摘要

Optimally ripened commercial cabbage kimchi is considered the main cause of enteric norovirus (NoV) outbreaks in Korea. This study investigated the effect of 1-10 kGy gamma radiation on the inactivation of murine norovirus-1 (MNV-1; initial inoculum of 5-6 log(10) PFU/ml), used as a human NoV surrogate, in kimchi. The effects of gamma radiation on the pH and acidity were also examined to address the index of quality and fermentation, respectively. Titers of MNV-1 significantly reduced (p < 0.05) in kimchi subjected to increasing gamma radiation doses: MNV-1 titers in kimchi after 1, 3, 5, 7, and 10 kGy were 4.82 (0.34-log(10) reduction), 4.45 (0.71-log(10) reduction), 4.18 (0.98-log(10) reduction), 3.71 (1.45-log(10) reduction), and 3.40 (1.76-log(10) reduction) log(10) PFU/ml, respectively. However, the values of pH (4.5-4.6) and acidity (0.6-0.7%) were not significantly different between non-irradiated and irradiated kimchi (p > 0.05). The D-value (1-log reduction) for MNV-1 in kimchi, calculated using first-order kinetics, was 5.75 kGy (R-2 = 0.98, RMSE = 0.10). Therefore, this study suggests that the use of 5.75 kGy gamma radiation in the kimchi manufacturing industry could be very effective in reducing NoV contamination by > 90% (1 log), without causing changes in quality and fermentation.

  • 出版日期2017-10