Inactivation of Vibrio parahaemolyticus and Vibrio vulnificus in Phosphate-Buffered Saline and in Inoculated Whole Oysters by High-Pressure Processing

Abstract

Inactivation studies for <i>Vibrio parahaemolyticus</i> TX-2103 (serotype O3:K6) and <i>Vibrio vulnificus</i> MO-624 (clinical isolate) were conducted in phosphate-buffered saline (PBS) and in inoculated oysters under high-pressure processing conditions. <i>V. parahaemolyticus</i> was more resistant than <i>V. vulnificus</i> in PBS at all pressures and times. A 6-log reduction of <i>V. parahaemolyticus</i> and <i>V. vulnificus</i> in PBS at 241 MPa required 11 and 5 min, respectively, which included a 3-min pressure come-up time. A 4.5-log reduction of <i>V. parahaemolyticus</i> in oysters at 345 MPa required 7.7 min, which included a 6.7-min pressure come-up time. More than a 5.4-log reduction of <i>V. vulnificus</i> in oysters at 345 MPa occurred during the 6-min pressure come-up time. Both <i>V. parahaemolyticus</i> and <i>V. vulnificus</i> in PBS and in oysters were reduced to nondetectable numbers at 586 MPa during the 8- and 7-min pressure come-up times, respectively.