Sample records for radurization
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Conventional taxonomy of lactobacilli surviving radurization of meat.
Hastings, J W; Holzapfel, W H
1987-03-01
All of the 113 catalase-negative, Gram-positive, rod-shaped strains isolated from radurized minced beef (5 kGy) were homofermentative, non-thermophilic, and belonged to the sub-genus Streptobacterium. The majority of the strains (100) were identified as Lactobacillus sake. These were divided into four sub-groups based on their sugar fermentation pattern: group IA1 (melibiose (+), maltose (-), amygdalin (-), 76 strains); group IA2 (melibiose (+), maltose (-), amygdalin (+), 14 strains); group IB1 (melibiose (+), maltose (+), amygdalin (+), four strains); group IB2 (melibiose (+), maltose (+), amygdalin (-), six strains). Of the remaining strains, two produced L(+)-lactic acid and were identified as L. farciminis, three were identified as L. curvatus and eight showed characteristics of both L. sake and L. curvatus and were designated 'L. sake/curvatus.' With one exception, all strains were aciduric and relatively insensitive to the chemical preservatives tested. Most L. sake strains produced significant amounts of H2O2. Electron microscopy confirmed a possible relationship between the thickness of the cells and radiation resistance. The problems and limitations of this type of taxonomic study and possible reasons for the predominance of L. sake species in radurized meat are discussed.
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Health protection and food preservation by gamma irradiation
NASA Technical Reports Server (NTRS)
1976-01-01
Results of several major studies on food systems for space missions beginning with Apollo 12 through Apollo-Soyuz and investigations of the application of irradiation to food for manned space flight are reported. The study of flight food systems involved the application of radurization (pasteurizing levels) doses of gamma irradiation to flour and bread supplied by Pepperidge Farms in advance of the missions. All flights from Apollo 12 through 17 carried irradiated fresh bread. On Apollo 17, cooperation with Natick Laboratories permitted the introduction of a ham sandwich using irradiated bread and irradiated sterile ham. Investigations centered on irradiated bread were conducted during the course of these missions. Studies were applied to the concept of improving fresh bread from the point of view of mold inhibition. The studies considered how irradiation could best be applied at what levels and on a variety of bread types. Throughout the studies of the application of gamma irradiation the emphasis was placed upon using low levels of irradiation in the pasteurizing or radurizing doses--under a Megarad. The primary goal was to determine if a public health benefit could be demonstrated using radurization along with food preservation and food quality improvements. The public health benefit would be parallel to that of pasteurization of milk as a concept. Publications are included providing the details of these observations, one dealing with the flour characteristics and the other dealing with the influence on fresh bread types. These demonstrate the major findings noted during the period of the studies examining bread.
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Factors determining the viability of radiation processing in developing countries
NASA Astrophysics Data System (ADS)
van der Linde, HJ; Basson, RA
In the fifteen years since the introduction of radiation processing to South Africa, four commercial irradiation facilities have been established. These are involved in the processing of a large variety of products, from syringes and prostheses to strawberries and sugar yeast. Three of the facilities are devoted mainly to food irradiation and several thousand tonnes are now processed annually. During this period it was repeatedly experienced that the successful introduction of radiation processing in general, and food radurization in particular, on a commercial scale was critically dependent on the following factors: acceptance by the producer, industry and consumer; initial capital expenditure; running costs and overheads in general; and continous throughput. All of these factors contribute to the processing cost which is the ultimate factor in determing the value/price ratio for the potential entrepreneur and customer of this new technology. After a market survey had identified the need for a new food irradiation facility to cope with the growing interest in commercial food radurization in the Western Cape, the above-mentioned factors were of cardinal importance in the design and manufacture of a new irradiator. The resulting batch-pallet facility which was commisioned in August 1986, is rather inefficient as far as energy utilization is concerned but this shortcoming is compensated for by its low cost, versatility and low hold-up. Although the facility has limitations as far as the processing of really large volumes of produce is concerned, it is particularly suitable not only for developing countries, but for developed countries in the introductory phase of commercial food radurization.
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Radurization of commercial freshwater fish species
NASA Astrophysics Data System (ADS)
Chuaqui-Offermanns, N.; McDougall, T. E.; Sprung, W.; Sullivan, V.
