaccessibility and inhibitory effects on digestive enzymes of carnosic acid in sage and rosemary.

PubMed

Ercan, Pınar; El, Sedef Nehir

2018-04-28

In this study, the aim was to determine the bioaccessibilities of carnosic acid in sage and rosemary and in vitro inhibitory effects of these samples on lipid and starch digestive enzymes by evaluating the lipase, α-amylase and α-glucosidase enzyme inhibition activities. The content of carnosic acid in rosemary (18.72 ± 0.33 mg/g) was found to be higher than that content of that in sage (3.76 ± 0.13 mg/g) (p < 0.05). The carnosic acid bioaccessibilities were found as 45.10 ± 1.88% and 38.32 ± 0.21% in sage and rosemary, respectively. The tested sage and rosemary showed inhibitory activity against α-glucosidase (Concentration of inhibitor required to produce a 50% inhibition of the initial rate of reaction - IC 50 88.49 ± 2.35, 76.80 ± 1.68 μg/mL, respectively), α-amylase (IC 50 107.65 ± 12.64, 95.65 ± 2.73 μg/mL, respectively) and lipase (IC 50 6.20 ± 0.63, 4.31 ± 0.62 μg/mL, respectively). Furthermore, to the best of our knowledge, this is the first work that carnosic acid standard equivalent inhibition capacities (CAEIC 50 ) for these food samples were determined and these values were in agreement with the IC 50 values. These results show that sage and rosemary are potent inhibitors of lipase, α-amylase and α-glucosidase digestive enzymes. Copyright © 2018 Elsevier B.V. All rights reserved.

Anaerobic digestion of glycerol and co-digestion of glycerol and pig manure.

PubMed

Nuchdang, Sasikarn; Phalakornkule, Chantaraporn

2012-06-30

The potential of glycerol obtained from transesterification of waste cooking oil as a main carbon source for biogas production was investigated. The glycerol was highly contaminated with oils and fats and was pretreated with sulfuric acid. Using a carbon source of glucose as a control, we compared biogas production from the acid-treated glycerol in a synthetic medium and the acid-treated glycerol mixed with pig manure. The anaerobic digestion of acid-treated glycerol with supplement in a synthetic medium was found to be satisfactory at organic loading rates (OLR) between 1.3, 1.6 and 2.6 g chemical oxygen demand (COD) L(-1) d(-1). The maximum methane yield of 0.32 L at Standard temperature and pressure (STP) g(-1) COD removal was achieved at an OLR of 1.6 g COD L(-1) d(-1) and the methane content was 54% on an average. At a higher organic loading rate of 5.4 g COD L(-1) d(-1), the propionic acid to acetic acid ratio was higher than the critical threshold limit for metabolic imbalance. Anaerobic digestion of acid-treated glycerol with pig manure was also investigated at the COD ratio of 80:20 (glycerol:pig manure). The anaerobic digestion of acid-treated glycerol with pig manure was found to be satisfactory at organic loading rates between 1.3, 1.7, 2.9 and 5.0 g COD L(-1) d(-1) in terms of COD reduction (>80%) and methane content of (62% on an average). However, the biogas production rate was found to significantly decrease at the highest load. The maximum methane yield of 0.24 L STP g(-1) COD removal was achieved at an OLR of 1.3 g COD L(-1) d(-1). Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of Chain Length and Degree of Unsaturation of Fatty Acids on Structure and in Vitro Digestibility of Starch-Protein-Fatty Acid Complexes.

PubMed

Zheng, Mengge; Chao, Chen; Yu, Jinglin; Copeland, Les; Wang, Shuo; Wang, Shujun

2018-02-28

The effects of chain length and degree of unsaturation of fatty acids (FAs) on structure and in vitro digestibility of starch-protein-FA complexes were investigated in model systems. Studies with the rapid visco analyzer (RVA) showed that the formation of ternary complex resulted in higher viscosities than those of binary complex during the cooling and holding stages. The results of differential scanning calorimetry (DSC), Raman, and X-ray diffraction (XRD) showed that the structural differences for ternary complexes were much less than those for binary complexes. Starch-protein-FA complexes presented lower in vitro enzymatic digestibility compared with starch-FAs complexes. We conclude that shorter chain and lower unsaturation FAs favor the formation of ternary complexes but decrease the thermal stability of these complexes. FAs had a smaller effect on the ordered structures of ternary complexes than on those of binary complexes and little effect on enzymatic digestibility of both binary and ternary complexes.

Fermentation by amylolytic lactic acid bacteria and consequences for starch digestibility of plantain, breadfruit, and sweet potato flours.

PubMed

Haydersah, Julien; Chevallier, Isabelle; Rochette, Isabelle; Mouquet-Rivier, Claire; Picq, Christian; Marianne-Pépin, Thérèse; Icard-Vernière, Christèle; Guyot, Jean-Pierre

2012-08-01

The potential of tropical starchy plants such as plantain (Musa paradisiaca), breadfruit (Artocarpus communis), and sweet potato (Ipomoea batatas) for the development of new fermented foods was investigated by exploiting the capacity of some lactic acid bacteria to hydrolyze starch. The amylolytic lactic acid bacteria (ALAB) Lactobacillus plantarum A6 and Lactobacillus fermentum Ogi E1 were able to change the consistency of thick sticky gelatinized slurries of these starchy fruits and tubers into semiliquid to liquid products. Consequently, a decrease in apparent viscosity and an increase in Bostwick flow were observed. These changes and the production of maltooligosaccharides confirmed starch hydrolysis. Sucrose in sweet potato was not fermented by strain A6 and poorly fermented by strain Ogi E1, suggesting possible inhibition of sucrose fermentation. In all 3 starchy plants, rapidly digestible starch (RDS) was higher than slowly digestible starch (SDS) and resistant starch (RS) represented between 17% and 30% dry matter (DM). The digestibility of plantain was not affected by fermentation, whereas the RDS content of breadfruit and sweet potato decreased and the RS content increased after fermentation. The characteristics resulting from different combinations of gluten free starchy plants (plantain, breadfruit, sweet potato) and amylolytic lactic acid bacteria (ALAB) offer opportunities to develop new functional fermented beverages, mainly for breadfruit and sweet potato, after further investigation of their formulation, sensory attributes, nutritional, and prebiotic characteristics. Journal of Food Science © 2012 Institute of Food Technologists® No claim to original US government works.

Variability in amino acid digestibility and metabolizable energy of corn studied in cecectomized laying hens1.

PubMed

Zuber, T; Rodehutscord, M

2017-06-01

To optimize the use of corn grain in diets for laying hens, differences in amino acid (AA) digestibility and metabolizable energy among different corn samples should be considered in feed formulation. The present study investigated the variability of AA digestibility and AMEn concentration of 20 corn samples in cecectomized laying hens. Corn grains were characterized based on their physical properties (thousand seed weight, test weight, grain density, and extract viscoelasticity), chemical composition (proximate nutrients, AA, minerals, and inositol phosphates), gross energy concentration, and in vitro solubility of nitrogen to study any relationship with AA digestibility or AMEn. The animal study comprised 4 Latin squares (6 × 6) distributed between 2 subsequent runs. Cecectomized LSL-Classic hens were individually housed in metabolism cages and fed either a basal diet containing 500 g/kg cornstarch or one of 20 corn diets, each replacing the cornstarch with one corn batch, for 8 days. During the last 4 d, feed intake was recorded and excreta were collected quantitatively. A linear regression approach was used to calculate AA digestibility of the corn. The digestibility of all AA differed significantly between the 20 corn batches, including Lys (digestibility range 64 to 85%), Met (86 to 94%), Thr (72 to 89%), and Trp (21 to 88%). The AMEn of the corn batches ranged between 15.7 and 17.1 MJ/kg DM. However, consistent correlations between AA digestibility or AMEn and the physical and chemical characteristics of the grains were not detected. Equations to predict AA digestibility or AMEn based on the grain's physical and chemical characteristics were calculated by multiple linear regressions. The explanatory power (adjusted R2;) of prediction equations was below 0.6 for the majority of AA and AMEn, and, thus, was not sufficiently precise for practical use. Possible explanations for the variation in AA digestibility and AMEn beyond the determined characteristics

Different sources of omega-3 polyunsaturated fatty acids affects apparent digestibility, tissue deposition, and tissue oxidative stability in growing female rats.

PubMed

Tou, Janet C; Altman, Stephanie N; Gigliotti, Joseph C; Benedito, Vagner A; Cordonier, Elizabeth L

2011-10-14

Numerous health benefits associated with increased omega-3 polyunsaturated fatty acid (n-3 PUFA) consumption has lead to an increasing variety of available n-3 PUFA sources. However, sources differ in the type, amount, and structural form of the n-3 PUFAs. Therefore, the objective of this study was to determine the effect of different sources of ω-3 PUFAs on digestibility, tissue deposition, eicosanoid metabolism, and oxidative stability. Female Sprague-Dawley rats (age 28 d) were randomly assigned (n = 10/group) to be fed a high fat 12% (wt) diet consisting of either corn oil (CO) or n-3 PUFA rich flaxseed (FO), krill (KO), menhaden (MO), salmon (SO) or tuna (TO) oil for 8 weeks. Rats were individually housed in metabolic cages to determine fatty acid digestibility. Diet and tissue fatty acid composition was analyzed by gas chromatography and lipid classes using thin layer chromatography. Eicosanoid metabolism was determined by measuring urinary metabolites of 2-series prostaglandins (PGs) and thromoboxanes (TXBs) using enzyme immunoassays. Oxidative stability was assessed by measuring thiobarbituric acid reactive substances (TBARS) and total antioxidant capacity (TAC) using colorimetric assays. Gene expression of antioxidant defense enzymes was determined by real time quantitative polymerase chain reaction (RT-qPCR). Rats fed KO had significantly lower DHA digestibility and brain DHA incorporation than SO and TO-fed rats. Of the n-3 PUFA sources, rats fed SO and TO had the highest n-3 PUFAs digestibility and in turn, tissue accretion. Higher tissue n-3 LC-PUFAs had no significant effect on 2-series PG and TXB metabolites. Despite higher tissue n-3 LC-PUFA deposition, there was no increase in oxidation susceptibility indicated by no significant increase in TBARS or decrease in TAC and gene expression of antioxidant defense enzymes, in SO or TO-fed rats. On the basis that the optimal n-3 PUFA sources should provide high digestibility and efficient tissue

Mechanism, Kinetics and Microbiology of Inhibition Caused by Long-Chain Fatty Acids in Anaerobic Digestion of Algal Biomass

DOE PAGES

Ma, Jingwei; Zhao, Quan-Bao; Laurens, Lieve L.; ...

2015-09-15

Oleaginous microalgae contain a high level of lipids, which can be extracted and converted to biofuel. The lipid-extracted residue can then be further utilized through anaerobic digestion to produce biogas. However, long-chain fatty acids (LCFAs) have been identified as the main inhibitory factor on microbial activity of anaerobic consortium. In this study, the mechanism of LCFA inhibition on anaerobic digestion of whole and lipid-extracted algal biomass was investigated with a range of calcium concentrations against various inoculum to substrate ratios as a means to alleviate the LCFA inhibition.

Mechanism, Kinetics and Microbiology of Inhibition Caused by Long-Chain Fatty Acids in Anaerobic Digestion of Algal Biomass

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

Ma, Jingwei; Zhao, Quan-Bao; Laurens, Lieve L.

Oleaginous microalgae contain a high level of lipids, which can be extracted and converted to biofuel. The lipid-extracted residue can then be further utilized through anaerobic digestion to produce biogas. However, long-chain fatty acids (LCFAs) have been identified as the main inhibitory factor on microbial activity of anaerobic consortium. In this study, the mechanism of LCFA inhibition on anaerobic digestion of whole and lipid-extracted algal biomass was investigated with a range of calcium concentrations against various inoculum to substrate ratios as a means to alleviate the LCFA inhibition.

Assessment of the mobile bag method for estimation of in vivo starch digestibility.

PubMed

Ghoorchi, T; Lund, P; Larsen, M; Hvelplund, T; Hansen-Møller, J; Weisbjerg, M R

2013-02-01

The objective was to assess the ability of the in situ mobile nylon bag method for predicting small intestinal and total tract starch digestibility. Starch disappearance was measured for 18 samples of different cereals and legumes subjected to different physical and chemical processing methods and compared with coherent in vivo digestibility. Starch disappearance was measured both with and without initial ruminal pre-incubation during 4 h. Bags were retrieved from either the ileal cannula or faeces. Two dry Danish Holstein cows fitted with rumen cannulas were used for rumen pre-incubations and two lactating Danish Holstein cows fitted with duodenal and ileal cannulas were used for intestinal incubations. Rumen pre-incubation had no significant effect on disappearance from bags recovered in faeces. The disappearance of legume starch was lower, both in the rumen and small intestine, compared with starch from barley, wheat, oats, ear maize and maize. Transit times of the mobile bags from duodenum to ileum were not significantly different between feeds. A weak positive correlation was found between in vivo small intestinal and total tract digestibility of starch and disappearance obtained using the mobile bag technique across a broad range of starch sources. Omitting two less conventional starch sources (NaOH wheat and xylose-treated barley) resulted in a high (0.87) correlation between total tract in vivo digestibility and mobile bag disappearance. The use of the mobile bag method for estimation of in vivo starch digestibility will therefore depend on the starch type.

EPA Method 245.2: Mercury (Automated Cold Vapor Technique)

EPA Pesticide Factsheets

Method 245.2 describes procedures for preparation and analysis of drinking water samples for analysis of mercury using acid digestion and cold vapor atomic absorption. Samples are prepared using an acid digestion technique.

Effect of biopolymer encapsulation on the digestibility of lipid and cholesterol oxidation products in beef during in vitro human digestion.

PubMed

Hur, Sun Jin; Lee, Seung Yuan; Lee, Seung-Jae

2015-01-01

In this study, beef patties were encapsulated with 3% chitosan, pectin, onion powder, or green tea powder and the beef patties were then passed through an in vitro human digestion model. The total lipid digestibility was lowest (p<0.05) in beef patties encapsulated with chitosan and pectin after digestion in the small intestine. Thiobarbituric acid reactive substance (TBARS) values were significantly lower (p<0.05) for beef patties encapsulated with chitosan and pectin, when compared with the control, after digestion in the small intestine. In contrast, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging activity was highest (p<0.05) in beef patties encapsulated with onion powder and green tea powder after digestion in the small intestine. The total cholesterol oxidation product (COP) content was significantly lower (p<0.05) in beef patties encapsulated with biopolymers than in the control after digestion in the small intestine. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optimization of the pepsin digestion method for anisakids inspection in the fishing industry.

PubMed

Llarena-Reino, María; Piñeiro, Carmen; Antonio, José; Outeriño, Luis; Vello, Carlos; González, Ángel F; Pascual, Santiago

2013-01-31

During the last 50 years human anisakiasis has been rising while parasites have increased their prevalence at determined fisheries becoming an emergent major public health problem. Although artificial enzymatic digestion procedure by CODEX (STAN 244-2004: standard for salted Atlantic herring and salted sprat) is the recommended protocol for anisakids inspection, no international agreement has been achieved in veterinary and scientific digestion protocols to regulate this growing source of biological hazard in fish products. The aim of this work was to optimize the current artificial digestion protocol by CODEX with the purpose of offering a faster, more useful and safer procedure for factories workers, than the current one for anisakids detection. To achieve these objectives, the existing pepsin chemicals and the conditions of the digestion method were evaluated and assayed in fresh and frozen samples, both in lean and fatty fish species. Results showed that the new digestion procedure considerably reduces the assay time, and it is more handy and efficient (the quantity of the resulting residue was considerably lower after less time) than the widely used CODEX procedure. In conclusion, the new digestion method herein proposed based on liquid pepsin format is an accurate reproducible and user-friendly off-site tool, that can be useful in the implementation of screening programs for the prevention of human anisakiasis (and associated gastroallergic disorders) due to the consumption of raw or undercooked contaminated seafood products. Copyright © 2012 Elsevier B.V. All rights reserved.

Nitrogen utilization and digestibility of amino acids by lambs fed a high-concentrate diet with limestone or magnesium oxide.

PubMed

Christiansen, M L; Webb, K E

1990-07-01

Effects were evaluated of high dietary levels of magnesium oxide (MgO) or limestone on DM, OM and CP digestibility, N balance and intestinal absorption of amino acids by lambs fed a high concentrate diet. Twelve wether lambs equipped with abomasal and ileal cannulas were blocked by weight and breeding and allotted to treatments in a randomized block design in two consecutive trials. Diets were control (800 g), control plus 1.5% MgO (812 g), control plus 1.5% limestone (812 g) and control plus 3.0% limestone (824 g) fed in two equal portions at 12-h intervals. Ruminal fluid pH differences were small. The pH of ileal digesta was greater (P less than .05) with MgO than with limestone (8.23 vs 7.73). Fecal pH was higher (P less than .01) for lambs fed all mineral treatments (avg 8.75) than for lambs fed the control (7.61) and was higher (P less than .01) when MgO (9.53) rather than limestone (8.36) was fed. Ruminal NH3N was lower (P less than .01) when lambs were fed MgO (11.9 mg/dl) compared with limestone (avg 31.2 mg/dl). Preintestinal DM digestibility was greatest (P less than .10) with limestone (avg 49.5%) feeding compared with feeding MgO (31.2%) or the control (35.4%). About 41.5% more essential (P less than .05) and 48% more nonessential (P less than .03) amino acids reached the small intestine when MgO was fed than when limestone was fed. Partial digestibility of amino acids in the small intestine was reduced (P less than .03) an average of 5 percentage units when MgO or limestone was fed. Feeding high levels of MgO or limestone to lambs did not improve the overall digestibility of DM, OM or CP. In fact, feeding high levels of MgO or limestone appeared to be detrimental, reducing intestinal absorption of amino acids.

Anaerobic sludge digestion with a biocatalytic additive

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

Ghosh, S.; Henry, M.P.; Fedde, P.A.

1982-01-01

The objective of this research was to evaluate the effects of a lactobacillus additive an anaerobic sludge digestion under normal, variable, and overload operating conditions. The additive was a whey fermentation product of an acid-tolerant strain of Lactobacillus acidophilus fortified with CaCO/sub 3/, (NH/sub 4/)/sub 2/HPO/sub 4/, ferrous lactate, and lactic acid. The lactobacillus additive is multifunctional in nature and provides growth factors, metabolic intermediates, and enzymes needed for substrate degradation and cellular synthesis. The experimental work consisted of several pairs of parallel mesophilic (35/sup 0/C) digestion runs (control and test) conducted in five experimental phases. Baseline runs without themore » additive showed that the two experimental digesters had the same methane content, gas production rate (GPR), and ethane yield. The effect of the additive was to increase methane yield and GPR by about 5% (which was statistically significant) during digester operation at a loading rate (LR) of 3.2 kg VS/m/sup 3/-day and a hydraulic retention time (HRT) of 14 days. Data collected from the various experimental phases showed that the biochemical additive increased methane yield, gas production rate, and VS reduction, and decreased volatile acids accumulation. In addition, it enhanced digester buffer capacity and improved the fertilizer value and dewatering characteristics of the digested residue.« less

Phosphorus Concentrations in Sequentially Fractionated Soil Samples as Affected by Digestion Methods

PubMed Central

do Nascimento, Carlos A. C.; Pagliari, Paulo H.; Schmitt, Djalma; He, Zhongqi; Waldrip, Heidi

2015-01-01

Sequential fractionation has helped improving our understanding of the lability and bioavailability of P in soil. Nevertheless, there have been no reports on how manipulation of the different fractions prior to analyses affects the total P (TP) concentrations measured. This study investigated the effects of sample digestion, filtration, and acidification on the TP concentrations determined by ICP-OES in 20 soil samples. Total P in extracts were either determined without digestion by ICP-OES, or ICP-OES following block digestion, or autoclave digestion. The effects of sample filtration, and acidification on undigested alkaline extracts prior to ICP-OES were also evaluated. Results showed that, TP concentrations were greatest in the block-digested extracts, though the variability introduced by the block-digestion was the highest. Acidification of NaHCO3 extracts resulted in lower TP concentrations, while acidification of NaOH randomly increased or decreased TP concentrations. The precision observed with ICP-OES of undigested extracts suggests this should be the preferred method for TP determination in sequentially extracted samples. Thus, observations reported in this work would be helpful in appropriate sample handling for P determination, thereby improving the precision of P determination. The results are also useful for literature data comparison and discussion when there are differences in sample treatments. PMID:26647644

Expression of a fungal ferulic acid esterase in alfalfa modifies cell wall digestibility

PubMed Central

2014-01-01

Background Alfalfa (Medicago sativa) is an important forage crop in North America owing to its high biomass production, perennial nature and ability to fix nitrogen. Feruloyl esterase (EC 3.1.1.73) hydrolyzes ester linkages in plant cell walls and has the potential to further improve alfalfa as biomass for biofuel production. Results In this study, faeB [GenBank:AJ309807] was synthesized at GenScript and sub-cloned into a novel pEACH vector containing different signaling peptides to target type B ferulic acid esterase (FAEB) proteins to the apoplast, chloroplast, endoplasmic reticulum and vacuole. Four constructs harboring faeB were transiently expressed in Nicotiana leaves, with FAEB accumulating at high levels in all target sites, except chloroplast. Stable transformed lines of alfalfa were subsequently obtained using Agrobacterium tumefaciens (LBA4404). Out of 136 transgenic plants regenerated, 18 independent lines exhibited FAEB activity. Subsequent in vitro digestibility and Fourier transformed infrared spectroscopy (FTIR) analysis of FAEB-expressing lines showed that they possessed modified cell wall morphology and composition with a reduction in ester linkages and elevated lignin content. Consequently, they were more recalcitrant to digestion by mixed ruminal microorganisms. Interestingly, delignification by alkaline peroxide treatment followed by exposure to a commercial cellulase mixture resulted in higher glucose release from transgenic lines as compared to the control line. Conclusion Modifying cell wall crosslinking has the potential to lower recalcitrance of holocellulose, but also exhibited unintended consequences on alfalfa cell wall digestibility due to elevated lignin content. The combination of efficient delignification treatment (alkaline peroxide) and transgenic esterase activity complement each other towards efficient and effective digestion of transgenic lines. PMID:24650274

An efficient method to improve the production of methane from anaerobic digestion of waste activated sludge.

PubMed

Li, Xiaolan; Xu, Xueqin; Huang, Shansong; Zhou, Yun; Jia, Haijiang

2017-10-01

Methane production from waste activated sludge (WAS) anaerobic digestion is always low due to slow hydrolysis rate and inappropriate ratio of carbon to nitrogen (C/N). In this work, a novel approach, i.e., co-digestion of WAS and tobacco waste (TW) using ozone pretreatment, to greatly enhance the production of methane is reported. Experimental results showed the optimal C/N and ozone dosage for methane production was 24:1 and 90 mg/g suspended solids, and the corresponding methane production was 203.6 mL/g volatile suspended solids, which was 1.3-fold that in mono-WAS digestion. Further investigation showed the co-digestion of WAS and TW was beneficial to the consumptions of protein and cellulose; also, the presence of ozone enhanced the disruption of organic substrates and production of short chain fatty acids, which provided sufficient digestion substrates for methane generation. Analysis of microbial community structure suggested that members of the phyla Bacteroidetes and Firmicutes were the dominant species when ozone pretreatment was applied. The findings obtained in this work might be of great importance for the treatment of WAS and TW.

Neutral fat hydrolysis and long-chain fatty acid oxidation during anaerobic digestion of slaughterhouse wastewater.

PubMed

Masse, L; Massé, D I; Kennedy, K J; Chou, S P

2002-07-05

Neutral fat hydrolysis and long-chain fatty acid (LCFA) oxidation rates were determined during the digestion of slaughterhouse wastewater in anaerobic sequencing batch reactors operated at 25 degrees C. The experimental substrate consisted of filtered slaughterhouse wastewater supplemented with pork fat particles at various average initial sizes (D(in)) ranging from 60 to 450 microm. At the D(in) tested, there was no significant particle size effect on the first-order hydrolysis rate. The neutral fat hydrolysis rate averaged 0.63 +/- 0.07 d(-1). LCFA oxidation rate was modelled using a Monod-type equation. The maximum substrate utilization rate (kmax) and the half-saturation concentration (Ks) averaged 164 +/- 37 mg LCFA/L/d and 35 +/- 31 mg LCFA/L, respectively. Pork fat particle degradation was mainly controlled by LCFA oxidation rate and, to a lesser extent, by neutral fat hydrolysis rate. Hydrolysis pretreatment of fat-containing wastewaters and sludges should not substantially accelerate their anaerobic treatment. At a D(in) of 450 microm, fat particles were found to inhibit methane production during the initial 20 h of digestion. Inhibition of methane production in the early phase of digestion was the only significant effect of fat particle size on anaerobic digestion of pork slaughterhouse wastewater. Soluble COD could not be used to determine the rate of lipid hydrolysis due to LCFA adsorption on the biomass.

Semi-continuous anaerobic digestion of different silage crops: VFAs formation, methane yield from fiber and non-fiber components and digestate composition.

PubMed

Pokój, T; Bułkowska, K; Gusiatin, Z M; Klimiuk, E; Jankowski, K J

2015-08-01

This study presents the results of long-term semi-continuous experiments on anaerobic digestion at an HRT of 45d with ten silages: 2 annual and 4 perennial crops, and 4 mixtures of annual with perennial crops. The composition of substrates and digestates was determined with Van Soest's fractionation method. Removal of non-fiber materials ranged from 49.4% (Miscanthus sacchariflorus) to 89.3% (Zea mays alone and mixed with M. sacchariflorus), that of fiber materials like lignin ranged from 0.005% (Z. mays alone and mixed with grasses at VS ratio of 90:10%) to 46.5% (Sida hermaphrodita). The lowest stability of anaerobic digestion, as confirmed by normalized data concentrations of volatile fatty acids, was reported for both miscanthuses and sugar sorghum. The methane yield coefficients for non-fiber and fiber materials were 0.3666 and 0.2556L/g, respectively. All digestate residues had high fertilizing value, especially those from mixtures of crops. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Digestive utilization of purified cellulose in the rainbow trout (Salmo gairdneri) and the common carp (Cyprinus carpio)].

PubMed

Bergot, F

1981-01-01

A semi-purified diet containing 22 p. 100 of a wood cellulose extract without lignin but still containing 22 p. 100 of hemicelluloses was distributed for one month to rainbow trout and common carp reared at 17 and 20 degrees C, respectively. The digestibility of the main dietary constituents was determined by an indirect method using chrome oxide as an inert tracer. The feces were recovered by a continuous automatic collector which rapidly removed them from the water, minimizing alteration by leaching. The cellulose content was estimated by the Weende (crude fiber) and the Van Soest (neutral detergent fiber and acid detergent fiber) methods. The digestibility coefficients obtained for trout as well as for carp indicate that cellulose and hemicelluloses were not digested. In both species, volatile fatty acid concentration in the different segments of the digestive tract was low (less than 10 mM/l). These results lead us to suggest that trout and carp cannot degrade purified cellulose.

Plasmonic Thermal Decomposition/Digestion of Proteins: A Rapid On-Surface Protein Digestion Technique for Mass Spectrometry Imaging.

PubMed

Zhou, Rong; Basile, Franco

2017-09-05

A method based on plasmon surface resonance absorption and heating was developed to perform a rapid on-surface protein thermal decomposition and digestion suitable for imaging mass spectrometry (MS) and/or profiling. This photothermal process or plasmonic thermal decomposition/digestion (plasmonic-TDD) method incorporates a continuous wave (CW) laser excitation and gold nanoparticles (Au-NPs) to induce known thermal decomposition reactions that cleave peptides and proteins specifically at the C-terminus of aspartic acid and at the N-terminus of cysteine. These thermal decomposition reactions are induced by heating a solid protein sample to temperatures between 200 and 270 °C for a short period of time (10-50 s per 200 μm segment) and are reagentless and solventless, and thus are devoid of sample product delocalization. In the plasmonic-TDD setup the sample is coated with Au-NPs and irradiated with 532 nm laser radiation to induce thermoplasmonic heating and bring about site-specific thermal decomposition on solid peptide/protein samples. In this manner the Au-NPs act as nanoheaters that result in a highly localized thermal decomposition and digestion of the protein sample that is independent of the absorption properties of the protein, making the method universally applicable to all types of proteinaceous samples (e.g., tissues or protein arrays). Several experimental variables were optimized to maximize product yield, and they include heating time, laser intensity, size of Au-NPs, and surface coverage of Au-NPs. Using optimized parameters, proof-of-principle experiments confirmed the ability of the plasmonic-TDD method to induce both C-cleavage and D-cleavage on several peptide standards and the protein lysozyme by detecting their thermal decomposition products with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The high spatial specificity of the plasmonic-TDD method was demonstrated by using a mask to digest designated sections of

Investigation into the effect of high concentrations of volatile fatty acids in anaerobic digestion on methanogenic communities

PubMed Central

Franke-Whittle, Ingrid H.; Walter, Andreas; Ebner, Christian; Insam, Heribert

2014-01-01

A study was conducted to determine whether differences in the levels of volatile fatty acids (VFAs) in anaerobic digester plants could result in variations in the indigenous methanogenic communities. Two digesters (one operated under mesophilic conditions, the other under thermophilic conditions) were monitored, and sampled at points where VFA levels were high, as well as when VFA levels were low. Physical and chemical parameters were measured, and the methanogenic diversity was screened using the phylogenetic microarray ANAEROCHIP. In addition, real-time PCR was used to quantify the presence of the different methanogenic genera in the sludge samples. Array results indicated that the archaeal communities in the different reactors were stable, and that changes in the VFA levels of the anaerobic digesters did not greatly alter the dominating methanogenic organisms. In contrast, the two digesters were found to harbour different dominating methanogenic communities, which appeared to remain stable over time. Real-time PCR results were inline with those of microarray analysis indicating only minimal changes in methanogen numbers during periods of high VFAs, however, revealed a greater diversity in methanogens than found with the array. PMID:25164858

Larval digestion of different manure types by the black soldier fly (Diptera: Stratiomyidae) impacts associated volatile emissions.

PubMed

Beskin, Kelly V; Holcomb, Chelsea D; Cammack, Jonathan A; Crippen, Tawni L; Knap, Anthony H; Sweet, Stephen T; Tomberlin, Jeffery K

2018-04-01

Volatile emissions from decomposing animal waste are known environmental pollutants. The black soldier fly, Hermetia illucens (L.), is being evaluated for industrialization as a means to recycle wastes and produce protein for use as food and feed. We examined the ability of black soldier fly larvae to reduce odorous compounds associated with animal wastes. Black soldier fly larvae were reared under laboratory conditions on poultry, swine, and dairy manure at feed rates of 18.0 and 27.0 g every other day until 40% reached the prepupal stage. Volatile emissions were collected and analyzed from freshly thawed as well as the digested waste when 90% of the black soldier fly larvae reached the prepupal stage. Volatiles were also collected simultaneously from manure not inoculated with black soldier fly larvae (non-digested) and held under similar conditions. Manure samples were analyzed for relative amounts of nine select odorous volatile organic compounds: phenol, 4-methylphenol, indole, 3-methylindole, propanoic acid, 2-methylpropanoic acid, butanoic acid, 3-methylbutanoic acid and pentanoic acid. Black soldier fly larvae reduced emissions of all volatile organic compounds by 87% or greater. Complete reductions were observed for 2-methly propanoic acid in digested poultry manure, phenol, 4-methylphenol, indole and all five fatty acids in digested swine manure, and 4-methylphenol, indole, 3-methylindole and all five acids in digested dairy manure. This study is the first to identify volatile emissions from manure digested by black soldier fly larvae and compare to those found in non-digested manure. These data demonstrate additional benefits of using black soldier fly larvae as a cost-effective and environmentally friendly means of livestock manure management in comparison to current methods. Black soldier fly larvae are capable of altering the overall profile of volatile organic compounds and reducing levels of targeted odorous compounds in livestock manure

Effect of the amino acid histidine on the uptake of cadmium from the digestive system of the blue crab, Callinectes sapidus

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

Pecon, J.; Powell, E.N.

1981-07-01

The digestive tract functions in the storage, metabolism, and excretion of heavy metals in invertebrates. The importance of the digestive tract and the processes governing digestion and absorption of nutrients in heavy metal uptake is becoming increasingly clear. The results of this study suggest that in order to understand the processes controlling heavy metal uptake in invertebrates, it will be necessary to investigate the role that digestion and absorption play in determining the transport rate of metals across the gut wall into the blood. For example, some amino acids increase metal absorption rates, whereas other compounds, such as phytate, decreasemore » metal absorption rates. The results also suggest that experimental designs to investigate metal absorption must include an appreciation of the significant role that the feeding state of the animal (e.g. fed or starved) and the role chelators, particularly those produced by the organisms themselves during digestion, may play in the observed uptake rates of metal ions.« less

Strain typing of acetic acid bacteria responsible for vinegar production by the submerged elaboration method.

PubMed

Fernández-Pérez, Rocío; Torres, Carmen; Sanz, Susana; Ruiz-Larrea, Fernanda

2010-12-01

Strain typing of 103 acetic acid bacteria isolates from vinegars elaborated by the submerged method from ciders, wines and spirit ethanol, was carried on in this study. Two different molecular methods were utilised: pulsed field gel electrophoresis (PFGE) of total DNA digests with a number of restriction enzymes, and enterobacterial repetitive intergenic consensus (ERIC) - PCR analysis. The comparative study of both methods showed that restriction fragment PFGE of SpeI digests of total DNA was a suitable method for strain typing and for determining which strains were present in vinegar fermentations. Results showed that strains of the species Gluconacetobacter europaeus were the most frequent leader strains of fermentations by the submerged method in the studied vinegars, and among them strain R1 was the predominant one. Results showed as well that mixed populations (at least two different strains) occurred in vinegars from cider and wine, whereas unique strains were found in spirit vinegars, which offered the most stressing conditions for bacterial growth. Copyright © 2010 Elsevier Ltd. All rights reserved.

System for chemically digesting low level radioactive, solid waste material

DOEpatents

Cowan, Richard G.; Blasewitz, Albert G.

1982-01-01

An improved method and system for chemically digesting low level radioactive, solid waste material having a high through-put. The solid waste material is added to an annular vessel (10) substantially filled with concentrated sulfuric acid. Concentrated nitric acid or nitrogen dioxide is added to the sulfuric acid within the annular vessel while the sulfuric acid is reacting with the solid waste. The solid waste is mixed within the sulfuric acid so that the solid waste is substantilly fully immersed during the reaction. The off gas from the reaction and the products slurry residue is removed from the vessel during the reaction.

Functional and in vitro gastric digestibility of the whey protein hydrogel loaded with nanostructured lipid carriers and gelled via citric acid-mediated crosslinking.

PubMed

Hashemi, Behnaz; Madadlou, Ashkan; Salami, Maryam

2017-12-15

Nanostructured lipid carriers (NLCs) with mean size of 347nm were fabricated and added into a heat-denatured whey protein solution. The subsequent crosslinking of proteins by citric acid or CaCl 2 resulted in the formation of cold-set hydrogels. Fourier transform infrared spectroscopy (FTIR) proposed formation of more hydrogen bonds in gel due to NLC loading or citric acid-mediated gelation. It was also found based on FITR spectroscopy that citric acid crosslinking disordered whey proteins. Scanning electron microscopy (SEM) imaging showed a non-porous and finely meshed microstructure for the crosslinked gels compared to non-crosslinked counterparts. Crosslinking also increased the firmness and water-holding capacity of gels. In pepsin-free fluid, a strong correlation existed between reduction in gel swellability and digestibility over periods up to 60min due to NLC loading and citric acid gelation. However, in peptic fluid, NLC loading and citric acid crosslinking brought about much higher decrease in digestibility than swellability. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Lipid Sources with Different Fatty Acid Profiles on Intake, Nutrient Digestion and Ruminal Fermentation of Feedlot Nellore Steers

PubMed Central

Fiorentini, Giovani; Carvalho, Isabela P. C.; Messana, Juliana D.; Canesin, Roberta C.; Castagnino, Pablo S.; Lage, Josiane F.; Arcuri, Pedro B.; Berchielli, Telma T.

