紫山药多糖超声结合酶法提取工艺优化及抗氧化活性研究

以紫山药为实验材料,采用超声结合酶法提取多糖,用Sevag法脱蛋白,用活性炭除花青素,并对其进行体外抗氧化实验,研究了紫山药中多糖提纯工艺和体外抗氧化活性。实验结果表明,最佳工艺条件为加酶量1.5%、料液比1:10 g/m L、提取时间25 min、超声功率200 W。在上述最佳条件下,紫山药多糖平均得率为9.83%。经脱蛋白、去除花青素后的紫山药多糖粉末中多糖质量分数为58.9%。体外抗氧化实验中,紫山药多糖表现出明显的抗氧化能力,对1,1-二苯基-2-苦肼基自由基（DPPH·）的清除能力较维生素C弱,但对羟基自由基（·OH）的清除能力略强于维生素C。 

Study on optimization of ultrasonic-enzymatic extraction of polysaccharides from purple yam and its antioxidant activity

Taking purple yam as the experimental material, the extraction technology and antioxidant activity of polysaccharides from purple yam were studied by ultrasonic-enzymatic extraction, Sevag method for deproteinization, activated carbon for anthocyanins removal and in vitro antioxidant activity. Results showed that the optimum condition were as follows: cellulose amount 1.5%, material-solvent ratio 1: 10 ( g/m L) , extraction time 25 min, ultrasonic power 200 W.Under such conditions, the yield of polysaccharides was 9.83%.The mass fraction of polysaccharides from purple yam polysaccharides powder was 58.9% after deproteinization and anthocyanins removal.The extraction from purple yam showed significant antioxidant capacity, and the scavenging ability of DPPH· were weaker than vitamin C, but that of ·OH was slightly stronger than vitamin C.