γ-Irradiation effects on the physicochemical properties and biological activities of Schizophyllum commune polysaccharides

In this study, the effects of γ-irradiation on the physicochemical and structure properties as well as the biological activities of Schizophyllum commune polysaccharides were investigated. The results demonstrated that the total carbohydrate content, solubility, fat binding ability and foaming capability of polysaccharides were increased with the increasing γ-irradiation dose, while the average molecular weight of polysaccharides showed the contrary trend and it significantly decreased from 11.96 to 4.16 kDa. Mannose, glucose and xylose were the main monosaccharides of polysaccharides and γ-irradiation treatment hardly changed monosaccharide composition, but significantly affected the molar ratio of monosaccharides. γ-Irradiation treatment slightly improved the crystallinity of polysaccharides, and low-dose γ-irradiation treatment (4 and 8 kGy) could increase the zeta potential thus improved the stability of polysaccharides solution. Moreover, γ-irradiation treatment influenced the color and the surface topography of polysaccharides but had less impact on the triple helix structure. High dose γ-irradiation treatment (8–16 kGy) decreased the thermal stability of polysaccharides as well as the scavenging activity of ABTS radicals. These findings provide valuable insights into the physicochemical modification of polysaccharides via the γ-irradiation.