Emerging Nonthermal Technologies for the Production of Postbiotics

Postbiotics, defined as nonliving microbial cells and their components that confer health benefits to the host, represent a significant advancement in functional foods and dietary supplements. Compared to probiotics and prebiotics, postbiotics offer advantages in product stability, safety, and formulation flexibility. In general practice, heat killing is a widely used method to produce postbiotics. However, heat-killed postbiotics incur few drawbacks, such as burnt flavor, denaturation of immunomodulatory molecules, and loss of functional metabolites. This review paper examines how emerging nonthermal technologies perform compared to conventional methods in producing postbiotics, emphasizing their suitability for industrial-scale implementation and the advantages they provide over conventional thermal processing. Based on literature, the review examines key nonthermal technologies, including high-pressure processing (HPP), pulsed electric fields (PEFs), ultrasound, cold plasma, supercritical CO₂ (Sc-CO₂), and Irradiation. Their principles and industrial applicability are examined for impact on bioactivity, stability, and functional value of postbiotics, with evaluations highlighting their strengths, limitations, and optimization potential. Recent advancements in postbiotic research and nonthermal processing indicate significant innovation opportunities. However, challenges remain in scaling up methods, refining parameters, and addressing regulatory and economic constraints. Industrial integration of nonthermal technologies requires further evidence to confirm feasibility, cost-effectiveness, and safety compliance, identifying the key gaps in optimizing protocols for inactivation, exposure-response relationships, and clinical impacts. The review guides readers through postbiotic fundamentals, comparison of production methods, specific nonthermal technologies, and practical implementation considerations, thereby providing a foundation for future research aimed at optimizing the use of these technologies in clinical and industrial settings.