化橘红黄酮深共熔溶剂提取工艺优化及抗氧化活性研究

Optimization of deep eutectic solvent extraction process and antioxidant activities of flavonoids from exocarpium Citri grandis

[目的]提高化橘红在功能食品及医药等领域的应用。[方法]选取深共熔溶剂体系、深共熔溶剂含水率、料液比、提取温度和提取时间为试验因素,以黄酮得率为指标进行单因素试验,从中筛选出具有显著性差异的因素,并采用响应面法优化深共熔溶剂提取化橘红黄酮工艺;以DPPH自由基、ABTS自由基和羟自由基清除能力评价化橘红黄酮提取液的抗氧化活性。[结果]氯化胆碱—乙二醇体系提取的化橘红黄酮得率最高。深共熔溶剂含水率、料液比、提取温度对化橘红黄酮的得率有显著影响,以此为基础进行响应面分析得到化橘红黄酮的最优提取工艺:深共熔溶剂含水率43%、料液比1∶21(g/mL)、提取温度60℃,化橘红黄酮得率为(19.31±0.47)mg/g。对最优工艺条件下得到的化橘红黄酮提取液进行抗氧化活性研究,结果显示,化橘红黄酮提取液对DPPH自由基、ABTS自由基和羟自由基清除率的半最大效应质量浓度分别为(117.61±1.71),(36.91±0.46),(387.52±1.85)μg/mL。[结论]深共熔溶剂提取化橘红黄酮的得率显著优于传统水提法和乙醇溶剂提取法(P<0.05);化橘红黄酮具有作为天然抗氧化剂来源的潜力。

[Objective]This study aimed to optimize the process of deep eutectic solvent extraction of flavonoids from exocarpium Citri grandis and to evaluate its antioxidant activity.[Methods]The type of deep eutectic solvent system,the water content of deep eutectic solvent,material-to-liquid ratio,extraction temperature,and extraction time were selected as experimental variables,and the yield of flavonoids was used as response variables to conduct single factor experiment.Then the single factors with significant differences were screened to optimize the process of deep eutectic solvent extraction of exocarpium C.grandis flavonoids by response surface methods.Finally,the scavenging ability of exocarpium C.grandis flavonoid extract on DPPH radicals,ABTS radicals,and hydroxyl radicals was explored to analyze the antioxidant activity.[Results]The highest yield of exocarpium C.grandis flavonoid was obtained by the choline chloride-glycol system.The yield of flavonoids was significantly impacted by the deep eutectic solvent's water content,the material-to-liquid ratio,and the extraction temperature.The response surface method was used to determine the ideal flavonoid extraction procedure,which included the deep eutectic solvent's water content of 43%,the material-to-liquid ratio of 1∶21(g/mL),and the extraction temperature of 60℃.The yield of exocarpium C.grandis flavonoids was(19.31±0.47)mg/g.The results of antioxidant activity showed that the concentration for 50%of maximal effect values of DPPH radical,ABTS radical,and hydroxyl radical scavenging were(117.61±1.71),(36.91±0.46),(387.52±1.85)μg/mL.[Conclusion]The extraction of exocarpium C.grandis flavonoids using deep eutectic solvent resulted in significantly higher yields compared with conventional water and ethanol method.These flavonoid extracts had potential as a source of natural antioxidants.