Probiotics and thermal processing: A review of challenges and protective strategies

Probiotic organisms are widely acknowledged for their significant health benefits, particularly in supporting gut health, enhancing immune function, and reducing risks associated with chronic diseases. However, their broader application in thermally processed foods is restricted by their heat sensitivity, which leads to a substantial loss in viability during standard processing methods such as pasteurization, sterilization, and baking. This review presents a comprehensive overview of the mechanisms by which thermal stress impacts probiotic survival, including protein denaturation, membrane disruption, and metabolic damage. Emphasis is placed on innovative protective strategies, such as microencapsulation using advanced biopolymer systems, the use of spore-forming probiotics, and the integration of cryo- and thermo-protectants to enhance stability. Furthermore, non-thermal processing technologies—such as high-pressure processing (HPP), pulsed electric fields (PEF), ultrasound, and cold plasma—are explored as viable alternatives that preserve probiotic viability without compromising food safety. The emergence of postbiotics as heat-stable, health-promoting microbial metabolites is also discussed, offering new opportunities for functional food development. The paper concludes by highlighting future directions in formulation, regulatory guidance, and the design of next-generation probiotic and postbiotic products that align with global food system sustainability and health policy goals.