Enzymatic degradation, structural characterization, and in vitro antioxidant, hypoglycemic, and anti-inflammatory activities of Sanghuang vaninii polysaccharides

Polysaccharides are of interest due to their multiple biological activities. However, the molecular weight of natural polysaccharides is excessively high, resulting in low bioavailability. In this study, β-glucanase was used to degrade the polysaccharides of Sanghuang vaninii , and the hydroxyl radical scavenging rate was used as an indicator to optimize the enzymatic process. The monosaccharide composition, molecular weight, thermal stability, infrared spectra, and microstructure of Sanghuang vaninii polysaccharides (SVP) were characterized before and after enzymatic degradation under optimal conditions. Their properties, including antioxidant, hypoglycemic, and anti-inflammatory effects, were also measured. The findings indicated that for SVP, the optimal enzyme digestion conditions were an enzyme activity of 63 U/mL, a digestion time of 3.5 h, a pH value of 5.5, and a temperature of 50 °C. After undergoing enzymatic digestion, the SVP exhibited a hydroxyl radical scavenging rate of 87.3 %. No significant changes were observed in the monosaccharide composition and basic structure before and after enzymatic hydrolysis; however, the molecular weight decreased from 7.473 × 10 4  Da to 5.533 × 10 3  Da, and the original smooth lamellar structure was disrupted. In addition, the antioxidant, hypoglycemic, and anti-inflammatory activities of SVP were significantly enhanced after enzymatic digestion. This study provides a reference for the industrialization and activity research of SVP.