Capsaicinoids reduce the viability of a norovirus surrogate during kimchi fermentation

The present study investigated the survival of murine norovirus (MNV) during the fermentation of cabbage kimchi and baek kimchi at different temperatures. Changes in MNV titer, lactic acid bacteria (LAB) count, capsaicinoid and organic acid content, pH, salinity, and acidity were measured for 6 weeks. MNV titer was reduced to a greater degree during storage at 10 °C (P < 0.01) than at 4 °C. The reduction in titer was also greater for cabbage kimchi (1.57 ± 0.12 log10 PFU/g) than for baek kimchi (0.61 ± 0.13 log10 PFU/g). LAB, capsaicin (CAP), dihydroCAP, lactic acid, acetic acid, and acidity were negatively correlated, whereas pH was positively correlated with MNV titer for both types of kimchi during fermentation. Moreover, CAP levels strongly correlated with MNV titer at 4 °C (−0.973) and 10 °C (−0.969). Thus, the presence of CAP could inhibit MNV survival during kimchi fermentation.