Effect of Ozone and Gamma Irradiation for Eliminating the Contaminated Microorganisms in Food Materials for Kimchi Manufacturing

Food materials for kimchi manufacturing were treated by ozone or gamma irradiation to reduce the number of contaminated microorganisms before the manufacturing of kimchi. Counts of total aerobic bacteria, yeast and mold were and in the food materials, respectively. After treatment with ozone , the total aerobic bacteria were reduced to 1 log cycle or more, in a dose-dependent manner. In comparison, gamma irradiation was superior to ozone treatment. Especially, irradiation of 5 kGy fully eliminated the yeast and mold attached in the food materials for kimchi manufacturing. The contents of ascorbic acid and total and reducing sugar were not affected by ozone or gamma irradiation. Taken together, it is suggested that microorganisms contaminated on materials for kimchi manufacturing could be substantially reduced by ozone (up to 6 ppm) and gamma irradiation (up to 5 kGy), without effect on the nutritional contents.