Problems of Recovery from Injury, Stress Resistance, and Cross Protection of Bacteria in Food Pasteurization(Papers presented at the Seminar, "Acquisition of cross-tolerance against various stresses -current status and perspectives in cross-protection studies-")

Abstract

Food-borne pathogenic and spoilage bacteria can be killed by various methods in sterilization and pasteurization processes. In the process for minimizing the reduction in food quality, after the processing, bacterial cells often do not die but are in an injured state. During the post-treatment period these injured cells carry out the stress response and repair. Probably due to these functions, they become highly resistant to the subsequent secondary stress of not only the same type (acquired tolerance), but also other types (cross protection). I stress here a possibility of serious problems derived from the occurrence of these phenomena in practical use of a consecutive process consisting of two or more different methods for inactivation of bacterial cells. The clarification of the mechanisms of the acquired tolerance and cross protection at cellular and molecular levels is expected.