Thermal Inactivation of Murine Norovirus‐1 in Suspension and in Dried Mussels (Mytilus edulis)

The current study examined the effects of three different temperatures (60, 85 and 100C) and duration of heat treatment (ranging from 1 min at 100C to 30 min at 60C) on murine norovirus-1 (MNV-1) as a human norovirus model both from viral suspension and experimentally contaminated dried mussels. The log10 tissue culture infectious dose (TCID)50/mL values of 3.03, 3.69, 4.35, 5.05 and 5.88 were reduced in suspensions at 60C for 5 min, 60C for 15 min, 60C for 30 min, 85C for 3 min and 85C for 6 min, respectively. The log10TCID50/mL values of 0.78, 2.00, 3.35, 1.95 and 3.20 were reduced from dried mussels under the same conditions, respectively. Complete inactivation of MNV-1 from both suspension and dried mussel was achieved by 10 and 15 min at 85C, respectively, and by treatment for 1 min at 100C. At 60, 85 and 100C, the 1-log10TCID50 inactivation of MNV-1 from both suspension and dried mussels was 7.79 and 9.01 min, 1.11 and 3.06 min and 0.28 and 0.39 min, respectively. Practical Applications Our findings indicate that higher temperature and/or a shorter thermal treatment time than 85C for 10 min (for example, 100C for 1 min) could serve as a potential thermal method for direct application to real target foods for the complete inactivation of norovirus. Moreover, 85C for 15 min or 100C for 1 min could potentially be used to inactivate norovirus in dried seafood production.