Effect of high-pressure processing on Vibrio parahaemolyticus strains in pure culture and Pacific oysters

Different strains of Vibrio parahaemolyticus (Vp) in broth cultures and Vp-inoculated live Pacific oysters (Crassostrea gigas) were subjected to high-pressure processing (HPP) at 241, 276, 310, and 345 MPa. Results showed Vp numbers were reduced by HPP in both pure culture and whole oysters. Vp inactivation was dependent on time and pressure. Optimum conditions for reducing Vp in pure culture and oysters to nondetectable levels were achieved at 345 MPa for 30 and 90 s, respectively. Resistance variations were detected between Vp in pure culture and in oysters. HPP proved to be an efficient means of reducing Vp in oysters.