Thermal Inactivation of Murine Norovirus‐1 in Suspension and in Dried Mussels (<scp><i>M</i></scp><i>ytilus edulis</i>)

Abstract

Abstract The current study examined the effects of three different temperatures (60, 85 and 100 C ) and duration of heat treatment (ranging from 1 min at 100 C to 30 min at 60 C ) on murine norovirus‐1 ( MNV ‐1) as a human norovirus model both from viral suspension and experimentally contaminated dried mussels. The log 10 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 60 C for 5 min, 60 C for 15 min, 60 C for 30 min, 85 C for 3 min and 85 C for 6 min, respectively. The log 10 TCID 50 /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 85 C , respectively, and by treatment for 1 min at 100 C . At 60, 85 and 100 C , the 1‐log 10 TCID 50 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 85 C for 10 min (for example, 100 C for 1 min) could serve as a potential thermal method for direct application to real target foods for the complete inactivation of norovirus. Moreover, 85 C for 15 min or 100 C for 1 min could potentially be used to inactivate norovirus in dried seafood production.