2015-01-01

The present study was conducted to determine the effect of lipid sources with different fatty acid profiles on nutrient digestion and ruminal fermentation. Ten rumen and duodenal fistulated Nellore steers (268 body weight±27 kg) were distributed in a duplicated 5×5 Latin square. Dietary treatments were as follows: without fat (WF), palm oil (PO), linseed oil (LO), protected fat (PF; Lactoplus), and whole soybeans (WS). The roughage feed was corn silage (600 g/kg on a dry matter [DM] basis) plus concentrate (400 g/kg on a DM basis). The higher intake of DM and organic matter (OM) (p<0.001) was found in animals on the diet with PF and WF (around 4.38 and 4.20 kg/d, respectively). Treatments with PO and LO decreased by around 10% the total digestibility of DM and OM (p<0.05). The addition of LO decreased by around 22.3% the neutral detergent fiber digestibility (p = 0.047) compared with other diets. The higher microbial protein synthesis was found in animals on the diet with LO and WS (33 g N/kg OM apparently digested in the rumen; p = 0.040). The highest C18:0 and linolenic acid intakes occurred in animals fed LO (p<0.001), and the highest intake of oleic (p = 0.002) and C16 acids (p = 0.022) occurred with the diets with LO and PF. Diet with PF decreased biohydrogenation extent (p = 0.05) of C18:1 n9,c, C18:2 n6,c, and total unsaturated fatty acids (UFA; around 20%, 7%, and 13%, respectively). The diet with PF and WF increased the concentration of NH3-N (p<0.001); however, the diet did not change volatile fatty acids (p>0.05), such as the molar percentage of acetate, propionate, butyrate and the acetate:propionate ratio. Treatments PO, LO and with WS decreased by around 50% the concentration of protozoa (p<0.001). Diets with some type of protection (PF and WS) decreased the effects of lipid on ruminal fermentation and presented similar outflow of benefit UFA as LO. PMID:26580282

Stability of milk fat globule membrane proteins toward human enzymatic gastrointestinal digestion.

PubMed

Le, T T; Van de Wiele, T; Do, T N H; Debyser, G; Struijs, K; Devreese, B; Dewettinck, K; Van Camp, J

2012-05-01

The milk fat globule membrane (MFGM) fraction refers to the thin film of polar lipids and membrane proteins that surrounds fat globules in milk. It is its unique biochemical composition that renders MFGM with some beneficial biological activities, such as anti-adhesive effects toward pathogens. However, a prerequisite for the putative bioactivity of MFGM is its stability during gastrointestinal digestion. We, therefore, subjected MFGM material, isolated from raw milk, to an in vitro enzymatic gastrointestinal digestion. Sodium dodecyl sulfate PAGE, in combination with 2 staining methods, Coomassie Blue and periodic acid Schiff staining, was used to evaluate polypeptide patterns of the digest, whereas mass spectrometry was used to confirm the presence of specific MFGM proteins. Generally, it was observed that glycoproteins showed higher resistance to endogenous proteases compared with non-glycosylated proteins. Mucin 1 displayed the highest resistance to digestion and a considerable part of this protein was still detected at its original molecular weight after gastric and small intestine digestion. Cluster of differentiation 36 was also quite resistant to pepsin. A significant part of periodic acid Schiff 6/7 survived the gastric digestion, provided that the lipid moiety was not removed from the MFGM material. Overall, MFGM glycoproteins are generally more resistant to gastrointestinal digestion than serum milk proteins and the presence of lipids, besides glycosylation, may protect MFGM glycoproteins from gastrointestinal digestion. This gastrointestinal stability makes MFGM glycoproteins amenable to further studies in which their putative health-promoting effects can be explored. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

[Dependence of rumen fatty acid production on the composition of rations].

PubMed

Lebzien, P; Rohr, K; Oslage, H J

1981-10-01

In three experiments with two Black-and-White dairy cows the influence of soybean oil and coconut fat as well as that of rations rich in roughage and concentrated feed on the production of fatty acids were determined with the isotope dilution method. A change in the method of sampling from the rumen in the course of the investigations resulted in distinctly different absolute production quotas, which can presumably be traced back to the disproportionate mixing in of the isotope and/or different production quotas in various regions of the rumen. The relative differences between the production quotas dependent on the rations, however were approximately the same with both sampling methods, so that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation between the relation of acetic and propionic acid in the rumen fluid and the quotient from acetic and propionic acid produced. In contrast to this, a significant relation between the concentration of fatty acids and the production of fatty acids could not be ascertained. Soybean oil and coconut fat brought about a slightly better

Evaluation of collection method and diet effects on apparent digestibility and energy values of swine diets.

PubMed

Li, Y S; Tran, H; Bundy, J W; Burkey, T E; Kerr, B J; Nielsen, M K; Miller, P S

2016-06-01

Two experiments were conducted to investigate the effects of collection method and diet type on digestibility coefficients. In Exp. 1, 24 barrows were fed either a corn-soybean meal (CSBM) diet or CSBM with 20% dried distillers' grains with solubles (CSBM-DDGS). In Exp. 2, the effects of basal diet and collection method on determination of dried distillers' grains with solubles (DDGS) digestibility were studied using 24 barrows. The 4 diets used in Exp. 2 were: a CSBM (basal 1) , a barley-canola meal (BCM; basal 2), 80% basal 1 with 20% DDGS (CSBM-DDGS), and 80% basal 2 with 20% DDGS (BCM-DDGS). In both experiments, feces were collected using a time-based collection method (DY) or a "marker-to-marker" collection method (MM). Diets contained 0.5% of titanium dioxide (TiO) for estimating digestibility using the index marker approach (IM). The apparent total tract digestibility (ATTD) of DM and GE were lower ( < 0.05) in the CSBM-DDGS diet than in the CSBM diet in Exp. 1 but were not different in Exp. 2. All the estimates of BCM-based diets were consistently lower ( < 0.05) than those of CSBM-based diets. In Exp. 1, digestibility coefficients determined by the DY and MM were not different from each other, whereas those estimates were lower ( < 0.05) using the IM than those using the total collection approach (TC; DY and MM). In Exp. 2, interactions ( < 0.05) were observed between diet type and method for dietary digestibility coefficients. Digestibility and energy values estimated by the DY and MM were not different in pigs fed CSBM-based diets and the BCM-DDGS diet, whereas those estimates were greater ( < 0.05) using the DY than those using the MM in pigs fed the BCM. There were no interactions between basal diet and method for estimating DDGS digestibility. The ATTD of DM and GE of DDGS using the MM were greater ( < 0.05) than those using the IM, and ATTD of N tended to be greater ( < 0.10) using the MM than that using the IM. All estimates using the DY were not

VERIFICATION OF THE DEFENSE WASTE PROCESSING FACILITY PROCESS DIGESTION METHOD FOR THE SLUDGE BATCH 6 QUALIFICATION SAMPLE

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

Click, D.; Jones, M.; Edwards, T.

2010-06-09

For each sludge batch that is processed in the Defense Waste Processing Facility (DWPF), the Savannah River National Laboratory (SRNL) confirms applicability of the digestion method to be used by the DWPF lab for elemental analysis of Sludge Receipt and Adjustment Tank (SRAT) receipt samples and SRAT product process control samples.1 DWPF SRAT samples are typically dissolved using a room temperature HF-HNO3 acid dissolution (i.e., DWPF Cold Chem (CC) Method, see DWPF Procedure SW4-15.201) and then analyzed by inductively coupled plasma - atomic emission spectroscopy (ICPAES). In addition to the CC method confirmation, the DWPF lab's mercury (Hg) digestion methodmore » was also evaluated for applicability to SB6 (see DWPF procedure 'Mercury System Operating Manual', Manual: SW4-15.204. Section 6.1, Revision 5, Effective date: 12-04-03). This report contains the results and comparison of data generated from performing the Aqua Regia (AR), Sodium Peroxide/Hydroxide Fusion (PF) and DWPF Cold Chem (CC) method digestion of Sludge Batch 6 (SB6) SRAT Receipt and SB6 SRAT Product samples. For validation of the DWPF lab's Hg method, only SRAT receipt material was used and compared to AR digestion results. The SB6 SRAT Receipt and SB6 SRAT Product samples were prepared in the SRNL Shielded Cells, and the SRAT Receipt material is representative of the sludge that constitutes the SB6 Batch or qualification composition. This is the sludge in Tank 51 that is to be transferred into Tank 40, which will contain the heel of Sludge Batch 5 (SB5), to form the SB6 Blend composition. In addition to the 16 elements currently measured by the DWPF, this report includes Hg and thorium (Th) data (Th comprising {approx}2.5 - 3 Wt% of the total solids in SRAT Receipt and SRAT Product, respectively) and provides specific details of ICP-AES analysis of Th. Thorium was found to interfere with the U 367.007 nm emission line, and an inter-element correction (IEC) had to be applied to U data, which

Metabolic routes along digestive system of licorice: multicomponent sequential metabolism method in rat.

PubMed

Zhang, Lei; Zhao, Haiyu; Liu, Yang; Dong, Honghuan; Lv, Beiran; Fang, Min; Zhao, Huihui

2016-06-01

This study was conducted to establish the multicomponent sequential metabolism (MSM) method based on comparative analysis along the digestive system following oral administration of licorice (Glycyrrhiza uralensis Fisch., leguminosae), a traditional Chinese medicine widely used for harmonizing other ingredients in a formulae. The licorice water extract (LWE) dissolved in Krebs-Ringer buffer solution (1 g/mL) was used to carry out the experiments and the comparative analysis was performed using HPLC and LC-MS/MS methods. In vitro incubation, in situ closed-loop and in vivo blood sampling were used to measure the LWE metabolic profile along the digestive system. The incubation experiment showed that the LWE was basically stable in digestive juice. A comparative analysis presented the metabolic profile of each prototype and its corresponding metabolites then. Liver was the major metabolic organ for LWE, and the metabolism by the intestinal flora and gut wall was also an important part of the process. The MSM method was practical and could be a potential method to describe the metabolic routes of multiple components before absorption into the systemic blood stream. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Effects of a 6-phytase on the apparent ileal digestibility of minerals and amino acids in ileorectal anastomosed pigs fed on a corn-soybean meal-barley diet.

PubMed

Guggenbuhl, P; Waché, Y; Simoes Nunes, C; Fru, F

2012-12-01

Phosphorus of plant-based feedstuffs for monogastric animals is mainly in the form of phytic P, which has a very low bioavailability. The nondigested phytic P may contribute to P pollution. Furthermore, phytic acid may reduce digestibility of other minerals and protein. This study evaluated effects of the microbial 6-phytase RONOZYME HiPhos on apparent ileal digestibility of P, phytic acid, Ca, CP, energy, and AA in six 60-d-old ileorectal anastomosed pigs. In a duplicated 3 × 3 Latin square design, pigs had free access to alternatively a corn (Zea mays)-soybean (Glycine max) meal-barley (Hordeum vulgare)-based diet or this diet supplemented with RONOZYME HiPhos at either 500 units/kg (RH500) or 1000 units/kg (RH1000). Pigs fed diets supplemented with RH500 or RH1000 increased (P < 0.05) digestibility of P, Ca, and Lys. Pigs fed diet RH1000 increased (P < 0.05) digestibility of CP, total AA, indispensable AA, Glu + Gln, His, Gly, Ala, Tyr, Leu, Phe, and Met. Similar to growth trials with increased total tract digestibility of P and Ca, phytase increased apparent ileal digestibility of these indispensable minerals and phytate. The phytase increased digestibility of CP and indispensable AA indicating a better availability of plant-based proteins.

Quantitative Assessment of In-solution Digestion Efficiency Identifies Optimal Protocols for Unbiased Protein Analysis*

PubMed Central

León, Ileana R.; Schwämmle, Veit; Jensen, Ole N.; Sprenger, Richard R.

2013-01-01

The majority of mass spectrometry-based protein quantification studies uses peptide-centric analytical methods and thus strongly relies on efficient and unbiased protein digestion protocols for sample preparation. We present a novel objective approach to assess protein digestion efficiency using a combination of qualitative and quantitative liquid chromatography-tandem MS methods and statistical data analysis. In contrast to previous studies we employed both standard qualitative as well as data-independent quantitative workflows to systematically assess trypsin digestion efficiency and bias using mitochondrial protein fractions. We evaluated nine trypsin-based digestion protocols, based on standard in-solution or on spin filter-aided digestion, including new optimized protocols. We investigated various reagents for protein solubilization and denaturation (dodecyl sulfate, deoxycholate, urea), several trypsin digestion conditions (buffer, RapiGest, deoxycholate, urea), and two methods for removal of detergents before analysis of peptides (acid precipitation or phase separation with ethyl acetate). Our data-independent quantitative liquid chromatography-tandem MS workflow quantified over 3700 distinct peptides with 96% completeness between all protocols and replicates, with an average 40% protein sequence coverage and an average of 11 peptides identified per protein. Systematic quantitative and statistical analysis of physicochemical parameters demonstrated that deoxycholate-assisted in-solution digestion combined with phase transfer allows for efficient, unbiased generation and recovery of peptides from all protein classes, including membrane proteins. This deoxycholate-assisted protocol was also optimal for spin filter-aided digestions as compared with existing methods. PMID:23792921

Analysis of testosterone fatty acid esters in the digestive gland of mussels by liquid chromatography-high resolution mass spectrometry.

PubMed

Guercia, Cesare; Cianciullo, Piergiorgio; Porte, Cinta

2017-07-01

Several studies have indicated that up to 70% of the total steroids detected in molluscs are in the esterified form and that pollutants, by modifying the esterification of steroids with fatty acids, might act as endocrine disrupters. However, despite the strong physiological significance of this process, there is almost no information on which fatty acids form the steroid esters and how this process is modulated. This study (a) investigates the formation of fatty acid esters of testosterone in digestive gland microsomal fractions of the mussel Mytilus galloprovincialis incubated with either palmitoly-CoA or CoA and ATP, and (b) assesses whether the endocrine disruptor tributyltin (TBT) interferes with the esterification of testosterone. Analysis of testosterone esters was performed by liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). When microsomal fractions were incubated with testosterone and palmitoly-CoA, the formation of testosterone palmitate was detected. However, when microsomes were incubated with CoA and ATP, and no exogenous activated fatty acid was added, the synthesis of 16:0, 16:1, 20:5 and 22:6 testosterone esters was observed. The presence of 100µM TBT in the incubation mixture did not significantly alter the esterification of testosterone. These results evidence the conjugation of testosterone with the most abundant fatty acids in the digestive gland microsomal fraction of mussels. Copyright © 2017 Elsevier Inc. All rights reserved.

Digestive stimulant action of spices: a myth or reality?

PubMed

Platel, Kalpana; Srinivasan, K

2004-05-01

Spices have long been recognized for their digestive stimulant action. Several spices are also employed in medicinal preparations against digestive disorders in traditional and Indian systems of medicine. Earlier reports on the digestive stimulant action of spices are largely empirical; only in recent years, this beneficial attribute of spices has been authenticated in exhaustive animal studies. Animal studies have shown that many spices induce higher secretion of bile acids which play a vital role in fat digestion and absorption. When consumed through the diet also spices produce significant stimulation of the activities of pancreatic lipase, amylase and proteases. A few of them also have been shown to have beneficial effect on the terminal digestive enzymes of small intestinal mucosa. Concomitant with such a stimulation of either bile secretion or activity of digestive enzymes by these spices, leading to an accelerated digestion, a reduction in the food transit time in the gastrointestinal tract has also been shown. Thus, the digestive stimulant action of spices seems to be mediated through two possible modes: (i) by stimulating the liver to secrete bile rich in bile acids, components that are vital for fat digestion and absorption, and (ii) by a stimulation of enzyme activities that are responsible for digestion. This review highlights the available information on the influence of spices on the digestive secretions and enzymes.

Complete disassociation of adult pancreas into viable single cells through cold trypsin-EDTA digestion*

PubMed Central

Li, Dan; Peng, Shi-yun; Zhang, Zhen-wu; Feng, Rui-cheng; Li, Lu; Liang, Jie; Tai, Sheng; Teng, Chun-bo

2013-01-01

The in vitro isolation and analysis of pancreatic stem/progenitor cells are necessary for understanding their properties and function; however, the preparation of high-quality single-cell suspensions from adult pancreas is prerequisite. In this study, we applied a cold trypsin-ethylenediaminetetraacetic acid (EDTA) digestion method to disassociate adult mouse pancreata into single cells. The yield of single cells and the viability of the harvested cells were much higher than those obtained via the two commonly used warm digestion methods. Flow cytometric analysis showed that the ratio of ductal or BCRP1-positive cells in cell suspensions prepared through cold digestion was consistent with that found in vivo. Cell culture tests showed that pancreatic epithelial cells prepared by cold digestion maintained proliferative capacity comparable to those derived from warm collagenase digestion. These results indicate that cold trypsin-EDTA digestion can effectively disassociate an adult mouse pancreas into viable single cells with minimal cell loss, and can be used for the isolation and analysis of pancreatic stem/progenitor cells. PMID:23825145

Digestion of Crystalline Silicotitanate (CST)

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

DARREL, WALKER

2004-11-04

Researchers tested methods for chemically dissolving crystalline silicotitanate (CST) as a substitute for mechanical grinding to reduce particle size before vitrification. Testing used the commercially available form of CST, UOP IONSIV(R) IE-911. Reduction of the particle size to a range similar to that of the glass frit used by the Defense Waste Processing Facility (DWPF) could reduce problems with coupling cesium ion exchange to the vitrification process. This study found that IONSIV(R) IE-911 dissolves completely using a combination of acid, hydrogen peroxide, and fluoride ion. Neutralization of the resulting acidic solution precipitates components of the IONSIV(R) IE-911. Digestion requires extremelymore » corrosive conditions. Also, large particles may reform during neutralization, and the initiation and rate of gas generation are unpredictable. Therefore, the method is not recommended as a substitute for mechanical grinding.« less

Transcriptional response after exposure to domoic acid-producing Pseudo-nitzschia in the digestive gland of the mussel Mytilus galloprovincialis.

PubMed

Pazos, Antonio J; Ventoso, Pablo; Martínez-Escauriaza, Roi; Pérez-Parallé, M Luz; Blanco, Juan; Triviño, Juan C; Sánchez, José L

2017-12-15

Bivalve molluscs are filter feeding species that can accumulate biotoxins in their body tissues during harmful algal blooms. Amnesic Shellfish Poisoning (ASP) is caused by species of the diatom genus Pseudo-nitzschia, which produces the toxin domoic acid. The Mytilus galloprovincialis digestive gland transcriptome was de novo assembled based on the sequencing of 12 cDNA libraries, six obtained from control mussels and six from mussels naturally exposed to domoic acid-producing diatom Pseudo-nitzschia australis. After de novo assembly 94,727 transcripts were obtained, with an average length of 1015 bp and a N50 length of 761 bp. The assembled transcripts were clustered (homology > 90%) into 69,294 unigenes. Differential gene expression analysis was performed (DESeq2 algorithm) in the digestive gland following exposure to the toxic algae. A total of 1158 differentially expressed unigenes (absolute fold change > 1.5 and p-value < 0.05) were detected: 686 up-regulated and 472 down-regulated. Several membrane transporters belonging to the family of the SLC (solute carriers) were over-expressed in exposed mussels. Functional enrichment was performed using Pfam annotations obtained from the genes differentially expressed, 37 Pfam families were found to be significantly (FDR adjusted p-value < 0.1) enriched. Some of these families (sulfotransferases, aldo/keto reductases, carboxylesterases, C1q domain and fibrinogen C-terminal globular domain) could be putatively involved in detoxification processes, in the response against of the oxidative stress and in immunological processes. Protein network analysis with STRING algorithm found alteration of the Notch signaling pathway under the action of domoic acid-producing Pseudo-nitzschia. In conclusion, this study provides a high quality reference transcriptome of M. galloprovincialis digestive gland and identifies potential genes involved in the response to domoic acid. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of different ratios of feedstock to liquid anaerobic digestion effluent on the performance and microbiome of solid-state anaerobic digesters digesting corn stover.

PubMed

Li, Yueh-Fen; Shi, Jian; Nelson, Michael C; Chen, Po-Hsu; Graf, Joerg; Li, Yebo; Yu, Zhongtang

2016-01-01

The objective of this study was to understand how the non-microbial factors of L-AD effluent affected the microbiome composition and successions in the SS-AD digesters using both Illumina sequencing and qPCR quantification of major genera of methanogens. The SS-AD digesters started with a feedstock/total effluent (F/Et) ratio 2.2 (half of the effluent was autoclaved) performed stably, while the SS-AD digesters started with a 4.4 F/Et ratio (no autoclaved effluent) suffered from digester acidification, accumulation of volatile fatty acids, and ceased biogas production two weeks after startup. Some bacteria and methanogens were affected by non-microbial factors of the L-AD fluent. Alkalinity, the main difference between the two F/Et ratios, may be the crucial factor when SS-AD digesters were started using L-AD effluent. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biochemical, Transcriptomic and Proteomic Analyses of Digestion in the Scorpion Tityus serrulatus: Insights into Function and Evolution of Digestion in an Ancient Arthropod

PubMed Central

Fuzita, Felipe J.; Pinkse, Martijn W. H.; Patane, José S. L.; Juliano, Maria A.; Verhaert, Peter D. E. M.; Lopes, Adriana R.

2015-01-01

Scorpions are among the oldest terrestrial arthropods and they have passed through small morphological changes during their evolutionary history on land. They are efficient predators capable of capturing and consuming large preys and due to envenomation these animals can become a human health challenge. Understanding the physiology of scorpions can not only lead to evolutionary insights but also is a crucial step in the development of control strategies. However, the digestive process in scorpions has been scarcely studied. In this work, we describe the combinatory use of next generation sequencing, proteomic analysis and biochemical assays in order to investigate the digestive process in the yellow scorpion Tityus serrulatus, mainly focusing in the initial protein digestion. The transcriptome generated database allowed the quantitative identification by mass spectrometry of different enzymes and proteins involved in digestion. All the results suggested that cysteine cathepsins play an important role in protein digestion. Two digestive cysteine cathepsins were isolated and characterized presenting acidic characteristics (pH optima and stability), zymogen conversion to the mature form after acidic activation and a cross-class inhibition by pepstatin. A more elucidative picture of the molecular mechanism of digestion in a scorpion was proposed based on our results from Tityus serrulatus. The midgut and midgut glands (MMG) are composed by secretory and digestive cells. In fasting animals, the secretory granules are ready for the next predation event, containing enzymes needed for alkaline extra-oral digestion which will compose the digestive fluid, such as trypsins, astacins and chitinase. The digestive vacuoles are filled with an acidic proteolytic cocktail to the intracellular digestion composed by cathepsins L, B, F, D and legumain. Other proteins as lipases, carbohydrases, ctenitoxins and a chitolectin with a perithrophin domain were also detected. Evolutionarily

Biochemical, transcriptomic and proteomic analyses of digestion in the scorpion Tityus serrulatus: insights into function and evolution of digestion in an ancient arthropod.

PubMed

Fuzita, Felipe J; Pinkse, Martijn W H; Patane, José S L; Juliano, Maria A; Verhaert, Peter D E M; Lopes, Adriana R

2015-01-01

Scorpions are among the oldest terrestrial arthropods and they have passed through small morphological changes during their evolutionary history on land. They are efficient predators capable of capturing and consuming large preys and due to envenomation these animals can become a human health challenge. Understanding the physiology of scorpions can not only lead to evolutionary insights but also is a crucial step in the development of control strategies. However, the digestive process in scorpions has been scarcely studied. In this work, we describe the combinatory use of next generation sequencing, proteomic analysis and biochemical assays in order to investigate the digestive process in the yellow scorpion Tityus serrulatus, mainly focusing in the initial protein digestion. The transcriptome generated database allowed the quantitative identification by mass spectrometry of different enzymes and proteins involved in digestion. All the results suggested that cysteine cathepsins play an important role in protein digestion. Two digestive cysteine cathepsins were isolated and characterized presenting acidic characteristics (pH optima and stability), zymogen conversion to the mature form after acidic activation and a cross-class inhibition by pepstatin. A more elucidative picture of the molecular mechanism of digestion in a scorpion was proposed based on our results from Tityus serrulatus. The midgut and midgut glands (MMG) are composed by secretory and digestive cells. In fasting animals, the secretory granules are ready for the next predation event, containing enzymes needed for alkaline extra-oral digestion which will compose the digestive fluid, such as trypsins, astacins and chitinase. The digestive vacuoles are filled with an acidic proteolytic cocktail to the intracellular digestion composed by cathepsins L, B, F, D and legumain. Other proteins as lipases, carbohydrases, ctenitoxins and a chitolectin with a perithrophin domain were also detected. Evolutionarily

Effect of dietary fat type on intestinal digestibility of fatty acids, fatty acid profiles of breast meat and abdominal fat, and mRNA expression of lipid-related genes in broiler chickens.

PubMed

Skřivan, Miloš; Marounek, Milan; Englmaierová, Michaela; Čermák, Ladislav; Vlčková, Jana; Skřivanová, Eva

2018-01-01

A group of 240-day-old Ross cockerels were used in a 4-week experiment to assess the effect of the fat type on the intestinal digestibility of fatty acids (FAs), the FA profiles of breast meat and abdominal fat, and the mRNA expression of six hepatic lipid-related genes. Experimental diets were supplemented with rapeseed oil, pork lard or palm oil at 60 g/kg. In the control diet, wheat starch was substituted for the fat source. The highest ileal digestibility of the fat and all FAs (except stearic acid) was observed in chickens fed lard. The content of fat in the breast meat of chickens was not significantly influenced by the fat supplements. The FA profiles of breast meat and abdominal fat reflected the FA composition of the diet. In the meat of chickens fed rapeseed oil, oleic acid was the predominant FA. Palmitic acid was the most abundant FA in the meat of chickens fed lard or palm oil. Oleic acid was the most abundant FA in the abdominal fat of all chickens. The highest mRNA expression of desaturases (Δ5-, Δ6- and Δ9-) was observed in chickens fed palm oil. The mRNA expression of hepatic FA synthase was higher in chickens fed palm oil or lard than in chickens fed rapeseed oil. The expression of HMG-CoA reductase was higher in chickens fed palm oil than in those fed rapeseed oil or lard. It can be concluded that rapeseed oil and lard are better sources of lipids than palm oil. These former two sources contain more digestible fatty acids and provide a lower concentration of SFAs in the meat and fat of chickens.

Effect of dietary fat type on intestinal digestibility of fatty acids, fatty acid profiles of breast meat and abdominal fat, and mRNA expression of lipid-related genes in broiler chickens

PubMed Central

Marounek, Milan; Englmaierová, Michaela; Čermák, Ladislav; Vlčková, Jana; Skřivanová, Eva

2018-01-01

A group of 240-day-old Ross cockerels were used in a 4-week experiment to assess the effect of the fat type on the intestinal digestibility of fatty acids (FAs), the FA profiles of breast meat and abdominal fat, and the mRNA expression of six hepatic lipid-related genes. Experimental diets were supplemented with rapeseed oil, pork lard or palm oil at 60 g/kg. In the control diet, wheat starch was substituted for the fat source. The highest ileal digestibility of the fat and all FAs (except stearic acid) was observed in chickens fed lard. The content of fat in the breast meat of chickens was not significantly influenced by the fat supplements. The FA profiles of breast meat and abdominal fat reflected the FA composition of the diet. In the meat of chickens fed rapeseed oil, oleic acid was the predominant FA. Palmitic acid was the most abundant FA in the meat of chickens fed lard or palm oil. Oleic acid was the most abundant FA in the abdominal fat of all chickens. The highest mRNA expression of desaturases (Δ5-, Δ6- and Δ9-) was observed in chickens fed palm oil. The mRNA expression of hepatic FA synthase was higher in chickens fed palm oil or lard than in chickens fed rapeseed oil. The expression of HMG-CoA reductase was higher in chickens fed palm oil than in those fed rapeseed oil or lard. It can be concluded that rapeseed oil and lard are better sources of lipids than palm oil. These former two sources contain more digestible fatty acids and provide a lower concentration of SFAs in the meat and fat of chickens. PMID:29672634

Standardized Ileal Amino Acid Digestibility of Corn, Corn Distillers' Dried Grains with Solubles, Wheat Middlings, and Bakery By-Products in Broilers and Laying Hens.

PubMed

Adedokun, S A; Jaynes, P; Payne, R L; Applegate, T J

2015-10-01

Standardized ileal amino acid digestibility (SIAAD) of 5 samples of corn distillers dried grain with solubles (DDGS), 5 samples of bakery by-products (BBP), 3 samples of corn, and 1 sample of wheat middlings (WM) were evaluated in broilers and laying hens. Diets containing each of the 14 feed ingredients were evaluated in 21 day-old broiler chickens. The DDGS and BBP containing diets were fed to 30-week-old laying hens, while corn and wheat middling were evaluated in 50-week-old laying hens. All the diets were semi-purified with each feed ingredient being the only source of amino acid (AA). To obtain SIAAD values, apparent ileal AA digestibility was corrected for basal ileal endogenous AA losses using values generated from broilers and laying hens fed a nitrogen-free diet. Ileal crude protein digestibility for the 5 DDGS samples was higher (P < 0.05) in broilers than in laying hens. Broilers had higher SIAAD for DDGS 2, 3, 4, and 5 while there was no difference for DDGS 1 except for 4 AA where broilers had higher (P < 0.05) SIAAD values. Standardized ileal AA digestibility values for broilers were higher (P < 0.05) for BBP 1 and 4. Ileal CP digestibility for corn 1 was higher (P < 0.05) for broilers compared to laying hens, and SIAAD values for the 16 AA (9 indispensable and 7 dispensable) evaluated in this study were higher (P < 0.05) in broilers. Broilers had higher (P < 0.05) SIAAD values for 4 (histidine, leucine, phenylalanine, and valine) and 6 (histidine, leucine, methionine, phenylalanine, threonine, and valine) indispensable and 3 (cysteine, glutamic acid, and proline) and 4 (cysteine, glutamic acid, proline, and serine) dispensable AA for corn 2 and corn 3, respectively. No difference in SIAAD between broilers and laying hens was observed for WM. Results from this study confirm that high variability in digestibility exists between different samples of DDGS. Differences in SIAAD between broilers and laying hens were observed in some samples of

Effects of feeding lauric acid or coconut oil on ruminal protozoa numbers, fermentation pattern, digestion, omasal nutrient flow, and milk production in dairy cows.

PubMed

Faciola, A P; Broderick, G A

2014-01-01

The objectives of this study were to evaluate the feeding of coconut oil (CO), in which lauric acid (La) comprises about 50% of the fatty acid composition, as a practical rumen protozoa (RP) suppressing agent, to assess whether the source of La affects ruminal fermentation and animal performance and to test whether suppressing RP improves N utilization, nutrient digestion, nutrient flow at the omasal canal, and milk production. Fifteen multiparous Holstein cows (3 fitted with ruminal cannulas) and 15 primiparous Holstein cows (3 fitted with ruminal cannulas) were used in a replicated 3×3 Latin square experiment with 14d of adaptation and 14d of sample collection. Diets were fed as total mixed ration and contained (dry matter basis) 10% corn silage, 50% alfalfa silage, and 40% concentrate. The control diet contained 3% (dry matter basis) calcium soaps of palm oil fatty acids (Megalac, Church & Dwight Co. Inc., Princeton, NJ) as a ruminally inert fat source and had no added La or CO. Diets with La and CO were formulated to contain equal amounts of La (1.3%, dry matter basis). Dry matter intake was not affected by treatment. Both CO and La reduced RP numbers by about 40%. Lauric acid reduced yield of milk and milk components; however, CO did not affect yield of milk and yields of milk components. Both La and CO caused small reductions in total VFA concentration; CO increased molar proportion of ruminal propionate, reduced ruminal ammonia and branched-chain volatile fatty acids, suggesting reduced protein degradation, and reduced milk urea N and blood urea N concentrations, suggesting improved protein efficiency. Lauric acid reduced total-tract apparent digestibility of neutral detergent fiber and acid detergent fiber as well as ruminal apparent digestibility of neutral detergent fiber and acid detergent fiber as measured at the omasal canal; however, CO did not alter fiber digestion. Microbial protein flow at the omasal canal, as well as the flow of N fractions at

Ruminal bacteria and protozoa composition, digestibility, and amino acid profile determined by multiple hydrolysis times.

PubMed

Fessenden, S W; Hackmann, T J; Ross, D A; Foskolos, A; Van Amburgh, M E

2017-09-01

Microbial samples from 4 independent experiments in lactating dairy cattle were obtained and analyzed for nutrient composition, AA digestibility, and AA profile after multiple hydrolysis times ranging from 2 to 168 h. Similar bacterial and protozoal isolation techniques were used for all isolations. Omasal bacteria and protozoa samples were analyzed for AA digestibility using a new in vitro technique. Multiple time point hydrolysis and least squares nonlinear regression were used to determine the AA content of omasal bacteria and protozoa, and equivalency comparisons were made against single time point hydrolysis. Formalin was used in 1 experiment, which negatively affected AA digestibility and likely limited the complete release of AA during acid hydrolysis. The mean AA digestibility was 87.8 and 81.6% for non-formalin-treated bacteria and protozoa, respectively. Preservation of microbe samples in formalin likely decreased recovery of several individual AA. Results from the multiple time point hydrolysis indicated that Ile, Val, and Met hydrolyzed at a slower rate compared with other essential AA. Singe time point hydrolysis was found to be nonequivalent to multiple time point hydrolysis when considering biologically important changes in estimated microbial AA profiles. Several AA, including Met, Ile, and Val, were underpredicted using AA determination after a single 24-h hydrolysis. Models for predicting postruminal supply of AA might need to consider potential bias present in postruminal AA flow literature when AA determinations are performed after single time point hydrolysis and when using formalin as a preservative for microbial samples. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Using contaminated plants involved in phytoremediation for anaerobic digestion.

PubMed

Cao, Zewei; Wang, Shengxiao; Wang, Ting; Chang, Zhizhou; Shen, Zhenguo; Chen, Yahua

2015-01-01

This study investigated the anaerobic digestion capability of five plants and the effects of copper (Cu) and S,S'-ethylenediaminedisuccinic acid (EDDS, a chelator widely used in chelant-assisted phytoremediation) on biogas production to determine a feasible disposal method for plants used in remediation. The results showed that in addition to Phytolacca americana L., plants such as Zea mays L., Brassica napus L., Elsholtzia splendens Nakai ex F. Maekawa, and Oenothera biennis L. performed well in biogas production. Among these, O. biennis required the shortest period to finish anaerobic digestion. Compared to normal plants with low Cu content, the plants used in remediation with increased Cu levels (100 mg kg(-1)) not only promoted anaerobic digestion and required a shorter anaerobic digestion time, but also increased the methane content in biogas. When the Cu content in plants increased to 500, 1000, and 5000 mg kg(-1), the cumulative biogas production decreased by 12.3%, 14.6%, and 41.2%, respectively. Studies also found that EDDS conspicuously restrained biogas production from anaerobic digestion. The results suggest that anaerobic digestion has great potential for the disposal of contaminated plants and may provide a solution for the resource utilization of plants used in remediation.

