碱提法提取升麻渣多糖工艺优化及抗氧化活性分析

Process optimization and antioxidant activity of polysaccharide from Actaea cimicifuga L.residue extracted by alkaline method

【目的】采用碱提法提取升麻渣多糖,优化提取工艺并探究多糖的抗氧化能力,为升麻渣的综合开发利用提供参考。【方法】以水提醇沉后的升麻渣为试验材料,采用碱提法提取升麻渣多糖,分别考察碱液浓度、液料比、提取温度和提取时间对多糖提取率的影响,筛选最适单因素条件并建立响应面模型,依据体外自由基清除试验探索其抗氧化能力。【结果】以升麻渣碱提多糖提取率(Y)为响应值,以碱液浓度(A)、液料比(B)、提取温度(C)为自变量建立的二次多项拟合方程为Y=4.98+0.17A+0.27B+0.72C-0.34AB+0.21AC-0.073BC-0.76A^(2)-0.33B^(2)-0.79C^(2),响应面模型具有稳健性且拟合良好。各因素对升麻渣多糖提取率的影响顺序为提取温度>液料比>碱液浓度,其中,碱液浓度影响显著(P<0.05,下同),液料比和提取温度影响极显著(P<0.01,下同),碱液浓度与液料比交互作用影响极显著、碱液浓度与提取温度交互作用影响显著,而液料比与提取温度交互作用影响不显著(P>0.05)。通过响应面分析得到碱提法提取升麻渣多糖的最佳工艺条件:碱液浓度0.6 mol/L、液料比27∶1、提取温度75℃,该条件下升麻渣多糖平均提取率为5.17%。升麻渣多糖对1,1-二苯基-2-三硝基苯肼(DPPH)自由基、羟基自由基和2,2-联氮-双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(ABTS)自由基的半抑制浓度(IC_(50))分别为2.614、1.164和1.306 mg/mL,多糖浓度在1.2 mg/mL时清除率分别为45.83%、56.16%和45.12%。【结论】碱提法可高效提取升麻渣多糖,且升麻渣多糖存在体外抗氧化活性,其抗氧化能力与浓度存在剂量依赖关系。

【Objective】The extraction process of polysaccharide from Actaea cimicifuga L.residue was optimized by alkaline method,and antioxidant capacity of the polysaccharide was investigated,which provided reference for comprehensive development and utilization of A.cimicifuga L.residue.【Method】Using the water extracted and alcohol precipitated A.cimicifuga L.residue as the experimental material,the polysaccharide from the A.cimicifuga L.residue was extracted by alkaline extraction method.The effects of lye concentration,liquid-material ratio,extraction temperature and extraction time on the extraction rate of polysaccharide were investigated.The optimal single factor conditions were screened and the response surface model was established.The antioxidant capacity of polysaccharide was investigated by in vitro free radical scavenging test.【Result】With the extraction rate(Y)of alkaline extracted polysaccharide from A.cimicifuga L.residue as the response value,the quadratic polynomial fitting equation established with lye concentration(A),liquid-material ratio(B)and extraction temperature(C)as independent variables was Y=4.98+0.17A+0.27B+0.72C-0.34AB+0.21AC-0.073BC-0.76A^(2)-0.33B^(2)-0.79C^(2).The model obtained from the study was stable and well-fitted.The order of influencing factors on polysaccharide extraction rate was extraction temperature˃liquid-material ratio˃lye extraction concentration.Lye extraction concentration had significant effects(P<0.05,the same below),liquid-material ratio and extraction temperature had extremely significant effects(P<0.01,the same below),interaction between lye concentration and liquid-material ratio had extremely significant effects,the interaction between lye concentration and extraction temperature had significant effects.However,the interaction between liquid-material ratio and extraction temperature had no significant effect(P>0.05).Through response surface analysis,the optimal technological conditions for extracting polysaccharide from A.cimicifuga L.residue by alkali extraction were obtained:the concentration of lye was 0.6 mol/L,the liquid-material ratio was 27∶1,and the extraction temperature was 75℃,and the average extraction rate of polysaccharide was 5.17%.The median inhibition concentratin(IC_(50))values of polysaccharides from A.cimicifuga L.residue on 1,1-diphenyl-2-trinitrophenylhydrazine(DPPH)free radicals,hydroxyl free radicals and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)free radicals were 2.614,1.164 and 1.306 mg/mL.When polysaccharide concentration was 1.2 mg/mL,the clearance rates were 45.83%,56.16%and 45.12%respectively.【Conclusion】This method can extract polysaccharide from A.cimicifuga L.residue efficiently,and the polysaccharide from A.cimicifuga L.residue has antioxidant activity in vitro,and its antioxidant activity has dose dependent relationship with concentration.