Effects of a commercial heat-shock process on Vibrio vulnificus in the American oyster, Crassostrea virginica, harvested from the Gulf Coast

Oysters (Crassostrea virginica) harvested from the Gulf Coast, containing 1 0(2) to 10(4) most probable number (MPN) per gram of Vibrio vulnificus, wer e subjected to a commercial heat-shock process. After 1 to 4 min at interna l oyster meat temperatures exceeding 50 degrees C, shellstock oysters were shucked, chilled, washed, and packed. V. vulnificus and total bacterial lev els in Gulf Coast oysters were significantly reduced from 1 to 4 logs in th e finished product. Similar reductions were not observed in shellstock oyst ers that were subject to conventional processing. Under the National Shellf ish Sanitation Program, heat shocking is an acceptable process to use to as sist in the shucking of shellstock. This research revealed that the heat-sh ock process may also serve to significantly reduce V. vulnificus in summer Gulf Coast oysters.