Effects of sodium hypochlorite and peroxyacetic acid on the inactivation of murine norovirus-1 in Chinese cabbage and green onion

Chinese cabbage and green onion are important vegetables for a variety of foods in Korea. Because these vegetables are used after being briefly washed with water, the disinfecting washing needs to be applied to inactivate norovirus. We evaluate the effectiveness of sodium hypochlorite (NaOCl) and peroxyacetic acid (PAA) on inactivation of murine norovirus-1 (MNV-1) in Chinese cabbage and green onion. NaOCl treatment with 400 ppm chlorine decreased MNV-1 by more than 1 log(10) in both samples. One minute treatment with PAA at 300 ppm reduced MNV-1 by approximately 1 log(10) in Chinese cabbage and 1.2 log(10) in green onion, respectively. When concentrations permissible for use on food-contact surfaces by Korea Ministry of Food and Drug Safety (MFDS) were used to disinfect the vegetables, 300 ppm of PAA was significantly (P < 0.05) more effective than 200 ppm of NaOCl. Although color was unchanged with higher concentrations of NaOCl and PAA, increasing the concentration of NaOCl gradually reduced hardness values and produced an unpleasant chlorinated-odor in Chinese cabbage stems. Overall, our study indicates that PAA treatment at 300 ppm for green onion or 500 ppm for Chinese cabbage is suitable for inactivating MNV-1, and does not adversely affect the food quality.