The effect of radurization on the shelf life of fresh Whitefish obtained through ordinary commercial channels has been determined. Whitefish fillets irradiated at 1.2 kGy and stored at 3°C have a shelf life three times longer than the unirradiated fish. When the fish was irradiated at 0.82 kGy a two fold shelf-life extension was obtained. The shelf life was estimated by sensory, chemical and microbiological evaluations. Sensory evaluation involved organoleptic assessment of raw and cooked samples. Since freshwater fish do not contain trimethylamine oxide (TMAO), alternate tests for freshness were required. It was found the determination of hypoxanthine and total volatile acid number (VAN) are excellent tests for freshness and quality of freshwater fish; thus, these analyses were adopted. The degree of radiation-induced lipid oxidation was measured by the thiobarbituric acid test (TBA). It was found at doses of 0.82 and 1.2 kGy the TBA number remained within acceptable limits in all samples. Microbiological analyses consisted of the total microbial load assessment in the sample, as well as Pseudomonas and total psychrotrophic counts. The estimated shelf lives as determined by the three separate evaluations were in very good agreement.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Faizur Rahman, A.T.M.
1975-03-01
A review is given on the activities of the laboratories of the Atomic Energy Centre, Dacca in the field of food irradiation. A $sup 60$Co gamma source was used for these studies. The effects of irradiation on rice grains and rice starch is investigated as well as the radurization of fish, the extension of shelf-life of fresh mango juice by combined heat and irradiation treatment, and inhibition of sprouting of potatoes by irradiation. (MG)
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Hastings, J W; Holzapfel, W H; Niemand, J G
1986-10-01
Of 113 lactobacilli isolated from radurized (5 kGy) minced meat, 7 Lactobacillus sake strains, 1 L. curvatus strain, and 1 L. farciminis strain were used for radiation resistance studies in a semisynthetic substrate (i.e., modified MRS broth). Five reference Lactobacillus spp., one Staphylococcus aureus strain, and one Salmonella typhimurium strain were used for comparative purposes. All L. sake isolates exhibited the phenomenon of being more resistant to gamma-irradiation in the exponential (log) phase than in the stationary phase of their growth cycles by a factor of 28%. Four references strains also exhibited this phenomenon, with L. sake (DSM 20017) showing a 68% increase in resistance in the log phase over the stationary phase. This phenomenon was not common to all bacteria tested and is not common to all strains with high radiation resistance. Four L. sake isolates and three reference strains were used in radiation sensitivity testing in a natural food system (i.e., meat). The bacteria were irradiated in minced meat and packaged under four different conditions (air, vacuum, CO2, and N2). Organisms exhibited the highest death rate (lowest D10 values [doses required to reduce the logarithm of the bacterial population by 1] ) under CO2 packaging conditions, but resistance to irradiation was increased under N2. The D10 values of the isolates were generally greater than those of the reference strains. The D10 values were also higher (approximately two times) in meat than in semisynthetic growth medium.
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Hastings, J W; Holzapfel, W H; Niemand, J G
1986-01-01
Of 113 lactobacilli isolated from radurized (5 kGy) minced meat, 7 Lactobacillus sake strains, 1 L. curvatus strain, and 1 L. farciminis strain were used for radiation resistance studies in a semisynthetic substrate (i.e., modified MRS broth). Five reference Lactobacillus spp., one Staphylococcus aureus strain, and one Salmonella typhimurium strain were used for comparative purposes. All L. sake isolates exhibited the phenomenon of being more resistant to gamma-irradiation in the exponential (log) phase than in the stationary phase of their growth cycles by a factor of 28%. Four references strains also exhibited this phenomenon, with L. sake (DSM 20017) showing a 68% increase in resistance in the log phase over the stationary phase. This phenomenon was not common to all bacteria tested and is not common to all strains with high radiation resistance. Four L. sake isolates and three reference strains were used in radiation sensitivity testing in a natural food system (i.e., meat). The bacteria were irradiated in minced meat and packaged under four different conditions (air, vacuum, CO2, and N2). Organisms exhibited the highest death rate (lowest D10 values [doses required to reduce the logarithm of the bacterial population by 1] ) under CO2 packaging conditions, but resistance to irradiation was increased under N2. The D10 values of the isolates were generally greater than those of the reference strains. The D10 values were also higher (approximately two times) in meat than in semisynthetic growth medium. PMID:3096207
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Hastings, J.W.; Holzapfel, W.H.; Niemand, J.G.
1986-10-01
Of 113 lactobacilli isolated from radurized (5 kGy) minced meat, 7 Lactobacillus sake strains, 1 L. curvatus strain, and 1 L. farciminis strain were used for radiation resistance studies in a semisynthetic substrate (i.e., modified MRS broth). Five reference Lactobacillus spp. one Staphylococcus aureus strain, and one Salmonella typhimurium strain were used for comparative purposes. All L. sake isolates exhibited the phenomenon of being more resistant to gamma-irradiation in the exponential (log) phase than in the stationary phase of their growth cycles by a factor of 28%. Four reference strains also exhibited this phenomenon, with L. sake (DSM 20017) showingmore » a 68% increase in resistance in the log phase over the stationary phase. This phenomenon was not common to all bacteria tested and is not common to all strains with high radiation resistance. Four L. sake isolates and three reference strains were used in radiation sensitivity testing in a natural food system (i.e., meat). The bacteria were irradiated in minced meat and packaged under four different conditions (air, vacuum, CO/sub 2/, and N/sub 2/). Organisms exhibited the highest death rate (lowest D/sub 10/ values (doses required to reduce the logarithm of the bacterial population by 1) under CO/sub 2/ packaging conditions, but resistance to irradiation was increased under N/sub 2/. The D/sup 10/ values of the isolates were generally greater than those of the reference strains. The D/sup 10/ values were also higher (approximately two times) in meat than in a semisynthetic growth medium.« less
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[Secondary amyloidosis in patients with rheumatoid arthritis(RA)].
