Recent developments in preservation technologies allow for the delivery of food with nutritional value and superior taste. Of special interest are low-acid, shelf-stable foods in which the complete control or inactivation of bacterial endospores is the crucial step to ensure consumer safety. Relevant preservation methods can be classified into physicochemical or physical hurdles, and the latter can be subclassified into thermal and nonthermal processes. The underlying inactivation mechanisms for each of these physicochemical or physical processes impact different morphological or molecular structures essential for spore germination and integrity in the dormant state. This review provides an overview of distinct endospore defense mechanisms that affect emerging physical hurdles as well as which technologies address these mechanisms. The physical spore-inactivation technologies considered include thermal, dynamic, and isostatic high pressure and electromagnetic technologies, such as pulsed electric fields, UV light, cold atmospheric pressure plasma, and high- or low-energy electron beam.
Keywords: bacterial spore; inactivation mechanism; nonthermal; target structure; thermal.