采用纤维素酶、果胶酶、内切木聚糖酶、木瓜蛋白酶、胰酶五种酶分别对热水提取后的金针菇多糖进行降解，并研究其产物特性。结果发现，酶法降解后多糖的抗氧化活性得到不同程度的提高，其中胰酶降解的金针菇多糖的抗氧化活性最高，其DPPH自由基清除能力的IC50值为1.71±0.03 mg/mL，是空白样的1.5倍；在4.0 mg/mL的多糖浓度下，还原力达到1.15，是空白样的1.77倍；还有氧自由基清除能力(ORAC)值达到923.90±22.32 μmol Trolox/g，是空白样的2.24倍。其次木瓜蛋白酶和果胶酶降解的金针菇多糖的抗氧化活性也比较高。此外，酶法降解能使金针菇多糖的分子量有不同程度的减小。单糖组成测定结果表明金针菇多糖主要由葡萄糖、半乳糖、木糖、甘露糖和岩藻糖五种单糖组成，通过不同酶降解后金针菇多糖的单糖组成也不同。

Flammulina velutipes polysaccharides extracted from hot water were degraded by five enzymes (cellulase, pectinase, endo-xylanase, papain and trypsin). It was found that antioxidant properties of Flammulina velutipes polysaccharide degraded by different enzymes were improved. Among them, the Flammulina velutipes polysaccharides degraded by trypsin showed the best activities in DPPH radical scavenging activity (IC50 value 1.71±0.03 mg/mL), reducing power(1.15 at 4.0 mg/mL) and ORAC value(923.90±22.32 μmol Trolox/g), being of 1.5, 1.77 and 2.24 folds, respectively, of those of the control, followed by the polysaccharides prepared by papain and pectinase. Moreover, the molecular weights of the polysaccharides were decreased after different enzymes degradation. The monosaccharide compositions of the polysaccharides were mainly glucose, galactose, xylose, mannose and algae. They were also changed after different enzymatic hydrolysis.

国家自然科学基金（31101222）；广东省产学研项目（2010A090200041）；广东省科技计划项目（2011B030500004）；SRP项目《生物活性多糖的分离纯化及功效研究》