Effects of exogenous xylanase on performance, nutrient digestibility, volatile fatty acid production and digestive tract thermal profiles of broilers fed on wheat- or maize-based diet.

PubMed

Masey-O'Neill, H V; Singh, M; Cowieson, A J

2014-01-01

1. A previous experiment reported that caecal temperature was negatively correlated with d 49 feed conversion ratio (FCR). This increased temperature in the caeca may indicate a prebiotic effect. An experiment was designed to investigate whether caecal temperature was affected in diets based on maize and whether other portions of the tract were affected. 2. A total of 25 Ross 308-d-old male broilers were allocated to each of 8 replicate pens per treatment. Treatments followed a 2 × 3 factorial design: two diets based on wheat or maize and three levels of enzyme addition, 0, 16 000 or 32 000 BXU/kg. Growth performance was assessed between d 1 and 49. Digestibility measurements were taken at d 28 and 49. On d 49, the excised small and large intestine of each bird was thermally imaged, weighed and volatile fatty acids (VFA) measured. 3. On d 28 and d 49, birds on the maize diets had higher feed intake and weight gain than those offered wheat diets. Additionally, on d 28, birds that received the maize diet had lower FCR than those offered the wheat diet. Enzyme improved FCR at d 49, independently of cereal. On d 28, enzyme improved the coefficient of apparent ileal DM digestibility and the coefficient of apparent ileal nitrogen digestibility. Enzyme only improved apparent ileal digestible energy in wheat-based diets (interactive term). On d 49, all digestibility parameters were improved by enzyme. Enzyme increased gizzard weight in maize-fed birds and the caeca of those fed wheat were heavier. The higher enzyme dose decreased duodenal temperature. In summary of VFA data, wheat-based diets produced more total VFAs and the total amount also increased with enzyme. 4. It appears from this study that there is equal potential in both wheat and maize diets for xylanase to improve performance of broilers probably through different mechanisms.

Development of anaerobic digestion methods for palm oil mill effluent (POME) treatment.

PubMed

Poh, P E; Chong, M F

2009-01-01

Palm oil mill effluent (POME) is a highly polluting wastewater that pollutes the environment if discharged directly due to its high chemical oxygen demand (COD) and biochemical oxygen demand (BOD) concentration. Anaerobic digestion has been widely used for POME treatment with large emphasis placed on capturing the methane gas released as a product of this biodegradation treatment method. The anaerobic digestion method is recognized as a clean development mechanism (CDM) under the Kyoto protocol. Certified emission reduction (CER) can be obtained by using methane gas as a renewable energy. This review aims to discuss the various anaerobic treatments of POME and factors that influence the operation of anaerobic treatment. The POME treatment at both mesophilic and thermophilic temperature ranges are also analyzed.

Solid anaerobic digestion batch with liquid digestate recirculation and wet anaerobic digestion of organic waste: Comparison of system performances and identification of microbial guilds.

PubMed

Di Maria, Francesco; Barratta, Martino; Bianconi, Francesco; Placidi, Pisana; Passeri, Daniele

2017-01-01

Solid anaerobic digestion batch (SADB) with liquid digestate recirculation and wet anaerobic digestion of organic waste were experimentally investigated. SADB was operated at an organic loading rate (OLR) of 4.55kgVS/m 3 day, generating about 252NL CH 4 /kgVS, whereas the wet digester was operated at an OLR of 0.9kgVS/m 3 day, generating about 320NL CH 4 /kgVS. The initial total volatile fatty acids concentrations for SADB and wet digestion were about 12,500mg/L and 4500mg/L, respectively. There were higher concentrations of ammonium and COD for the SADB compared to the wet one. The genomic analysis performed by high throughput sequencing returned a number of sequences for each sample ranging from 110,619 to 373,307. More than 93% were assigned to the Bacteria domain. Seven and nine major phyla were sequenced for the SADB and wet digestion, respectively, with Bacteroidetes, Firmicutes and Proteobacteria being the dominant phyla in both digesters. Taxonomic profiles suggested a methanogenic pathway characterized by a relevant syntrophic acetate-oxidizing metabolism mainly in the liquid digestate of the SADB. This result also confirms the benefits of liquid digestate recirculation for improving the efficiency of AD performed with high solids (>30%w/w) content. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ilex paraguariensis and its main component chlorogenic acid inhibit fructose formation of advanced glycation endproducts with amino acids at conditions compatible with those in the digestive system.

PubMed

Bains, Yasmin; Gugliucci, Alejandro

2017-03-01

We have previously shown that Ilex paraguariensis extracts have potent antiglycation actions. Associations of excess free fructose consumption with inflammatory diseases have been proposed to be mediated through in situ enteral formation of fructose AGEs, which, after being absorbed may contribute to inflammatory diseases via engagement of RAGE. In this proof of principle investigation we show fluorescent AGE formation between amino acids (Arg, Lys, Gly at 10-50mM) and fructose (10-50mM) under time, temperature, pH and concentrations compatible with the digestive system lumen and its inhibition by Ilex paraguariensis extracts. Incubation of amino acids with fructose (but not glucose) leads to a time dependent formation of AGE fluorescence, already apparent after just 1h incubation, a time frame well compatible with the digestive process. Ilex paraguariensis (mate tea) inhibited AGE formation by 83% at 50μl/ml (p<0.001). Its main phenolics, caffeic acid and cholorogenic acid were as potent as aminoguanidine-a specific antiglycation agent: IC50 of 0.9mM (p<0.001). Our results suggest that AGE adducts form between fructose and amino acids at times and concentrations plausibly found in the intestines. The reaction is inhibited by mate tea and its individual phenolics (caffeic acid and chlorogenic acids). The study provides the first evidence for the proposed mechanism to explain epidemiological correlations between excess fructose consumption and inflammatory diseases. Enteral fructose-AGE formation would be inhibited by co-intake of Ilex paraguariensis, and potentially other beverages, fruits and vegetables that contain comparable concentrations of phenolics as in IP (mate tea). Copyright © 2016 Elsevier B.V. All rights reserved.

Removal of uranium from soil sample digests for ICP-OES analysis of trace metals

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

Foust, R.D. Jr.; Bidabad, M.

1996-10-01

An analytical procedure has been developed to quantitatively remove uranium from soil sample digests, permitting ICP-OES analysis of trace metals. The procedure involves digesting a soil sample with standard procedures (EPA SW-846, Method 3050), and passing the sample digestate through commercially available resin (U/TEVA{sm_bullet}Spec, Eichrom Industries, Inc.) containing diarryl amylphosphonate as the stationary phase. Quantitative removal of uranium was achieved with soil samples containing up to 60% uranium, and percent recoveries averaged better than 85% for 9 of the 10 metals evaluated (Ag, As, Cd. Cr, Cu, Ni, Pb, Se and Tl). The U/TEVA{sm_bullet}Spec column was regenerated by washing withmore » 200 mL of a 0.01 M oxalic acid/0.02 M nitric acid solution, permitting re-use of the column. GFAAS analysis of a sample spiked with 56.5% uranium, after treatment of the digestate with a U/TEVA{sm_bullet}Spec resin column, resulted in percent recoveries of 97% or better for all target metals.« less

Hemicellulose conversion by anaerobic digestion

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

Ghosh, S.; Henry, M.P.; Christopher, R.W.

1982-01-01

The digestibility of an aquatic biomass (water hyacinth), a land-based biomass (Coastal Bermuda grass), and a biomass-waste blend (a mixture of hyacinth, grass, MSW, and sludge) under various digestion conditions was studied. Anaerobic digestion of hemicellulose consists of the steps of enzymatic hydrolysis of hemicellulose to glucans, mannans, galactans, xylans, and arabans, and then to simple hexose and pentose sugars; production of C/sub 2/ and higher fatty acids from the simple sugars; conversion of higher fatty acids to acetate; and finally, production of methane and CO/sub 2/ from acetate, and CO/sub 2/ and hydrogen. The conversion of hemicellulose was highermore » under mesophilic conditions than those of cellulose or protein for all biomass test feeds, probably because the hemicellulose structure was more vulnerable to enzymatic attack than that of the lignocellulosic component. Cellulose conversion efficiencies at the mesophilic and thermophilic temperatures were about the same. However, hemicellulose was converted at a much lower efficiency than cellulose during thermophilic digestion - a situation that was the reverse of that observed at the mesophilic temperature. Cellulose was utilized in preference to hemicellulose during mesophilic digestion of nitrogen-supplemented Bermuda grass. It was speculated that Bermuda grass cellulose was converted at a higher efficiency than hemicellulose in the presence of external nitrogen because the metabolism of the breakdown product (glucose) of cellulose requires the least investment of enzymes and energy.« less

Comparison of Two Static in Vitro Digestion Methods for Screening the Bioaccessibility of Carotenoids in Fruits, Vegetables, and Animal Products.

PubMed

Rodrigues, Daniele B; Chitchumroonchokchai, Chureeporn; Mariutti, Lilian R B; Mercadante, Adriana Z; Failla, Mark L

2017-12-27

In vitro digestion methods are routinely used to assess the bioaccessibility of carotenoids and other dietary lipophilic compounds. Here, we compared the recovery of carotenoids and their efficiency of micellarization in digested fruits, vegetables, egg yolk, and salmon and also in mixed-vegetable salads with and without either egg yolk or salmon using the static INFOGEST method22 and the procedure of Failla et al.16 Carotenoid stability during the simulated digestion was ≥70%. The efficiencies of the partitioning of carotenoids into mixed micelles were similar when individual plant foods and salad meals were digested using the two static methods. Furthermore, the addition of cooked egg or salmon to vegetable salads increased the bioaccessibility of some carotenoids. Our findings showed that the two methods of in vitro digestion generated similar estimates of carotenoid retention and bioaccessibility for diverse foods.

Ex vivo Digestion of Milk from Red Chittagong Cattle Focusing Proteolysis and Lipolysis

PubMed Central

Islam, Mohammad Ashiqul; Ekeberg, Dag; Rukke, Elling-Olav; Vegarud, Gerd Elisabeth

2015-01-01

Ex vivo digestion of proteins and fat in Red Chittagong Cattle milk from Bangladesh was carried out using human gastrointestinal enzymes. This was done to investigate the protein digestion in this bovine breed’s milk with an especial focus on the degradation of the allergenic milk proteins; αs1-casein and β-lactoglobulin and also to record the generation of peptides. Lipolysis of the milk fat and release of fatty acids were also under consideration. After 40 min of gastric digestion, all the αs-caseins were digested completely while β-lactoglobulin remained intact. During 120 min of duodenal digestion β-lactoglobulin was reduced, however, still some intact β-lactoglobulin was observed. The highest number of peptides was identified from β-casein and almost all the peptides from κ-casein and β-lactoglobulin were identified from the gastric and duodenal samples, respectively. No lipolysis was observed in the gastric phase of digestion. After 120 min of duodenal digestion, milk fat showed 48% lipolysis. Medium (C10:0 to C16:0) and long (≥C17:0) chain fatty acids showed 6% to 19% less lipolysis than the short (C6:0 to C8:0) chain fatty acids. Among the unsaturated fatty acids C18:1∑others showed highest lipolysis (81%) which was more than three times of C18:2∑all and all other unsaturated fatty acids showed lipolysis ranging from 32% to 38%. The overall digestion of Bangladeshi Red Cattle milk was more or less similar to the digestion of Nordic bovine milk (Norwegian Red Cattle). PMID:25656195

Application of next-generation sequencing methods for microbial monitoring of anaerobic digestion of lignocellulosic biomass.

PubMed

Bozan, Mahir; Akyol, Çağrı; Ince, Orhan; Aydin, Sevcan; Ince, Bahar

2017-09-01

The anaerobic digestion of lignocellulosic wastes is considered an efficient method for managing the world's energy shortages and resolving contemporary environmental problems. However, the recalcitrance of lignocellulosic biomass represents a barrier to maximizing biogas production. The purpose of this review is to examine the extent to which sequencing methods can be employed to monitor such biofuel conversion processes. From a microbial perspective, we present a detailed insight into anaerobic digesters that utilize lignocellulosic biomass and discuss some benefits and disadvantages associated with the microbial sequencing techniques that are typically applied. We further evaluate the extent to which a hybrid approach incorporating a variation of existing methods can be utilized to develop a more in-depth understanding of microbial communities. It is hoped that this deeper knowledge will enhance the reliability and extent of research findings with the end objective of improving the stability of anaerobic digesters that manage lignocellulosic biomass.

Evaluation of a High Intensity Focused Ultrasound-Immobilized Trypsin Digestion and 18O-Labeling Method for Quantitative Proteomics

PubMed Central

López-Ferrer, Daniel; Hixson, Kim K.; Smallwood, Heather; Squier, Thomas C.; Petritis, Konstantinos; Smith, Richard D.

2009-01-01

A new method that uses immobilized trypsin concomitant with ultrasonic irradiation results in ultra-rapid digestion and thorough 18O labeling for quantitative protein comparisons. The reproducible and highly efficient method provided effective digestions in <1 min with a minimized amount of enzyme required compared to traditional methods. This method was demonstrated for digestion of both simple and complex protein mixtures, including bovine serum albumin, a global proteome extract from the bacteria Shewanella oneidensis, and mouse plasma, as well as 18O labeling of such complex protein mixtures, which validated the application of this method for differential proteomic measurements. This approach is simple, reproducible, cost effective, rapid, and thus well-suited for automation. PMID:19555078

Effect of protein oxidation on the in vitro digestibility of soy protein isolate.

PubMed

Chen, Nannan; Zhao, Mouming; Sun, Weizheng

2013-12-01

Soy protein isolate (SPI) was modified by 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) oxidation pretreatment, and the in vitro digestibility of oxidised SPI was investigated. Results indicated that oxidation induced amino acid modification. The amount of most amino acids decreased, accompanied by decreasing digestive proteolysis susceptibility. Peptide size distribution implied that oxidation generated protein aggregates that could not be degraded by pepsin, but could be digested by pancreatin. Oxidation induced a maximum of 16.6% and 14.6% loss, respectively, for free essential and free total amino acid in the digests of oxidised SPI. Antioxidant activities evaluation of oxygen radical absorbance capacity (ORAC) value and DPPH scavenging activity showed that oxidation deteriorated the antioxidant activities of the digests from oxidised SPI. Copyright © 2013 Elsevier Ltd. All rights reserved.

Investigation into the effect of high concentrations of volatile fatty acids in anaerobic digestion on methanogenic communities

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

Franke-Whittle, Ingrid H., E-mail: ingrid.whittle@uibk.ac.at; Walter, Andreas; Ebner, Christian

Highlights: • Different methanogenic communities in mesophilic and thermophilic reactors. • High VFA levels do not cause major changes in archaeal communities. • Real-time PCR indicated greater diversity than ANAEROCHIP microarray. - Abstract: A study was conducted to determine whether differences in the levels of volatile fatty acids (VFAs) in anaerobic digester plants could result in variations in the indigenous methanogenic communities. Two digesters (one operated under mesophilic conditions, the other under thermophilic conditions) were monitored, and sampled at points where VFA levels were high, as well as when VFA levels were low. Physical and chemical parameters were measured, andmore » the methanogenic diversity was screened using the phylogenetic microarray ANAEROCHIP. In addition, real-time PCR was used to quantify the presence of the different methanogenic genera in the sludge samples. Array results indicated that the archaeal communities in the different reactors were stable, and that changes in the VFA levels of the anaerobic digesters did not greatly alter the dominating methanogenic organisms. In contrast, the two digesters were found to harbour different dominating methanogenic communities, which appeared to remain stable over time. Real-time PCR results were inline with those of microarray analysis indicating only minimal changes in methanogen numbers during periods of high VFAs, however, revealed a greater diversity in methanogens than found with the array.« less

Biodegradable microparticles based on poly(D,L-lactide) as a protective transport system in ruminant digestion.

PubMed

Jay, Steven M; Peevy, Nolan J; Jenkins, Thomas C; Burg, Karen J L

2006-01-01

Despite its abundance in their diet, cattle are unable to directly digest cellulose. The bovine digestive tract overcomes this problem via the rumen, a portion of the stomach containing mixed anaerobic bacteria. These microbes, while breaking down foodstuffs, also perform undesirable processes such as biohydrogenation, in which unsaturated fatty acids become saturated, with deleterious cardiovascular effects. An approach to preventing this saturation entailing the use of polymeric microspheres to encapsulate feed supplements is proposed, with a single emulsion, solvent evaporation method used to formulate poly(D,L-lactide) microparticles for delivery of unsaturated fatty acids to ruminant abomasum.

Anaerobic digestion and co-digestion of slaughterhouse waste (SHW): influence of heat and pressure pre-treatment in biogas yield.

PubMed

Cuetos, M J; Gómez, X; Otero, M; Morán, A

2010-10-01

Mesophilic anaerobic digestion (34+/-1 degrees C) of pre-treated (for 20 min at 133 degrees C, >3 bar) slaughterhouse waste and its co-digestion with the organic fraction of municipal solid waste (OFMSW) have been assessed. Semi-continuously-fed digesters worked with a hydraulic retention time (HRT) of 36 d and organic loading rates (OLR) of 1.2 and 2.6 kg VS(feed)/m(3)d for digestion and co-digestion, respectively, with a previous acclimatization period in all cases. It was not possible to carry out an efficient treatment of hygienized waste, even less so when OFMSW was added as co-substrate. These digesters presented volatile fatty acids (VFA), long chain fatty acids (LCFA) and fats accumulation, leading to instability and inhibition of the degradation process. The aim of applying a heat and pressure pre-treatment to promote splitting of complex lipids and nitrogen-rich waste into simpler and more biodegradable constituents and to enhance biogas production was not successful. These results indicate that the temperature and the high pressure of the pre-treatment applied favoured the formation of compounds that are refractory to anaerobic digestion. The pre-treated slaughterhouse wastes and the final products of these systems were analyzed by FTIR and TGA. These tools verified the existence of complex nitrogen-containing polymers in the final effluents, confirming the formation of refractory compounds during pre-treatment. (c) 2010 Elsevier Ltd. All rights reserved.

Anaerobic co-digestion of livestock and vegetable processing wastes: fibre degradation and digestate stability.

PubMed

Molinuevo-Salces, Beatriz; Gómez, Xiomar; Morán, Antonio; García-González, Mari Cruz

2013-06-01

Anaerobic digestion of livestock wastes (swine manure (SM) and poultry litter (PL)) and vegetable processing wastes (VPW) mixtures was evaluated in terms of methane yield, volatile solids removal and lignocellulosic material degradation. Batch experiments were performed with 2% VS (volatile solids) to ensure complete conversion of TVFAs (total volatile fatty acids) and to avoid ammonia inhibition. Experimental methane yields obtained for the mixtures resulted in higher values than those obtained from the sum of the methane yields from the individual components. VPW addition to livestock wastes before anaerobic digestion also resulted in improved VS elimination. In SM-VPW co-digestions, CH4 yield increased from 111 to 244 mL CH4 g VS added(-1), and the percentage of VS removed increased from 50% to 86%. For PL-VPW co-digestions, the corresponding values were increased from 158 to 223 mL CH4 g VS added(-1) and from 70% to 92% VS removed. Hemicelluloses and more than 50% of cellulose were degraded during anaerobic digestion. Thermal analyses indicated that the stabilization of the wastes during anaerobic digestion resulted in significantly less energy being released by digestate samples than fresh samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

Intake, digestibility, and composition of orchardgrass and alfalfa silages treated with cellulase, inoculant, and formic acid fed to lambs.

PubMed

Nadeau, E M; Russell, J R; Buxton, D R

2000-11-01

The objectives of this study were to determine the effect of a cellulase (from Trichoderma longibrachiatum) alone or combined with a bacterial inoculant (Lactobacillus plantarum and Pediococcus cerevisiae) or formic acid on composition, intake, and digestibility of orchardgrass (Dactylis glomerata L.) and alfalfa (Medicago sativa L.) silages. Orchardgrass and alfalfa were harvested at the early heading stage and at the early bloom stage of maturity and wilted to approximately 22 and 32% DM, respectively. Forages were then ensiled in 100-L sealed barrels for at least 60 d before they were fed to lambs. Silage treated with cellulase had lower (P < .001) pH and lower (P < .001) acetic acid and NH3 N concentrations than untreated silage of both plant species and a higher (P = .004) lactic acid concentration than the control treatment of alfalfa silage. Fermentation characteristics of cellulase-treated silages, especially of alfalfa, were further enhanced by use of inoculant. Formic acid addition increased (P < .001), reducing sugar concentration of cellulase-treated orchardgrass and alfalfa silage by 90 and 154%, respectively, and decreased (P < .001) NH3 N concentration of cellulase-treated alfalfa silage by 19%. Averaged across plant species, cellulase, combined with inoculant or formic acid, resulted in 8 and 13% greater (P = .03) DMI, respectively, than the control silage. Extensive enzymatic cell-wall degradation during ensiling decreased (P = .003) NDF intake of cellulase-treated orchardgrass silage by 25% and decreased (P = .001) cellulose intake by 23%, when averaged across plant species. Addition of formic acid increased (P = .003) NDF intake of cellulase-treated orchardgrass silage by 19%. Averaged across species, cellulase application decreased (P < .05) silage NDF digestibility by 18%. Greater sugar and lower acetic acid, NH3 N, and NDF concentrations resulted in greater DMI of cellulase-treated silage than of control silage, when cellulase was combined

Ruminal fermentation and nutrient digestion in sheep fed hydroxyethylsoyamide.

PubMed

Jenkins, T C

1997-08-01

Hydroxyethylsoyamide (HESA) was reported previously to protect soybean oil from ruminal biohydrogenation and increase plasma unsaturated fatty acids in sheep. Two digestibility trials with sheep and a rumen in vitro trials were conducted in this study to determine the effects of HESA on ruminal VFA and nutrient digestibility. Trial 1 was a 4 x 4 Latin square with 17-d periods in which four wethers were fed either a control diet (CON) with no added fat, 2.5% soybean oil (SBO), 5% butylsoyamide (BuSA), or 5% HESA. The HESA diet was ground with a mortar and pestle before feeding to disperse fat lumps that formed during diet mixing. Compared with the CON diet, the HESA diet reduced DMI, acetate/ propionate (A/P), and total tract fiber digestibility, but these were not affected by SBO or BuSA. Trial 2 was a 24-h rumen in vitro study showing that total VFA concentration and A/P in cultures were reduced by 10% linoleic acid but not by 10% ethanolamine or 10% HESA. In Trial 3, four wethers were fed the CON and HESA diets in a replicated 2 x 2 Latin square to determine digestibility responses to HESA when grinding was avoided. Fiber digestibilities and A/P were not affected by HESA in Trial 3. The HESA in this study had variable effects on fiber digestibility that may have been related to physical attributes of the diet, including particle size. Substitution of ethanolamine for butylamine during synthesis of the amide increased fatty acid digestibility but reduced dry matter intake.

Effects of red wine, tannic acid, or ethanol on glucose tolerance in non-insulin-dependent diabetic patients and on starch digestibility in vitro.

PubMed

Gin, H; Rigalleau, V; Caubet, O; Masquelier, J; Aubertin, J

1999-09-01

This study examines the effect of moderate intake of red wine, tannic acid, or ethanol during a meal in type 2 diabetic patients and the influence of tannic acid on the digestibility of starch by alpha-amylase. Thirty non-insulin-dependent diabetes mellitus (NIDDM) patients aged 53 +/- 6 years were studied (in vivo study) 10 of whom received red wine (200 mL), 10 tannic acid (150 mg), and 10 ethanol (16 g) with their midday meal (600 calories, 65 g carbohydrate, 20 g lipid, and 34 g protein). All patients were tested on two occasions (water or placebo v wine, alcohol, or tannic acid). The influence of tannic acid (0.25, 0.5, and 1 mg) on the digestibility of starch (100 mg) by alpha-amylase (100 U) was tested in vitro by sequential incubation at 37 degrees C (in vitro study). The maximum glucose excursion after lunch was 2.6 +/- 0.8 mmol/L at 90 minutes (T90) for water and 1.8 +/- 0.9 mmol/L at T90 for red wine taken with the meal. The values at T60 and T90 were significant (P < .01). Comparable results were obtained with tannic acid alone (nonalcoholic component of wine): the maximum glucose excursion after lunch was 2.76 +/- 0.9 mmol/L at T120 for placebo and 1.97 +/- 0.9 mmol/L at T90 for tannic acid (P < .01); no difference in glucose and insulin excursion was observed between water and ethanol. No interaction between tannic acid and starch was observed in the in vitro experiments, although after preincubation of alpha-amylase with tannic acid, digestion was slowed in a dose-dependent manner (6.1 +/- 1.1 minutes for 0.25 mg tannic acid and 13.1 +/- 1.59 minutes for 1 mg tannic acid). Drinking red wine with a meal did not increase blood glucose in NIDDM patients, and led to a slight decrease in some instances. The effect appeared to be mediated by the nonalcoholic compounds in wine such as tannic acid. Ethanol itself had no effect on plasma glucose or insulin levels.

Microbial communities in liquid and fiber fractions of food waste digestates are differentially resistant to inhibition by ammonia.

PubMed

Peng, Wei; Lü, Fan; Shao, Liming; He, Pinjing

2015-04-01

The effect of different concentrations of ammonia (1.0-7.0 g/L) during mesophilic anaerobic digestion with fiber or liquid digestate as inoculum was examined. Evolution of microbial community within fiber and liquid digestates was quantitatively assessed by the intact lipid analysis methods and qualitatively by DNA fingerprint methods in order to determine their resistance to ammonia inhibition. The results showed that an increased level of total ammonia nitrogen prolonged the lag phase of fiber digestates while reduced the metabolic rate of liquid digestates. Fiber digestates had 19.6-50.9-fold higher concentrations of phospholipid fatty acids (PLFA) compared to liquid digestates, whereas concentrations of phospholipid ether lipids (PLEL) in the fiber digestates were only 2.91-17.6-fold higher compared to liquid digestates. Although the cell concentration in liquid fraction was far lower than that in the fiber one, the ammonia-resistant ability and the methanization efficiency of the liquid digestate was superior to the fiber digestate. The bacterial profiles were affected more by the type of digestate inoculum compared to the concentration of ammonia. Principal component analysis indicated that the lipids technique was superior to the DNA technique for bacterial quantification but detected less archaeal diversity.

The influence of soy oligosaccharides on apparent and true ileal amino acid digestibilities and fecal consistency in growing pigs.

PubMed

Smiricky, M R; Grieshop, C M; Albin, D M; Wubben, J E; Gabert, V M; Fahey, G C

2002-09-01

Fourteen ileally cannulated pigs (BW = 35 +/- 2 kg) were randomly allotted to a replicated 7 x 7 Latin square design experiment to evaluate the influence of the soybean oligosaccharides (OS), raffinose and stachyose, on ileal nutrient digestibility and fecal consistency. Semipurified diets containing soy protein concentrate (SPC) or soybean meal (SBM) as the sole protein sources were fed. Soy solubles (SS), a by-product of SBM processing containing 3.5% raffinose and 11.5% stachyose, were used to increase dietary raffinose and stachyose concentrations. The seven dietary treatments were SPC, SPC + 9% SS, SBM, SBM + 9% SS, SBM + 18% SS, SBM + 24,000 U alpha-galactosidase enzyme preparation/kg diet, and a low-protein casein (LPC) diet used to calculate true digestibility. Diets, with the exception of the LPC diet, were formulated to contain 17% CP. All diets contained 0.5% chromic oxide as a marker for ileal digestibility determination. The experimental periods were divided into a 5-d diet adaptation followed by 2-d of ileal digesta collection. Diets and digesta were analyzed for DM, N, Cr, amino acids (AA), raffinose, and stachyose. Fecal consistency was determined on d 6 and 7 of each experimental period. The apparent and true ileal AA digestibilities were not different (P < 0.05) for the SPC and SBM control diets. When SS was added to the SPC diet, apparent and true N and AA digestibilities were depressed (P < 0.05) with the exception of Trp and Pro. The apparent and true ileal N and AA digestibilities were not different (P > 0.05) between the SBM control and SBM + 9% SS diets with the exception of Glu. There was a linear decrease (P < 0.05) in apparent and true DM, Val, Gly, and Tyr digestibilities when increasing levels of SS were added to the SBM diet. The addition of alpha-galactosidase did not improve apparent or true ileal N or AA digestibilities except for apparent and true Val and Tyr. Ileal raffinose digestibility was improved (P < 0.05) by addition of a

The site of net absorption of Ca from the intestinal tract of growing pigs and effect of phytic acid, Ca level and Ca source on Ca digestibility.

PubMed

González-Vega, J Caroline; Walk, Carrie L; Liu, Yanhong; Stein, Hans H

2014-01-01

An experiment was conducted to test the hypothesis that the standardised digestibility of Ca in calcium carbonate and Lithothamnium calcareum Ca is not different regardless of the level of dietary Ca, and that phytic acid affects the digestibility of Ca in these two ingredients to the same degree. The objectives were to determine where in the intestinal tract Ca absorption takes place and if there are measurable quantities of basal endogenous Ca fluxes in the stomach, small intestine or large intestine. Diets contained calcium carbonate or L. calcareum Ca as the sole source of Ca, 0% or 1% phytic acid and 0.4% or 0.8% Ca. A Ca-free diet was also formulated and used to measure endogenous fluxes and losses of Ca. Nine growing pigs (initial body weight 23.8 ± 1.3 kg) were cannulated in the duodenum and in the distal ileum, and faecal, ileal and duodenal samples were collected. Duodenal endogenous fluxes of Ca were greater (p < 0.05) than ileal endogenous fluxes and total tract endogenous losses of Ca, but ileal endogenous fluxes were less (p < 0.05) than total tract endogenous losses. Standardised digestibility of Ca was not affected by the level of phytic acid, but decreased (p < 0.05) as Ca level increased in L. calcareum Ca diets, but that was not the case if calcium carbonate was the source of Ca (interaction, p < 0.05). The standardised duodenal digestibility (SDD), standardised ileal digestibility (SID) and standardised total tract digestibility (STTD) of Ca were not different if calcium carbonate was the source of dietary Ca. However, the STTD of Ca in L. calcareum Ca was greater (p < 0.05) than the SID and SDD of Ca. The SDD, SID and STTD of Ca in calcium carbonate were greater (p < 0.05) than those of L. calcareum Ca. In conclusion, under the conditions of this experiment, standardised digestibility of Ca is not affected by the level of phytic acid, but may be affected by dietary Ca level depending on the Ca source. Calcium from calcium carbonate is mostly

Watching fat digestion: a microscopic method assessing intraluminal lipolysis.

PubMed

Alliet, P; Eggermont, E

1990-01-01

We investigated the utility of a microscopic method assessing lipolytic activity of duodenal fluid. The method is based on evaluating microscopically physicochemical changes along time when olive oil is mixed with duodenal fluid in the presence of excess bile salts (13 mM) and calcium ions (8 mM) at pH 6.5. Data are analyzed on duodenal aspirations from 155 children referred for failure to thrive or gastrointestinal disorders. The "fat digestion index" (FDI) is the percentage of intact olive oil droplets that underwent complete hydrolysis or are transformed into amorphous reticular bodies (ARB) at steady state. In all patients with proven exocrine pancreatic disorder, a FDI less than 25% was found. This value was thus considered as a cut-off value. When no microscopic lipolysis (FDI = 0) was observed, exocrine pancreatic enzyme assays are suggestive for a total exocrine pancreatic insufficiency. In the group of children with FDI ranging 5-25%, however, no statistical difference in exocrine pancreatic enzymes could be found, as compared to control values. Our tests thus evaluate fat digestion in a dynamic way. It further seems to give additional information on intraluminal lipolysis as compared to exocrine pancreatic enzyme concentrations, since it gives an idea about the integrated action of (co)lipase and bile salts.

A MIDGUT DIGESTIVE PHOSPHOLIPASE A2 IN LARVAL MOSQUITOES, AEDES ALBOPICTUS AND CULEX QUINQUEFASCIATUS

USDA-ARS?s Scientific Manuscript database

Phospholipase A2 (PLA2) is a secretory digestive enzyme that hydrolyzes ester bond at sn-2 position of dietary phospholipids, creating free fatty acid and lysophopholipid. The free fatty acids (arachidonic acid) are absorbed into midgut cells. Aedes albopictus and Culex quinquefasciatus digestive PL...

Effect of particle size distribution of maize and soybean meal on the precaecal amino acid digestibility in broiler chickens.

PubMed

Siegert, W; Ganzer, C; Kluth, H; Rodehutscord, M

2018-02-01

1. Herein, it was investigated whether different particle size distributions of feed ingredients achieved by grinding through a 2- or 3-mm grid would have an effect on precaecal (pc) amino acid (AA) digestibility. Maize and soybean meal were used as the test ingredients. 2. Maize and soybean meal was ground with grid sizes of 2 or 3 mm. Nine diets were prepared. The basal diet contained 500 g/kg of maize starch. The other experimental diets contained maize or soybean meal samples at concentrations of 250 and 500, and 150 and 300 g/kg, respectively, instead of maize starch. Each diet was tested using 6 replicate groups of 10 birds each. The regression approach was applied to calculate the pc AA digestibility of the test ingredients. 3. The reduction of the grid size from 3 to 2 mm reduced the average particle size of both maize and soybean meal, mainly by reducing the proportion of coarse particles. Reducing the grid size significantly (P < 0.050) increased the pc digestibility of all AA in the soybean meal. In maize, reducing the grid size decreased the pc digestibility of all AA numerically, but not significantly (P > 0.050). The mean numerical differences in pc AA digestibility between the grid sizes were 0.045 and 0.055 in maize and soybean meal, respectively. 4. Future studies investigating the pc AA digestibility should specify the particle size distribution and should investigate the test ingredients ground similarly for practical applications.

Recovery of failed solid-state anaerobic digesters.

PubMed

Yang, Liangcheng; Ge, Xumeng; Li, Yebo

2016-08-01

This study examined the performance of three methods for recovering failed solid-state anaerobic digesters. The 9-L digesters, which were fed with corn stover, failed at a feedstock/inoculum (F/I) ratio of 10 with negligible methane yields. To recover the systems, inoculum was added to bring the F/I ratio to 4. Inoculum was either added to the top of a failed digester, injected into it, or well-mixed with the existing feedstock. Digesters using top-addition and injection methods quickly resumed and achieved peak yields in 10days, while digesters using well-mixed method recovered slowly but showed 50% higher peak yields. Overall, these methods recovered 30-40% methane from failed digesters. The well-mixed method showed the highest methane yield, followed by the injection and top-addition methods. Recovered digesters outperformed digesters had a constant F/I ratio of 4. Slow mass transfer and slow growth of microbes were believed to be the major limiting factors for recovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of an in vitro system to simulate equine foregut digestion and the influence of acidity on protein and fructan degradation in the horse's stomach.

