红托竹荪菌托多糖提取工艺及抗氧化降血糖活性

为利用红托竹荪菌托，采用酶解法提取菌托多糖，优化多糖提取工艺，并测定多糖分子量、单糖组成、抗氧化及降血糖活性。结果表明，最佳酶解法提取工艺为纤维素酶2.5%、果胶酶0.4%、木瓜蛋白酶1.5%，50 ℃酶解1 h，料液比1:60、提取温度80 ℃、时间3 h，该条件下多糖提取率达15.37%，比热水浸提法提高39.60%。酶解法多糖分子量为3 344 Da (Mn)、522 208 Da (Mw)、2 929 Da (Mp)，主要由葡萄糖、甘露糖、葡萄糖醛酸、半乳糖和岩藻糖等组成，葡萄糖占最高，达48.82%。菌托多糖为2.0 mg/mL时，DPPH·清除率为93.83%，Fe³⁺还原能力为0.140 7，α-葡萄糖苷酶活性抑制率为54.62%、α-淀粉酶活性抑制率为56.45%，与热水浸提法相比差异极显著或显著。酶解法提取红托竹荪菌托多糖，提取率较高，具有较高的抗氧化、降血糖活性，具有推广应用价值。

Extraction process and antioxidant hypoglycemic activities of polysaccharides from Dictyophora rubrovolvata volva

The polysaccharide from volva of Dictyophora rubrovolvata is extracted by enzymatic method, and the extraction process is optimized. The molecular weight, monosaccharide composition, antioxidant and hypoglycemic activity of polysaccharides are determined. The results showed that the best process for the enzymatic extraction of polysaccharides is: cellulase 2.5%, pectinase 0.4% and papain 1.5%; enzymatic digestion at 50 °C for 1 h; regulation of material to liquid ratio of 1:60 and extraction temperature of 80 °C. Under such conditions the extraction yield of polysaccharides in 3h reaches 15.37%, 39.60% higher than that under hot water extraction condition. The molecular weights of polysaccharides extracted by enzymatic method are 3 344 Da (Mn), 522 208 Da (Mw), and 2 929 Da (Mp). The polysaccharides are mainly composed of glucose, mannose, glucuronic acid, galactose and fucose, with the highest percentage of glucose being 48.82%. Under polysaccharide concentration of 2.0 mg/mL, clearance of DPPH· is 93.83%, capability of Fe³⁺ reduction is 0.140 7, inhibition rate of α-glucosidase activity is 54.62%, and α-amylase activity inhibition rate is 56.45%, showing extremely significant difference or significant difference as compared with the polysaccharide extracted by hot water. The polysaccharide extraction process by using enzymatic method shows high-yielding and the extracted polysaccharides have better antioxidant and hypoglycemic activities, and thereby the process is worth popularization and application.