Response of Listeria monocytogenes and Vibrio parahaemolyticus to High Hydrostatic Pressure

Listeria monocytogenes Scott A and CA, were subjected at 23°C to hydrostatic pressures ranging from 2,380 to 3,400 atm and Vibrio parahaemolyticus T‐3765‐1 from 680 to 1,700 atm. For L. monocytogenes Scott A, pressurization in ultra‐high temperature‐processed (UHT) milk and raw milk appeared to provide a protective effect and lessened cell death as compared to pressurization in phosphate‐buffered saline (100 mM, pH 7.0). A population of about 10 6 CFU/mL L. monocytogenes was killed by exposure to 3,400 atm within 80 min at 23°C in UHT milk. A population of about 10 6 CFU/mL V. parahaemolyticus was killed by exposure to 1,700 atm within 10 min at 23°C in clam juice.