Efficiency of high pressure treatment for destruction of Listeria monocytogenes in fruit juices

The objective of this study was to compare high pressure resistance of Listeria monocytogenes strains at 25degreesC and 50degreesC at 350 MPa and to use high pressure (250 MPa and 350 MPa) at 30degreesC and 40degreesC for the inactivation of the relatively most pressure resistant strain inoculated in pasteurized apple, apricot, cherry and orange juices. L. monocytogenes CA was found to be the relatively most pressure resistant strain and increasing pressurization from 250 MPa to 350 MPa at 30degreesC had an additional three to four log cycle reduction in viability, still leaving viable cells after 5 min. When 350 MPa at 40degreesC for 5 min was applied more than eight log cycle reduction in cell population of all fruit juices was achieved. This study demonstrated that low temperature (40degreesC) high pressure (350 MPa) treatment has the potential to inactivate relatively pressure resistant L. monocytogenes strains inoculated in different fruit juices within 5 min. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.