[en] The changes in bacteriological quality and acidity of Nham (fermented pork sausage) at each day of fermentation (1-5 days) were investigated. The effect of gamma irradiation at dose of 1, 2 and 3 kGy on bacteriological quality of Nham were also studied. It was found that there was little change in total viable count of Nham during the five days of storage. The initial amount of Enterobacteriaceae of Nham decreased by 2 log cycles whereas, the initial amount of Lactobacillus increased by 2 log cycles. The amount of lactic acid in Nham increased with increasing storage time. Irradiation at doses of 2 and 3 kGy resulted in 2 and 3 log cycles reduction of total viable bacterial count, Enterobacteriaceae, Lactobacillus, yeasts and molds. Sensory quality evaluation showed no significant differences in colour, odor, flavor and texture between non-irradiated and irradiated Nham. The amount of lactic acid in irradiated Nham was found to be lower than the amount in the non-irradiated one at the same period of storage. The optimal time for best palatable Nham is between 1-3 days of fermentation prior to irradiation at 2 kGy. Irradiated Nham can be kept for 10 days at room temperature or 9 weeks in refrigerated condition (5+-2⁰C)

[en] Pilot scale storage tests were carried out in co-operation with commercial onions traders in the years 1986 and 1987 to evaluate the efficacy of irradiation for sprout inhibition of onions under actual commercial stored in commercial cold storage at 1-10 degrees C and 70-90% relative humidity. The results show that irradiation reduce sprouting in onions by 11 and 40 per cent and weight loss by 3 and 5 per cent after 5 and 6 months of storage, respectively. Storage losses are minimum when radiation is applied within two weeks of harvest. A maximum storage life of six months as against five months for controls is attained. Post cold storage life at ambient temperature for irradiated onions after withdrawal from cold storage is one week longer than that of non-irradiated controls. The radio inhibition process is technically feasible and economically justified as a profit can be made during the extended storage period. Marketing trials of irradiated onions conducted during and after termination of storage revealed no adverse comments from consumers and retailers/wholesalers. Wholesalers.retailers and consumers preferred irradiated onions because of their better physical quality and longer marketable life

[en] On the study of microbiological quality of 12 samples of chicken meat produced in several different area in Japan, total aerobic bacteria were determined as 8x10⁴ to 5x10⁷ per g. Coliforms were 8x10¹ to 3x10⁴ per g with Escherichia, Proteus and Klebsiella. Dominant putrefactive bacteria were determined as lactic acid bacteria, Pseudomonas and Flavobacterium. The shelf life of irradiated chicken meat at 1 kGy extended more than 6 days at 10degC storage. Irradiation of chicken meat at 3 kGy extended 12 days. Coliforms were disappeared at 1 kGy irradiation

[en] On the study of microbiological quality of 12 samples of chicken meat produced in several different area in Japan, total aerobic bacteria were determined as 8x10⁴ to 5x10⁷ per g. Coliforms were 8x10¹ to 3x10⁴ per g with Escherichia, Proteus and Klebsiella. Dominant putrefactive bacteria were determined as lactic acid bacteria, Pseudomonas and Flavobacterium. The shelf life of irradiated chicken meat at 1 kGy extended more than 6 days at 10degC storage. Irradiation of chicken meat at 3 kGy extended 12 days. Coliforms were disappeared at 1 kGy irradiation. (author)

[en] Pilot storage tests were carried out in co-operation with commercial onion traders in 1986-1988 to evaluate the efficacy of irradiation for sprout inhibition in onions and garlic under actual commercial storage conditions. Slightly over 800 tonnes of onions were irradiated 10-50 days after harvest at average doses of 75 and 100 Gy and stored in commercial cold storage at 1-10 deg. C and 70-90% relative humidity. The results show that irradiation reduced sprouting by 11 and 40% and weight loss by 3 and 5% after 5 and 6 months of storage, respectively. Storage losses were least when radiation was applied within 2-4 weeks of harvest. A maximum storage life of 6 months was attained, as against 5 months for the controls. The post-storage life of the irradiated onions at ambient temperature after withdrawal from cold storage was 1 week longer than that of the non-irradiated controls. Garlic irradiated with 70 Gy can be stored in commercial cold storage for 9 months without sprouting. The radioinhibition process is technically feasible and economically justified, since a profit can be made during the extended storage period. The marketing trials of the irradiated onions and garlic, conducted during and after termination of storage, elicited no adverse comments from the consumers, retailers or wholesalers. All preferred irradiated onions because they had a better physical quality and a longer marketable life. (author). 13 refs, 1 fig., 10 tabs

[en] The impact of gamma irradiation with doses between 0 and 8 kGy on microbiological quality of chicken meat produced in Japan and micro flora change of irradiated chicken meat were studied. Radiation at the dose 2 kGy resulted in 4 log cycles reduction of total aerobic bacteria, 5 - 6 log cycles reduction of lactic acid bacteria and 2 log cycles reduction of fungi and yeasts. For the coliforms, it could be eliminated below detectable level by irradiation dose of 1 kGy. For the chicken flora-analysis, it was found that chicken of each area had their own specific microbial community structure. Flavobacterium and Pseudomonas were found to be dominant organisms in the microflora of Japanese chicken meat. Irradiation with dose 2 kGy resulted in disappearance of Lactobacillus and Pseudomonas. The microorganisms which dominated in irradiated chickens with doses of 2 kGy and higher were Psychrobacter and yeast. These studies support the view that radiation improves the microbiological quality of chicken meat and substantiate that radiation does not present hazard resulting from a change in the microflora of irradiated chicken