PubMed

Strauch, S; Wichert, B; Greef, J M; Hillegeist, D; Zeyner, A; Liesegang, A

2017-06-01

The aim of this study was to improve an in vitro system in order to gather optimized information on the digestion of different forages in the horse's upper gastrointestinal tract. Therefore, foregut digestion of several forages was simulated in vitro (Part 1). The effect of different pH values on in vitro fructan degradation of two selected grasses (Part 2) was tested subsequently. Part 1: We hypothesized that our system produces representative results simulating digestive processes in the upper alimentary tract, but neglects microbial fermentation. In vitro digestion of six forages (grass mixture for horses, grass mixture for cows (GMC), tall fescue, English perennial ryegrass (ER), white clover, lucerne) was performed in two phases with pepsin and pancreatin. The results are consistent with current data from in vivo studies, including a degradation of crude protein and monosaccharides as well as a relative increase in fibres. Interestingly, a loss of fructan was measured in two feedstuffs (ER/GMC: 4.1/4.4% DM fructan before and 0.59/0.00% DM after simulated foregut digestion). Part 2: As fructans are thought not to be fragmented by digestive enzymes, another hypothesis was developed: acidic hydrolysis leads to a degradation of fructans. To evaluate the influence of gastric pH on the digestion of fructan and protein, different pH values (2, 3 and 4) were adjusted in a second series of in vitro foregut digestion trials with ER and GMC. As expected, the highest degradation of protein was seen at the lowest pH (protein in ER/GMC at pH 2: 6.11/8.28% DM and at pH 4: 7.73/10.64% DM), whereas fructan degradation was highest at pH 4 (fructan in ER/GMC at pH 2: 1.63/1.95% DM and at pH 4: 1.31/0.91% DM). We presume that not only acidic hydrolysis but also plant enzymes cause the loss of fructans in an acidic environment. Journal of Animal Physiology and Animal Nutrition © 2017 Blackwell Verlag GmbH.

Deficiencies in acetyl-CoA carboxylase and fatty acid synthase 1 differentially affect eggshell formation and blood meal digestion in Aedes aegypti

PubMed Central

Alabaster, Amy; Isoe, Jun; Zhou, Guoli; Lee, Ada; Murphy, Ashleigh; Day, W. Anthony; Miesfeld, Roger L.

2011-01-01

To better understand the mechanism of de novo lipid biosynthesis in blood fed Ae. aegypti mosquitoes, we quantitated acetyl-CoA carboxylase (ACC) and fatty acid synthase 1 (FAS1) transcript levels in blood fed mosquitoes, and used RNAi methods to generate ACC and FAS1 deficient mosquitoes. Using the ketogenic amino acid 14C-leucine as a metabolic precursor of 14C-acetyl-CoA, we found that 14C-triacylglycerol and 14C-phospholipid levels were significantly reduced in both ACC and FAS1 deficient mosquitoes, confirming that ACC and FAS1 are required for de novo lipid biosynthesis after blood feeding. Surprisingly however, we also found that ACC deficient mosquitoes, but not FAS1 deficient mosquitoes, produced defective oocytes, which lacked an intact eggshell and gave rise to inviable eggs. This severe phenotype was restricted to the 1st gonotrophic cycle, suggesting that the eggshell defect was due to ACC deficiencies in the follicular epithelial cells, which are replaced after each gonotrophic cycle. Consistent with lower amounts of de novo lipid biosynthesis, both ACC and FAS1 deficient mosquitoes produced significantly fewer eggs than control mosquitoes in both the 1st and 2nd gonotrophic cycles. Lastly, FAS1 deficient mosquitoes, but not ACC deficient mosquitoes, showed delayed blood meal digestion, suggesting that a feedback control mechanism may coordinate rates of fat body lipid biosynthesis and midgut digestion during feeding. We propose that decreased ACC and FAS1 enzyme levels lead to reduced lipid biosynthesis and lower fecundity, whereas altered levels of the regulatory metabolites acetyl-CoA and malonyl-CoA account for the observed defects in eggshell formation and blood meal digestion, respectively. PMID:21971482

Deficiencies in acetyl-CoA carboxylase and fatty acid synthase 1 differentially affect eggshell formation and blood meal digestion in Aedes aegypti.

PubMed

Alabaster, Amy; Isoe, Jun; Zhou, Guoli; Lee, Ada; Murphy, Ashleigh; Day, W Anthony; Miesfeld, Roger L

2011-12-01

To better understand the mechanism of de novo lipid biosynthesis in blood fed Aedes aegypti mosquitoes, we quantitated acetyl-CoA carboxylase (ACC) and fatty acid synthase 1 (FAS1) transcript levels in blood fed mosquitoes, and used RNAi methods to generate ACC and FAS1 deficient mosquitoes. Using the ketogenic amino acid (14)C-leucine as a metabolic precursor of (14)C-acetyl-CoA, we found that (14)C-triacylglycerol and (14)C-phospholipid levels were significantly reduced in both ACC and FAS1 deficient mosquitoes, confirming that ACC and FAS1 are required for de novo lipid biosynthesis after blood feeding. Surprisingly however, we also found that ACC deficient mosquitoes, but not FAS1 deficient mosquitoes, produced defective oocytes, which lacked an intact eggshell and gave rise to inviable eggs. This severe phenotype was restricted to the 1st gonotrophic cycle, suggesting that the eggshell defect was due to ACC deficiencies in the follicular epithelial cells, which are replaced after each gonotrophic cycle. Consistent with lower amounts of de novo lipid biosynthesis, both ACC and FAS1 deficient mosquitoes produced significantly fewer eggs than control mosquitoes in both the 1st and 2nd gonotrophic cycles. Lastly, FAS1 deficient mosquitoes, but not ACC deficient mosquitoes, showed delayed blood meal digestion, suggesting that a feedback control mechanism may coordinate rates of fat body lipid biosynthesis and midgut digestion during feeding. We propose that decreased ACC and FAS1 enzyme levels lead to reduced lipid biosynthesis and lower fecundity, whereas altered levels of the regulatory metabolites acetyl-CoA and malonyl-CoA account for the observed defects in eggshell formation and blood meal digestion, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dietary protein reduction on microbial protein, amino acid digestibility, and body retention in beef cattle: 2. Amino acid intestinal absorption and their efficiency for whole-body deposition.

PubMed

Mariz, L D S; Amaral, P M; Valadares Filho, S C; Santos, S A; Detmann, E; Marcondes, M I; Pereira, J M V; Silva Júnior, J M; Prados, L F; Faciola, A P

2018-03-06

The objective of this study was to determine the apparent and true intestinal digestibility of total and individual AA, and to estimate the efficiency of whole-body AA retention from individual and total absorbed AA. Four Nellore animals (241.3 kg initial BW) and four crossbred Angus × Nellore (263.4 kg initial BW) cannulated in rumen and ileum were randomly allocated in two 4 × 4 Latin squares. The experiment lasted four 17 d periods, with 10 d for adaptation to diets and another 7 d for data collection. The diets consisted of increasing CP levels: 100, 120, or 140 g/kg of DM offered ad libitum, and restricted intake diet with 120 g CP/kg DM (experiment 1). In experiment 2, forty-four bulls (22 Nellore and 22 crossbred F1 Angus × Nellore) with 8 months and initial shrunk BW 215.0 ± 15.0 kg (Nellore = 208.0 ± 12.78 kg; Angus × Nellore = 221.9 ± 14.16 kg) were used. Eight of those animals were slaughtered at the beginning of the experiment. The remaining 36 bulls were allocated in a completely randomized design with six replicates, in a 2 (genetic groups) × 3 (CP contents) factorial scheme. The amount of essential AA (EAA) and nonessential AA (NEAA) reaching the small intestine increased linearly (P < 0.05) in response to CP content. The apparent digestibility of EAA was not affected (P > 0.05) by CP content, with exception for histidine (P = 0.07, linear effect), leucine (P = 0.01, linear effect), and methionine (P = 0.05, linear effect). Differences existed among AA when compared the apparent digestibility of NEAA. The apparent digestibility of alanine (P = 0.05), aspartic acid (P = 0.07), glutamic acid (P = 0.02), glycine (P = 0.05), proline (P = 0.02), and serine (P = 0.04) responded quadratically to CP content increase. However, the apparent digestibility of cystine and tyrosine was not affected (P > 0.05) by increasing dietary CP. The true intestinal digestibilities of total, essential, nonessential AA, lysine, and methionine were 75.0%, 77.0%, 74

Digestibility of gluten proteins is reduced by baking and enhanced by starch digestion

PubMed Central

Pan, Xiaoyan; Bellido, Vincent; Toole, Geraldine A.; Gates, Fred K.; Wickham, Martin S. J.; Shewry, Peter R.; Bakalis, Serafim; Padfield, Philip; Mills, E. N. Clare

2015-01-01

Scope Resistance of proteins to gastrointestinal digestion may play a role in determining immune‐mediated adverse reactions to foods. However, digestion studies have largely been restricted to purified proteins and the impact of food processing and food matrices on protein digestibility is poorly understood. Methods and results Digestibility of a total gliadin fraction (TGF), flour (cv Hereward), and bread was assessed using in vitro batch digestion with simulated oral, gastric, and duodenal phases. Protein digestion was monitored by SDS‐PAGE and immunoblotting using monoclonal antibodies specific for celiac‐toxic sequences (QQSF, QPFP) and starch digestion by measuring undigested starch. Whereas the TGF was rapidly digested during the gastric phase the gluten proteins in bread were virtually undigested and digested rapidly during the duodenal phase only if amylase was included. Duodenal starch digestion was also slower in the absence of duodenal proteases. Conclusion The baking process reduces the digestibility of wheat gluten proteins, including those containing sequences active in celiac disease. Starch digestion affects the extent of protein digestion, probably because of gluten‐starch complex formation during baking. Digestion studies using purified protein fractions alone are therefore not predictive of digestion in complex food matrices. PMID:26202208

Addition of granular activated carbon and trace elements to favor volatile fatty acid consumption during anaerobic digestion of food waste.

PubMed

Capson-Tojo, Gabriel; Moscoviz, Roman; Ruiz, Diane; Santa-Catalina, Gaëlle; Trably, Eric; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Bernet, Nicolas; Delgenès, Jean-Philippe; Escudié, Renaud

2018-07-01

The effect of supplementing granular activated carbon and trace elements on the anaerobic digestion performance of consecutive batch reactors treating food waste was investigated. The results from the first batch suggest that addition of activated carbon favored biomass acclimation, improving acetic acid consumption and enhancing methane production. Adding trace elements allowed a faster consumption of propionic acid. A second batch proved that a synergy existed when activated carbon and trace elements were supplemented simultaneously. The degradation kinetics of propionate oxidation were particularly improved, reducing significantly the batch duration and improving the average methane productivities. Addition of activated carbon favored the growth of archaea and syntrophic bacteria, suggesting that interactions between these microorganisms were enhanced. Interestingly, microbial analyses showed that hydrogenotrophic methanogens were predominant. This study shows for the first time that addition of granular activated carbon and trace elements may be a feasible solution to stabilize food waste anaerobic digestion. Copyright © 2018 Elsevier Ltd. All rights reserved.

Phylogenetic comparison of the methanogenic communities from an acidic, oligotrophic fen and an anaerobic digester treating municipal wastewater sludge.

PubMed

Steinberg, Lisa M; Regan, John M

2008-11-01

Methanogens play a critical role in the decomposition of organics under anaerobic conditions. The methanogenic consortia in saturated wetland soils are often subjected to large temperature fluctuations and acidic conditions, imposing a selective pressure for psychro- and acidotolerant community members; however, methanogenic communities in engineered digesters are frequently maintained within a narrow range of mesophilic and circumneutral conditions to retain system stability. To investigate the hypothesis that these two disparate environments have distinct methanogenic communities, the methanogens in an oligotrophic acidic fen and a mesophilic anaerobic digester treating municipal wastewater sludge were characterized by creating clone libraries for the 16S rRNA and methyl coenzyme M reductase alpha subunit (mcrA) genes. A quantitative framework was developed to assess the differences between these two communities by calculating the average sequence similarity for 16S rRNA genes and mcrA within a genus and family using sequences of isolated and characterized methanogens within the approved methanogen taxonomy. The average sequence similarities for 16S rRNA genes within a genus and family were 96.0 and 93.5%, respectively, and the average sequence similarities for mcrA within a genus and family were 88.9 and 79%, respectively. The clone libraries of the bog and digester environments showed no overlap at the species level and almost no overlap at the family level. Both libraries were dominated by clones related to uncultured methanogen groups within the Methanomicrobiales, although members of the Methanosarcinales and Methanobacteriales were also found in both libraries. Diversity indices for the 16S rRNA gene library of the bog and both mcrA libraries were similar, but these indices indicated much lower diversity in the 16S digester library than in the other three libraries.

Determination of metals in coal fly ashes using ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry.

PubMed

Pontes, Fernanda V M; Mendes, Bruna A de O; de Souza, Evelyn M F; Ferreira, Fernanda N; da Silva, Lílian I D; Carneiro, Manuel C; Monteiro, Maria I C; de Almeida, Marcelo D; Neto, Arnaldo A; Vaitsman, Delmo S

2010-02-05

A method for determination of Co, Cr, Cu, Fe, Mn, Ni, Ti, V and Zn in coal fly ash samples using ultrasound-assisted digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) is proposed. The digestion procedure consisted in the sonication of the previously dried sample with hydrofluoric acid and aqua regia at 80 degrees C for 30 min, elimination of fluorides by heating until dryness for about 1h and dissolution of the residue with nitric acid solution. A classical digestion method, used as comparative method, consisted in the addition of HCl, HNO(3) and HF to 1 g of sample, and heating on a hot plate until dryness for about 6h. The proposed method presents several advantages: it requires lower amounts of sample and reagents, and it is faster. It is also advantageous when compared to the published methods, which also use ultrasound-assisted digestion procedure: lower detection limits for Co, Cu, Ni, V and Zn, and it does not require shaking during the digestion. The detection limits (microg g(-1)) for Co, Cr, Cu, Fe, Mn, Ni, Ti, V and Zn were 0.06, 0.37, 1.0, 25, 0.93, 0.45, 4.0, 1.7 and 4.3, respectively. The results were in good agreement with those obtained by the classical method and reference values. The exception was Cr, which presented low recoveries in classical and proposed methods (83 and 87%, respectively). Also, the concentration for Cu obtained by the proposed method was significantly different from the reference value, in spite of the good recovery (91+/-1%). Copyright 2009 Elsevier B.V. All rights reserved.

Food matrix effects on in vitro digestion of microencapsulated tuna oil powder.

PubMed

Shen, Zhiping; Apriani, Christina; Weerakkody, Rangika; Sanguansri, Luz; Augustin, Mary Ann

2011-08-10

Tuna oil, containing 53 mg of eicosapentaenoic acid (EPA) and 241 mg of docosahexaenoic acid (DHA) per gram of oil, delivered as a neat microencapsulated tuna oil powder (25% oil loading) or in food matrices (orange juice, yogurt, or cereal bar) fortified with microencapsulated tuna oil powder was digested in simulated gastric fluid or sequentially in simulated gastric fluid and simulated intestinal fluid. The level of fortification was equivalent to 1 g of tuna oil per recommended serving size (i.e., per 200 g of orange juice or yogurt or 60 g of cereal bar). The changes in particle size of oil droplets during digestion were influenced by the method of delivery of the microencapsulated tuna oil powder. Lipolysis in simulated gastric fluid was low, with only 4.4-6.1% EPA and ≤1.5% DHA released after digestion (as a % of total fatty acids present). After sequential exposure to simulated gastric and intestinal fluids, much higher extents of lipolysis of both glycerol-bound EPA and DHA were obtained (73.2-78.6% for the neat powder, fortified orange juice, and yogurt; 60.3-64.0% for the fortified cereal bar). This research demonstrates that the choice of food matrix may influence the lipolysis of microencapsulated tuna oil.

Development of the Digestive System-Experimental Challenges and Approaches of Infant Lipid Digestion.

PubMed

Abrahamse, Evan; Minekus, Mans; van Aken, George A; van de Heijning, Bert; Knol, Jan; Bartke, Nana; Oozeer, Raish; van der Beek, Eline M; Ludwig, Thomas

2012-12-01

At least during the first 6 months after birth, the nutrition of infants should ideally consist of human milk which provides 40-60 % of energy from lipids. Beyond energy, human milk also delivers lipids with a specific functionality, such as essential fatty acids (FA), phospholipids, and cholesterol. Healthy development, especially of the nervous and digestive systems, depends fundamentally on these. Epidemiological data suggest that human milk provides unique health benefits during early infancy that extend to long-lasting benefits. Preclinical findings show that qualitative changes in dietary lipids, i.e., lipid structure and FA composition, during early life may contribute to the reported long-term effects. Little is known in this respect about the development of digestive function and the digestion and absorption of lipids by the newborn. This review gives a detailed overview of the distinct functionalities that dietary lipids from human milk and infant formula provide and the profound differences in the physiology and biochemistry of lipid digestion between infants and adults. Fundamental mechanisms of infant lipid digestion can, however, almost exclusively be elucidated in vitro. Experimental approaches and their challenges are reviewed in depth.

Long-term observation of water-soluble chemical components and acid-digested metals in the total suspended particles collected at Okinawa, Japan

NASA Astrophysics Data System (ADS)

Handa, D.; Okada, K.; Kuroki, Y.; Nakama, Y.; Nakajima, H.; Somada, Y.; Ijyu, M.; Azechi, S.; Oshiro, Y.; Nakaema, F.; Miyagi, Y.; Arakaki, T.; Tanahara, A.

2011-12-01

The economic growth and population increase in recent Asia have been increasing air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location is ideal in observing East Asia's air quality because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background clean air and can be compared with continental air masses which have been affected by anthropogenic activities. We collected total suspended particles (TSP) on quartz filters by using a high volume air sampler at the Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS), Okinawa, Japan during August 2005 and August 2010. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations, water-soluble organic carbon (WSOC) and acid-digested metals in TSP samples using ion chromatography, atomic absorption spectrometry, total organic carbon analyzer and Inductively Coupled Plasma Mass spectrometry (ICP-MS), respectively. Seasonal variation of water-soluble chemical components and acid-digested metals showed that the concentrations were the lowest in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian continent, the concentrations of water-soluble chemical components and acid-digested metals were much higher compared to the other directions, suggesting long-range transport of air pollutants from Asian continent. Also, when the air mass came from Asian continent (75-100% dominant), the mean concentrations of non-sea salt sulfate and nitrate increased ca. 1.8 times and ca. 3.7 times, respectively between 2005 and 2010, and the ratio of nitrate to

Formation of reactive aldehydes (MDA, HHE, HNE) during the digestion of cod liver oil: comparison of human and porcine in vitro digestion models.

PubMed

Tullberg, Cecilia; Larsson, Karin; Carlsson, Nils-Gunnar; Comi, Irene; Scheers, Nathalie; Vegarud, Gerd; Undeland, Ingrid

2016-03-01

In this work, we investigated lipid oxidation of cod liver oil during gastrointestinal (GI) digestion using two types of in vitro digestion models. In the first type of model, we used human GI juices, while we used digestive enzymes and bile from porcine origin in the second type of model. Human and porcine models were matched with respect to factors important for lipolysis, using a standardized digestion protocol. The digests were analysed for reactive oxidation products: malondialdehyde (MDA), 4-hydroxy-trans-2-nonenal (HNE), and 4-hydroxy-trans-2-hexenal (HHE) by liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS), and for free fatty acids (FFA) obtained during the digestion by gas chromatography-mass spectrometry (GC-MS). The formation of the oxidation products MDA, HHE, and HNE was low during the gastric digestion, however, it increased during the duodenal digestion. The formation of the oxidation products reached higher levels when digestive juices of human origin were used (60 μM of MDA, 0.96 μM of HHE, and 1.6 μM of HNE) compared to when using enzymes and bile of porcine origin (9.8, and 0.36 μM of MDA; 0.16, and 0.026 μM of HHE; 0.23, and 0.005 μM of HNE, respectively, in porcine models I and II). In all models, FFA release was only detected during the intestinal step, and reached up to 31% of total fatty acids (FA). The findings in this work may be of importance when designing oxidation oriented lipid digestion studies.

Method of digesting an explosive nitro compound

DOEpatents

Shah, Manish M.

2000-01-01

The present invention is a process wherein bleaching oxidants are used to digest explosive nitro compounds. The process has an excellent reaction rate for digesting explosives and operates under multivariate conditions. Reaction solutions may be aqueous, non-aqueous or a combination thereof, and can also be any pH, but preferably have a pH between 2 and 9. The temperature may be ambient as well as any temperature above which freezing of the solution would occur and below which any degradation of the bleaching oxidant would occur or below which any explosive reaction would be initiated. The pressure may be any pressure, but is preferably ambient or atmospheric, or a pressure above a vapor pressure of the aqueous solution to avoid boiling of the solution. Because the bleaching oxidant molecules are small, much smaller than an enzyme molecule for example, they can penetrate the microstructure of plastic explosives faster. The bleaching oxidants generate reactive hydroxyl radicals, which can destroy other organic contaminants, if necessary, along with digesting the explosive nitro compound.

Kinetic study of dry anaerobic co-digestion of food waste and cardboard for methane production.

PubMed

Capson-Tojo, Gabriel; Rouez, Maxime; Crest, Marion; Trably, Eric; Steyer, Jean-Philippe; Bernet, Nicolas; Delgenès, Jean-Philippe; Escudié, Renaud

2017-11-01

Dry anaerobic digestion is a promising option for food waste treatment and valorization. However, accumulation of ammonia and volatile fatty acids often occurs, leading to inefficient processes and digestion failure. Co-digestion with cardboard may be a solution to overcome this problem. The effect of the initial substrate to inoculum ratio (0.25 to 1gVS·gVS -1 ) and the initial total solids contents (20-30%) on the kinetics and performance of dry food waste mono-digestion and co-digestion with cardboard was investigated in batch tests. All the conditions produced methane efficiently (71-93% of the biochemical methane potential). However, due to lack of methanogenic activity, volatile fatty acids accumulated at the beginning of the digestion and lag phases in the methane production were observed. At increasing substrate to inoculum ratios, the initial acid accumulation was more pronounced and lower cumulative methane yields were obtained. Higher amounts of soluble organic matter remained undegraded at higher substrate loads. Although causing slightly longer lag phases, high initial total solids contents did not jeopardize the methane yields. Cardboard addition reduced acid accumulation and the decline in the yields at increasing substrate loads. However, cardboard addition also caused higher concentrations of propionic acid, which appeared as the most last acid to be degraded. Nevertheless, dry co-digestion of food waste and cardboard in urban areas is demonstrated asan interesting feasible valorization option. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synergism and effect of high initial volatile fatty acid concentrations during food waste and pig manure anaerobic co-digestion.

PubMed

Dennehy, Conor; Lawlor, Peadar G; Croize, Thomas; Jiang, Yan; Morrison, Liam; Gardiner, Gillian E; Zhan, Xinmin

2016-10-01

Anaerobic co-digestion of food waste (FW) and pig manure (PM) was undertaken in batch mode at 37°C in order to identify and quantify the synergistic effects of co-digestion on the specific methane yield (SMY) and reaction kinetics. The effects of the high initial volatile fatty acid (VFA) concentrations in PM on synergy observed during co-digestion, and on kinetic modelling were investigated. PM to FW mixing ratios of 1/0, 4/1, 3/2, 2/3, 1/4 and 0/1 (VS basis) were examined. No VFA or ammonia inhibition was observed. The highest SMY of 521±29ml CH4/gVS was achieved at a PM/FW mixing ratio of 1/4. Synergy in terms of both reaction kinetics and SMY occurred at PM/FW mixing ratios of 3/2, 2/3 and 1/4. Initial VFA concentrations did not explain the synergy observed. Throughout the study the conversion of butyric acid was inhibited. Due to the high initial VFA content of PM, conventional first order and Gompertz models were inappropriate for determining reaction kinetics. A dual pooled first order model was found to provide the best fit for the data generated in this study. The optimal mixing ratio in terms of both reaction kinetics and SMY was found at a PM/FW mixing ratio of 1/4. Copyright © 2016 Elsevier Ltd. All rights reserved.

Short communication: Evaluation of acid-insoluble ash and indigestible neutral detergent fiber as total-tract digestibility markers in dairy cows fed corn silage-based diets.

PubMed

Lee, C; Hristov, A N

2013-08-01

The objective of this experiment was to evaluate acid-insoluble ash (AIA) and indigestible NDF (iNDF) as intrinsic digestibility markers in comparison with total fecal collection (TC) in dairy cows fed corn silage- and alfalfa haylage-based diets. The experiment was part of a larger experiment, which involved 8 Holstein cows [102±28.4 d in milk, 26.4±0.27 kg/d of dry matter (DM) intake, and 43±5.3 kg/d milk yield]. The experimental design was a replicated 4×4 Latin square with the following treatments: metabolizable protein (MP)-adequate diet [15.6% crude protein (CP); high-CP], MP-deficient diet (14.0% CP; low-CP), and 2 other low-CP diets supplemented (top-dressed) with ruminally protected Lys or Lys and Met. Data for the 3 low-CP diets were combined for this analysis. Total feces were collected for 5 consecutive days during each period to estimate total-tract apparent digestibility. Digestibility was also estimated using AIA (digestion with 2 N HCl) and iNDF (12-d ruminal incubation in 25-μm-pore-size bags). Significant diet × digestibility method interactions were observed for fecal output of nutrients and digestibility. Fecal output of nutrients estimated using AIA or iNDF was lower compared with TC and fecal output of DM, organic matter, and CP tended to be higher for iNDF compared with AIA for the high-CP diet. For the low-CP diet, however, fecal output of all nutrients was lower for AIA compared with TC and was higher for iNDF compared with TC. Data from this experiment showed that, compared with TC, AIA underestimated fecal output and overestimated digestibility, particularly evident with the fiber fractions and the protein-deficient diet. Compared with TC, fecal output was overestimated and digestibility of the low-CP diet was underestimated when iNDF was used as a marker, although the magnitude of the difference was smaller compared with that for AIA. In the conditions of the current study, iNDF appeared to be a more reliable digestibility marker

Volatile fatty acids (VFAs) production from swine manure through short-term dry anaerobic digestion and its separation from nitrogen and phosphorus resources in the digestate.

PubMed

Huang, Weiwei; Huang, Wenli; Yuan, Tian; Zhao, Ziwen; Cai, Wei; Zhang, Zhenya; Lei, Zhongfang; Feng, Chuanping

2016-03-01

The sustainability of an agricultural system depends highly upon the recycling of all useful substances from agricultural wastes. This study explored the feasibility of comprehensive utilization of C, N and P resources in swine manure (SM) through short-term dry anaerobic digestion (AD) followed by dry ammonia stripping, aiming at achieving (1) effective total volatile fatty acids (VFAs) production and separation; (2) ammonia recovery from the digestate; and (3) preservation of high P bioavailability in the solid residue for further applications. Specifically, two ammonia stripping strategies were applied and compared in this work: (I) ammonia stripping was directly performed with the digestate from dry AD of SM (i.e. dry ammonia stripping); and (II) wet ammonia stripping was conducted by using the resultant filtrate from solid-liquid separation of the mixture of digestate and added water. Results showed that dry AD of the tested SM at 55 °C, 20% TS and unadjusted initial pH (8.6) for 8 days produced relatively high concentrations of total VFAs (94.4 mg-COD/g-VS) and ammonia-N (20.0 mg/g-VS) with high potentially bioavailable P (10.6 mg/g-TS) remained in the digestate, which was considered optimal in this study. In addition, high ammonia removal efficiencies of 96.2% and 99.7% were achieved through 3 h' dry and wet stripping (at 55 °C and initial pH 11.0), respectively, while the total VFAs concentration in the digestate/filtrate remained favorably unchanged. All experimental data from the two stripping processes well fitted to the pseudo first-order kinetic model (R(2) = 0.9916-0.9997) with comparable theoretical maximum ammonia removal efficiencies (Aeq, >90%) being obtained under the tested dry and wet stripping conditions, implying that the former was more advantageous due to its much higher volumetric total ammonia-N removal rate thus much smaller reactor volume, less energy/chemicals consumption and no foaming problems. After 8 days' dry AD and 3�

Source analysis of organic matter in swine wastewater after anaerobic digestion with EEM-PARAFAC.

PubMed

Zeng, Zhuo; Zheng, Ping; Ding, Aqiang; Zhang, Meng; Abbas, Ghulam; Li, Wei

2017-03-01

Swine wastewater is one of the most serious pollution sources, and it has attracted a great public concern in China. Anaerobic digestion technology is extensively used in swine wastewater treatment. However, the anaerobic digestion effluents are difficult to meet the discharge standard. The results from batch experiments showed that plenty of refractory organic matter remained in the effluents after mesophilic anaerobic digestion for 30 days. The effluent total COD (tCOD) and soluble COD (sCOD) were 483 and 324 mg/L, respectively, with the sCOD/tCOD ratio of 0.671. Fluorescence excitation-emission matrix (EEM) coupled with parallel factor analysis (PARAFAC) revealed that the dissolved organic matter in the effluents was tryptophan-like substance, humic acid substance, and fulvic acid substance. Based on the appearance time during anaerobic digestion, tryptophan-like substance and humic acid substance were inferred to originate from the raw swine wastewater, and the fulvic acid substance was inferred to be formed in the anaerobic digestion. This work has revealed the source of residual organic matter in anaerobic digestion of swine wastewater and has provided some valuable information for the post-treatment.

Determination of arsenic in traditional Chinese medicine by microwave digestion with flow injection-inductively coupled plasma mass spectrometry (FI-ICP-MS).

PubMed

Ong, E S; Yong, Y L; Woo, S O

1999-01-01

A simple, rapid, and sensitive method with high sample throughput was developed for determining arsenic in traditional Chinese medicine (TCM) in the form of uncoated tablets, sugar-coated tablets, black pills, capsules, powders, and syrups. The method involves microwave digestion with flow injection-inductively coupled plasma mass spectrometry (FI-ICP-MS). Method precision was 2.7-10.1% (relative standard deviation, n = 6) for different concentrations of arsenic in different TCM samples analyzed by different analysts on different days. Method accuracy was checked with a certified reference material (sea lettuce, Ulva lactuca, BCR CRM 279) for external calibration and by spiking arsenic standard into different TCMs. Recoveries of 89-92% were obtained for the certified reference material and higher than 95% for spiked TCMs. Matrix interference was insignificant for samples analyzed by the method of standard addition. Hence, no correction equation was used in the analysis of arsenic in the samples studied. Sample preparation using microwave digestion gave results that were very similar to those obtained by conventional wet acid digestion using nitric acid.

Chemical digestion of low level nuclear solid waste material

DOEpatents

Cooley, Carl R.; Lerch, Ronald E.

1976-01-01

A chemical digestion for treatment of low level combustible nuclear solid waste material is provided and comprises reacting the solid waste material with concentrated sulfuric acid at a temperature within the range of 230.degree.-300.degree.C and simultaneously and/or thereafter contacting the reacting mixture with concentrated nitric acid or nitrogen dioxide. In a special embodiment spent ion exchange resins are converted by this chemical digestion to noncombustible gases and a low volume noncombustible residue.

Effect of milk replacer feeding rate and functional fatty acids on dairy calf performance and digestion of nutrients.

PubMed

Hill, T M; Quigley, J D; Suarez-Mena, F X; Bateman, H G; Schlotterbeck, R L

2016-08-01

Calves fed large amounts of milk replacer (MR) gain more body weight preweaning than calves fed less MR; however, postweaning growth may be reduced because of impaired digestion of nutrients. This was explored in the current research, as was the inclusion of functional fatty acids (NT) that could ameliorate some poor growth and digestion issues in calves fed large amounts of MR. Two MR rates [moderate (MOD) or aggressive (AGG)] with and without NT were compared using 48 male Holstein calves initially 3d old (43±1.5kg of body weight) randomly assigned to treatments. The MOD rate was fed at 0.66kg of dry matter (DM) for 49d. The AGG rate was fed for 4d at 0.66kg of DM, 4d at 0.96kg of DM, then 34d at 1.31kg of DM, followed by 0.66kg of DM for the last 7d. Calves were completely weaned at 49d. The MR contained 27% crude protein and 17% fat. The textured starter was 20% crude protein. Starter and water were fed free-choice for the first 56d when calves were housed in individual pens. From 56 to 112d, calves were grouped (4 calves/pen), maintaining the same MR rate and NT treatments, and fed starter blended with 5% chopped grass hay free-choice with free-choice water. Digestibility was estimated from fecal collections made on d 19 to 23, 40 to 44, and 52 to 56. Data were analyzed as a completely randomized design with a factorial arrangement of MR rate and NT using repeated measures with a mixed procedure. Fiber and starch digestion increased with age and was lower for AGG versus MOD. Calf average daily gain and hip width change were greater before approximately 6wk of age for AGG versus MOD, but this was reversed from approximately 6 to 16wk. Calves fed AGG had lower average daily gain per unit intake of DM, crude protein, and metabolizable energy from 8 to 16wk than calves fed MOD. Preweaning starter intake was less for calves fed AGG versus MOD. Calves fed AGG had greater body weight gain than MOD over 112d, but hip width change did not differ. Feeding NT improved

In vitro digestibility of individual amino acids in rumen-undegraded protein: the modified three-step procedure and the immobilized digestive enzyme assay.

PubMed

Boucher, S E; Calsamiglia, S; Parsons, C M; Stern, M D; Moreno, M Ruiz; Vázquez-Añón, M; Schwab, C G

2009-08-01

Three soybean meal, 3 SoyPlus (West Central Cooperative, Ralston, IA), 5 distillers dried grains with solubles, and 5 fish meal samples were used to evaluate the modified 3-step in vitro procedure (TSP) and the in vitro immobilized digestive enzyme assay (IDEA; Novus International Inc., St. Louis, MO) for estimating digestibility of AA in rumen-undegraded protein (RUP-AA). In a previous experiment, each sample was ruminally incubated in situ for 16 h, and in vivo digestibility of AA in the intact samples and in the rumen-undegraded residues (RUR) was obtained for all samples using the precision-fed cecectomized rooster assay. For the modified TSP, 5 g of RUR was weighed into polyester bags, which were then heat-sealed and placed into Daisy(II) incubator bottles. Samples were incubated in a pepsin/HCl solution followed by incubation in a pancreatin solution. After this incubation, residues remaining in the bags were analyzed for AA, and digestibility of RUP-AA was calculated based on disappearance from the bags. In vitro RUP-AA digestibility estimates obtained with this procedure were highly correlated to in vivo estimates. Corresponding intact feeds were also analyzed via the pepsin/pancreatin steps of the modified TSP. In vitro estimates of AA digestibility of the feeds were highly correlated to in vivo RUP-AA digestibility, which suggests that the feeds may not need to be ruminally incubated before determining RUP-AA digestibility in vitro. The RUR were also analyzed via the IDEA kits. The IDEA values of the RUR were good predictors of RUP-AA digestibility in soybean meal, SoyPlus, and distillers dried grains with solubles, but the IDEA values were not as good predictors of RUP-AA digestibility in fish meal. However, the IDEA values of intact feed samples were also determined and were highly correlated to in vivo RUP-AA digestibility for all feed types, suggesting that the IDEA value of intact feeds may be a better predictor of RUP-AA digestibility than the IDEA

Effect of the chlortetracycline addition method on methane production from the anaerobic digestion of swine wastewater.

