复合酶辅助提取荷叶多糖工艺优化及其体外抗氧化活性

Optimization of Complex Enzyme-Assisted Extraction of Polysaccharide from Lotus Leaves and Its Antioxidant Activity

以荷叶为原材料,在单因素试验的基础上,以pH值、温度、液料比、复合酶添加量(纤维素酶∶木瓜蛋白酶质量比1∶1)、提取时间为自变量,以荷叶多糖得率为响应值,采用五因素三水平的响应面分析法优化荷叶多糖提取工艺,同时测定荷叶多糖对DPPH自由基和羟自由基的清除能力。结果表明,最佳酶解提取工艺为pH7.0、温度52℃、液料比39∶1(mL/g)、复合酶添加量0.7%、提取时间116 min,多糖得率为3.26%,与预测值相符。荷叶多糖具有较好的抗氧化活性,DPPH自由基和羟自由基的IC50值分别为2.355、0.3312 mg/mL。

On the basis of single factor tests,the extraction conditions of polysaccharide from lotus leaves,including pH,temperature,liquid-to-solid ratio,addition amount of complex enzyme(cellulase∶papain mass ratio=1∶1),and time were optimized by the response surface methodology with the yield of polysaccharide as the response value.Furthermore,the scavenging activities of the extracted polysaccharide against DPPH·and hydroxyl free radicals were measured.The results showed that the optimum extraction process was extraction at pH 7.0,52℃,liquid-to-solid ratio of 39∶1(mL/g),and complex enzyme addition of 0.7%for 116 min,under which the yield of polysaccharide reached 3.26%,consistent with the expected value.In addition,the lotus leaf polysaccharide had good antioxidant activity,with the IC50 values of 2.355 mg/mL and 0.3312 mg/mL for scavenging DPPH and hydroxyl free radicals,respectively.