Research Progress on Isolation, Preparation and Functional Characteristics of Postbiotics and Their Applications in Dairy Products

Probiotics have been extensively researched for their health advantages, but their poor stability and viability prevent them from being used in foods and medicine on a larger scale. Compared with probiotics, postbiotics have the advantages of higher safety and stability in its existing form, which avoids the limitation of probiotics. In 2021, the International Scientific Association for Probiotics and Prebiotics defined postbiotics as preparation of inanimate microorganisms and/or their components that confers a health benefit on the host including bacterial components and metabolites, such as cell-free supernatant, cell lysate, extracellular polysaccharide, peptidoglycan, short-chain fatty acids, and organic acids. Postbiotic components exhibit varying beneficial effects on the host, such as regulating immunity and lipid metabolism, anti-inflammatory, antioxidant, anti-tumor, and antibacterial activities, and on product processing as an antibacterial, stabilizing and emulsifying agent. This paper provides an overview of the methods for separating, preparing and identifying postbiotics. It also summarizes the potential functional characteristics of probiotics, their processing characteristics in dairy products and their potential application value. This review provides a theoretical basis for the application of postbiotics as good raw materials in the medical and food fields.