PubMed

Huang, Lu; Wen, Xin; Wang, Yan; Zou, Yongde; Ma, Baohua; Liao, Xindi; Liang, Juanboo; Wu, Yinbao

2014-10-01

Effects of antibiotic residues on methane production in anaerobic digestion are commonly studied using the following two antibiotic addition methods: (1) adding manure from animals that consume a diet containing antibiotics, and (2) adding antibiotic-free animal manure spiked with antibiotics. This study used chlortetracycline (CTC) as a model antibiotic to examine the effects of the antibiotic addition method on methane production in anaerobic digestion under two different swine wastewater concentrations (0.55 and 0.22mg CTC/g dry manure). The results showed that CTC degradation rate in which manure was directly added at 0.55mg CTC/g (HSPIKE treatment) was lower than the control values and the rest of the treatment groups. Methane production from the HSPIKE treatment was reduced (p<0.05) by 12% during the whole experimental period and 15% during the first 7days. The treatments had no significant effect on the pH and chemical oxygen demand value of the digesters, and the total nitrogen of the 0.55mg CTC/kg manure collected from mediated swine was significantly higher than the other values. Therefore, different methane production under different antibiotic addition methods might be explained by the microbial activity and the concentrations of antibiotic intermediate products and metabolites. Because the primary entry route of veterinary antibiotics into an anaerobic digester is by contaminated animal manure, the most appropriate method for studying antibiotic residue effects on methane production may be using manure from animals that are given a particular antibiotic, rather than adding the antibiotic directly to the anaerobic digester. Copyright © 2014. Published by Elsevier B.V.

Digestive Enzyme Supplementation in Gastrointestinal Diseases.

PubMed

Ianiro, Gianluca; Pecere, Silvia; Giorgio, Valentina; Gasbarrini, Antonio; Cammarota, Giovanni

2016-01-01

Digestive enzymes are able to break down proteins and carbohydrates and lipids, and their supplementation may play a role in the management of digestive disorders, from lactose intolerance to cystic fibrosis. To date, several formulations of digestive enzymes are available on the market, being different each other in terms of enzyme type, source and origin, and dosage. This review, performed through a non-systematic search of the available literature, will provide an overview of the current knowledge of digestive enzyme supplementation in gastrointestinal disorders, discussion of the use of pancreatic enzymes, lactase (β-galactosidase) and conjugated bile acids, and also exploring the future perspective of digestive enzyme supplementation. Currently, the animal-derived enzymes represent an established standard of care, however the growing study of plant-based and microbe-derived enzymes offers great promise in the advancement of digestive enzyme therapy. New frontiers of enzyme replacement are being evaluated also in the treatment of diseases not specifically related to enzyme deficiency, whereas the combination of different enzymes might constitute an intriguing therapeutic option in the future.

Digestive system dysfunction in cystic fibrosis: challenges for nutrition therapy.

PubMed

Li, Li; Somerset, Shawn

2014-10-01

Cystic fibrosis can affect food digestion and nutrient absorption. The underlying mutation of the cystic fibrosis trans-membrane regulator gene depletes functional cystic fibrosis trans-membrane regulator on the surface of epithelial cells lining the digestive tract and associated organs, where Cl(-) secretion and subsequently secretion of water and other ions are impaired. This alters pH and dehydrates secretions that precipitate and obstruct the lumen, causing inflammation and the eventual degradation of the pancreas, liver, gallbladder and intestine. Associated conditions include exocrine pancreatic insufficiency, impaired bicarbonate and bile acid secretion and aberrant mucus formation, commonly leading to maldigestion and malabsorption, particularly of fat and fat-soluble vitamins. Pancreatic enzyme replacement therapy is used to address this insufficiency. The susceptibility of pancreatic lipase to acidic and enzymatic inactivation and decreased bile availability often impedes its efficacy. Brush border digestive enzyme activity and intestinal uptake of certain disaccharides and amino acids await clarification. Other complications that may contribute to maldigestion/malabsorption include small intestine bacterial overgrowth, enteric circular muscle dysfunction, abnormal intestinal mucus, and intestinal inflammation. However, there is some evidence that gastric digestive enzymes, colonic microflora, correction of fatty acid abnormalities using dietary n-3 polyunsaturated fatty acid supplementation and emerging intestinal biomarkers can complement nutrition management in cystic fibrosis. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Enhancement in mesophilic aerobic digestion of waste activated sludge by chemically assisted thermal pretreatment method.

PubMed

Tyagi, Vinay Kumar; Lo, Shang-Lien

2012-09-01

The effects of hybrid microwave (MW)-alkali pretreatment methods on the efficiency of mesophilic aerobic digestion were studied. The MW-alkali pretreatment (95°C-pH 12) was observed to enhance the sludge solubilization synergistically from 0.5% (raw) to 52.5% (MW-NaOH) and 48.7% (MW-KOH), which are 20% greater than the additive value of MW only and alkali only (16%(MW)+28.4%(NaOH)=44.4% and 16%(MW)+25.5(KOH)=41.5). The higher VSS solubilization was observed for hybrid MW-NaOH (53.9%) and MW-KOH (47.4%) methods. The batch mesophilic (35°C) aerobic digestion system led to 81.1% TCOD degradation and 72.4% VSS degradation at 20 days of retention time, with 35% higher TCOD and VSS reduction in comparison with the control system. The filterability of microwave-alkali pretreated sludge was improved remarkably after aerobic digestion. Moreover, the proposed method is capable of effectively sanitize the sewage sludge and produce Class A biosolids. Copyright © 2012 Elsevier Ltd. All rights reserved.

Pre-digestion to enhance volatile fatty acids (VFAs) concentration as a carbon source for denitrification in treatment of liquid swine manure.

PubMed

Wu, Sarah Xiao; Chen, Lide; Zhu, Jun; Walquist, McKenzie; Christian, David

2018-04-30

Insufficient denitrification in biological treatment is often a result of the lack of a carbon source. In this study, use of the volatile fatty acids (VFAs) generated via pre-digestion as a carbon source to improve denitrification in sequencing batch reactor (SBR) treatment of liquid swine manure was investigated. The pre-digestion of swine manure was realized by storing the manure in a sealed container in room temperature and samples were taken periodically from the container to determine the VFA levels. The results showed that after 14 days of pre-digestion, the VFA level in the digested liquid was increased by 200%. A polynomial relationship for the VFA level in the digested manure with the digestion time was observed with a correlation coefficient being 0.9748. Two identical SBRs were built and operated on 8-h cycles in parallel, with one fed with pre-digested and the other raw swine manure. There were five phases included in each cycle, i.e., anaerobic (90 min), anoxic (150 min), anoxic/anaerobic (90 min), anoxic/aerobic (120 min), and settle/decant (30 min), and the feeding was split to 600 mL/200 mL and performed at the beginning of and 240 min into the cycle. The SBR fed on pre-digested swine manure achieved successful denitrification with only 0.35 mg/L nitrate left in the effluent, compared to 15.9 mg/L found in the effluent of the other SBR. Nitrite was not detected in the effluent from both SBRs. The results also indicated that there was no negative impact of feeding SBRs with the pre-digested liquid swine manure for treatment on the removal of other constituents such as total solids (TS), volatile solids (VS), suspended solids (SS), volatile suspended solids (VSS), and soluble chemical oxygen demand (COD). Therefore, anaerobic digestion as a pretreatment can be an effective way to condition liquid swine manure for SBR treatment to achieve sufficient nitrate removal.

Effects of blend of canola oil and palm oil on nutrient intake and digestibility, growth performance, rumen fermentation and fatty acids in goats.

PubMed

Adeyemi, Kazeem Dauda; Sazili, Awis Qurni; Ebrahimi, Mahdi; Samsudin, Anjas Asmara; Alimon, Abd Rasak; Karim, Roselina; Karsani, Saiful Anuar; Sabow, Azad Behnan

2016-09-01

The study examined the effects of blend of 80% canola oil and 20% palm oil (BCPO) on nutrient intake and digestibility, growth performance, rumen fermentation and fatty acids (FA) in goats. Twenty-four Boer bucks were randomly assigned to diets containing 0, 4 and 8% BCPO on a dry matter basis, fed for 100 days and slaughtered. Diet did not affect feed efficiency, growth performance, intake and digestibility of all nutrients except ether extract. Intakes and digestibilities of ether extract, unsaturated fatty acids (FA) and total FA were higher (P < 0.05) while digestibility of C18:0 was lower (P < 0.05) in oil-fed goats than the control goats. Total volatile FA, acetate, butyrate, acetate/propionate ratio and methane decreased (P < 0.05) with increasing BCPO but propionate, NH3 -N and rumen pH did not differ between diets. Ruminal concentration of C18:0, n-3 FA and total FA increased (P < 0.05) while C12:0, C14:0, C15:0 and n-6 FA decreased with increasing BCPO. Analysis of the FA composition of Triceps brachii muscle showed that concentrations of C16:0, C14:0 and C18:2n-6 were lower (P < 0.05) while C18:1n-9, C18:3n-3 and C20:5n-3 were higher in oil-fed goats compared with control goats. Dietary BCPO altered muscle lipids without having detrimental effects on nutrient intake and digestibility and growth performance in goats. © 2015 Japanese Society of Animal Science.

Extracellular digestion during hyposaline exposure in the Dungeness crab, Cancer magister, and the blue crab, Callinectes sapidus.

PubMed

Curtis, Daniel L; van Breukelen, Frank; McGaw, Iain J

2013-12-01

Extracellular digestive processes were examined in the Dungeness crab, Cancer magister and the blue crab, Callinectes sapidus, during hyposaline exposure. Both species are found in estuaries as adults, but vary in their ability to balance the cardiovascular and respiratory demands of concurrent osmoregulation and digestion. The weak osmoregulator, C. magister, is unable to balance the demands of osmoregulation and digestion. Concordant with observed decreases in oxygen consumption and mechanical digestion, proteolytic digestion within the foregut and hepatopancreas was delayed, resulting in a relative reduction of circulating amino acids post-feeding in low salinity. In contrast, the efficient osmoregulator, C. sapidus, balances the demands of osmoregulation and digestion, and mechanical digestion continues unabated in low salinity. Protease activity in the gut fluid and hepatopancreas showed either no change or a reduction over time. The transport of amino acids into the cells post-feeding is opposed by an efflux of amino acids at the cellular level, and resulted in a build up of amino acids in the hemolymph. Despite differences in the extracellular responses to low salinity exposure following feeding, both species were able to maintain high digestive efficiencies. © 2013.

Comparative energy content and amino acid digestibility of barley obtained from diverse sources fed to growing pigs.

PubMed

Wang, Hong Liang; Shi, Meng; Xu, Xiao; Ma, Xiao Kang; Liu, Ling; Piao, Xiang Shu

2017-07-01

Two experiments were conducted to determine the content of digestible energy (DE) and metabolizable energy (ME) as well as the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in barley grains obtained from Australia, France or Canada. In Exp. 1, 18 growing barrows (Duroc×Landrace×Yorkshire; 31.5±3.2 kg) were individually placed in stainless-steel metabolism crates (1.4×0.7×0.6 m) and randomly allotted to 1 of 3 test diets. In Exp. 2, eight crossbred pigs (30.9±1.8 kg) were allotted to a replicate 3×4 Youden Square designed experiment with three periods and four diets. Two pigs received each diet during each test period. The diets included one nitrogen-free diet and three test diets. The relative amounts of gross energy (GE), CP, and all AA in the Canadian barley were higher than those in Australian and French barley while higher concentrations of neutral detergent fiber, acid detergent fiber, total dietary fiber, insoluble dietary fiber and β-glucan as well as lower concentrations of GE and ether extract were observed in the French barley compared with the other two barley sources. The DE and ME as well as the SID of histidine, isoleucine, leucine and phenylalanine in Canadian barley were higher (p<0.05) than those in French barley but did not differ from Australian barley. Differences in the chemical composition, energy content and the SID and AID of AA were observed among barley sources obtained from three countries. The feeding value of barley from Canada and Australia was superior to barley obtained from France which is important information in developing feeding systems for growing pigs where imported grains are used.

Antioxidant activity and bioactive compound contents before and after in vitro digestion of new tomato hybrids.

PubMed

Tommonaro, Giuseppina; Speranza, Giovanna; De Prisco, Rocco; Iodice, Carmine; Crudele, Egle; Abbamondi, Gennaro Roberto; Nicolaus, Barbara

2017-12-01

The antioxidant properties and bioactive compound contents of fresh new tomato hybrids before and after in vitro digestion were investigated. To this aim, the antioxidant activities of lipophilic, hydrophilic and polyphenolic extracts of tomato hybrids were determined by ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), DMPD (N,N-dimethyl-p-phenylenediamine dihydrochloride) and DPPH (2,2-diphenyl-1-picrylhydrazyl) methods respectively, while the bioactive compound contents were estimated via Folin-Ciocalteu (polyphenols), pH differential (anthocyanins) and high-performance liquid chromatography (lycopene and β-carotene) methods. After the digestion process, a marked loss (ranging from 37 to 77%) of antioxidant capacity linked to the hydrophilic fraction was observed. In contrast, the lipophilic and methanolic fractions showed an increase in antioxidant activity (ranging from 9 to 40%) after gastric digestion, and a rapid decrease was observed after total digestion. Moreover, the presence of anthocyanins and carotenoids after simulated digestion was a notable result. The bioavailability of bioactive metabolites from nutraceutical food and their healthful properties in humans are strictly dependent on the digestion process. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Stability of Pycnogenol® as an ingredient in fruit juices subjected to in vitro gastrointestinal digestion.

PubMed

Frontela, Carmen; Ros, Gaspar; Martínez, Carmen; Sánchez-Siles, Luis M; Canali, Raffaella; Virgili, Fabio

2011-01-30

The enrichment of fruit juices with concentrated polyphenolic extracts is an expedient strategy to compensate possible phenolic loss through gastrointestinal processing. Pycnogenol, a standardised procyanidin-rich extract from pine bark, has been proposed as a potential candidate for polyphenol enrichment of foods. In this study the effects of in vitro digestion on the phenolic profile of fruit juices enriched with Pycnogenol were investigated. After in vitro digestion the level of detectable total phenolic compounds (expressed as gallic acid equivalent) was higher in both pineapple and red fruit juices enriched with Pycnogenol than in non-enriched commercial juices. Five phenolic monomeric compounds were identified by high-performance liquid chromatography, namely chlorogenic acid, caffeic acid, ferulic acid, gallic acid and taxifolin, the last two being predominant. In vitro digestion of both Pycnogenol-enriched pineapple and red fruit juices led to a significant (P < 0.05) increase in detectable chlorogenic and ferulic acids, indicating that hydrolysis of more complex molecules occurs. On the other hand, in vitro digestion of non-enriched juices was associated with a decrease in gallic and caffeic acids in pineapple juice and with a decrease in ferulic acid in red fruit juice. In no case did in vitro digestion increase the amount of detectable phenolic compounds in non-enriched juices. The stability of Pycnogenol after in vitro gastrointestinal digestion makes it a good choice for phenolic enrichment of fruit juices. 2010 Society of Chemical Industry.

Changes in chemical composition and digestibility of three maize stover components digested by white-rot fungi.

PubMed

Lynch, J P; O'Kiely, P; Murphy, R; Doyle, E M

2014-08-01

Maize stover (total stem and leaves) is not considered a ruminant feed of high nutritive value. Therefore, an improvement in its digestibility may increase the viability of total forage maize production systems in marginal growth regions. The objective of this study was to describe the changes in chemical composition during the storage of contrasting components of maize stover (leaf, upper stem and lower stem) treated with either of two lignin degrading white-rot fungi (WRF; Pleurotus ostreatus, Trametes versicolor). Three components of maize stover (leaf, upper stem and lower stem), harvested at a conventional maturity for silage production, were digested with either of two WRF for one of four digestion durations (1-4 months). Samples taken prior to fungal inoculation were used to benchmark the changes that occurred. The degradation of acid detergent lignin was observed in all sample types digested with P. ostreatus; however, the loss of digestible substrate in all samples inoculated with P. ostreatus was high, and therefore, P. ostreatus-digested samples had a lower dry matter digestibility than samples prior to inoculation. Similarly, T. veriscolor-digested leaf underwent a non-selective degradation of the rumen-digestible components of fibre. The changes in chemical composition of leaf, upper stem and lower stem digested with either P. ostreatus or T. veriscolor were not beneficial to the feed value of the forage, and incurred high DM losses. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

Amino acid sequences of peptides from a tryptic digest of a urea-soluble protein fraction (U.S.3) from oxidized wool

PubMed Central

Corfield, M. C.; Fletcher, J. C.; Robson, A.

1967-01-01

1. A tryptic digest of the protein fraction U.S.3 from oxidized wool has been separated into 32 peptide fractions by cation-exchange resin chromatography. 2. Most of these fractions have been resolved into their component peptides by a combination of the techniques of cation-exchange resin chromatography, paper chromatography and paper electrophoresis. 3. The amino acid compositions of 58 of the peptides in the digest present in the largest amounts have been determined. 4. The amino acid sequences of 38 of these have been completely elucidated and those of six others partially derived. 5. These findings indicate that the parent protein in wool from which the protein fraction U.S.3 is derived has a minimum molecular weight of 74000. 6. The structures of wool proteins are discussed in the light of the peptide sequences determined, and, in particular, of those sequences in fraction U.S.3 that could not be elucidated. PMID:16742497

Antioxidant and antidiabetic properties of tartary buckwheat rice flavonoids after in vitro digestion*

PubMed Central

Bao, Tao; Wang, Ye; Li, Yu-ting; Gowd, Vemana; Niu, Xin-he; Yang, Hai-ying; Chen, Li-shui; Chen, Wei; Sun, Chong-de

2016-01-01

Oxidative stress and diabetes have a tendency to alter protein, lipid, and DNA moieties. One of the strategic methods used to reduce diabetes-associated oxidative stress is to inhibit the carbohydrate-digesting enzymes, thereby decreasing gastrointestinal glucose production. Plant-derived natural antioxidant molecules are considered a therapeutic tool in the treatment of oxidative stress and diabetes. The objective of this study was to identify tartary buckwheat rice flavonoids and evaluate the effect of in vitro digestion on their antioxidant and antidiabetic properties. High performance liquid chromatography (HPLC) analysis indicated the presence of rutin as a major component and quercitrin as a minor component of both digested and non-digested flavonoids. Both extracts showed a significant antioxidant capacity, but digested flavonoids showed reduced activity compared to non-digested. There were some decreases of the antioxidant activities (2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazy (DPPH) radical, and ferric reducing antioxidant power (FRAP)) of digested tartary buckwheat rice flavonoids compared with non-digested. Flavonoids from both groups significantly inhibited reactive oxygen species (ROS) production and α-glucosidase activity. Both digested and non-digested flavonoids markedly increased glucose consumption and glycogen content in HepG2 cells. Tartary buckwheat rice flavonoids showed appreciable antioxidant and antidiabetic properties, even after digestion. Tartary buckwheat rice appears to be a promising functional food with potent antioxidant and antidiabetic properties. PMID:27921399

Advanced glycation endproducts form during ovalbumin digestion in the presence of fructose: Inhibition by chlorogenic acid.

PubMed

Bains, Yasmin; Gugliucci, Alejandro; Caccavello, Russell

2017-07-01

One mechanism by which fructose could exert deleterious effects is through intestinal formation and absorption of pro-inflammatory advanced glycation endproducts via the Maillard reaction. We employed simulated stomach and duodenum digestion of ovalbumin (OVA) to test the hypothesis that advanced glycation endproducts (AGEs) are formed by fructose during simulated digestion of a ubiquitous food protein under model physiological conditions. OVA was subjected to simulated gastric and intestinal digestion using standard models, in presence of fructose or glucose (0-100mM). Peptide fractions were analyzed by fluorescence spectroscopy and intensity at Excitation: λ370nm, Emission: λ 440nm. AGE adducts formed between fructose and OVA, evidenced by the peptide fractions (<5kDa) at times (30min) and concentration ranges (10mM) plausibly found in the intestines, whereas no reaction occurs with glucose. The reaction was inhibited by chlorogenic acid at concentrations compatible with those found in the gut. The reaction was also inhibited by aminoguanidine, a specific antiglycation agent. Our study showed fructose-AGE formation on a ubiquitous dietary protein under model physiological conditions. Our study also suggests ways to decrease the damage: enteral fructose-AGE formation may be partially inhibited by co-intake of beverages, fruits and vegetables with concentrations of phenolics high enough to serve as anti-glycation agents. Copyright © 2017 Elsevier B.V. All rights reserved.

VALIDATION FOR THE PERMANGANATE DIGESTION OF REILLEX HPQ ANION RESIN

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

Kyser, E.

2009-09-23

The flowsheet for the digestion of Reillex{trademark} HPQ was validated both under the traditional alkaline conditions and under strongly acidic conditions. Due to difficulty in performing a pH adjustment in the large tank where this flowsheet must be performed, the recommended digestion conditions were changed from pH 8-10 to 8 M HNO{sub 3}. Thus, no pH adjustment of the solution is required prior to performing the permanganate addition and digestion and the need to sample the digestion tank to confirm appropriate pH range for digestion may be avoided. Neutralization of the acidic digestion solution will be performed after completion ofmore » the resin digestion cycle. The amount of permanganate required for this type of resin (Reillex{trademark} HPQ) was increased from 1 kg/L resin to 4 kg/L resin to reduce the amount of residual resin solids to a minimal amount (<5%). The length of digestion time at 70 C remains unchanged at 15 hours. These parameters are not optimized but are expected to be adequate for the conditions. The flowsheet generates a significant amount of fine manganese dioxide (MnO{sub 2}) solids (1.71 kg/L resin) and involves the generation of a significant liquid volume due to the low solubility of permanganate. However, since only two batches of resin (40 L each) are expected to be digested, the total waste generated is limited.« less

Effects of feeding hull-less barley on production performance, milk fatty acid composition, and nutrient digestibility of lactating dairy cows.

PubMed

Yang, Y; Ferreira, G; Teets, C L; Corl, B A; Thomason, W E; Griffey, C A

2017-05-01

The objectives of this study were to evaluate production performance, milk fatty acid composition, and nutrient digestibility in high-producing dairy cows consuming diets containing corn and hull-less barley (cultivar Amaze 10) in different proportions as the grain source. Eight primiparous and 16 multiparous Holstein cows were assigned to 1 of 4 diets in a replicated 4 × 4 Latin square design with 21-d periods. Cows were fed once daily (1200 h) by means of a Calan gate system (American Calan Inc., Northwood, NH). All diets contained ∼20% grain (dry matter basis). Treatments consisted of 100% corn (0B), 67% corn and 33% hull-less barley (33B), 33% corn and 67% hull-less barley (67B), and 100% hull-less barley (100B) as the grain sources. Total-tract nutrient digestibility was estimated using lanthanum chloride (LaCl 3 ) as an external marker. Dry matter intake differed quadratically among treatments, being lowest for 67B and highest for 0B and 100B. Feeding hull-less barley did not affect milk yield, and milk fat concentration differed cubically among treatments. The cubic response was attributed to the higher milk fat concentration observed for the diet containing 67B. Neither the concentrations in milk of protein and lactose nor the yields of protein and lactose differed among treatments. The proportion of de novo synthesized fatty acids in milk did not differ among treatments. The apparent total-tract digestibility of dry matter, crude protein, and neutral detergent fiber did not differ among treatments. Although a quadratic effect was observed, starch digestibility was minimally affected by treatments. In conclusion, this study indicates that hull-less barley grain is as good as corn grain as an energy source when formulating diets for high-producing dairy cows. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Cysteic Acid in Dietary Keratin is Metabolized to Glutathione and Liver Taurine in a Rat Model of Human Digestion

PubMed Central

Wolber, Frances M.; McGrath, Michelle; Jackson, Felicity; Wylie, Kim; Broomfield, Anne

2016-01-01

Poultry feathers, consisting largely of keratin, are a low-value product of the poultry industry. The safety and digestibility of a dietary protein produced from keratin (KER) was compared to a cysteine-supplemented casein-based diet in a growing rat model for four weeks. KER proved to be an effective substitute for casein at 50% of the total dietary protein, with no changes in the rats’ food intake, weight gain, organ weight, bone mineral density, white blood cell counts, liver glutathione, or blood glutathione. Inclusion of KER in the diet reduced total protein digestibility from 94% to 86% but significantly increased total dietary cysteine uptake and subsequent liver taurine levels. The KER diet also significantly increased caecum weight and significantly decreased fat digestibility, resulting in a lower proportion of body fat, and induced a significant increase in blood haemoglobin. KER is therefore a safe and suitable protein substitute for casein, and the cysteic acid in keratin is metabolised to maintain normal liver and blood glutathione levels. PMID:26907334

Method for isolating nucleic acids

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

Hurt, Jr., Richard Ashley; Elias, Dwayne A.

The current disclosure provides methods and kits for isolating nucleic acid from an environmental sample. The current methods and compositions further provide methods for isolating nucleic acids by reducing adsorption of nucleic acids by charged ions and particles within an environmental sample. The methods of the current disclosure provide methods for isolating nucleic acids by releasing adsorbed nucleic acids from charged particles during the nucleic acid isolation process. The current disclosure facilitates the isolation of nucleic acids of sufficient quality and quantity to enable one of ordinary skill in the art to utilize or analyze the isolated nucleic acids formore » a wide variety of applications including, sequencing or species population analysis.« less

Apparent and true ileal and total tract digestibility of fat in canola press-cake or canola oil and effects of increasing dietary fat on amino acid and energy digestibility in growing pigs.

PubMed

Zhou, X; Beltranena, E; Zijlstra, R T

2017-06-01

Digestibility of remaining oil in canola press-cake (CPC) may be lower than that of extracted, liquid canola oil (CO) because oil may be partly entrapped in the CPC matrix. To determine true digestibility of fat in ingredients, endogenous fat losses should be estimated. Dietary fat may interact with digestion of other dietary components. To test these hypotheses, 10 ileal-cannulated pigs (initial BW, 25.4 kg) were fed 10 diets for 8 periods in a 10 × 8 Youden square. A basal diet was formulated based on wheat, barley, and canola meal. The 4 CPC and 4 CO test diets were prepared by replacing identical portion of basal diet with 10%, 20%, 30%, or 40% CPC, or 1.5%, 3.0%, 4.5%, or 6.0% CO, respectively, to match the fat content of CPC diet with CO diet at each fat level. An N-free diet based on corn starch was prepared to measure basal endogenous losses of AA. Apparent total tract digestibility (ATTD) and apparent ileal digestibility (AID) of acid-hydrolyzed ether extract (AEE) were calculated for each diet. True ileal digestibility (TID) and true total tract (TTTD) digestibility of AEE in CPC and CO, and total endogenous losses of AEE were estimated by regressing apparent digestible AEE (g/kg of DMI) against dietary AEE intake (g/kg of DM) at the total tract and distal ileum, respectively. The mean AID and ATTD of AEE in CPC diets were 78.9% and 61.5%, which were lower ( < 0.01) than 81.9% and 63.4% in CO diets. Apparent ileal and total tract digestible AEE content in CPC and CO diets increased linearly ( < 0.01) with increasing AEE intake. Endogenous losses of AEE were greater ( < 0.05) for the total tract than for the ileum (23.4 vs. 9.4 g/kg of DMI). Dietary fat source did not affect ( > 0.05) total tract or ileal endogenous losses of AEE. The TID and TTTD of AEE in CPC were 92.3% and 94.5%, respectively, lower ( < 0.01) than 96.5% and 100% in CO. Increasing dietary inclusion of CO linearly increased ( < 0.001) standardized ileal digestibility (SID) of CP, Lys

Protein digestibility-corrected amino acid scores for bean and bean-rice infant weaning food products.

PubMed

Kannan, S; Nielsen, S S; Mason, A C

2001-10-01

Vegetable proteins are an integral part of infant weaning diets in Latin America. Protein quality in plant-based products, however, is constrained by amino acid composition and intrinsically present antinutritional factors. The goal of this study was to improve bean protein quality by utilizing fermentation and germination processing. The objectives were to determine if protein quality, as measured by Food and Agricultural Organization (FAO) approved True Protein Digestibility (TPD) and Protein Digestibility-Corrected Amino Acid Scores (PDCAAS), of formulated bean-based weaning products could be improved upon fermentation and germination and if protein quality could be further improved when processed beans were combined with cooked rice. Results showed that the highest TPD and PDCAAS values were obtained for cooked germinated beans combined with rice. The TPD values for products ranged from 80 to 91%, and the PDCAAS values were 0.38-0.51. There was no significant increase (P < 0.05) of either TPD or PDCAAS values upon fermentation. Germination increased TPD of cooked bean products; this increase was not, however, accompanied by an increase in PDCAAS. When combined with rice, the PDCAAS values for all bean products improved significantly, thus supporting the concept of cereal-legume complementation. In conclusion, this study showed the range of PDCAAS in processed black bean and bean-rice infant weaning food products. The potential for incorporation of these products into the diets of weaning age Latin American children would, however, be confirmed only after validation with growth or metabolic balance studies in human infants.

Digestion of feed amino acids in the rumen and intestine of steers measured using a mobile nylon bag technique.

PubMed

Taghizadeh, A; Danesh Mesgaran, M; Valizadeh, R; Shahroodi, F Eftekhar; Stanford, K

2005-05-01

The disappearance of dry matter (DM), crude protein (CP), and amino acids (AA) in steers after rumen incubation and intestinal passage of alfalfa hay, barley hay, corn silage, barley grain, corn grain, wheat bran, meat meal, fish meal, cottonseed meal, and soybean meal were measured in 3 steers using a mobile nylon bag technique. Ruminal degradation of individual AA differed between feedstuffs. For barley hay and corn silage, the ruminal disappearance of total AA was higher and lower than the other feedstuffs, respectively. The intestinal digestibility of total AA in alfalfa hay was lower than the digestion of CP. The intestinal digestibility of Arg and His was higher than that of total AA in alfalfa hay, meat meal, cottonseed meal, soybean meal, barley hay, and wheat bran. In addition, the intestinal digestibility of Lys was higher than that of total AA in alfalfa hay, meat meal, cottonseed meal, soybean meal, barley hay, corn silage, and wheat bran. The intestinal disappearance of CP in most cases was higher than that of DM. The results indicated that feedstuffs with lower ruminal disappearance of DM, CP, total AA, essential AA, and nonessential AA generally had a higher intestinal disappearance, resulting in a relatively constant total tract disappearance. These results could be used to improve the current system of diet formulation in ruminants.

Conductive heating and microwave hydrolysis under identical heating profiles for advanced anaerobic digestion of municipal sludge.

PubMed

Mehdizadeh, Seyedeh Neda; Eskicioglu, Cigdem; Bobowski, Jake; Johnson, Thomas

2013-09-15

Microwave (2.45 GHz, 1200 W) and conventional heating (custom pressure vessel) pretreatments were applied to dewatered municipal waste sludge (18% total solids) using identical heating profiles that span a wide range of temperatures (80-160 °C). Fourteen lab-scale semi-continuous digesters were set up to optimize the energy (methane) output and sludge retention time (SRT) requirements of untreated (control) and thermally pretreated anaerobic digesters operated under mesophilic and thermophilic temperatures. Both pretreatment methods indicated that in the pretreatment range of 80-160 °C, temperature was a statistically significant factor (p-value < 0.05) for increasing solubilization of chemical oxygen demand and biopolymers (proteins, sugars, humic acids) of the waste sludge. However, the type of pretreatment method, i.e. microwave versus conventional heating, had no statistically significant effect (p-value >0.05) on sludge solubilization. With the exception of the control digesters at a 5-d SRT, all control and pretreated digesters achieved steady state at all three SRTs, corresponding to volumetric organic loading rates of 1.74-6.96 g chemical oxygen demand/L/d. At an SRT of 5 d, both mesophilic and thermophilic controls stopped producing biogas after 20 d of operation with total volatile fatty acids concentrations exceeding 1818 mg/L at pH <5.64 for mesophilic and 2853 mg/L at pH <7.02 for thermophilic controls, while the pretreated digesters continued producing biogas. Furthermore, relative (to control) organic removal efficiencies dramatically increased as SRT was shortened from 20 to 10 and then 5 d, indicating that the control digesters were challenged as the organic loading rate was increased. Energy analysis showed that, at an elevated temperature of 160 °C, the amount of methane recovered was not enough to compensate for the energy input. Among the digesters with positive net energy productions, control and pretreated digesters at 80 °C were more

Temperature and solids retention time control microbial population dynamics and volatile fatty acid production in replicated anaerobic digesters

PubMed Central

Vanwonterghem, Inka; Jensen, Paul D.; Rabaey, Korneel; Tyson, Gene W.

2015-01-01

Anaerobic digestion is a widely used technology for waste stabilization and generation of biogas, and has recently emerged as a potentially important process for the production of high value volatile fatty acids (VFAs) and alcohols. Here, three reactors were seeded with inoculum from a stably performing methanogenic digester, and selective operating conditions (37°C and 55°C; 12 day and 4 day solids retention time) were applied to restrict methanogenesis while maintaining hydrolysis and fermentation. Replicated experiments performed at each set of operating conditions led to reproducible VFA production profiles which could be correlated with specific changes in microbial community composition. The mesophilic reactor at short solids retention time showed accumulation of propionate and acetate (42 ± 2% and 15 ± 6% of CODhydrolyzed, respectively), and dominance of Fibrobacter and Bacteroidales. Acetate accumulation (>50% of CODhydrolyzed) was also observed in the thermophilic reactors, which were dominated by Clostridium. Under all tested conditions, there was a shift from acetoclastic to hydrogenotrophic methanogenesis, and a reduction in methane production by >50% of CODhydrolyzed. Our results demonstrate that shortening the SRT and increasing the temperature are effective strategies for driving microbial communities towards controlled production of high levels of specific volatile fatty acids. PMID:25683239

Temperature and solids retention time control microbial population dynamics and volatile fatty acid production in replicated anaerobic digesters

NASA Astrophysics Data System (ADS)

Vanwonterghem, Inka; Jensen, Paul D.; Rabaey, Korneel; Tyson, Gene W.

2015-02-01

Anaerobic digestion is a widely used technology for waste stabilization and generation of biogas, and has recently emerged as a potentially important process for the production of high value volatile fatty acids (VFAs) and alcohols. Here, three reactors were seeded with inoculum from a stably performing methanogenic digester, and selective operating conditions (37°C and 55°C 12 day and 4 day solids retention time) were applied to restrict methanogenesis while maintaining hydrolysis and fermentation. Replicated experiments performed at each set of operating conditions led to reproducible VFA production profiles which could be correlated with specific changes in microbial community composition. The mesophilic reactor at short solids retention time showed accumulation of propionate and acetate (42 +/- 2% and 15 +/- 6% of CODhydrolyzed, respectively), and dominance of Fibrobacter and Bacteroidales. Acetate accumulation (>50% of CODhydrolyzed) was also observed in the thermophilic reactors, which were dominated by Clostridium. Under all tested conditions, there was a shift from acetoclastic to hydrogenotrophic methanogenesis, and a reduction in methane production by >50% of CODhydrolyzed. Our results demonstrate that shortening the SRT and increasing the temperature are effective strategies for driving microbial communities towards controlled production of high levels of specific volatile fatty acids.

Effects of digestion, chemical separation, and deposition on Po-210 quantitative analysis

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

Seiner, Brienne N.; Morley, Shannon M.; Beacham, Tere A.