[en] The possible use of gamma irradiation at doses of 1.6 to 4.0 kGy to improve bacteriological quality of frozen chicken was investigated. The effects of gamma irradiation on salmonella viability in frozen chicken and on sensory quality of frozen chicken were also evaluated. D₁₀-values for different isolated strains of salmonella in frozen chicken varied from 0.41 to 0.57 kGy. A dose of 4 kGy is required for a seven log cycle reduction of salmonella contamination in frozen chicken. Approximately 21 per cent of frozen chicken examined were contaminated with salmonella. Salmonella typhimurium, salmonella virchow, and salmonella java were predominant. Irradiation of frozen chicken at a minimum dose of 3.2 kGy eliminated salmonella, coliform, Escherichia coli, and Staphylococcus aureus and, in addition, reduced baterial load by 2 log cycles. Faecal streptococci was still present in a 3.2 kGy samples but in a very small percentage and the count was not over 100 colonies per g. Discoloring of chicken meat was noted after a 2 kGy treatment. The sensory quality of frozen chicken irradiated at 3 and 4 kGy tended to decrease during frozen storage but was within the acceptable range on a nine point hedonic scale even after eight months of frozen storage. Dosage at 3.2 kGy appeared to be sufficient for improving bacteriological quality of frozen chicken

[en] Seven brands of shrimp paste (Kapi) sold in supermarkets were investigated for microbiological quality and quantity of salt. The effect of gamma radiation at dose 1 to 6 kGy on microbiological quality and on sensory quality of shrimp paste were also evaluated. Total viable bacterial counts of surveyed samples ranged from 1.20 x 10⁴ to 4.00 x 10⁵ colony forming unit (cfu) per gram and no detectable number of Enterobacteriaceae, coliforms, Faecal coliforms, Escherichia coil, Salmonella, Vibrio parahaemolyticus and Staphylococcus aureus was found. The most probable number (MPN) per gram of Clostridium perfringens is ranged from 9 to 240. Percentage of salt in surveyed shrimp pastes was rather high (ranged from 19.08 to 25.08). Radiation with 4 kGy resulted in 2 log cycles reduction of total viable bacterial counts and 2-4 log cycles reduction of halophilic bacteria, but no decrease in the most probable number per gram of CI. perfringens. A dose of 6 kGy gamma radiation was adequate for decreasing the MPN per gram of C. perfringens. No significant change in sensory scores for odour and flavor was observed in irradiated shrimp paste. Only in irradiated at dose of 6 kGy was the significant change in colour observed

[en] Quality of non-irradiated and irradiated frozen shrimp after shipping trial from Thailand to the Netherlands were investigated. Commercial frozen shell on headless shrimp and pre-cooked and peeled shrimp were irradiated with 0, 2, and 3 kGy at the Office of Atomic Energy for Peace (OAEP), Thailand, and transported by sea to the International Facility for Food Irradiation Technology (IFFIT), the Netherlands. It was found that both types of frozen shrimp before shipment are of good quality. Radiation with 3 kGy resulted in 2-3 log cycles reduction of mesophilic and psychrotrophic colony counts and caused no significant change in sensory quality. The irradiated products were found to be free from coliforms, faecal coliforms, Escherichia coli, salmonella, vibrio parahaemolyticus and Staphylococcus aureus. There was no increase in bacterial count in irradiated frozen shrimps after two months of transportation. The results of flora analysis show that radiation does not present any hazard resulting from a shift in the microflora. The surviving microflora in both types of irradiated frozen shrimp consisted mainly of Micrococcus spp.. Besides, irradiation with dose of 3 kGy did not affect the sensory quality of the frozen shrimp within duration of transportation. It can be concluded that irradiation improves the bacteriological quality of frozen shrimp for transportation to the Netherlands

[en] Gnathostoma spinigerum infective larvae were found to be very resistant to gamma ray. The larvae were still viable, motile and capable to infect white mice with no observable abnormality in both internal and external structures and their sizes after exposure to 0-7.0 KGy of gamma ray. At doses of 0, 0.3, 0.6, 1.0, 1.5, 2.0, 3.0, 5.0 and 7.0 KGy, the infective rates were 72%, 78%, 64%, 54%, 28%, 42%, 26%, 14% and 5% respectively. The infective rates of the irradiated larvae exposed to 8 KGy and 10 KGy of irradiation in mice became zero. The reduction of motility and infectivity was first observed after exposure of larvae to 1.5 KGy of gamma ray. It was also found that motility and infectivity decreased in relationship to the higher doses of gamma ray. At 10.0 KGy of irradiation which was the highest dose used in this experiment could not devitalize the larvae but inhibit infectivity. Irradiation of the larvae mixed in food prepared from fishes at 8 KGy was proved to inhibit the infectivity. On the study, the dose of 8.0 KGy was suggested to be the minimum effective dose that inhibited the infectivity of the infective stage. To confirm the effective dose, the mixture of the infective larvae and Somfuk, a local food, was treated by 8 KGy and these irradiated larvae precisely lost their infectivity in mice