Optimization of enzyme-assisted extraction and characterization of polysaccharides from Hericium erinaceus

•The HEP yield increased by 67.62% by EAE when compared to HWE.•FT-IR showed the functional groups of HEP extracted by HWE and EAE were identical.•CD and AFM showed the conformation was changed by HWE and EAE.•HEP extracted by HWE and EAE were consisted of Gal, Glc, Xyl, and Man by GC. The enzyme-assisted extraction (EAE) of polysaccharides from the fruits of Hericium erinaceus was studied. In this study, response surface methodology and the Box–Behnken design based on single-factor and orthogonal experiments were applied to optimize the EAE conditions. The optimal extraction conditions were as follows: a pH of 5.71, a temperature of 52.03°C and a time of 33.79min. The optimal extraction conditions resulted in the highest H. erinaceus polysaccharides (HEP) yield, with a value 13.46±0.37%, which represented an increase of 67.72% compared to hot water extraction (HWE). The polysaccharides were characterized by FT-IR, SEM, CD, AFM, and GC. The results showed that HEP was composed of mannose, glucose, xylose, and galactose in a molar ratio of 15.16:5.55:4.21:1. The functional groups of the H. erinaceus polysaccharides extracted by HWE and EAE were fundamentally identical but had apparent conformational changes.