裸藻多糖提取工艺优化及抗氧化活性研究

Optimization of the extraction process of polysaccharides from euglena and its antioxidant activity

以裸藻为原料,考察超声功率、超声时间、酶解时间、酶添加量4个因素对超声波辅助酶法提取裸藻多糖得率的影响。结果表明,最佳提取工艺为超声功率360W,超声时间19min,中性蛋白酶添加量3.7%,酶解时间3.5h,该条件下的多糖得率为3.68%。采用超滤法对裸藻多糖进行分级,得到3~5,5~10,>10kDa 3个不同分子量段的裸藻多糖。抗氧化活性分析表明,3~5kDa的羟基自由基清除能力、超氧阴离子清除能力、Fe^(2+)螯合能力、还原力最强,>10kDa的脂质过氧化抑制能力最强,各分子量段裸藻多糖均无DPPH自由基清除能力。

Taking the euglena as the raw material,the extraction of euglena polysaccharide by ultrasonic-assisted enzymatic method and the optimal extraction conditions were studied,from the ultrasonic power,ultrasonic time,enzymolysis time,and enzyme concentration by response surface analysis(RSA)based on single factor tests.The results showed that the optimal process parameters were;ultrasonic power 360 W,ultrasonic time 19 min,neutral protease addition 3.7%,enzymatic hydrolysis time 3.5 h.Under the conditions,the yield of euglena polysaccharide reached 3.68The euglena polysaccharide(EGPS)was separated to three different ranges of molecular weight by ultrafiltration membrane,which were 35,510 and>10 kDa,and the antioxidant activity of three EGPSs were analyzed.The results showed that,35 kDa has better hydroxyl radical scavenging ability,superoxide anion scavenging ability,Fe^2+chelation ability,reducing power,and more than 10 kDa has better lipid peroxidation inhibition ability,none of the EGPSs has DPPH freedom.