[en] Irradiation of garlic on a pilot scale and storage in cold room under commercial condition was carried out in co-operation with garlic trader in 1986-1987. Garlic bulbs from local cultivars were irradiated seven weeks after harvest with average dose of 70 Gy and stored for nine months at low (1-7 degrees C) and ambient (25-34 degrees C) temperatures. The treatment proved to be effective in controlling sprouting and in reducing weight loss and rotting. After 9 months of cold storage the weight loss and rotting of irradiated bulbs were reduced by 18 and 13 per cent. The radio inhibition process is technically feasible and economically justified as a profit can be made during the extended storage period. Small scale marketing trials of irradiated garlic conducted during and after termination of storage revealed no adverse comments from consumers

[en] The possible use of gamma irradiation at doses of 2 and 3 kGy to improve bacteriological quality of frozen shrimp was investigated. The effects of gamma irradiation on salmonella viability in frozen shrimp and on sensory quality of frozen shrimp were also evaluated. Treatment of frozen shrimp at 3 kGy reduced bacterial load by 2 log cycles and eliminated Enterobacteriaceae, E. coli, V. parahaemolyticus, and S. aureus. Coliform was still present in a 3 kGy treated samples but in a very small percentage and the count was less than 10 cell/g. Salmonella was not detected in either irradiated or non-irradiated frozen shrimp. A difference in radiation resistance was noted among five salmonella serotypes tested. S. lexington was the most resistant and S. anatum was the least resistant. Salmonella resistance was higher in frozen inoculated shrimp than in refrigerated inoculated shrimp. A dose of at least 4.2 kGy is required for a seven log cycle reduction of salmonella contamination in frozen shrimp. Off-flavors were produced in frozen shrimp irradiated at 4.2 kGy but diminished during subsequent frozen storage. However, irradiated frozen shrimp was of acceptable quality for at least four months. Dosage at 3 kGy appeared to be sufficient for improving bacteriological quality of frozen shrimp

[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] The effects of gamma irradiation at doses of 2 and 3 kGy on bacteriological, chemical and sensory quality of fresh ground beef were investigated and compared with non-irradiated controls. Changes in bacterial counts, pH, lipid oxidation (TBA number) and sensory quality of those samples were determined on the next day after irradiation and storage at 3 degree celsius. The results indicated that irradiation at 2 and 3 kGy reduced total aerobic bacteria counts by 1-2 and 1-3 log cycles, respectively. Lactobacillus spp. was also decreased significantly. Irradiation at 2 kGy eliminated Escherichia coli and Staphylococcus aureus. Salmonella spp. was not detected in both non-irradiated and irradiated samples. TBA number of irradiated fresh ground beef ball was significantly increased whereas pH values tended to be decreased. The sensory test showed that color and odour scores of fresh irradiated samples and colour, odour, flavour and texture of fried irradiated samples were not significantly changed from those of non-irradiated controls and were accepted by the panelists. Dosage at 2 kGy appeared to be sufficient for improvement of bacterial quality of fresh ground beef

[en] The effects of gamma irradiation at doses of 1-3 kGy on bacteriological, chemical and sensory quality of beef ball from commercial producer were investigated. The shelf-life at 3 degrees C of beef ball, irradiated at 0, 0.9 and 1.8 kGy was determined and compared to those packed under atmospheric condition. Two replications of beef ball were carried out. Changes in mesophilic count, psychrotrophic count, Lactobacillus count, pH, TB A number and sensory quality of irradiated and non-irradiated beef ball were determined every 1, 7, 10, 14, 21 and 24 days. The results indicated that irradiation of beef ball at 2 kGy eliminated Escherichia coli, Staphylococcus aureus and reduced bacterial load by 2-3 log cycles. Salmonella sp. was not detected in both irradiated and non-irradiated products. Significant changes in odor and TB A number were observed after 1 kGy treatment. The shelf-life of non-irradiated beef ball based on psychrotrophic count was approximately 7 days compared with 21 and 24 days for beef ball irradiated at 0.9 and 1.8 kGy. The sensory quality of irradiated beef ball tended to decrease during storage but was within the acceptable range even after 24 days of storage at 3 degrees C. Packing of beef ball under vacuum or atmospheric condition gave similar results. Dosage at 2 kGy appeared to be sufficient for improving bacteriological quality and increasing the shelf-life of beef ball without affecting sensory quality

No abstract available

[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] Two lots of frozen precooked shrimps from Thailand ''PENAEUS MONODON'' Black tiger variety were irradiated at 1.8 to 3.6 kGy. This way, it was hoped to compare the effects of gamma irradiation on the microbiological quality and the organoleptic properties of frozen precooked shrimps after transportation from Thailand to Canada. The results indicated that the extension of shelf-life based on mesophiles content was from 33 days for the control to more than 47 days for the irradiated shrimps stored at 3 ± 1^oC. The results of sensory evaluation gave slightly fresher odor for the control than the irradiated shrimps. On day one, this effect was more apparent. The results of hedonic tests showed that the irradiated shrimps were acceptable during storage. In conclusion, the results demonstrate that the combined treatments (freezing plus irradiation) of precooked shrimps are useful for increasing the storage life of shrimps without affecting consumer acceptability. (Author)

[en] Two lots of frozen precooked shrimps from Thailand ''PENAEUS MONODON'' Black tiger variety were irradiated at 1.8 to 3.6 kGy. This way, it was hoped to compare the effects of gamma irradiation on the chemical and physical qualities of frozen precooked shrimps after transportation from Thailand to Canada. The results indicated that the color measurement expressed in terms of lightness (L*) showed a relative stability during storage of processed shrimps. However, based on the value (θ) a more intense red color was observed for the control and the reference. The cooked irradiated and nonirradiated shrimps presented a significant decrease (p ≤ 0.01) of 22% in firmness during the first week of storage. Thus, irradiation did not impair the firmness of shrimps after treatment or during storage. Also, based on the statistical analysis, the irradiation treatment did not affect the content of amino acids of precooked shrimps. (Author)

[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