INACTIVATION OF MURINE NOROVIRUS ON STRAWBERRIES USING PULSED LIGHT

Norovirus have become the predominant viral causes of foodborne illnesses worldwide, the foodborne happened mainly in schools and childcare facilities, strawberries were identified as the most likely vehicle according to the analytical epidemiological studies. So this study evaluated the efficacy of pulsed light (PL) treatments to inactivate murine norovirus (MNV-1), a human norovirus surrogate, inoculated onto strawberries. Two different PL treatments were evaluated - 3 Hz and 100 Hz PL treatments. PL treatments inactivated 1.5-3 log PFU/g MNV-1 on strawberry in a time-dependent manner of 30-120 s at both 3 and 100 Hz. The inactivation efficacy of PL is dependent on the pulsed frequency received with both PL treatment parameters. It can achieve 1.7 log PFU/g reduction after 120 s 3 Hz PL treatment at the distance of 8.3 cm from the quartz window, on the other hand, MNV-1 was inactivated by 3.2 log PFU/g after 120 s exposure to 100 Hz PL treatment at the distance of 8.3 cm from the quartz window. These results demonstrated that higher inactivation effect of MNV-1 on strawberry was associated with higher frequency of PL treatment. Therefore, this technology could be used to improve the microbial safety of fresh strawberries.M.S. in Food Process Engineering, December 201