Abstract: Edible mushroom polysaccharides, major bioactive components derived from the fruiting bodies, mycelia, or fermentation broth of edible fungi, exhibit diverse biological activities, including immunomodulatory, antioxidant, and gut microbiota-modulating effects, highlighting their potential applications in functional foods, pharmaceuticals, and nutraceuticals. Molecular mass is a critical structural parameter affecting the functional properties of edible mushroom polysaccharides, and its role in regulating polysaccharide bioactivity has attracted increasing research interest in the context of precision nutrition and high-value utilization of polysaccharides. However, current studies addressing the effect of molecular mass on the physicochemical and biological properties of edible mushroom polysaccharides remain scattered and lack systematic synthesis. In this review, the methods for the fractionation and degradation of edible mushroom polysaccharides are systematically summarized. Furthermore, the effect of the molecular mass of edible mushroom polysaccharides on their physicochemical properties is briefly discussed, with particular emphasis placed on elucidating the impact of molecular mass differences on their biological functions. This review aims to provide a theoretical basis for the rational development and application of edible mushroom polysaccharides.

Key words: edible mushroom polysaccharides; molecular mass; fractionation and degradation strategies; physicochemical properties; biological functions