响应面法优化马齿苋多糖酶法提取工艺

以多糖得率和对DPPH自由基清除率为响应值,采用响应面法优化果胶酶辅助提取马齿苋多糖,在单因素试验的基础上,根据Box-Behnken中心组合原理设计,选取果胶酶添加量、酶解温度、酶解时间3个因素,优化从鲜马齿苋中提取多糖的最佳工艺条件。结果表明最佳工艺条件为:料液比1∶20(g/mL)、果胶酶添加量0.15 g/L、酶解温度39℃、酶解时间2.0 h,在此条件下平行3次试验,马齿苋多糖得率为4.22 g/kg,相对标准偏差(relative standard deviation,RSD)为1.53%,与理论预测值(4.15 g/kg)的相对误差为1.52%;对DPPH自由基的平均清除率为53.1%,RSD为1.49%,与预测值(54.4%)的相对误差为2.39%,说明响应面法优化酶法提取马齿苋多糖的工艺条件稳定可行。

Optimization of Enzymatic Extraction Technology of Polysaccharide from Portulaca oleracea by Response Surface Methodology

Optimizing pectinase-assisted extraction of Portulaca oleracea.polysaccharides by response surface methodology with polysaccharides yield and DPPH free radical scavenging rate.Based on the single factor experiment,according to the design principle of Box-Behnken center combination,the three factors of pectinase dosage,enzymatic hydrolysis temperature and extraction time were selected.Three factors and three levels response surface method was used to optimize the extraction conditions of polysaccharides from fresh Portulaca oleracea.The results showed that the optimum conditions were as follows solid-liquid ratio 1∶20(g/mL),pectinase dosage 0.15 g/L,enzymatic hydrolysis temperature 39℃and enzymatic hydrolysis time 2.0 h.Under these conditions,the yield of Portulaca oleracea polysaccharide was 4.22 g/kg,relative standard deviation(RSD)was 1.53%,which was in agreement with the theoretical predicted value(4.15 g/kg).The relative error was 1.52%;the average clearance of DPPH free radical was 53.1%,RSD was 1.49%,and the relative error with the predicted value(54.4%)was 2.39%.It indicated that the optimization of enzymatic extraction of antioxidant components from Portulaca oleracea by response surface methodology was stable and feasible.