1.Chinese Academy of Agricultural Engineering;2.Guizhou Institute of Technology
选用不同离子组合的低共熔溶剂提取黄精多糖,筛选确定尿素-氯化胆碱低共熔溶剂提取 黄精多糖效果最好,随后在单因素考察的基础上,采用响应面分析法优化尿素-氯化胆碱低共熔溶剂提取黄精多糖的工艺条件,并进行了低共熔溶剂重复利用对多糖提取率和含量的影响研究。通过测定总抗氧化能力、超氧阴离子自由基(superoxide radical,O2- ·)和1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率考察黄精多糖体外抗氧化活性。结果表明:低共熔溶剂提取黄精多糖的优化工艺参数为温度70 ℃、尿素-氯化胆碱摩尔比1.19、时间42.30 min、液料比20.75 mL/ g,此条件下的多糖提取率为18.55%,较预测值相对误差为2.69%,比传统的热水浸提法增加了139.97%。低共熔溶剂重复利用不仅对黄精多糖提取率没有影响,在重复利用第3 次时提取率最高,较新鲜溶剂提高了83.9%;而且黄精多糖含量随重复次数增加呈不断增加后趋于稳定的趋势,重复利用4、5 次后多糖含量基本趋于稳定,达到63.48%、64.12%,说明其纯度不断 提高。黄精多糖的O2 -自由基清除能力、DPPH 自由基清除能力、总抗氧化能力随质量浓度的增加而增加;在测定的质量浓度范围内,清除O2- 自由基和DPPH 自由基的IC50 分别为0.524 mg/ mL 和0.951 mg/ mL,总抗氧化能力最高为241.2 μg/ mL。因此,低共熔溶剂法是一种效率高、清洁环保的新型黄精多糖提取方法。
In this study, Polygonatum Sibiricum Polysaccharides were extracted from several deep eutectic solvents with different ion combinations. The best extraction effect of urea/choline chloride deep eutectic solvents was obtained. Then, based on single factor investigation, response surface analysis was used. The optimum conditions for the extraction of the polysaccharides from Polygonatum Sibiricum by urea/choline chloride eutectic solvent were investigated. The antioxidant activity of the polysaccharides in vitro was determined by measuring the total antioxidant capacity, O2-·free radicals and DPPH free radical scavenging rate. The results showed that the optimum process parameters for extracting the polysaccharides by deep eutectic solvents were temperature 70 ℃, urea/choline chloride molar ratio 1.19 mol/mol, time 42.30 min, liquid to material ratio 20.75 mL/g. This condition, the extraction rate is 18.55% of the polysaccharides, and the relative error is 2.69% compared with the predicted value, which is 139.97% higher than the traditional hot water extraction. The total antioxidant capacity, O2-·free radical and DPPH free radical scavenging rate of the polysaccharides were dose-effect relationship with mass concentration, and increased with the increase of mass concentration, which had certain antioxidant capacity, O2-·free radical and DPPH free radical scavenging ability. The total internal antioxidant capacity was 241.2 units/mL, and the IC50 values of O2-·free radicals and DPPH free radical scavenging capacity were 0.524 mg/mL and 0.951 mg/mL, respectively. Therefore, the deep eutectic solventsmethod is a new high-efficiency, clean and environment friendly method for extracting the polysaccharides.