The effect of gamma irradiation on the stability and hygienic quality of semi-dried Pacific saury (Cololabis seira) flesh

This study was carried out to investigate the effects of gamma irradiation on the improvement of hygienic quality and the extension of shelf life of Kwamegi prepared from semi-dried Pacific saury (Cololabis seira) flesh. Commercial Kwamegi was purchased from a domestic market, vacuum-packaged, and irradiated to doses of 0, 3, 5, 7 or 10 kGy. Non-irradiated Kwamegi rapidly deteriorated during storage at 5degreesC, and some bacteria presumed as Salmonella and/or Shigella species were detected using selective medium. However, the total viable cells and presumptive pathogens were reduced with increased radiation dose, and a dose level of 7-10 kGy was considered to be an optimum and effective dose for the preservation of Kwamegi. Thiobarbituric acid values did not differ, regardless of irradiation dose and storage time. Sensory evaluation results were not different in all samples immediately after irradiation. After 60-day storage, the sensory quality of irradiated Kwamegi was adequate; however the quality of the control deteriorated. (C) 2002 Elsevier Science Ltd. All rights reserved.