Probiotic microcapsule polysaccharide-protein composite system: construction, mechanism and application

Microencapsulation technology can effectively protect the activity of endogenous probiotics, extend the shelf life of probiotics, and achieve their targeted release in vitro. Therefore, it has been widely used in the field of food processing. However, the complex food environment requires careful selection of microcapsule synthesis methods and materials. Polysaccharide-protein composite microcapsules represent a popular strategy for probiotic protection. However, most existing studies evaluate the protective performance of carriers based on simplified in vitro models, and experimental conclusions are highly condition dependent. There is a lack of horizontal trade-off comparisons regarding the advantages and drawbacks of different carriers, and substantial gaps remain in translating laboratory systems to real food and in vivo environments. In this paper, five types of typical polysaccharide-protein composite carriers are selected to systematically summarize the molecular interaction mechanisms and encapsulation processes, and to critically analyze the applicable scenarios, inherent shortcomings of each system and limitations of existing research. The study reveals that raw material batch variation, difficulties in large-scale preparation, and insufficient evidence of in vivo effects are the core bottlenecks restricting the commercialization of this technology. This paper summarizes the mechanistic controversies and industrialization barriers of polysaccharide-protein probiotic microcapsules, aiming to provide references for the targeted design of subsequent probiotic delivery carriers and the establishment of evaluation systems.