Gamma irradiation at 20 kGy was apploed to salted and fermented shrimps to evaluate its possible genotoxicity. The genotoxicity of irradiated salted and fermented shrimps was evaluated by Salmonella typhimurium reversion assay, chromosomal aberration test and in vivo micronucleus assay. The results were negative in the bacterial reversion assay with S. typhimurium TA98, TA100. No mutagenicity was detected in the assay both with and without metabolic activation. In chromosomal aberration tests with CHL cells and in vivo mouse micronucleus assay, no significant difference in the incidences of chromosomal aberration and micronuclei was observed between nonirradiated and 20 kGy-irradiated salted and fermented shrimps. These results indicate that salted and fermented shrimps irradiated at 20 kGy did not show any genotoxic effects under these experimental conditions.

The effect of irradiation of heat treatment either alone or in combination on the shelf-life of mixed mountain edible herb drinks (MMEHD) was investigated during storage. The MMEHD made from fresh Spuriopinella bracycarpar, Ligularia fischeri and Aster scaber was gamma -irradiated at doses of 0.1 kGy to 1 kGy. Microbial population, color change, vitamin C content, and sensory quality were evaluated during storage at 4, 25 and 35oC. Heated MMEHD induced the growth of total counts, mold and yeast as compared to the non-heated MMEHD. While some reduction in the microbial growth was observed in 1kGy-irradiated groups of both with or without heating. In both groups, L and b values decreased, but a value increased during storage. Also, heating drinks showed increased L and b values and reduced a value, compared to the non-heating drinks. Non-heated drinks showed 82% loss of vitamin C, whereas 25% loss of vitamin C was occurred in the irradiated drinks during storage at 4oC for 4days. In the meanwhile, non-irradiated heating drinks showed 99% loss of vitamin C, but irradiated heating drinks showed 58-65% reduction of vitamin C. Non-irradiated drinks without heating showed more bright color than irradiated ones, but irradiated drinks showed more enhanced brightness during storage. Also, irradiated drinks showed better falvor, sensory quality, and overall acceptability than non-irradiated drinks.