Polonium-210 is a radioactive isotope often used to study sedimentation processes, food chains, aerosol behavior, and atmospheric circulations related to environmental sciences. Materials for the analysis of Po-210 range from tobacco leaves or cotton fibers, to soils and sediments. The purpose of this work was to determine polonium losses from a variety of sample types (soil, cotton fiber, and air filter) due to digestion technique, chemical separation, and deposition method for alpha energy analysis. Results demonstrated that yields from a perchloric acid wet-ash were similar to that from a microwave digestion. Both were greater than the dry-ash procedure. The poloniummore » yield from the perchloric acid wet ash was 87 ± 5%, the microwave digestion had a yield of 100 ± 7%, and the dry ash had a yield of 38 ± 5%. The chemical separation of polonium by an anion exchange resin was used only on the soil samples due to the complex nature of this sample. The yield of Po-209 tracer after chemical separation and deposition for alpha analysis was 83 ± 7% for the soil samples. Spontaneous deposition yields for the cotton and air filters were 87 ± 4% and 92 ± 6%, respectively. Based on the overall process yields for each sample type the amount of Po-210 was quantified using alpha energy analysis. The soil contained 0.18 ± 0.08 Bq/g, the cotton swipe contained 0.7 mBq/g, and the air filter contained 0.04 ± 0.02 mBq/g. High and robust yields of polonium are possible using a suitable digestion, separation, and deposition method.« less

Nepenthesin protease activity indicates digestive fluid dynamics in carnivorous nepenthes plants.

PubMed

Buch, Franziska; Kaman, Wendy E; Bikker, Floris J; Yilamujiang, Ayufu; Mithöfer, Axel

2015-01-01

Carnivorous plants use different morphological features to attract, trap and digest prey, mainly insects. Plants from the genus Nepenthes possess specialized leaves called pitchers that function as pitfall-traps. These pitchers are filled with a digestive fluid that is generated by the plants themselves. In order to digest caught prey in their pitchers, Nepenthes plants produce various hydrolytic enzymes including aspartic proteases, nepenthesins (Nep). Knowledge about the generation and induction of these proteases is limited. Here, by employing a FRET (fluorescent resonance energy transfer)-based technique that uses a synthetic fluorescent substrate an easy and rapid detection of protease activities in the digestive fluids of various Nepenthes species was feasible. Biochemical studies and the heterologously expressed Nep II from Nepenthes mirabilis proved that the proteolytic activity relied on aspartic proteases, however an acid-mediated auto-activation mechanism was necessary. Employing the FRET-based approach, the induction and dynamics of nepenthesin in the digestive pitcher fluid of various Nepenthes plants could be studied directly with insect (Drosophila melanogaster) prey or plant material. Moreover, we observed that proteolytic activity was induced by the phytohormone jasmonic acid but not by salicylic acid suggesting that jasmonate-dependent signaling pathways are involved in plant carnivory.

Nepenthesin Protease Activity Indicates Digestive Fluid Dynamics in Carnivorous Nepenthes Plants

PubMed Central

Buch, Franziska; Kaman, Wendy E.; Bikker, Floris J.; Yilamujiang, Ayufu; Mithöfer, Axel

2015-01-01

Carnivorous plants use different morphological features to attract, trap and digest prey, mainly insects. Plants from the genus Nepenthes possess specialized leaves called pitchers that function as pitfall-traps. These pitchers are filled with a digestive fluid that is generated by the plants themselves. In order to digest caught prey in their pitchers, Nepenthes plants produce various hydrolytic enzymes including aspartic proteases, nepenthesins (Nep). Knowledge about the generation and induction of these proteases is limited. Here, by employing a FRET (fluorescent resonance energy transfer)-based technique that uses a synthetic fluorescent substrate an easy and rapid detection of protease activities in the digestive fluids of various Nepenthes species was feasible. Biochemical studies and the heterologously expressed Nep II from Nepenthes mirabilis proved that the proteolytic activity relied on aspartic proteases, however an acid-mediated auto-activation mechanism was necessary. Employing the FRET-based approach, the induction and dynamics of nepenthesin in the digestive pitcher fluid of various Nepenthes plants could be studied directly with insect (Drosophila melanogaster) prey or plant material. Moreover, we observed that proteolytic activity was induced by the phytohormone jasmonic acid but not by salicylic acid suggesting that jasmonate-dependent signaling pathways are involved in plant carnivory. PMID:25750992

Modified Anaerobic Digestion Model No.1 for dry and semi-dry anaerobic digestion of solid organic waste.

PubMed

Liotta, Flavia; Chatellier, Patrice; Esposito, Giovanni; Fabbricino, Massimiliano; Frunzo, Luigi; van Hullebusch, Eric D; Lens, Piet N L; Pirozzi, Francesco

2015-01-01

The role of total solids (TS) content in anaerobic digestion of selected complex organic matter, e.g. rice straw and food waste, was investigated. A range of TS from wet (4.5%) to dry (23%) was evaluated. A modified version of the Anaerobic Digestion Model No.1 for a complex organic substrate is proposed to take into account the effect of the TS content on anaerobic digestion. A linear function that correlates the kinetic constants of three specific processes (i.e. disintegration, acetate and propionate up-take) was included in the model. Results of biomethanation and volatile fatty acids production tests were used to calibrate the proposed model. Model simulations showed a good agreement between numerical and observed data.

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

The anaerobic digestion process

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

Rivard, C.J.; Boone, D.R.

1996-01-01

The microbial process of converting organic matter into methane and carbon dioxide is so complex that anaerobic digesters have long been treated as {open_quotes}black boxes.{close_quotes} Research into this process during the past few decades has gradually unraveled this complexity, but many questions remain. The major biochemical reactions for forming methane by methanogens are largely understood, and evolutionary studies indicate that these microbes are as different from bacteria as they are from plants and animals. In anaerobic digesters, methanogens are at the terminus of a metabolic web, in which the reactions of myriads of other microbes produce a very limited rangemore » of compounds - mainly acetate, hydrogen, and formate - on which the methanogens grow and from which they form methane. {open_quotes}Interspecies hydrogen-transfer{close_quotes} and {open_quotes}interspecies formate-transfer{close_quotes} are major mechanisms by which methanogens obtain their substrates and by which volatile fatty acids are degraded. Present understanding of these reactions and other complex interactions among the bacteria involved in anaerobic digestion is only now to the point where anaerobic digesters need no longer be treated as black boxes.« less

Removal of volatile fatty acids and ammonia recovery from unstable anaerobic digesters with a microbial electrolysis cell.

PubMed

Cerrillo, Míriam; Viñas, Marc; Bonmatí, August

2016-11-01

Continuous assays with a microbial electrolysis cell (MEC) fed with digested pig slurry were performed to evaluate its stability and robustness to malfunction periods of an anaerobic digestion (AD) reactor and its feasibility as a strategy to recover ammonia. When performing punctual pulses of volatile fatty acids (VFA) in the anode compartment of the MEC, simulating a malfunction of the AD process, an increase in the current density was produced (up to 14 times, reaching values of 3500mAm(-2)) as a result of the added chemical oxygen demand (COD), especially when acetate was used. Furthermore, ammonium diffusion from the anode to the cathode compartment was enhanced and the removal efficiency achieved up to 60% during daily basis VFA pulses. An AD-MEC combined system has proven to be a robust and stable configuration to obtain a high quality effluent, with a lower organic and ammonium content. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fast production of methane by anaerobic digestion. Annual progress report, May 24, 1976--May 23, 1977

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

Finney, C.D.; Evans II, R.S.; Finney, K.A.

1977-06-01

Since the productional cost of methane generated by anaerobic digestion of cellulose is on the economic borderline and the cost could be reduced by increasing the rate of the digestion process, a research program was undertaken to delineate the most promising areas of development. The concept that the step involving transfer of products from solution is rate-limiting and inhibiting in anaerobic digestion was supported by all evidence available. The most significant design implication of this concept is that faster gas production can be achieved in a two-stage digestion system in which unreactive solids are eliminated after the hydrolysis step somore » that the effluent to the gas-producing stage possesses a low viscosity. The advantages and disadvantages of three hydrolysis methods (enzymatic, anaerobic, and acid) are reviewed.« less

Lyophilization decreases the formation of dialyzable iron by extraction and digestion of chicken breast muscle.

PubMed

Karava, Nilesh B; Mahoney, Raymond R

2011-06-01

We studied the effect of lyophilization of chicken breast muscle on the formation of dialyzable iron from ferric iron. Chicken breast muscle was used chilled, frozen or lyophilized and was analyzed for sulfhydryl and histidine content. It was then homogenized and mixed with ferric iron. The mixture was extracted with acid or digested with pepsin and pancreatin. The extracts and digests were analyzed for dialyzable ferrous and dialyzable total iron and also for protein. In the chilled muscle, similar amounts of dialyzable iron were formed after acid extraction and after proteolytic digestion; however, digestion led to more dialyzable ferrous iron. Freezing had no effect but lyophilization of the homogenized muscle caused large decreases in dialyzable iron and dialyzable ferrous iron for both extraction and digestion processes. Lyophilization also resulted in decreased extraction of peptides, decreased digestion of muscle proteins and reduced levels of sulfhydryl and histidine residues. Our results demonstrate that dialyzable iron is produced both by acid-soluble low molecular weight muscle component(s) and also by peptides resulting from digestion of muscle proteins: both of which reduce and chelate iron. Reduced formation of dialyzable iron by both mechanisms following lyophilization could be explained by sulfhydryl oxidation and impaired digestion due to protein crosslinking.

Pressurized Pepsin Digestion in Proteomics

PubMed Central

López-Ferrer, Daniel; Petritis, Konstantinos; Robinson, Errol W.; Hixson, Kim K.; Tian, Zhixin; Lee, Jung Hwa; Lee, Sang-Won; Tolić, Nikola; Weitz, Karl K.; Belov, Mikhail E.; Smith, Richard D.; Paša-Tolić, Ljiljana

2011-01-01

Integrated top-down bottom-up proteomics combined with on-line digestion has great potential to improve the characterization of protein isoforms in biological systems and is amendable to high throughput proteomics experiments. Bottom-up proteomics ultimately provides the peptide sequences derived from the tandem MS analyses of peptides after the proteome has been digested. Top-down proteomics conversely entails the MS analyses of intact proteins for more effective characterization of genetic variations and/or post-translational modifications. Herein, we describe recent efforts toward efficient integration of bottom-up and top-down LC-MS-based proteomics strategies. Since most proteomics separations utilize acidic conditions, we exploited the compatibility of pepsin (where the optimal digestion conditions are at low pH) for integration into bottom-up and top-down proteomics work flows. Pressure-enhanced pepsin digestions were successfully performed and characterized with several standard proteins in either an off-line mode using a Barocycler or an on-line mode using a modified high pressure LC system referred to as a fast on-line digestion system (FOLDS). FOLDS was tested using pepsin and a whole microbial proteome, and the results were compared against traditional trypsin digestions on the same platform. Additionally, FOLDS was integrated with a RePlay configuration to demonstrate an ultrarapid integrated bottom-up top-down proteomics strategy using a standard mixture of proteins and a monkey pox virus proteome. PMID:20627868

True ileal amino acid digestibility and endogenous ileal amino acid losses in growing pigs fed wheat shorts- or casein-based diets.

PubMed

Libao-Mercado, A J; Yin, Y; van Eys, J; de Lange, C F M

2006-06-01

Use of dietary AA in growing pigs reflects digestion and use of digested AA for various body functions. Before evaluating dietary effects on use of digestible AA intake for body protein deposition, a digestibility study was conducted to investigate true ileal AA digestibility and endogenous ileal AA losses in growing pigs fed graded levels of wheat shorts (WS) or casein (CS; control). A casein-based basal diet (basal) was formulated to contain 0.27 g of standardized ileal digestible (SID) Lys per MJ of DE, to which extra Lys was added from WS (WS2, +0.10 g of SID Lys per MJ of DE; WS3, +0.20 g of SID Lys per MJ of DE) or casein (CS3, +0.20 g of SID Lys per MJ of DE). A fifth diet was formulated to be similar in CP level and source as CS3 but in which 6% pectin, a source of soluble non-starch polysaccharides (NSP), was included at the expense of cornstarch (CS3 + pectin). Five Yorkshire barrows (17.5 +/- 1.5 kg of BW) were fitted with a T-cannula at the distal ileum and randomly assigned to 1 of the 5 experimental diets in a 5 x 5 Latin Square design. Apparent ileal digestibility (AID), true ileal digestibility (TID), and endogenous ileal protein losses (EPL) were determined using the homoarginine method. Diet CS level did not influence (P > or = 0.10) TID of most essential AA or EPL (10.4 g/kg of DM intake). Including pectin in the diet did not influence TID of AA (P > or = 0.10) but increased EPL (15.6 g/kg of DM intake; P > or = 0.01). Inclusion of WS in the diet reduced TID of most essential AA (P < 0.01). The TID values for most essential AA, however, were the same (P > or = 0.10) for both dietary WS levels, except for Lys and Met, which were further reduced at the greatest dietary WS level. Increased EPL (P < 0.01) was only observed for WS3 (16 g/kg of DMI). We concluded that (1) the effects of dietary protein source on AID of AA can be attributed both to reduced TID of AA and increased EPL, (2) the impact of dietary WS level on TID of AA and EPL does not seem

The flame characteristics of the biogas has produced through the digester method with various starters

NASA Astrophysics Data System (ADS)

Ketut, Caturwati Ni; Agung, Sudrajat; Mekro, Permana; Heri, Haryanto; Bachtiar

2018-01-01

Increasing the volume of waste, especially in urban areas is a source of problems in realizing the comfort and health of the environment. It needs to do a good handling of garbage so as to provide benefits for the whole community. Organic waste processing through bio-digester method to produce a biogas as an energy source is an effort. This research was conducted to test the characteristics of biogas flame generated from organic waste processing through digester with various of the starter such as: cow dung, goat manure, and leachate that obtained from the landfill at Bagendung-Cilegon. The flame height and maximum temperature of the flame are measured for the same pressure of biogas. The measurements showed the flame produced by bio-digester with leachate starter has the lowest flame height compared to the other types of biogas, and the highest flame height is given by biogas from digester with cow dung as a starter. The maximum flame temperature of biogas produced by leachate as a starter reaches 1027 °C. This value is 7% lower than the maximum flame temperature of biogas produced by cow dung as a starter. Cow dung was observed to be the best starter compared to goat manure and leachate, but the use of leachate as a starter in producing biogas with biodigester method is not the best but it worked.

Free nitrous acid pre-treatment of waste activated sludge enhances volatile solids destruction and improves sludge dewaterability in continuous anaerobic digestion.

PubMed

Wei, Wei; Wang, Qilin; Zhang, Liguo; Laloo, Andrew; Duan, Haoran; Batstone, Damien J; Yuan, Zhiguo

2018-03-01

Previous work has demonstrated that pre-treatment of waste activated sludge (WAS) with free nitrous acid (FNA i.e. HNO 2 ) enhances the biodegradability of WAS, identified by a 20-50% increase in specific methane production in biochemical methane potential (BMP) tests. This suggests that FNA pre-treatment would enhance the destruction of volatile solids (VS) in an anaerobic sludge digester, and reduce overall sludge disposal costs, provided that the dewaterability of the digested sludge is not negatively affected. This study experimentally evaluates the impact of FNA pre-treatment on the VS destruction in anaerobic sludge digestion and on the dewaterability of digested sludge, using continuously operated bench-scale anaerobic digesters. Pre-treatment of full-scale WAS for 24 h at an FNA concentration of 1.8 mg NN/L enhanced VS destruction by 17 ± 1% (from 29.2 ± 0.9% to 34.2 ± 1.1%) and increased dewaterability (centrifuge test) from 12.4 ± 0.4% to 14.1 ± 0.4%. Supporting the VS destruction data, methane production increased by 16 ± 1%. Biochemical methane potential tests indicated that the final digestate stability was also improved with a lower potential from FNA treated digestate. Further, a 2.1 ± 0.2 log improvement in pathogen reduction was also achieved. With inorganic solids representing 15-22% of the full-scale WAS used, FNA pre-treatment resulted in a 16-17% reduction in the volume of dewatered sludge for final disposal. This results in significantly reduced costs as assessed by economic analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determination of trace nickel in hydrogenated cottonseed oil by electrothermal atomic absorption spectrometry after microwave-assisted digestion.

PubMed

Zhang, Gai

2012-01-01

Microwave digestion of hydrogenated cottonseed oil prior to trace nickel determination by electrothermal atomic absorption spectrometry (ETAAS) is proposed here for the first time. Currently, the methods outlined in U.S. Pharmacopeia 28 (USP28) or British Pharmacopeia (BP2003) are recommended as the official methods for analyzing nickel in hydrogenated cottonseed oil. With these methods the samples may be pre-treated by a silica or a platinum crucible. However, the samples were easily tarnished during sample pretreatment when using a silica crucible. In contrast, when using a platinum crucible, hydrogenated cottonseed oil acting as a reducing material may react with the platinum and destroy the crucible. The proposed microwave-assisted digestion avoided tarnishing of sample in the process of sample pretreatment and also reduced the cycle of analysis. The programs of microwave digestion and the parameters of ETAAS were optimized. The accuracy of the proposed method was investigated by analyzing real samples. The results were compared with the ones by pressurized-PTFE-bomb acid digestion and ones obtained by the U.S. Pharmacopeia 28 (USP28) method. The new method involves a relatively rapid matrix destruction technique compared with other present methods for the quantification of metals in oil. © 2011 Institute of Food Technologists®

Biogas Production from Rice Husk Waste by using Solid State Anaerobic Digestion (SSAD) Method

NASA Astrophysics Data System (ADS)

Matin, Hashfi Hawali Abdul; Hadiyanto

2018-02-01

An effort to obtain alternative energy is still interesting subject to be studied, especially production of biogas from agriculture waste. This paper was an overview of the latest development of biogas researches from rice husk waste by Solid State Anaerobic Digestion (SSAD). The main obstacle of biogas production from rice husk waste was the lignin content which is very difficult degraded by microbes. Various pretreatments have been conducted, either physically, chemically as well as biologically. The SSAD method was an attractive option because of the low water content of rice husk waste. The biogas yield by SSAD method gave more attractive result compared to Liquid Anaerobic Digestion (LAD) method. Various studies were still conducted in batch mode laboratory scale and also has not found optimum operating conditions. Research on a larger scale such as bench and pilot scale with continuous systems will be an increase trend in the future research.

Digestive challenges for vertebrate animals: microbial diversity, cardiorespiratory coupling, and dietary specialization.

PubMed

Barboza, P S; Bennett, A; Lignot, J-H; Mackie, R I; McWhorter, T J; Secor, S M; Skovgaard, N; Sundset, M A; Wang, T

2010-01-01

The digestive system is the interface between the supply of food for an animal and the demand for energy and nutrients to maintain the body, to grow, and to reproduce. Digestive systems are not morphologically static but rather dynamically respond to changes in the physical and chemical characteristics of the diet and the level of food intake. In this article, we discuss three themes that affect the ability of an animal to alter digestive function in relation to novel substrates and changing food supply: (1) the fermentative digestion in herbivores, (2) the integration of cardiopulmonary and digestive functions, and (3) the evolution of dietary specialization. Herbivores consume, digest, and detoxify complex diets by using a wide variety of enzymes expressed by bacteria, predominantly in the phyla Firmicutes and Bacteroidetes. Carnivores, such as snakes that feed intermittently, sometimes process very large meals that require compensatory adjustments in blood flow, acid secretion, and regulation of acid-base homeostasis. Snakes and birds that specialize in simple diets of prey or nectar retain their ability to digest a wider selection of prey. The digestive system continues to be of interest to comparative physiologists because of its plasticity, both phenotypic and evolutionary, and because of its widespread integration with other physiological systems, including thermoregulation, circulation, ventilation, homeostasis, immunity, and reproduction.

[Anaerobic digestion of animal manure contaminated by tetracyclines].

PubMed

Tong, Zi-Lin; Liu, Yuan-Lu; Hu, Zhen-Hu; Yuan, Shou-Jun

2012-03-01

Anaerobic digestion of pig manure spiked with tetracycline (TC) and chlortetracycline (CTC) and the degradation of the two antibiotics during the anaerobic digestion at 35 degrees C were investigated. The results indicate that propionate was the main volatile fatty acid produced during the anaerobic digestion followed by acetate. Compared with the CTC addition, TC + CTC addition showed obvious inhibitory effect on the hydrolysis and acidification of easily digestible organic components of pig manure. The cumulative methane production of TC, CTC, TC + CTC and CK2 during anaerobic digestion was 386.4 mL, 406.0 mL, 412.1 mL and 464.6 mL, respectively. Degradation of TC and CTC followed the first-order kinetic equation. The half-life of TC and CTC was 14-18 days and 10 days, respectively. After the treatment of 45-day anaerobic digestion, the degradation efficiency of TC was 88.6%-91.6% with 97.7%-98.2% of CTC. Therefore, anaerobic digestion shows the benefit on the management of animal manures contaminated by tetracyclines.

Comparison of amino acid digestibility coefficients for soybean meal, canola meal, fish meal, and meat and bone meal among 3 different bioassays

USDA-ARS?s Scientific Manuscript database

The objective of this study was to determine amino acid digestibility of 4 feedstuffs [soybean meal (SBM), canola meal, fish meal, and meat and bone meal (MBM)] using the precision-fed cecectomized rooster assay (PFR), the standardized ileal assay (SIAAD), and a newly developed precision-fed ileal b...

Effect of lignin linkages with other plant cell wall components on in vitro and in vivo neutral detergent fiber digestibility and rate of digestion of grass forages.

PubMed

Raffrenato, E; Fievisohn, R; Cotanch, K W; Grant, R J; Chase, L E; Van Amburgh, M E

2017-10-01

The objective of this study was to correlate in vitro and in vivo neutral detergent fiber (NDF) digestibility (NDFD) with the chemical composition of forages and specific chemical linkages, primarily ester- and ether-linked para-coumaric (pCA) and ferulic acids (FA) in forages fed to dairy cattle. The content of acid detergent lignin (ADL) and its relationship with NDF does not fully explain the observed variability in NDFD. The ferulic and p-coumaric acid linkages between ADL and cell wall polysaccharides, rather than the amount of ADL, might be a better predictor of NDFD. Twenty-three forages, including conventional and brown midrib corn silages and grasses at various stages of maturity were incubated in vitro for measurement of 24-h and 96-h NDFD. Undigested and digested residues were analyzed for NDF, acid detergent fiber (ADF), ADL, and Klason lignin (KL); ester- and ether-linked pCA and FA were determined in these fractions. To determine whether in vitro observations of ester- and ether-linked pCA and FA and digestibility were similar to in vivo observations, 3 corn silages selected for digestibility were fed to 6 ruminally fistulated cows for 3 wk in 3 iso-NDF diets. Intact samples and NDF and ADF residues of diet, rumen, and feces were analyzed for ester- and ether-linked pCA and FA. From the in vitro study, the phenolic acid content (total pCA and FA) was highest for corn silages, and overall the content of ester- and ether-linked pCA and FA in both NDF and ADF residues were correlated with NDF digestibility parameters, reflecting the competitive effect of these linkages on digestibility. Also, Klason lignin and ADL were negatively correlated with ether-linked ferulic acid on an NDF basis. Overall, esterified FA and esterified pCA were negatively correlated with all of the measured fiber fractions on both a dry matter and an NDF basis. The lignin content of the plant residues and chemical linkages explained most of the variation in both rate and extent of

Enhancement of waste activated sludge anaerobic digestion by a novel chemical free acid/alkaline pretreatment using electrolysis.

PubMed

Charles, W; Ng, B; Cord-Ruwisch, R; Cheng, L; Ho, G; Kayaalp, A

2013-01-01

Anaerobic digestion of waste activated sludge (WAS) is relatively poor due to hydrolysis limitations. Acid and alkaline pretreatments are effective in enhancing hydrolysis leading to higher methane yields. However, chemical costs often prohibit full-scale application. In this study, 12 V two-chamber electrolysis using an anion exchange membrane alters sludge pH without chemical dosing. pH dropped from 6.9 to 2.5 in the anode chamber and increased to 10.1 in the cathode chamber within 15 h. The volatile suspended solids solubilisation of WAS was 31.1% in the anode chamber and 34.0% in the cathode chamber. As a result, dissolved chemical oxygen demand increased from 164 to 1,787 mg/L and 1,256 mg/L in the anode and cathode chambers, respectively. Remixing of sludge from the two chambers brought the pH back to 6.5, hence no chemical neutralisation was required prior to anaerobic digestion. Methane yield during anaerobic digestion at 20 d retention time was 31% higher than that of untreated sludge. An energy balance assessment indicated that the non-optimised process could approximately recover the energy (electricity) expended in the electrolysis process. With suitable optimisation of treatment time and voltages, significant energy savings would be expected in addition to the benefit of decreased sludge volume.

The Physical State of Emulsified Edible Oil Modulates Its in Vitro Digestion.

PubMed

Guo, Qing; Bellissimo, Nick; Rousseau, Dérick

2017-10-18

Emulsified lipid digestion was tailored by manipulating the physical state of dispersed oil droplets in whey protein stabilized oil-in-water (O/W) emulsions, where the oil phase consisted of one of five ratios of soybean oil (SO) and fully hydrogenated soybean oil (FHSO). The evolution in particle size distribution, structural changes during oral, gastric, and intestinal digestion, and free fatty acid release during intestinal digestion were all investigated. Irrespective of the physical state and structure of the dispersed oil/fat, all emulsions were stable against droplet size increases during oral digestion. During gastric digestion, the 50:50 SO:FHSO emulsion was more stable against physical breakdown than any other emulsion. All emulsions underwent flocculation and coalescence or partial coalescence upon intestinal digestion, with the SO emulsion being hydrolyzed the most rapidly. The melting point of all emulsions containing FHSO was above 37 °C, with the presence of solid fat within the dispersed oil droplets greatly limiting lipolysis. Fat crystal polymorph and nanoplatelet size did not play an important role in the rate and extent of lipid digestion. Free fatty acid release modeled by the Weibull distribution function showed that the rate of lipid digestion (κ) decreased with increasing solid fat content, and followed an exponential relationship (R 2 = 0.95). Overall, lipid digestion was heavily altered by the physical state of the dispersed oil phase within O/W emulsions.

Low cost digester monitoring under realistic conditions: Rural use of biogas and digestate quality.

PubMed

Castro, L; Escalante, H; Jaimes-Estévez, J; Díaz, L J; Vecino, K; Rojas, G; Mantilla, L

2017-09-01

The purpose of this work was to assess the behaviour of anaerobic digestion of cattle manure in a rural digester under realistic conditions, and estimate the quality and properties of the digestate. The data obtained during monitoring indicated that the digester operation was stable without risk of inhibition. It produced an average of 0.85Nm 3 biogas/d at 65.6% methane, providing an energy savings of 76%. In addition, the digestate contained high nutrient concentrations, which is an important feature of fertilizers. However, this method requires post-treatment due to the presence of pathogens. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Comparison of the activity and yield rate of osteoblast obtained by different digestion methods].

PubMed

Li, Ling-hui; Ding, Dao-Fang; Du, Guo-Qing; Wang, Hui-Hao; Zhan, Hong-Sheng

2013-04-01

To compared the activity and yield rate of osteoblast obtained by different collagenase digestion methods, to find a better way to extract osteoblast for the experimental researches of osteoporosis. Ten 24-hour-old SD rats were were euthanized. The cranium of rats were removed and cuted into blocks of 1 mm x 1 mm size. After digested by trypsin for 15 min, all the cranium were divided into two equal parts, and randomly divided into two groups which would be digested by type I collagenase and type II collagenase separately for two times. The rat cells of the two groups were cultured in thermostat incubator with 5% CO2 under the condition of 37 degrees C. The primary culture osteoblasts were counted by using a haemacytometer after digestion and 72 hours later. The second generation osteoblasts cultured 48 h were dyed by NBT/BCIP staining solution, and were detected by quantitative measurement with PNPP. The cells had irregular shapes. The results of cell counting showed that the cell number of type I group was larger than type 11 group. Alkaline phosphatase dyeing were positive. Detecting of alkaline phosphatase using the method of PNPP showed that the absorbance value in type I group were higher than type II group (P<0.05). Two types of collagenase are both suitable for the in vitro culture of rat osteoblasts. The activity and yield rate of osteoblasts in type I group are higher which could provide more stable seed cells for the treatment of osteoporosis.

Effect of exogenous enzymes in maize-based diets varying in nutrient density for young broilers: growth performance and digestibility of energy, minerals and amino acids.

PubMed

Cowieson, A J; Ravindran, V

2008-01-01

1. A total of 192 male broilers (Cobb 500) were used in a growth and digestibility assay, involving a 2 x 2 factorial arrangement of treatments, to assess the effects of an enzyme cocktail of xylanase, amylase and protease in maize-based diets. 2. The following two diets were formulated: a positive control diet containing adequate nutrient concentrations for broiler starters as per breeder recommendations and a negative control diet to contain approximately 0.63 MJ/kg apparent metabolisable energy (AME) and 3% amino acids less than the positive control. 3. A further two dietary treatments were developed by supplementing each control diet with an enzyme product containing xylanase, amylase and protease. 4. Birds fed on the negative control diet had poorer weight gain and feed efficiency than those given the positive control diet. There was no effect of diet or enzyme on feed intake. The digestibility of nitrogen, calcium, phosphorus and most amino acids were unaffected by dietary nutrient density. 5. Supplementation of both the positive and negative control diets with the enzyme improved weight gain and feed efficiency compared with the unsupplemented diets. In the case of the negative control, supplemental enzyme improved performance to that of the unsupplemented positive control diet. There was no interaction between diet and enzyme for either weight gain or FCR, suggesting similar beneficial responses regardless of the nutrient density of the diet. 6. In both diets, enzyme supplementation improved AME by an average of 3% (0.35 MJ/kg DM) and nitrogen retention by an average of 11.7% (26 g/kg DM intake vs 29 g/kg DM intake). There was no interaction between diet and enzyme for AME or nitrogen retention. 7. Ileal digestibilities of calcium and phosphorus were not influenced by supplemental enzyme, whereas the digestibility of nitrogen and most amino acids was improved by enzyme addition compared with the unsupplemented control diets. There was no interaction between

Amino acid sequences of peptides from a chymotryptic digest of a urea-soluble protein fraction (U.S.3) from oxidized wool

PubMed Central

Corfield, M. C.; Fletcher, J. C.

1969-01-01

1. A chymotryptic digest of the protein fraction U.S.3. from oxidized wool was separated into 51 peptide fractions by chromatography on a column of cation-exchange resin. 2. The less acidic fractions were separated into their component peptides by a combination of cation-exchange-resin chromatography, paper chromatography and paper electrophoresis. 3. The amino acid sequences of 34 of these peptides were elucidated, and those of 14 others partially determined. 4. Overlaps between the tryptic and chymotryptic peptides from fraction U.S.3 have enabled ten extended amino acid sequences to be deduced, the longest containing 20 amino acid residues. 5. The relevance of the results to the structures of the helical and non-helical regions of wool is discussed. PMID:5395876

[Determination of metals in waste bag filter of steel works by microwave digestion-flame atomic absorption spectrometry].

PubMed

Ning, Xun-An; Zhou, Yun; Liu, Jing-Yong; Wang, Jiang-Hui; Li, Lei; Ma, Xiao-Guo

2011-09-01

A method of microwave digestion technique-flame atomic absorption spectrometry was proposed to determine the total contents of Cu, Zn, Pb, Cd, Cr and Ni in five different kinds of waste bag filters from a steel plant. The digestion effects of the six acid systems on the heavy metals digestion were studied for the first time. The relative standard deviation (RSD) of the method was between 1.02% and 9.35%, and the recovery rates obtained by standard addition method ranged from 87.7% to 105.6%. The results indicated that the proposed method exhibited the advantages of simplicity, speediness, accuracy and repeatability, and it was suitable for determining the metal elements of the waste bag filter. The results also showed that different digestion systems should be used according to different waste bag filters. The waste bag filter samples from different production processes had different metal elements content. The Pb and Zn were the highest in the waste bag filters, while the Cu, Ni, Cd and Cr were relatively lower. These determination results provided the scientific data for further treatment and disposal of the waste bag filter.

[Mechanism of action and control in the digestion of proteins and peptides in humans].

PubMed

Frenhani, P B; Burini, R C

1999-01-01

This review aims to report the major control mechanisms of protein and peptides digestion of special interest in human patients. Regarding protein assimilation its digestive process begins at the stomach with some not so indispensable actions comparatively to those of duodenal/jejunal lumen. However even the intestine processes are partially under gastric secretion control. Proteolytic enzyme activities are related to protein structure and amino acid constituents, tertiary and quartenary structures need HCl denaturation prior to enzymatic hydrolysis. Thereafter the exopeptidases are guided by either NH2 (aminopeptidases) or COOH (carboxypeptidases) terminals of the molecule while endopeptidases are oriented by the specific amino acids constituents of the peptide. Both dietary and luminal secreted proteins and polypeptides undergo to either limited or complete proteolysis resulting basic or neutral free-amino acids (40%) or dioctapeptides. The brush border peptidases continue to degrade oligopeptide to di-tripeptides and neutral free-amino acids. Some peptides are uptaked by the enterocytes whose cytosolic peptidases complete the hydrolysis. Hence the digestive products flowing in the portal vein are mainly free-amino acids from either luminal or cytosolic hydrolysis and some di-tripeptides intactly absorbed. Both mechanical and chemical processes of digestion are under neural (vagal), neuroendocrinal (acetilcholine), endocrinal (gastrin, secretin and cholecystokinin) or paracrinal (histamine) controls. The gastric phase (hydrochloric acid and pepsinogen secretions) is activated by gastrin, histamine and acetilcholine which respond to both dietary-amino acids (tryptophan and phenylalanine) and mechanic distention of stomach. The pancreatic secretion is stimulated by either cephalic or gastric phases and has influence on the intestinal phase of digestion. The intestinal types of cells S and I release secretin and cholecystokinin respectively in response of acid quimo

The one-stage autothermal thermophilic aerobic digestion for sewage sludge treatment: stabilization process and mechanism.

PubMed

Liu, Shugen; Zhu, Nanwen; Li, Loretta Y

2012-01-01

Batch experiment was carried out in a simulated thermophilic aerobic digester to investigate the digestion process of one-stage autothermal thermophilic aerobic digester and to explore the sludge stabilization mechanism. Volatile solids removal was 38.4% at 408 h and 45.0% at 552 h. Chemical oxidation demand, total nitrogen, and ammonia nitrogen in supernatant increased rapidly up to 168 h, and all of them fluctuated moderately after 360 h. Volatile fatty acid (VFA) accumulated rapidly up to 24 to 168 h, then declined sharply, reaching a low concentration after 312 h. Propionic, iso-valeric, and iso-butyric acids, in addition to acetic acids, were also the major components of VFA. As the biochemical metabolic process was inhibited under oxygen-deficiency condition, the digestion system can produce acetic, propionic, butyric acids and other VFA constituents to meet the demand for NAD(+) and maximize ATP generation. The ORP affected the VFA production and depletion as well as sulfate levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

Nutritional strategies to cope with reduced litter weight gain and total tract digestibility in lactating sows.

PubMed

Álvarez-Rodríguez, J; Mir, L; Seradj, A R; Morazán, H; Balcells, J; Babot, D

2017-10-01

Twelve lactating sows were used to evaluate the effects of reducing dietary crude protein (CP) (14% vs. 12%) and increasing neutral detergent fibre (NDF) levels (18% vs. 22%) on litter performance, total tract apparent digestibility and manure composition in a 4 × 4 latin square arrangement during a 36-day lactation period. Diets were isoenergetic (2.9 Mcal ME/kg) and had similar total lysine content (0.9%). In addition, a second aim was to compare a reference external marker method (Cr 2 O 3 ) with an internal feed marker [acid-insoluble ash (AIA)] for the calculation of apparent total tract digestibility of nutrients in lactating sows. The reduction of dietary CP level in lactating sows had no effect on either live-weight or backfat thickness or apparent total tract digestibility of nutrients. However, the piglets' average daily gain (ADG) was reduced in low dietary CP diets, which suggests that sows reduced milk production due to an underestimation of certain essential amino acid requirements (e.g. valine). The increase of dietary NDF level did not affect sow and litter performance. Nevertheless, the total tract apparent digestibility of organic matter, CP and carbohydrates was reduced, and ether extract digestion was increased in high NDF compared to normal NDF diets equally balanced for ME and lysine content. The coefficients of total tract apparent digestibility of nutrients in lactating sows were greater when using AIA compared to Cr 2 O 3 marker, regardless of dietary CP or NDF level, but their coefficients of variation were lower in the former than in the latter. In lactating sows, a trade-off between litter performance and nutrient digestion is established when reducing dietary CP or increasing NDF levels while maintaining similar lysine content through synthetic amino acids and balancing metabolizable energy through dietary fat sources. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Enhanced anaerobic digestion of waste activated sludge digestion by the addition of zero valent iron.

