响应面法优化糯高粱多糖提取工艺及其抗氧化活性分析

Response surface analysis for the optimization of extraction process for polysaccharides from glutinous sorghum and antioxidant activity of the extracted polysaccharides

【目的】优化糯高粱多糖提取工艺,并分析其抗氧化活性,为糯高粱食品开发利用提供理论依据。【方法】以国窖红1号糯高粱籽粒为材料,在单因素试验的基础上,采用响应面法优化其多糖提取工艺,并测定所提取多糖清除DPPH自由基和羟基自由基的能力。【结果】建立了料液比(X1)、微波功率(X2)和提取时间(X3)与糯高粱多糖提取率(Y)的回归模拟方程:Y=6.43277+0.26425X1+0.89398X2+0.35226X3-0.09537X1X2-0.14083X1X3-0.10898X2X3-1.39713X1^2-1.35532X2^2-0.26889X3^2,回归方程模型极显著(P<0.01),R2=0.999885,方程拟合程度高。糯高粱多糖提取的最佳工艺条件为:料液比1∶400、微波功率480 W、提取时间110 s,在此条件下,得到多糖平均值为6.48%,与预测值(6.68%)相对误差为2.91%。糯高粱多糖的DPPH自由基清除率随多糖质量浓度的增加先增后减,多糖质量浓度为0.4 mg/mL时,清除率最高达54.38%,低于对照2,6-二叔丁基对甲酚(BHT)的清除率;羟基自由基清除率随多糖质量浓度的增加而增加,多糖质量浓度为0.10 mg/mL时达最大值(94.70%),高于相同质量浓度对照BHT的清除率。【结论】采用响应面法优化的工艺条件可用于糯高粱多糖提取,且糯高粱多糖具有较强的抗氧化活性,可用于健康食品开发。

【Objective】The objective of this study was to optimize extraction process conditions of glutinous sorghum polysaccharide and analyze its antioxidant activity,and provide theoretical basis for the development and utilization of glutinous sorghum food products.【Method】The experiment used glutinous sorghum Guojiaohong No.1 as the materials.The extraction conditions were optimized using response surface methodology on the basis of single factor experiments,and the DPPH and hydroxyl radical scavenging capacity of the polysaccharide was detected.【Result】The regression equation of material-liquid ratio(X1),microwave power(X2),extraction time(X3)and polysaccharide extraction yield(Y)of glutinous sorghum was Y=6.43277+0.26425X1+0.89398X2+0.35226X3-0.09537X1X2-0.14083X1X3-0.10898X2X3-1.39713X1^2-1.35532X2^2-0.26889X3^2,the regression equation model established between the respective variables and the polysaccharide extraction yield was extremely significant(P<0.01),compound correlation coefficient R2=0.999885,the equation was highly fitted.The optimal extraction process of glutinous sorghum polysaccharides was solid-to-liquid ratio 1∶400,microware power 480 W,extraction time 110 s,the model-predicted and experimentally measured values of polysaccharide yield were 6.68%and 6.48%,respectively,revealing a relative error of only 2.91%between them.The DPPH free radical scavenging rate of glutinous sorghum polysaccharide increased first and then decreased with the increase of mass concentration of polysaccharide.When the mass concentration was 0.4 mg/mL,the scavenging rate was up to 54.38%,which was lower than the scavenging rate of control 2,6-di-tert.-butyl-4-methyl phenol(BHT).The hydroxyl radical scavenging rate increased with the increase of mass concentration,and reached the maximum(94.70%)at the mass concentration of 1.0 mg/mL,which was higher than the clearing rate of the control BHT of the same mass concentration.【Conclusion】The processing technology optimized by response surface can be applied to extraction of polysaccharides from glutinous sorghum.Glutinous sorghum polysaccharides has strong antioxidant activity,and can be developed into healthcare food.