藜麦麸皮多糖的提取及理化性质和活性研究

Extraction, Physicochemical Properties and Activity of Quinoa Husk Polysaccharide

以藜麦麸皮为原料,采用乙醇提取法粗提多糖并用4种(碱性、中性、复合和风味)蛋白酶除去蛋白,依次命名为多糖A、B、C、D,并对4种多糖的理化性质、抗氧化活性、酪氨酸酶抑制率和Fe^(2+)螯合能力进行了研究。结果表明,4种多糖溶于蒸馏水,不溶于乙醇、乙醚、甲醇等有机溶剂,不含淀粉和酚类物质,但都含有一定的糖醛酸和蛋白质;测其单糖组成主要由甘露糖、核糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸和葡萄糖组成。经碱性蛋白酶去除蛋白得到的多糖A提取率最高为9.64%;在活性方面,多糖A、B、C、D均具有一定的还原力,多糖D对DPPH自由基清除能力较强为73.00%,多糖A对羟自由基的清除率为35.91%;多糖B在5 mg/mL表现出良好的酪氨酸酶抑制率以及Fe^(2+)螯合能力,分别为58.54%和70.24%。综上所述藜麦麸皮多糖具有良好的生物活性,为藜麦麸皮开发利用提供理论依据。

Using quinoa husk as raw material,polysaccharides were extracted by ethanol and removed proteins by four kinds of proteases (alkaline,neutral,compound and flavor),which were named polysaccharides A,B,C,D.The physical and chemical properties,antioxidant activity,tyrosinase inhibition rate and Fe^(2+) chelating ability of the four polysaccharides were studied.The results showed that the four polysaccharides were soluble in distilled water,insoluble in ethanol,ether,methanol and other organic solvents,did not contain starch and phenols,but all contained certain uronic acid and protein,mainly composed of mannose,ribose,rhamnose,glucuronic acid,galacturonic acid and glucose.The highest extraction rate of polysaccharides A obtained by alkaline protease was 9.64%.As far as activity is concerned,polysaccharide A,B,C and D of some reducing power.The polysaccharides D had strong scavenging ability to DPPH free radicals,which was 73.00%.The scavenging rates of polysaccharides A to hydroxyl radicals were 35.91%.Polysaccharide B showed good tyrossinase inhibition rates at 5 mg/mL and Fe^(2+) chelation capacity of 58.54% and 70.24%,respectively.It shows that quinoa husk polysaccharides have good biological activity,which provides a theoretical basis for the development and utilization of quinoa husk.