Abstract:Hericium erinaceus was used as the raw material to optimize the extraction process of H.erinaceus polysaccharides（HEP）via single-factor experiments and response surface methodology.Different degradation methods were applied to obtain degraded HEP fractions，and their structural characteristics and antioxidant activities were comparatively evaluated.The optimal extraction conditions for HEP were determined as a liquid-tosolid ratio of 25∶1（mL/g），extraction temperature of 85 ℃，and extraction time of 3.0 h，under which the HEP yield reached 9.12%.Infrared spectroscopy revealed that acid hydrolysis primarily affected the C pagenumber_ebook=120,pagenumber_book=112O，C—O，and OCH functional groups of HEP，whereas enzymatic hydrolysis mainly altered the proportion of glycosidic residue configurations.Compared with acid hydrolysis，enzymatic hydrolysis had a greater impact on the molecular weight of HEP.Both insufficient and excessive degradation failed to produce polysaccharide fractions with optimal antioxidant activity.Among them，the M2 enzymaically degraded Hericium erinaceus polysaccharides（EHEP）exhibited the strongest hydroxyl radical（·OH）scavenging activity，with an IC50 value of 2.08 mg/mL.Cellular antioxidant assays demonstrated that both HEP and EHEP significantly reduced hydrogen peroxide（H2O2）-induced hepatocyte apoptosis and reactive oxygen species（ROS）levels，with EHEP showing superior efficacy.These findings indicate that optimizing the extraction process and degradation treatment yields EHEP with outstanding antioxidant activity.