PubMed

Feng, Yinghong; Zhang, Yaobin; Quan, Xie; Chen, Suo

2014-04-01

Anaerobic digestion is promising technology to recover energy from waste activated sludge. However, the sludge digestion is limited by its low efficiency of hydrolysis-acidification. Zero valent iron (ZVI) as a reducing material is expected to enhance anaerobic process including the hydrolysis-acidification process. Considering that, ZVI was added into an anaerobic sludge digestion system to accelerate the sludge digestion in this study. The results indicated that ZVI effectively enhanced the decomposition of protein and cellulose, the two main components of the sludge. Compared to the control test without ZVI, the degradation of protein increased 21.9% and the volatile fatty acids production increased 37.3% with adding ZVI. More acetate and less propionate are found during the hydrolysis-acidification with ZVI. The activities of several key enzymes in the hydrolysis and acidification increased 0.6-1 time. ZVI made the methane production raise 43.5% and sludge reduction ratio increase 12.2 percent points. Fluorescence in situ hybridization analysis showed that the abundances of hydrogen-consuming microorganisms including homoacetogens and hydrogenotrophic methanogens with ZVI were higher than the control, which reduced the H2 accumulation to create a beneficial condition for the sludge digestion in thermodynamics. Copyright © 2013 Elsevier Ltd. All rights reserved.

Prediction of crude protein digestibility of animal by-product meals for dogs by the protein solubility in pepsin method.

PubMed

Kawauchi, Iris M; Sakomura, Nilva K; Pontieri, Cristiana F F; Rebelato, Aline; Putarov, Thaila C; Malheiros, Euclides B; Gomes, Márcia de O S; Castrillo, Carlos; Carciofi, Aulus C

2014-01-01

Animal by-product meals have large variability in crude protein (CP) content and digestibility. In vivo digestibility procedures are precise but laborious, and in vitro methods could be an alternative to evaluate and classify these ingredients. The present study reports prediction equations to estimate the CP digestibility of meat and bone meal (MBM) and poultry by-product meal (PM) using the protein solubility in pepsin method (PSP). Total tract CP digestibility of eight MBM and eight PM samples was determined in dogs by the substitution method. A basal diet was formulated for dog maintenance, and sixteen diets were produced by mixing 70 % of the basal diet and 30 % of each tested meal. Six dogs per diet were used to determine ingredient digestibility. In addition, PSP of the MBM and PM samples was determined using three pepsin concentrations: 0·02, 0·002 and 0·0002 %. The CP content of MBM and PM ranged from 39 to 46 % and 57 to 69 %, respectively, and their mean CP digestibility by dogs was 76 (2·4) and 85 (2·6) %, respectively. The pepsin concentration with higher Pearson correlation coefficients with the in vivo results were 0·0002 % for MBM (r 0·380; P = 0·008) and 0·02 % for PM (r 0·482; P = 0·005). The relationship between the in vivo and in vitro results was better explained by the following equations: CP digestibility of MBM = 61·7 + 0·2644 × PSP at 0·0002 % (P = 0·008; R (2) 0·126); and CP digestibility of PM = 54·1 + 0·3833 × PSP at 0·02 % (P = 0·005; R (2) 0·216). Although significant, the coefficients of determination were low, indicating that the models were weak and need to be used with caution.

Comparison of the acetyl bromide spectrophotometric method with other analytical lignin methods for determining lignin concentration in forage samples.

PubMed

Fukushima, Romualdo S; Hatfield, Ronald D

2004-06-16

Present analytical methods to quantify lignin in herbaceous plants are not totally satisfactory. A spectrophotometric method, acetyl bromide soluble lignin (ABSL), has been employed to determine lignin concentration in a range of plant materials. In this work, lignin extracted with acidic dioxane was used to develop standard curves and to calculate the derived linear regression equation (slope equals absorptivity value or extinction coefficient) for determining the lignin concentration of respective cell wall samples. This procedure yielded lignin values that were different from those obtained with Klason lignin, acid detergent acid insoluble lignin, or permanganate lignin procedures. Correlations with in vitro dry matter or cell wall digestibility of samples were highest with data from the spectrophotometric technique. The ABSL method employing as standard lignin extracted with acidic dioxane has the potential to be employed as an analytical method to determine lignin concentration in a range of forage materials. It may be useful in developing a quick and easy method to predict in vitro digestibility on the basis of the total lignin content of a sample.

Effects of multi-carbohydrase and phytase on standardized ileal digestibility of amino acids and apparent metabolizable energy in canola meal fed to broiler chicks.

PubMed

Gallardo, C; Dadalt, J C; Kiarie, E; Trindade Neto, M A

2017-09-01

Two assays were conducted to evaluate nutritive value of canola meal (CM) fed to broiler chicks without or with a multi-carbohydrase (MC) preparation (700 U α-galactosidase, 2,200 U galactomannanase, 30,000 U xylanase, and 22,000 U β-glucanase per kg of diet) and phytase (Phy, 500 FTU per kg of diet). Assay 1 determined apparent total tract digestibility (ATTD) of nutrients and metabolizable energy (AME) by the difference method. Assay 2 determined apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids by the index method. Two reference diets (RD) - an 85% corn based and a 5% casein-cornstarch diet fortified with vitamins and minerals - were made for assays 1 and 2, respectively. For each assay, the test diets were made by mixing RD and CM 7:3 wt/wt basis and fed without or with MC or Phy or combination. A total of 245 day-old male broilers (Cobb 500) was allocated to 5 treatments to give 7 replicates (7 birds/cage). The birds were fed a commercial diet from day zero to 10 followed by assay 1 fed from d 11 to 18 and assay 2 fed from d 19 to 21. Excreta samples were collected on d 15 to18, and all birds were slaughtered on d 21 for ileal digesta. There was an interaction (P < 0.05) between MC and Phy on ATTD of DM, N, and P. There was no interaction (P > 0.05) between MC and Phy on AMEn; however, MC and Phy individually improved AMEn retention. Enzymes interacted (P < 0.05) on SID of Arg, His, Leu, Met, Thr, Ala, Asp, Gln, and Gly. In this context, feeding a combination of MC and Phy resulted in higher (P < 0.05) SID of Arg, His, Met, and Thr relative to single activity or control. Both enzymes improved (P < 0.05) SID of Lys independently. The combination of carbohydrase and Phy may be an effective strategy to improve amino acid utilization in CM for poultry. © 2017 Poultry Science Association Inc.

Solid Loss of Carrots During Simulated Gastric Digestion.

PubMed

Kong, Fanbin; Singh, R Paul

2011-03-01

The knowledge of solid loss kinetics of foods during digestion is crucial for understanding the factors that constrain the release of nutrients from the food matrix and their fate of digestion. The objective of this study was to investigate the solid loss of carrots during simulated gastric digestion as affected by pH, temperature, viscosity of gastric fluids, mechanical force present in stomach, and cooking. Cylindrical carrot samples were tested by static soaking method and using a model stomach system. The weight retention, moisture, and loss of dry mass were determined. The results indicated that acid hydrolysis is critical for an efficient mass transfer and carrot digestion. Internal resistance rather than external resistance is dominant in the transfer of soluble solids from carrot to gastric fluid. Increase in viscosity of gastric fluid by adding 0.5% gum (w/w) significantly increased the external resistance and decreased mass transfer rate of carrots in static soaking. When mechanical force was not present, 61% of the solids in the raw carrot samples were released into gastric fluid after 4 h of static soaking in simulated gastric juice. Mechanical force significantly increased solid loss by causing surface erosion. Boiling increased the disintegration of carrot during digestion that may favor the loss of solids meanwhile reducing the amount of solids available for loss in gastric juice. Weibull function was successfully used to describe the solid loss of carrot during simulated digestion. The effective diffusion coefficients of solids were calculated using the Fick's second law of diffusion for an infinite cylinder, which are between 0.75 × 10(-11) and 8.72 × 10(-11) m(2)/s, depending on the pH of the gastric fluid.

The gas chromatographic determination of volatile fatty acids in wastewater samples: evaluation of experimental biases in direct injection method against thermal desorption method.

PubMed

Ullah, Md Ahsan; Kim, Ki-Hyun; Szulejko, Jan E; Cho, Jinwoo

2014-04-11

The production of short-chained volatile fatty acids (VFAs) by the anaerobic bacterial digestion of sewage (wastewater) affords an excellent opportunity to alternative greener viable bio-energy fuels (i.e., microbial fuel cell). VFAs in wastewater (sewage) samples are commonly quantified through direct injection (DI) into a gas chromatograph with a flame ionization detector (GC-FID). In this study, the reliability of VFA analysis by the DI-GC method has been examined against a thermal desorption (TD-GC) method. The results indicate that the VFA concentrations determined from an aliquot from each wastewater sample by the DI-GC method were generally underestimated, e.g., reductions of 7% (acetic acid) to 93.4% (hexanoic acid) relative to the TD-GC method. The observed differences between the two methods suggest the possibly important role of the matrix effect to give rise to the negative biases in DI-GC analysis. To further explore this possibility, an ancillary experiment was performed to examine bias patterns of three DI-GC approaches. For instance, the results of the standard addition (SA) method confirm the definite role of matrix effect when analyzing wastewater samples by DI-GC. More importantly, their biases tend to increase systematically with increasing molecular weight and decreasing VFA concentrations. As such, the use of DI-GC method, if applied for the analysis of samples with a complicated matrix, needs a thorough validation to improve the reliability in data acquisition. Copyright © 2014 Elsevier B.V. All rights reserved.

Standardized ileal digestibility of proteins and amino acids in sesame expeller and soya bean meal in weaning piglets.

PubMed

Aguilera, A; Reis de Souza, T C; Mariscal-Landín, G; Escobar, K; Montaño, S; Bernal, M G

2015-08-01

Apparent ileal digestibility (AID) of diets containing sesame expeller (SE) and soya bean meal (SBM) was determined using 15 piglets (Genetiporc(®)), weaned at 17 ± 0.4 days with average body weight of 6.4 ± 0.7 kg (Fertilis 20 × G Performance, Genetiporc(®), PIC México, Querétaro, México). Piglets were randomly assigned to three treatments: (i) a reference diet with casein as the sole protein source; (ii) a mixed diet of casein-SE; and (iii) a mixed diet of casein-SBM. The chemical composition of SE and SBM was determined, and AID and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AAs) were determined for each protein source. SE contained greater quantities of ether extract, neutral detergent fibre, phytic acid, methionine and arginine than SBM. Lysine and proline contents and trypsin inhibitor activity were higher in SBM than in SE. The AID and SID of CP and AA (except for lysine and proline) were similar in SE and SBM. The AID of lysine and proline was higher in SBM than in SE (p < 0.05), and the SID of proline was higher in SE than in SBM (p < 0.05). These findings indicate that SE is an appropriate alternative protein source for early weaned pigs. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : evaluation of alkaline persulfate digestion as an alternative to Kjeldahl digestion for determination of total and dissolved nitrogen and phosphorus in water

USGS Publications Warehouse

Patton, Charles J.; Kryskalla, Jennifer R.

2003-01-01

Alkaline persulfate digestion was evaluated and validated as a more sensitive, accurate, and less toxic alternative to Kjeldahl digestion for routine determination of nitrogen and phosphorus in surface- and ground-water samples in a large-scale and geographically diverse study conducted by U.S. Geological Survey (USGS) between October 1, 2001, and September 30, 2002. Data for this study were obtained from about 2,100 surface- and ground-water samples that were analyzed for Kjeldahl nitrogen and Kjeldahl phosphorus in the course of routine operations at the USGS National Water Quality Laboratory (NWQL). These samples were analyzed independently for total nitrogen and total phosphorus using an alkaline persulfate digestion method developed by the NWQL Methods Research and Development Program. About half of these samples were collected during nominally high-flow (April-June) conditions and the other half were collected during nominally low-flow (August-September) conditions. The number of filtered and whole-water samples analyzed from each flow regime was about equal.By operational definition, Kjeldahl nitrogen (ammonium + organic nitrogen) and alkaline persulfate digestion total nitrogen (ammonium + nitrite + nitrate + organic nitrogen) are not equivalent. It was necessary, therefore, to reconcile this operational difference by subtracting nitrate + nitrite concentra-tions from alkaline persulfate dissolved and total nitrogen concentrations prior to graphical and statistical comparisons with dissolved and total Kjeldahl nitrogen concentrations. On the basis of two-population paired t-test statistics, the means of all nitrate-corrected alkaline persulfate nitrogen and Kjeldahl nitrogen concentrations (2,066 paired results) were significantly different from zero at the p = 0.05 level. Statistically, the means of Kjeldahl nitrogen concentrations were greater than those of nitrate-corrected alkaline persulfate nitrogen concentrations. Experimental evidence strongly

Understanding the impact of cationic polyacrylamide on anaerobic digestion of waste activated sludge.

PubMed

Wang, Dongbo; Liu, Xuran; Zeng, Guangming; Zhao, Jianwei; Liu, Yiwen; Wang, Qilin; Chen, Fei; Li, Xiaoming; Yang, Qi

2018-03-01

Previous investigations showed that cationic polyacrylamide (cPAM), a flocculant widely used in wastewater pretreatment and waste activated sludge dewatering, deteriorated methane production during anaerobic digestion of sludge. However, details of how cPAM affects methane production are poorly understood, hindering deep control of sludge anaerobic digestion systems. In this study, the mechanisms of cPAM affecting sludge anaerobic digestion were investigated in batch and long-term tests using either real sludge or synthetic wastewaters as the digestion substrates. Experimental results showed that the presence of cPAM not only slowed the process of anaerobic digestion but also decreased methane yield. The maximal methane yield decreased from 139.1 to 86.7 mL/g of volatile suspended solids (i.e., 1861.5 to 1187.0 mL/L) with the cPAM level increasing from 0 to 12 g/kg of total suspended solids (i.e., 0-236.7 mg/L), whereas the corresponding digestion time increased from 22 to 26 d. Mechanism explorations revealed that the addition of cPAM significantly restrained the sludge solubilization, hydrolysis, acidogenesis, and methanogenesis processes. It was found that ∼46% of cAPM was degraded in the anaerobic digestion, and the degradation products significantly affected methane production. Although the theoretically biochemical methane potential of cPAM is higher than that of protein and carbohydrate, only 6.7% of the degraded cPAM was transformed to the final product, methane. Acrylamide, acrylic acid, and polyacrylic acid were found to be the main degradation metabolites, and their amount accounted for ∼50% of the degraded cPAM. Further investigations showed that polyacrylic acid inhibited all the solubilization, hydrolysis, acidogenesis, and methanogenesis processes while acrylamide and acrylic acid inhibited the methanogenesis significantly. Copyright © 2017 Elsevier Ltd. All rights reserved.

Semi-continuous anaerobic co-digestion of cow manure and steam-exploded Salix with recirculation of liquid digestate.

PubMed

Estevez, Maria M; Sapci, Zehra; Linjordet, Roar; Schnürer, Anna; Morken, John

2014-04-01

The effects of recirculating the liquid fraction of the digestate during mesophilic anaerobic co-digestion of steam-exploded Salix and cow manure were investigated in laboratory-scale continuously stirred tank reactors. An average organic loading rate of 2.6 g VS L(-1) d(-1) and a hydraulic retention time (HRT) of 30 days were employed. Co-digestion of Salix and manure gave better methane yields than digestion of manure alone. Also, a 16% increase in the methane yield was achieved when digestate was recirculated and used instead of water to dilute the feedstock (1:1 dilution ratio). The reactor in which the larger fraction of digestate was recirculated (1:3 dilution ratio) gave the highest methane yields. Ammonia and volatile fatty acids did not reach inhibitory levels, and some potentially inhibitory compounds released during steam explosion (i.e., furfural and 5-hydroxy methyl furfural) were only detected at trace levels throughout the entire study period. However, accumulation of solids, which was more pronounced in the recycling reactors, led to decreased methane yields in those systems after three HRTs. Refraining from the use of fresh water to dilute biomass with a high-solids content and obtaining a final digestate with increased dry matter content might offer important economic benefits in full-scale processes. To ensure long-term stability in such an approach, it would be necessary to optimize separation of the fraction of digestate to be recirculated and also perform proper monitoring to avoid accumulation of solids. Copyright © 2014 Elsevier Ltd. All rights reserved.

Secondary Structure and Subunit Composition of Soy Protein In Vitro Digested by Pepsin and Its Relation with Digestibility

PubMed Central

Yang, Yong; Wang, Zhongjiang; Wang, Rui; Sui, Xiaonan; Qi, Baokun; Han, Feifei; Li, Yang; Jiang, Lianzhou

2016-01-01

In the present study, in vitro digestibility and structure of soybean protein isolates (SPIs) prepared from five soybean varieties were investigated in simulated gastric fluid (SGF), using FT-IR microspectroscopy and SDS-PAGE. The result indicated that β-conformations were prone to be hydrolyzed by pepsin preferentially and transformed to unordered structure during in vitro digestion, followed by the digestion of α-helix and unordered structure. A negative linear correlation coefficient was found between the β-conformation contents of five SPIs and their in vitro digestibility values. The intensities of the protein bands corresponding to 7S and 11S fractions were decreased and many peptide bands appeared at 11~15 kDa during enzymatic hydrolysis. β-conglycinin was poorly hydrolyzed with pepsin, especially the β-7S subunit. On the other hand, basic polypeptides of glycinin degraded slower than acidic polypeptides and represented a large proportion of the residual protein after digestion. 11S-A3 of all SPIs disappeared after 1 h digestion. Moreover, a significant negative linear correlation coefficient (r = −0.89) was found between the β-7S contents of five SPIs and their in vitro digestibility values. These results are useful for further studies of the functional properties and bioactive properties of these varieties and laid theoretical foundations for the development of the specific functional soy protein isolate. PMID:27298825

Serum lipid profiles, total tract nutrient digestibility, and gastrointestinal tolerance by dogs of α-cyclodextrin.

PubMed

Guevara, M A; Bauer, L L; Garleb, K A; Fahey, G C; de Godoy, M R C

2015-05-01

The objectives were to quantify gastrointestinal tolerance, total tract nutrient digestibility, and serum lipid profiles of dogs as affected by α-cyclodextrin (ACD) supplementation and to validate the accuracy of fat analyses techniques using novel ACD-fat complexes. The ACD was hydrolyzed and free sugars and hydrolyzed monosaccharides were quantified using high performance liquid chromatography. Known amount of fats were complexed with ACD, and fat content of complexes were determined using the ether extraction and acid-hydrolyzed fat methods. Nine mixed-breed hounds were used in a crossover design with 3 periods of 10 d each, including 6 d for diet adaptation and 4 d for fecal collection. Dogs were fed twice daily a diet with poultry byproduct meal and brewer's rice as the main ingredients, and chromic oxide (0.2%) was included as a digestion marker. Dogs were supplemented with either 0, 3, or 6 g of ACD diluted in 15 mL of water twice per day for a total of 0, 6, and 12 g ACD per day. The ACD had a very low free sugar concentration and, once hydrolyzed, released only glucose, as expected. Average daily food intake, fecal output (DM basis), and fecal scores were not significantly different among treatments. Body weight and condition score and serum triglycerides and cholesterol concentrations remained unaltered throughout the duration of the experiment. Dry matter, OM, and fat digestibility coefficients were lower (P < 0.05) for both treatment groups compared to the control. The acid-hydrolyzed fat method was valid to measure fat that was bound to ACD. Intake of ACD lowered fat digestibility somewhat but not to the extent previously reported, without affecting serum lipid concentrations or outcomes related to tolerance. Therefore, ACD supplementation resulted in a small decrease in fat digestibility, but ACD supplementation might have potential in modifying serum lipid profiles.

Anaerobic co-digestion of kitchen waste and pig manure with different mixing ratios.

PubMed

Tian, Hailin; Duan, Na; Lin, Cong; Li, Xue; Zhong, Mingzhu

2015-07-01

Anaerobic co-digestion of kitchen waste (KW) and pig manure (PM) with seven different PM to KW total solids (TS) ratios of 1:0, 5:1, 3:1, 1:1, 1:3, 1:5 and 0:1 was conducted at mesophilic temperature (35 ± 1 °C) to investigate the feasibility and process performance. The co-digestion of PM and KW was found to be an available way to enhance methane production compared with solo-digestion of PM or KW. The ratio of PM to KW of 1:1 got the highest biodegradability (BDA) of 85.03% and a methane yield of 409.5 mL/gVS. For the co-digestion of KW and PM, there was no obvious inhibition of ammonia nitrogen because it was in an acceptable range from 1380 mg/L to 2020 mg/L in the whole process. However, severe methane inhibition and long lag phase due to the accumulation of volatile fatty acids (VFAs) was observed while the KW content was over 50%, and in the lag phase, propionic acid and butyric acid made up the major constituents of the total VFAs. The technical digestion time (T80: the time it takes to produce 80% of the digester's maximum gas production) of the above 7 ratios was 15, 21, 22, 27, 49, 62 and 61 days, respectively. In this study, a mixing ratio of 1:1 for PM and KW was found to maximize BDA and methane yield, provided a short digestion time and stable digestion performance and was therefore recommended for further study and engineering application. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Anaerobic digestion of citrus waste using two-stage membrane bioreactor

NASA Astrophysics Data System (ADS)

Millati, Ria; Lukitawesa; Dwi Permanasari, Ervina; Wulan Sari, Kartika; Nur Cahyanto, Muhammad; Niklasson, Claes; Taherzadeh, Mohammad J.

2018-03-01

Anaerobic digestion is a promising method to treat citrus waste. However, the presence of limonene in citrus waste inhibits anaerobic digestion process. Limonene is an antimicrobial compound and could inhibit methane forming bacteria that takes a longer time to recover than the injured acid forming bacteria. Hence, volatile fatty acids will be accumulated and methane production will be decreased. One way to solve this problem is by conducting anaerobic digestion process into two stages. The first step is aimed for hydrolysis, acidogenesis, and acetogenesis reactions and the second stage is aimed for methanogenesis reaction. The separation of the system would further allow each stage in their optimum conditions making the process more stable. In this research, anaerobic digestion was carried out in batch operations using 120 ml-glass bottle bioreactors in 2 stages. The first stage was performed in free-cells bioreactor, whereas the second stage was performed in both bioreactor of free cells and membrane bioreactor. In the first stage, the reactor was set into ‘anaerobic’ and ‘semi-aerobic’ conditions to examine the effect of oxygen on facultative anaerobic bacteria in acid production. In the second stage, the protection of membrane towards the cells against limonene was tested. For the first stage, the basal medium was prepared with 1.5 g VS of inoculum and 4.5 g VS of citrus waste. The digestion process was carried out at 55°C for four days. For the second stage, the membrane bioreactor was prepared with 3 g of cells that were encased and sealed in a 3×6 cm2 polyvinylidene fluoride membrane. The medium contained 40 ml basal medium and 10 ml liquid from the first stage. The bioreactors were incubated at 55°C for 2 days under anaerobic condition. The results from the first stage showed that the maximum total sugar under ‘anaerobic’ and ‘semi-aerobic’ conditions was 294.3 g/l and 244.7 g/l, respectively. The corresponding values for total volatile

Anaerobic digestion of pre-fermented potato peel wastes for methane production.

PubMed

Liang, Shaobo; McDonald, Armando G

2015-12-01

This study investigated the feasibility of anaerobic digestion (AD) of potato peel waste (PPW) and its lactic acid fermentation residue (PPW-FR) for methane (CH4) production. The experimental results showed that about 60-70% CH4 content was obtained. The digester using PPW-FR as feedstock exhibited better performance and produced a highest cumulative CH4 production of 273 L/kg VS fed, followed by 239 L/kg VS fed using PPW under the same conditions. However, with increasing solid loadings of PPW-FR feedstock from 6.4% to 9.1%, the CH4 production was inhibited. The generation, accumulation, and degradation of volatile fatty acids (VFAs) in digesters were also investigated in this research. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biogas by semi-continuous anaerobic digestion of food waste.

PubMed

Zhang, Cunsheng; Su, Haijia; Wang, Zhenbin; Tan, Tianwei; Qin, Peiyong

2015-04-01

The semi-continuous anaerobic digestion of food waste was investigated in 1-L and 20-L continuously stirred tank reactors (CSTRs), to identify the optimum operation condition and the methane production of the semi-continuous anaerobic process. Results from a 1-L digester indicated that the optimum organic loading rate (OLR) for semi-continuous digestion is 8 g VS/L/day. The corresponding methane yield and chemical oxygen demand (COD) reduction were 385 mL/g VS and 80.2 %, respectively. Anaerobic digestion was inhibited at high OLRs (12 and 16 g VS/L/day), due to volatile fatty acid (VFA) accumulation. Results from a 20-L digester indicated that a higher methane yield of 423 mL/g VS was obtained at this larger scale. The analysis showed that the methane production at the optimum OLR fitted well with the determined kinetics equation. An obvious decrease on the methane content was observed at the initial of digestion. The increased metabolization of microbes and the activity decrease of methanogen caused by VFA accumulation explained the lower methane content at the initial of digestion.

Effect of lauric acid and coconut oil on ruminal fermentation, digestion, ammonia losses from manure, and milk fatty acid composition in lactating cows.

PubMed

Hristov, A N; Vander Pol, M; Agle, M; Zaman, S; Schneider, C; Ndegwa, P; Vaddella, V K; Johnson, K; Shingfield, K J; Karnati, S K R

2009-11-01

This experiment (replicated 3 x 3 Latin square design) was conducted to investigate the effects of lauric acid (LA) or coconut oil (CO) on ruminal fermentation, nutrient digestibility, ammonia losses from manure, and milk fatty acid (FA) composition in lactating cows. Treatments consisted of intraruminal doses of 240 g of stearic acid/d (SA; control), 240 g of LA/d, or 530 g of CO/d administered once daily, before feeding. Between periods, cows were inoculated with ruminal contents from donor cows and allowed a 7-d recovery period. Treatment did not affect dry matter intake, milk yield, or milk composition. Ruminal pH was slightly increased by CO compared with the other treatments, whereas LA and CO decreased ruminal ammonia concentration compared with SA. Both LA and CO decreased protozoal counts by 80% or more compared with SA. Methane production rate in the rumen was reduced by CO compared with LA and SA, with no differences between LA and SA. Treatments had no effect on total tract apparent dry matter, organic matter, N, and neutral detergent fiber digestibility coefficients or on cumulative (15 d) in vitro ammonia losses from manure. Compared with SA, LA and CO increased milk fat 12:0, cis-9 12:1, and trans-9 12:1 content and decreased 6:0, 8:0, 10:0, cis-9 10:1, 16:0, 18:0, cis 18:1, total 18:2, 18:3 n-3 and total polyunsaturated FA concentrations. Administration of LA and 14:0 (as CO) in the rumen were apparently transferred into milk fat with a mean efficiency of 18 and 15%, respectively. In conclusion, current data confirmed that LA and CO exhibit strong antiprotozoal activity when dosed intraruminally, an effect that is accompanied by decreases in ammonia concentration and, for CO, lowered methane production. Administration of LA and CO in the rumen also altered milk FA composition.

Enhancing anaerobic digestion performance of crude lipid in food waste by enzymatic pretreatment.

PubMed

Meng, Ying; Luan, Fubo; Yuan, Hairong; Chen, Xue; Li, Xiujin

2017-01-01

Three lipases were applied to hydrolyze the floatable grease (FG) in the food waste for eliminating FG inhibition and enhancing digestion performance in anaerobic process. Lipase-I, Lipase-II, and Lipase-III obtained from different sources were used. Animal fat (AF) and vegetable oil (VO) are major crude lipids in Chinese food waste, therefore, applied as substrates for anaerobic digestion tests. The results showed that Lipase-I and Lipase-II were capable of obviously releasing long chain fatty acid in AF, VO, and FG when hydrolyzed in the conditions of 24h, 1000-1500μL and 40-50°C. Compared to the untreated controls, the biomethane production rate were increased by 80.8-157.7%, 26.9-53.8%, and 37.0-40.7% for AF, VO, and FG, respectively, and the digestion time was shortened by 10-40d. The finding suggests that pretreating lipids with appropriate lipase could be one of effective methods for enhancing anaerobic digestion of food waste rich in crude lipid. Copyright © 2016. Published by Elsevier Ltd.

The anaerobic digestion of biologically and physicochemically pretreated oily wastewater.

PubMed

Peng, Liyu; Bao, Meidan; Wang, Qingfeng; Wang, Fangchao; Su, Haijia

2014-01-01

To enhance the degradation of oily wastewater and its biogas production, a biological-physicochemical pretreatment was introduced prior to the anaerobic digestion system. The digestion thereafter proceeded more efficiently due to the inoculation by oil degrading bacteria (Bacillus). A 2-stage pre-mixing is more effective than directly mixing. The effects on the methane production were also investigated by pre-treatment with ultrasonic (US) treatment, combined with citric acid (CA) addition. US pre-treatment was found to improve the initial methane production, and CA pre-treatment could maintain this improvement during the whole digestion stage. Pre-mixing Bacillus at 9 wt.% inoculation, combined with US for 10 min and a CA concentration of 500 mg/L provided the optimum conditions. The most effective enhancement of methane yield was 1100.46 ml/g VS, exceeding that of the control by 280%. The change of coenobium shape and fatty acid content further proved that such pretreatment of oily wastewater can facilitate digestion. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enhanced methane production from Taihu Lake blue algae by anaerobic co-digestion with corn straw in continuous feed digesters.

PubMed

Zhong, Weizhang; Chi, Lina; Luo, Yijing; Zhang, Zhongzhi; Zhang, Zhenjia; Wu, Wei-Min

2013-04-01

Anaerobic digestion of Taihu blue algae was tested in laboratory scale, continuous feed digesters (hydraulic retention time 10 days) at 35°C and various organic loading rates (OLR). The methane production and biomass digestion performed well at OLR below 4.00 gVSL(-1)d(-1) but deteriorated as OLR increased due to the increased ammonia concentration, causing inhibition mainly to acetate and propionate degradation. Supplementing corn straw as co-feedstock significantly improved the digestion performance. The optimal C/N ratio for the co-digestion was 20:1 at OLR of 6.00 gVSL(-1) d(-1). Methane yield of 234 mL CH4 gVS(-1) and methane productivity of 1404 mL CH4 L(-1) d(-1) were achieved with solid removal of 63%. Compared with the algae alone, the methane productivity was increased by 46% with less accumulation of ammonia and fatty acids. The reactor rate-limiting step was acetate and propionate degradation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Aged-engineered nanoparticles effect on sludge anaerobic digestion performance and associated microbial communities.

PubMed

Eduok, Samuel; Ferguson, Robert; Jefferson, Bruce; Villa, Raffaella; Coulon, Frédéric

2017-12-31

To investigate the potential effect of aged engineered nanoparticles (a-ENPs) on sludge digestion performance, 150L pilot anaerobic digesters (AD) were fed with a blend of primary and waste activated sludge spiked either with a mixture of silver oxide, titanium dioxide and zinc oxide or a mixture of their equivalent bulk metal salts to achieve a target concentration of 250, 2000, and 2800mgkg -1 dry weight, respectively. Volatile fatty acids (VFA) were 1.2 times higher in the spiked digesters and significantly different (p=0.05) from the control conditions. Specifically, isovaleric acid concentration was 2 times lower in the control digester compared to the spiked digesters, whereas hydrogen sulfide was 2 times lower in the ENPs spiked digester indicating inhibitory effect on sulfate reducing microorganisms. Based on the ether-linked isoprenoids concentration, the total abundance of methanogens was 1.4 times lower in the ENPs spiked digester than in the control and metal salt spiked digesters. Pyrosequencing indicated 80% decrease in abundance and diversity of methanogens in ENPs spiked digester compared to the control digester. Methanosarcina acetivorans and Methanosarcina barkeri were identified as nano-tolerant as their relative abundance increased by a factor of 6 and 11, respectively, compared to the other digesters. The results further provide compelling evidence on the resilience of Fusobacteria, Actinobacteria and the Trojan horse-like effect of ENPs which offered a competitive advantage to some organisms while reducing microbial abundance and diversity. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Simulation of anaerobic digestion processes using stochastic algorithm.

PubMed

Palanichamy, Jegathambal; Palani, Sundarambal

2014-01-01

The Anaerobic Digestion (AD) processes involve numerous complex biological and chemical reactions occurring simultaneously. Appropriate and efficient models are to be developed for simulation of anaerobic digestion systems. Although several models have been developed, mostly they suffer from lack of knowledge on constants, complexity and weak generalization. The basis of the deterministic approach for modelling the physico and bio-chemical reactions occurring in the AD system is the law of mass action, which gives the simple relationship between the reaction rates and the species concentrations. The assumptions made in the deterministic models are not hold true for the reactions involving chemical species of low concentration. The stochastic behaviour of the physicochemical processes can be modeled at mesoscopic level by application of the stochastic algorithms. In this paper a stochastic algorithm (Gillespie Tau Leap Method) developed in MATLAB was applied to predict the concentration of glucose, acids and methane formation at different time intervals. By this the performance of the digester system can be controlled. The processes given by ADM1 (Anaerobic Digestion Model 1) were taken for verification of the model. The proposed model was verified by comparing the results of Gillespie's algorithms with the deterministic solution for conversion of glucose into methane through degraders. At higher value of 'τ' (timestep), the computational time required for reaching the steady state is more since the number of chosen reactions is less. When the simulation time step is reduced, the results are similar to ODE solver. It was concluded that the stochastic algorithm is a suitable approach for the simulation of complex anaerobic digestion processes. The accuracy of the results depends on the optimum selection of tau value.

Immunohistochemical study of the digestive tract of Oligosarcus hepsetus

PubMed Central

Vieira-Lopes, Danielle A; Pinheiro, Nadja L; Sales, Armando; Ventura, Adriana; Araújo, Francisco G; Gomes, Iracema D; Nascimento, Aparecida A

2013-01-01

AIM: To describe the histology of the digestive tract and to investigate the occurrence of endocrine cells in Oligosarcus hepsetus (O. hepsetus). METHODS: The digestive tract (DT) of O. hepsetus was divided into esophagus, two stomach regions (glandular and non-glandular) and two intestinal regions (anterior and posterior). These specimens were processed by routine histological techniques and stained with hematoxylin-eosin, Gomori’s trichrome, periodic acid Schiff (PAS) and Alcian blue (AB). An immunohistochemical method using avidin-biotin-peroxidase was employed. RESULTS: The esophagus is lined with a non-keratinized stratified squamous epithelium that is reactive to PAS and AB. The stomach has a mucosa lined with a simple columnar epithelium with mucus-secreting cells that are reactive only to PAS. The intestine has a simple columnar epithelium with a brush border and goblet cells that are reactive to PAS and AB. Somatostatin, serotonin and cholecystokinin immunoreactive cells were identified throughout the DT. CONCLUSION: This study revealed adaptations for the species’ diet and showed that the distribution and relative frequency of immunoreactive cells are similar to those of other fish. PMID:23569337

Effects of Temperature during Moist Heat Treatment on Ruminal Degradability and Intestinal Digestibility of Protein and Amino Acids in Hempseed Cake.