Inada, Shinichi
2002-12-01
The amyloidoses are a group of protein deposition diseases in which amyloid proteins composed of insoluble fibrils are deposited in various organs. Most cases of the secondary amyloidosis(AA amyloidosis) in which amyloid A(AA) protein is deposited followed by uncontrolled, long term RA(duration 7 to 10 years). It has been revealed that the multi-organ dysfunction associated with AA amyloidosis causes the deterioration of RA prognosis. Since the mechanism of amyloid protein deposition is still unknown, the diagnosis of AA amyloidosis is difficult and there is no fundamental therapy for it; there are only supportive therapies for the malfunction of involved organs.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Schulman, M.
1975-03-01
A report is given of the activities of the USA in the field of food irradiation. The existing facilities and the dosimetric procedures are described including several new dosimeter systems. Chemical changes due to irradiation were studied in a lot of foodstuffs such as soybeans, shrimps, meat, and chicken- based pet food products as well as in model systems. Effects of irradiation on the content of Clostridium botulinum in foodstuffs were investigated. Studies in radicidation, radurization and the combination of ionizing radiation with UV, heat, or microwave treatment were performed. Radiopreservation was studied in a lot of foodstuffs. Extensive feedingmore » studies were performed in rats, mice and dogs to assess the wholesomeness of irradiated beef, strawberries and papayas. Furthermore, a short review is given of the present legislation and clearances and the economics. (MG)« less
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The studies and legislation on radiation disinfestation, Taiwan
NASA Astrophysics Data System (ADS)
Fu, Ying-Kai; Chang, Ming-Shia; Hu, Tsan
The studies of radiation disinfestation at the Institute of Nuclear Energy Research cover four harmful cereal insects, tobacco beetles, and dry beam insects etc. The four most harmful insects of stored rice in Taiwan are Sitophilus zeamais Mostschulsky. Rhyzopertha dominica F. Tribolitum custaneum Herbst, and Sitotroga cerealella Oliver. Adults, eggs or larvae of these insect pests were irradiated by 60Co gamma rays. The results show that 400 Gy of gamma irradiation could completely control these four species of pests in stored rice. Tobacco beetle ( Lasioderma serricorne F.) is the most serious pest of stored tobaccos in Taiwan. The aim of this study is to use 60Co gamma ray irradiation to control tabacco beetles of stored tobaccos. The results are (1) the sterility dose of adults irradiated by 60Co gamma rays is 96 Gy, with an immediate lethal dose of 5 kGy and a total death 18 days post-irradiation at 2 kGy; (2) the immediate lethal dose of larvae is 4 kGy, with a nonemerging dose of 2 kGy; (3) adults could not emerge from the pupae irradiated by 60Co gamma rays at 2 kGy; (4) larvae could not be hatched from the oval stage irradiated by 250 Gy. In conclusion, 60Co gamma ray irradiation of 2 kGy could be applied to stored tobaccos to control tobacco beetles with total disinfestation of larvae and adults and complete nonappearence of F 1 generation 18 days post-irradiation. The cowpea weevil ( Callosobruchus chinensis L.) was one of the most serious pests of stored dry beans in Taiwan. It caused damage during larval stage. Treatment of gamma irradiation with 10 Gy to eggs of the cowpea weevil prevented their hatching; a dose of 20 Gy applied to larvae prevented their development. The sterility dosage aginst the pupae and adult were 20 and 50 Gy, respectively. It is concluded that a 50 Gy gamma irradiation could be applied to stored dry beans to control the cowpea weevils. The food irradiation legislation has been approved by the Department of Health, Taiwan, R.O.C. in January 1983, not only on sprout inhibition on potatoes, sweat potatoes, shallot, onions, garlic within 150 Gy, radurization on papaya, mango within 1.5 kGy, but also on radiation disinfestation on rice, tobacco with 1 kGy and small red bean, mungbean within 200 Gy. The prospects for the radiation disinfestation are very promising and bright in Taiwan, R.O.C. and all preparation are being made to adopt this technology from research to commercial scale.