PubMed

Karlsson, L; Ruiz-Moreno, M; Stern, M D; Martinsson, K

2012-11-01

The objective of this study was to evaluate ruminal degradability and intestinal digestibility of crude protein (CP) and amino acids (AA) in hempseed cake (HC) that were moist heat treated at different temperatures. Samples of cold-pressed HC were autoclaved for 30 min at 110, 120 or 130°C, and a sample of untreated HC was used as the control. Ruminal degradability of CP was estimated, using the in situ Dacron bag technique; intestinal CP digestibility was estimated for the 16 h in situ residue using a three-step in vitro procedure. AA content was determined for the HC samples (heat treated and untreated) of the intact feed, the 16 h in situ residue and the residue after the three-step procedure. There was a linear increase in RUP (p = 0.001) and intestinal digestibility of RUP (p = 0.003) with increasing temperature during heat treatment. The 130°C treatment increased RUP from 259 to 629 g/kg CP, while intestinal digestibility increased from 176 to 730 g/kg RUP, compared to the control. Hence, the intestinal available dietary CP increased more than eight times. Increasing temperatures during heat treatment resulted in linear decreases in ruminal degradability of total AA (p = 0.006) and individual AA (p<0.05) and an increase in intestinal digestibility that could be explained both by a linear and a quadratic model for total AA and most individual AA (p<0.05). The 130°C treatment decreased ruminal degradability of total AA from 837 to 471 g/kg, while intestinal digestibility increased from 267 to 813 g/kg of rumen undegradable AA, compared with the control. There were differences between ruminal AA degradability and between intestinal AA digestibility within all individual HC treatments (p<0.001). It is concluded that moist heat treatment at 130°C did not overprotect the CP of HC and could be used to shift the site of CP and AA digestion from the rumen to the small intestine. This may increase the value of HC as a protein supplement for ruminants.

Effects of Temperature during Moist Heat Treatment on Ruminal Degradability and Intestinal Digestibility of Protein and Amino Acids in Hempseed Cake

PubMed Central

Karlsson, L.; Ruiz-Moreno, M.; Stern, M. D.; Martinsson, K.

2012-01-01

The objective of this study was to evaluate ruminal degradability and intestinal digestibility of crude protein (CP) and amino acids (AA) in hempseed cake (HC) that were moist heat treated at different temperatures. Samples of cold-pressed HC were autoclaved for 30 min at 110, 120 or 130°C, and a sample of untreated HC was used as the control. Ruminal degradability of CP was estimated, using the in situ Dacron bag technique; intestinal CP digestibility was estimated for the 16 h in situ residue using a three-step in vitro procedure. AA content was determined for the HC samples (heat treated and untreated) of the intact feed, the 16 h in situ residue and the residue after the three-step procedure. There was a linear increase in RUP (p = 0.001) and intestinal digestibility of RUP (p = 0.003) with increasing temperature during heat treatment. The 130°C treatment increased RUP from 259 to 629 g/kg CP, while intestinal digestibility increased from 176 to 730 g/kg RUP, compared to the control. Hence, the intestinal available dietary CP increased more than eight times. Increasing temperatures during heat treatment resulted in linear decreases in ruminal degradability of total AA (p = 0.006) and individual AA (p<0.05) and an increase in intestinal digestibility that could be explained both by a linear and a quadratic model for total AA and most individual AA (p<0.05). The 130°C treatment decreased ruminal degradability of total AA from 837 to 471 g/kg, while intestinal digestibility increased from 267 to 813 g/kg of rumen undegradable AA, compared with the control. There were differences between ruminal AA degradability and between intestinal AA digestibility within all individual HC treatments (p<0.001). It is concluded that moist heat treatment at 130°C did not overprotect the CP of HC and could be used to shift the site of CP and AA digestion from the rumen to the small intestine. This may increase the value of HC as a protein supplement for ruminants. PMID:25049517

Physical changes in white and brown rice during simulated gastric digestion.

PubMed

Kong, Fanbin; Oztop, Mecit Halil; Singh, R Paul; McCarthy, Michael J

2011-08-01

Previous studies have shown that brown rice generates lower glycemic responses than white rice, a trait that may be beneficial in the dietary management of chronic diseases such as diabetes and hyperlipidemia. The objective of this study was to investigate influence of rice digestion on the physical properties of the gastric digesta that may further impact intestinal absorption. A dynamic stomach model, human gastric simulator, was used to simulate the gastric digestion of white and brown rice. The pH, solids content, and rheological properties of the gastric digesta, as well as the size distribution of particles were studied. Static soaking was conducted to reveal the changes in moisture absorption and texture in rice kernels during simulated gastric digestion, as affected by shaking and the acid in gastric juice. Magnetic resonance imaging (MRI) was used to image the diffusion of gastric juice into the rice kernels. The results indicate that the bran layer on brown rice had a profound effect in digestion, as it inhibited the absorption of moisture and acid leading to decreased texture degradation, thus delaying the rice disintegration as well as dissolution and slowing emptying of solids. MRI is effective in exhibiting the diffusion of gastric juice as affected by gastric acid and the influence of bran. This study provided quantitative evidence regarding the manner in which structural differences between white and brown rice affect their gastric digestion. The study presented in this paper focuses on how the structural differences in white and brown rice affect their gastric digestion. This information may help consumers to better understand the health benefits associated with eating brown rice. © 2011 Institute of Food Technologists®

Measurement of true ileal calcium digestibility in meat and bone meal for broiler chickens using the direct method.

PubMed

Anwar, M N; Ravindran, V; Morel, P C H; Ravindran, G; Cowieson, A J

2016-01-01

The objective of the study that is presented herein was to determine the true ileal calcium (Ca) digestibility in meat and bone meal (MBM) for broiler chickens using the direct method. Four MBM samples (coded as MBM-1, MBM-2, MBM-3 and MBM-4) were obtained and analyzed for nutrient composition, particle size distribution and bone to soft tissue ratio. The Ca concentrations of MBM-1, MBM-2, MBM-3 and MBM-4 were determined to be 71, 118, 114 and 81 g/kg, respectively. The corresponding geometric mean particle diameters and bone to soft tissue ratios were 0.866, 0.622, 0.875 and 0.781 mm, and 1:1.49, 1:0.98, 1:0.92 and 1:1.35, respectively. Five experimental diets, including four diets with similar Ca concentration (8.3 g/kg) from each MBM and a Ca and phosphorus-free diet, were developed. Meat and bone meal served as the sole source of Ca in the MBM diets. Titanium dioxide (3 g/kg) was incorporated in all diets as an indigestible marker. Each experimental diet was randomly allotted to six replicate cages (eight birds per cage) and offered from d 28 to 31 post-hatch. Apparent ileal Ca digestibility was calculated by the indicator method and corrected for ileal endogenous Ca losses to determine the true ileal Ca digestibility. Ileal endogenous Ca losses were determined to be 88 mg/kg dry matter intake. True ileal Ca digestibility coefficients of MBM-1, MBM-2, MBM-3 and MBM-4 were determined to be 0.560, 0.446, 0.517 and 0.413, respectively. True Ca digestibility of MBM-1 was higher (P < 0.05) than MBM-2 and MBM-4 but similar (P > 0.05) to that of MBM-3. True Ca digestibility of MBM-2 was similar (P > 0.05) to MBM-3 and MBM-4, while that of MBM-3 was higher (P < 0.05) than MBM-4. These results demonstrated that the direct method can be used for the determination of true Ca digestibility in feed ingredients and that Ca in MBM is not highly available as often assumed. The variability in true Ca digestibility of MBM samples could not be attributed to Ca content, percentage

Binturong (Arctictis binturong) and Kinkajou (Potos flavus) Digestive Strategy: Implications for Interpreting Frugivory in Carnivora and Primates

PubMed Central

Lambert, Joanna E.; Fellner, Vivek; McKenney, Erin; Hartstone-Rose, Adam

2014-01-01

Exclusive frugivory is rare. As a food resource, fruit is temporally and spatially patchy, low in protein, and variable in terms of energy yield from different carbohydrate types. Here, we evaluate the digestive physiology of two frugivorous Carnivora species (Potos flavus, Arctictis binturong) that converge with primates in a diversity of ecological and anatomical traits related to fruit consumption. We conducted feeding trials to determine mean digestive retention times (MRT) on captive animals at the Carnivore Preservation Trust (now Carolina Tiger Rescue), Pittsboro, NC. Fecal samples were collected on study subjects for in vitro analysis to determine methane, pH, and short chain fatty acid profiles; fiber was assayed using standard neutral detergent (NDF) and acid detergent (ADF) fiber methods. Results indicate that both carnivoran species have rapid digestive passage for mammals that consume a predominantly plant-based diet: A. binturong MRT = 6.5 hrs (0.3); P. flavus MRT = 2.5 hrs (1.6). In vitro experiments revealed no fermentation of structural polysaccharides – methane levels did not shift from 0 h to either 24 or 48 hours and no short chain fatty acids were detected. In both species, however, pH declined from one incubation period to another suggesting acidification and bacterial activity of microbes using soluble carbohydrates. A comparison with primates indicates that the study species are most similar in digestive retention times to Ateles – the most frugivorous anthropoid primate taxon. PMID:25157614

Prediction of in vivo neutral detergent fiber digestibility and digestion rate of potentially digestible neutral detergent fiber: comparison of models.

PubMed

Huhtanen, P; Seppälä, A; Ahvenjärvi, S; Rinne, M

2008-10-01

Eleven 1-pool, seven 2-pool, and three 3-pool models were compared in fitting gas production data and predicting in vivo NDF digestibility and effective first-order digestion rate of potentially digestible NDF (pdNDF). Isolated NDF from 15 grass silages harvested at different stages of maturity was incubated in triplicate in rumen fluid-buffer solution for 72 h to estimate the digestion kinetics from cumulative gas production profiles. In vivo digestibility was estimated by the total fecal collection method in sheep fed at a maintenance level of feeding. The concentration of pdNDF was estimated by a 12-d in situ incubation. The parameter values from gas production profiles and pdNDF were used in a 2-compartment rumen model to predict pdNDF digestibility using 50 h of rumen residence time distributed in a ratio of 0.4:0.6 between the non-escapable and escapable pools. The effective first-order digestion rate was computed both from observed in vivo and model-predicted pdNDF digestibility assuming the passage kinetic model described above. There were marked differences between the models in fitting the gas production data. The fit improved with increasing number of pools, suggesting that silage pdNDF is not a homogenous substrate. Generally, the models predicted in vivo NDF digestibility and digestion rate accurately. However, a good fit of gas production data was not necessarily translated into improved predictions of the in vivo data. The models overestimating the asymptotic gas volumes tended to underestimate the in vivo digestibility. Investigating the time-related residuals during the later phases of fermentation is important when the data are used to estimate the first-order digestion rate of pdNDF. Relatively simple models such as the France model or even a single exponential model with discrete lag period satisfied the minimum criteria for a good model. Further, the comparison of feedstuffs on the basis of parameter values is more unequivocal than in the case

DNA-SIP based genome-centric metagenomics identifies key long-chain fatty acid-degrading populations in anaerobic digesters with different feeding frequencies

PubMed Central

Ziels, Ryan M; Sousa, Diana Z; Stensel, H David; Beck, David A C

2018-01-01

Fats, oils and greases (FOG) are energy-dense wastes that can be added to anaerobic digesters to substantially increase biomethane recovery via their conversion through long-chain fatty acids (LCFAs). However, a better understanding of the ecophysiology of syntrophic LCFA-degrading microbial communities in anaerobic digesters is needed to develop operating strategies that mitigate inhibitory LCFA accumulation from FOG. In this research, DNA stable isotope probing (SIP) was coupled with metagenomic sequencing for a genome-centric comparison of oleate (C18:1)-degrading populations in two anaerobic codigesters operated with either a pulse feeding or continuous-feeding strategy. The pulse-fed codigester microcosms converted oleate into methane at over 20% higher rates than the continuous-fed codigester microcosms. Differential coverage binning was demonstrated for the first time to recover population genome bins (GBs) from DNA-SIP metagenomes. About 70% of the 13C-enriched GBs were taxonomically assigned to the Syntrophomonas genus, thus substantiating the importance of Syntrophomonas species to LCFA degradation in anaerobic digesters. Phylogenetic comparisons of 13C-enriched GBs showed that phylogenetically distinct Syntrophomonas GBs were unique to each codigester. Overall, these results suggest that syntrophic populations in anaerobic digesters can have different adaptive capacities, and that selection for divergent populations may be achieved by adjusting reactor operating conditions to maximize biomethane recovery. PMID:28895946

Mitigating ammonia inhibition of thermophilic anaerobic treatment of digested piggery wastewater: use of pH reduction, zeolite, biomass and humic acid.

PubMed

Ho, L; Ho, G

2012-09-15

High free ammonia released during anaerobic digestion of livestock wastes is widely known to inhibit methanogenic microorganisms and result in low methane production. This was encountered during our earlier thermophilic semi-continuously fed continuously-stirred tank reactor (CSTR) treatment of piggery wastewater. This study explored chemical and biological means to mitigate ammonia inhibition on thermophilic anaerobic treatment of piggery wastewater with the aim to increase organic volatile carbon reduction and methane production. A series of thermophilic anaerobic batch experiments were conducted on the digested piggery effluent to investigate the effects of pH reduction (pH 8.3 to 7.5, 7.0 and 6.5) and additions of biomass (10% v/v and 19% v/v anaerobic digested piggery biomass and aerobic-anaerobic digested municipal biomass), natural zeolite (10, 15 and 20 g/L) and humic acid (1, 5 and 10 g/L) on methane production at 55 °C for 9-11 days. Reduction of the wastewater pH from its initial pH of 8.3 to 6.5 produced the greatest stimulation of methane production (3.4 fold) coupled with reductions in free ammonia (38 fold) and total volatile fatty acids (58% TVFA), particularly acetate and propionate. Addition of 10-20 g/L zeolite to piggery wastewater with and without pH reduction to 6.5 further enhanced total VFA reduction and methane production over their respective controls, with 20 g/L zeolite producing the highest enhancement effect despite the ammonia-nitrogen concentrations of the treated wastewaters remaining high. Without pH reduction, zeolite concentration up to 20 g/L was required to achieve comparable methane enhancement as the pH-reduced wastewater at pH 6.5. Although biomass (10% v/v piggery and municipal wastes) and low humic acid (1 and 5 g/L) additions enhanced total VFA reduction and methane production, they elevated the residual effluent total COD concentrations over the control wastewaters (pH-unadjusted and pH-reduced) unlike zeolite

Bacteriological aspects of selective decontamination of the digestive tract as a method of infection prevention in granulocytopenic patients.

PubMed Central

de Vries-Hospers, H G; Sleijfer, D T; Mulder, N H; van der Waaij, D; Neiweg, H O; van Saene, H K

1981-01-01

We describe the bacteriological results of a controlled clinical trial of selective decontamination of the digestive tract as a method of infection prevention in granulocytopenic patients. Selective elimination of Enterobacteriaceae and Pseudomonadaceae species was accomplished by the oral administration of nalidixic acid, co-trimoxazole, or polymyxin. Yeasts were eliminated selectively by amphotericin B or nystatin treatment. The drugs used in this study were chosen because of their capacities to selectively eliminate gram-negative rods and yeast without affecting the anaerobic part of the gut flora which is responsible for colonization resistance. Compared with the control group, the selectively decontaminated patients had significantly fewer (P less than 0.0005) gram-negative rods or yeasts or both in their throat swab cultures and in their feces. This reduction may explain the clinical effectiveness of selective decontamination. PMID:7027923

Phenylethanoid Glycoside Profiles and Antioxidant Activities of Osmanthus fragrans Lour. Flowers by UPLC/PDA/MS and Simulated Digestion Model.

PubMed

Jiang, Yirong; Mao, Shuqin; Huang, Weisu; Lu, Baiyi; Cai, Zengxuan; Zhou, Fei; Li, Maiquan; Lou, Tiantian; Zhao, Yajing

2016-03-30

Variations of phenylethanoid glycoside profiles and antioxidant activities in Osmanthus fragrans flowers through the digestive tract were evaluated by a simulated digestion model and UPLC/PDA/MS. Major phenylethanoid glycosides and phenolic acids, namely, salidroside, acteoside, isoacteoside, chlorogenic acid, and caffeic acid, were identified in four cultivars of O. fragrans flowers, and the concentration of acteoside was the highest, being up to 71.79 mg/g dry weight. After simulated digestion, total phenylethanoid glycoside contents and antioxidant activities were significantly decreased. Acteoside was identified as decomposing into caffeic acid, whereas salidroside was found to be stable during simulated digestion. According to Pearson's correlation analysis, acteoside contents showed good correlations with antioxidant activities during simulated digestion (R(2) = 0.994, P < 0.01). In conclusion, acteoside was the major contributor to the antioxidant activity of O. fragrans flowers, and salidroside was considered as the major antioxidant compound of O. fragrans flowers in vivo.

Enhancement of dewatering performance of digested paper mill sludge by chemical pretreatment

NASA Astrophysics Data System (ADS)

Lin, Y. Q.; Zeng, C.; Wu, H. H.; Zeng, B. X.

2016-08-01

The wide application of anaerobic digestion (AD) for waste sludge results in a huge amount of digested sludge, while the appropriate reuse of digested sludge depends on effective solid-liquid separation. Thus, chemical (acid/alkali) pretreatment effects on dewaterability of digested paper mill sludge (DPMS) for better downstream reuse based on enhanced solid- liquid separation were investigated in this research. The dewatering properties of paper mill sludge (PMS) were also investigated to elucidate the impact of AD on sludge dewaterability. The results indicated that a higher DPMS dewaterability was noted with acid pretreatment (pH5). A 41.37% moisture content and 74.41% dewatering efficiency were determined for DPMS after acid (pH5) pretreatment within 25 min. In addition, a 7.13 mg•g-1 VSS of extracellular polymeric substances (EPS) and 101.50 μm of average particle size were observed. It was also observed that both EPS concentrations and particle sizes were key parameters influencing DPMS dewaterability. Lower EPS concentrations with larger average particle sizes contributed to enhanced sludge dewaterability. Moreover, dewaterability of PMS was higher than that of DPMS, which illustrated that AD would decrease the sludge dewaterability.

A Simplified Digestion Protocol for the Analysis of Hg in Fish by Cold Vapor Atomic Absorption Spectroscopy

ERIC Educational Resources Information Center

Kristian, Kathleen E.; Friedbauer, Scott; Kabashi, Donika; Ferencz, Kristen M.; Barajas, Jennifer C.; O'Brien, Kelly

2015-01-01

Analysis of mercury in fish is an interesting problem with the potential to motivate students in chemistry laboratory courses. The recommended method for mercury analysis in fish is cold vapor atomic absorption spectroscopy (CVAAS), which requires homogeneous analyte solutions, typically prepared by acid digestion. Previously published digestion…

Comparison of some aspects of the in situ and in vitro methods in evaluation of neutral detergent fiber digestion.

PubMed

Krizsan, S J; Jančík, F; Ramin, M; Huhtanen, P

2013-02-01

The objective of the present study was to compare digestion rates (kd) of NDF for different feeds estimated with the in situ method or derived from an automated gas in vitro system. A meta-analysis was conducted to evaluate how in situ derived kd of NDF related to in vivo digestibility of NDF. Furthermore, in vitro true digestibility of the feed samples incubated within filter bags or dispersed in the medium was compared, and kd for insoluble and soluble components of those feeds were estimated. Four different concentrates and 4 forages were used in this study. Two lactating Swedish Red cows fed a diet of 60% grass silage and 40% concentrate on DM basis were used for in situ incubations and for collection of rumen fluid. The feed samples were ground through a 2.0-mm screen before the in situ incubations and a 1.0-mm screen before the in vitro gas incubations. In situ nylon bags were introduced into the rumen for determination of kd of NDF. Additional kinetic data were produced from isolated NDF and intact samples subjected to in vitro incubations in which gas production was recorded for 72 h. Samples were weighed in the bottles or within filter bags (for fiber and in vitro studies) that were placed in the bottles. The interaction between feed and method was significant (P < 0.01); kd of NDF for grass hay tended (P = 0.06) to be less whereas kd of NDF for alfalfa, barley grain, canola meal, and dried sugar beet pulp were greater (P < 0.01) when estimated with the in situ method than from gas production recordings. The meta-analysis suggested that in situ derived kd of NDF were biased and underestimated in vivo digestibility of NDF. Digestion rates of the intact samples were lower for all feeds, except for the hay, when incubated within the bags compared with dispersed in the medium (P < 0.01). Less OM and NDF were digested for all feeds when incubated within bags than dispersed in the medium (P < 0.01). It is concluded from the in vitro study that microbial activity

Bioactive compounds and antioxidant properties of pseudocereals-enriched water biscuits and their in vitro digestates.

PubMed

Hidalgo, Alyssa; Ferraretto, Anita; De Noni, Ivano; Bottani, Michela; Cattaneo, Stefano; Galli, Simone; Brandolini, Andrea

2018-02-01

Carotenoids, tocols, phenolic acids and antioxidant capacity were studied during in vitro digestion of water biscuits (WB) from bread wheat, einkorn and einkorn-pseudocereals. Antioxidant and cytotoxic activities of digestates were also measured using a 70% Caco2/30% HT-29 human intestinal co-culture layer. Antioxidant profiles differed among WB formulations. Only hydrophilic molecules were solubilised by gastric digestion. After intestinal digestion, 77% carotenoids and 67% tocols were released. Soluble-conjugated phenolic acids increased (30%) and insoluble-bound forms decreased (17%), suggesting partial conversion from bound to conjugated form. After intestinal digestion, antioxidant capacity increased regardless of type and amount of antioxidants in undigested or digested WB. All WB, especially those with quinoa flour, reduced the AAPH pro-oxidant capacity in co-culture cells. These results highlight the potential health benefits of underutilized crops and the need for in vitro or in vivo models to better address potential bioactivity at intestinal and target organs level. Copyright © 2017 Elsevier Ltd. All rights reserved.

Application of Pineapple Juice in the Fish Digestion Process for Carcinogenic Liver Fluke Metacercaria Collection

PubMed Central

Sripan, Panupan; Aukkanimart, Ratchadawan; Boonmars, Thidarut; Pranee, Sriraj; Songsri, Jiraporn; Boueroy, Parichart; Khueangchaingkhwang, Sukhonthip; Pumhirunroj, Benjamabhorn; Artchayasawat, Atchara

2017-01-01

Pepsin is common digestive enzyme used for fish digestion in the laboratory to collect trematode metacercariae. In a field study, to survey the infected fish is needed a huge yield of pepsin and it is very expensive. Therefore, our purpose of this study was to investigate the candidate enzyme from pineapple juice which has a digestive enzyme called bromelain, a mixture of proteolytic enzymes, to digest fish in order to harvest metacercariae. Fish were divided into 2 groups: one group in which metacercariae were harvested using acid pepsin as a control and other groups in which the fish was digested using fresh pineapple juices. The results showed that pineapple juice is able to digest fish similarly to pepsin. The Pattavia pineapple juice had the highest number of metacercariae similar to the control. For Trat Si Thong pineapple juice, we found the number of metacercariae was less than control. This result suggests that the Pattavia pineapple juice was optimal juice for fish digestion to metacercaria collection and can be used instread of pepsin acid. PMID:28441786

Effect of flaxseed physical form on digestibility of lactation diets fed to Holstein steers.

PubMed

Schroeder, J W; Bauer, M L; Bork, N R

2014-09-01

Four multicannulated (rumen, duodenum, and ileum) Holstein steers (459.7±46.4kg of initial body weight) were used in a 4×4 Latin square design to determine the effect of flaxseed processing method on ruminal fermentation and digestibility. Treatments were based on inclusion of (1) 7.5% linseed meal (control), (2) 10% whole flaxseed, (3) 10% rolled flaxseed, or (4) 10% ground flaxseed on a dry matter (DM) basis, and were formulated to mimic typical high-producing dairy cow lactation diets. The control diet contained linseed meal in a proportion to provide crude protein (CP) equal to the amount of CP contributed by the flaxseed in the other treatments. Diets were fed for ad libitum intake and contained 30% corn silage, 17% chopped alfalfa hay, 6% sugar beet pulp, and 47% concentrate (comprising ground corn, supplemental protein, trace minerals and vitamins, and either flaxseed or linseed meal (DM basis). Diets were formulated to contain 17% CP, 34% neutral detergent fiber, 21% acid detergent fiber, and 4% fatty acid (DM basis). Periods were 14 d long and consisted of 7 d of adaptation and 7 d of sample collection. Dry matter intake (as a % of body weight) was similar (2.41±0.17) for all treatments. The inclusion of flaxseed, regardless of processing method, tended to decrease total-tract organic matter digestibility relative to the linseed control, but no differences in CP intake, duodenal CP flow (bacterial, apparent feed, or total), ileal CP flow, fecal CP output, microbial efficiency, or CP digestibility (apparent ruminal, true ruminal, small intestine, large intestine, or total tract) were observed between treatments. Method of processing did not alter ruminal pH, ammonia, or volatile fatty acids production. The ground flaxseed treatment had the fastest rate of in situ DM degradation (11.25%/h), followed by the control (7.46%/h), rolled flaxseed (4.53%/h), and whole flaxseed (0.57%/h) treatments. Degradability of CP and fat followed the same pattern as DM

Comparison of digestion methods for determination of trace and minor metals in plant samples.

PubMed

Lavilla, I; Filgueiras, A V; Bendicho, C

1999-12-01

In this paper, three dissolution methods using pressure digestion vessels (low-, medium-, and high-pressure vessels) for the determination of metals in plant samples are described. The Plackett-Burman saturated factorial design was used to identify the significant factors influencing wet ashing and to select optimized dissolution conditions. The three methods were statistically compared (on-way ANOVA) on the same sample; no significant differences were obtained. In all cases the relative standard deviation values were <3%. The digestion method based on the use of low-pressure vessels and a microwave oven was validated against CRM GBW07605 tea leaves. This method was applied to the determination of Cu, Zn, Mn, Fe, Mg, and Ca in 22 different medicinal, aromatic, and seasoning plants by flame-atomic absorption spectrometry. The concentration intervals of metal in the plants analyzed were the following: Cu, 4 (Allium sativum)-35 (Thea sinensis) microg g(-1); Zn, 7 (Piper nigrum)-90 (Betula alba) microg g(-1); Mn, 9 (Allium sativum)-939 (Caryophylus aromaticus) microg g(-1); Fe, 33 (Allium sativum)-2486 (Anethum graveolens) microg g(-1); Mg, 495 (Allium sativum)-7458 (Ocimum basilicum) microg g(-1); Ca, 386 (Allium sativum)-21500 (Ocimum basilicum) microg g(-1).

Rumen Degradability and Post-ruminal Digestion of Dry Matter, Nitrogen and Amino Acids of Three Protein Supplements.

PubMed

Gao, Wei; Chen, Aodong; Zhang, Bowen; Kong, Ping; Liu, Chenli; Zhao, Jie

2015-04-01

This study evaluated the in situ ruminal degradability, and subsequent small intestinal digestibility (SID) of dry matter, crude protein (CP), and amino acids (AA) of cottonseed meal (CSM), sunflower seed meal (SFSM) and distillers dried grains with solubles (DDGS) by using the modified three-step in vitro procedure. The ruminal degradability and subsequent SID of AA in rumen-undegradable protein (RUP-AA) varied among three protein supplements. The result show that the effective degradability of DM for SFSM, CSM, and DDGS was 60.8%, 56.4%, and 41.0% and their ruminal fermentable organic matter was 60.0%, 55.9%, and 39.9%, respectively. The ruminal degradable protein (RDP) content in CP for SFSM, CSM, and DDGS was 68.3%, 39.0%, and 32.9%, respectively, at the ruminal solid passage rate of 1.84%/h. The SFSM is a good source of RDP for rumen micro-organisms; however, the SID of RUP of SFSM was lower. The DDGS and CSM are good sources of RUP for lambs to digest in the small intestine to complement ruminal microbial AA of growing lambs. Individual RUP-AA from each protein source was selectively removed by the rumen micro-organisms, especially for Trp, Arg, His, and Lys (p<0.01). The SID of individual RUP-AA was different within specific RUP origin (p<0.01). Limiting amino acid was Leu for RUP of CSM and Lys for both RUP of SFSM and DDGS, respectively. Therefore, different protein supplements with specific limitations should be selected and combined carefully in growing lambs ration to optimize AA balance.

A vegetable oil feeding history affects digestibility and intestinal fatty acid uptake in juvenile rainbow trout Oncorhynchus mykiss.

PubMed

Geurden, Inge; Jutfelt, Fredrik; Olsen, Rolf-Erik; Sundell, Kristina S

2009-04-01

Future expansion of aquaculture relies on the use of alternatives to fish oil in fish feed. This study examined to what extent the nature of the feed oil affects intestinal lipid uptake properties in rainbow trout. The fish were fed a diet containing fish (FO), rapeseed (RO) or linseed (LO) oil for 8 weeks after which absorptive properties were assessed. Differences in digestibility due to feed oil history were measured using diet FO with an indigestible marker. Intestinal integrity, paracellular permeability, in vitro transepithelial fatty acid transport (3H-18:3n-3 and 14C-16:0) and their incorporation into intestinal epithelia were compared using Ussing chambers. Feed oil history did not affect the triacylglycerol/phosphatidylcholine ratio (TAG/PC) of the newly synthesized lipids in the segments. The lower TAG/PC ratio with 16:0 (2:1) than with 18:3 (10:1) showed the preferential incorporation of 16:0 into polar lipids. The FO-feeding history decreased permeability and increased transepithelial resistance of the intestinal segments. Transepithelial passage rates of 18:3n-3 were higher when pre-fed LO compared to RO or FO. Similarly, pre-feeding LO increased apparent lipid and fatty acid digestibilities compared to RO or FO. These results demonstrate that the absorptive intestinal functions in fish can be altered by the feed oil history and that the effect remains after a return to a standard fish oil diet.

Engineering Digestion: Multiscale Processes of Food Digestion.

PubMed

Bornhorst, Gail M; Gouseti, Ourania; Wickham, Martin S J; Bakalis, Serafim

2016-03-01

Food digestion is a complex, multiscale process that has recently become of interest to the food industry due to the developing links between food and health or disease. Food digestion can be studied by using either in vitro or in vivo models, each having certain advantages or disadvantages. The recent interest in food digestion has resulted in a large number of studies in this area, yet few have provided an in-depth, quantitative description of digestion processes. To provide a framework to develop these quantitative comparisons, a summary is given here between digestion processes and parallel unit operations in the food and chemical industry. Characterization parameters and phenomena are suggested for each step of digestion. In addition to the quantitative characterization of digestion processes, the multiscale aspect of digestion must also be considered. In both food systems and the gastrointestinal tract, multiple length scales are involved in food breakdown, mixing, absorption. These different length scales influence digestion processes independently as well as through interrelated mechanisms. To facilitate optimized development of functional food products, a multiscale, engineering approach may be taken to describe food digestion processes. A framework for this approach is described in this review, as well as examples that demonstrate the importance of process characterization as well as the multiple, interrelated length scales in the digestion process. © 2016 Institute of Food Technologists®

Prediction of the amino acid digestibility of legume seeds in growing pigs: a meta-analysis approach.

PubMed

Messad, F; Létourneau-Montminy, M P; Charbonneau, E; Sauvant, D; Guay, F

2018-05-01

On pig farms, a high proportion of the cost of production comes from feed costs. However, the use of alternative ingredients such as legume seeds may help to reduce this cost. In fact, legume seeds are an important source of essential amino acids (EAA) and can therefore be an alternative to oilseed meals. However, the accurate use of these legume seeds requires a precise knowledge of the standardized ileal digestibility (SID) of EAA, which may vary depending on its botanical variety. A meta-analysis was performed on a database compiling data from 41 studies published between 1981 and 2013 and 178 dietary treatments. Models of prediction of the SID of EAA as well as the dietary concentration of digestible standardized EAA (dEAA) were obtained, based on the chemical composition of ingredients reported in the publications. The effect of the type of legume seeds (faba bean, lupin, pea and soya bean), surgical procedures (T-cannula, re-entrant cannulas, post valve T-cannulas and ileo-rectal anastomosis), and BW of pigs (BW⩽25 kg BW>25 kg) were also tested in each model. Results showed that dietary CP and crude fibre (CF) were, respectively, the best predictors of each EAA SID for faba bean, lupin and pea (R 2=0.42 to 0.89) and soya bean (R 2=0.32 to 0.77). For the dEAA content, the best prediction models included dietary CP and ADF for faba bean, lupin and pea and soya bean, respectively, with R 2 ranging from 0.66 to 0.98. Models developed in this study allow predicting the digestibility of EAA in these alternatives feedstuffs.

Verification Of The Defense Waste Processing Facility's (DWPF) Process Digestion Methods For The Sludge Batch 8 Qualification Sample

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

Click, D. R.; Edwards, T. B.; Wiedenman, B. J.

2013-03-18

This report contains the results and comparison of data generated from inductively coupled plasma – atomic emission spectroscopy (ICP-AES) analysis of Aqua Regia (AR), Sodium Peroxide/Sodium Hydroxide Fusion Dissolution (PF) and Cold Chem (CC) method digestions and Cold Vapor Atomic Absorption analysis of Hg digestions from the DWPF Hg digestion method of Sludge Batch 8 (SB8) Sludge Receipt and Adjustment Tank (SRAT) Receipt and SB8 SRAT Product samples. The SB8 SRAT Receipt and SB8 SRAT Product samples were prepared in the SRNL Shielded Cells, and the SRAT Receipt material is representative of the sludge that constitutes the SB8 Batch ormore » qualification composition. This is the sludge in Tank 51 that is to be transferred into Tank 40, which will contain the heel of Sludge Batch 7b (SB7b), to form the SB8 Blend composition.« less

In vitro gastrointestinal digestion promotes the protective effect of blackberry extract against acrylamide-induced oxidative stress

NASA Astrophysics Data System (ADS)

Chen, Wei; Su, Hongming; Xu, Yang; Jin, Chao

2017-01-01

Acrylamide (AA)-induced toxicity has been associated with accumulation of excessive reactive oxygen species. The present study was therefore undertaken to investigate the protective effect of blackberry digests produced after (BBD) in vitro gastrointestinal (GI) digestion against AA-induced oxidative damage. The results indicated that the BBD (0.5 mg/mL) pretreatment significantly suppressed AA-induced intracellular ROS generation (56.6 ± 2.9% of AA treatment), mitochondrial membrane potential (MMP) decrease (297 ± 18% of AA treatment) and glutathione (GSH) depletion (307 ± 23% of AA treatment), thereby ameliorating cytotoxicity. Furthermore, LC/MS/MS analysis identified eight phenolic compounds with high contents in BBD, including ellagic acid, ellagic acid pentoside, ellagic acid glucuronoside, methyl-ellagic acid pentoside, methyl-ellagic acid glucuronoside, cyanidin glucoside, gallic acid and galloyl esters, as primary active compounds responsible for antioxidant action. Collectively, our study uncovered that the protective effect of blackberry was reserved after gastrointestinal digestion in combating exogenous pollutant-induced oxidative stress.

[Anaerobic digestion of lignocellulosic biomass with animal digestion mechanisms].