藜麦黄酮提取及其抗氧化活性研究

Research on the extraction of flavonoids from Chenopodium quinoa and its antioxidant activity

以藜麦(Chenopodium quinoa Willd.)种子为研究对象,基于超声时间、固液比、负压等条件的单因素试验,结合藜麦粉末SEM表征结果,通过响应面法优化获得藜麦黄酮最优提取工艺条件;藜麦黄酮粗提物经乙酸乙酯萃取后过硅胶柱洗脱(洗脱剂为丙酮)分离纯化,得到纯度较高的藜麦黄酮,对其进行体外抗氧化活性测试。结果表明,超声-负压法提取藜麦黄酮最佳工艺参数为超声时间27 min、固液比1∶36(g/mL)、负压0.059 MPa,该条件下藜麦黄酮提取率为(5.31±0.038)mg/g,与预测提取值5.28 mg/g接近。影响藜麦黄酮提取率的因素依次为固液比>负压>超声时间。藜麦黄酮抗氧化活性与浓度呈正相关,浓度越大,抗氧化能力越强。当浓度为0.25 mg/mL时,其对DPPH自由基的清除率达到(89.5±0.430)%。

Taking the seeds of Chenopodium quinoa as the research object,based on ultrasonic time,solid-liquid ratio,and negative pressure of single factor experiment,combined with the characterization results of SEM of Chenopodium quinoa powder,the optimal extraction process condition of flavonoids from Chenopodium quinoa was obtained by response surface optimization.The crude extract of flavonoids from Chenopodium quinoa was extracted with ethyl acetate and purified by the silica gel column(The eluent was acetone)to obtain the flavonoids with high purity,which was tested for antioxidant activity in vitro.The results showed that the best process parameter for the extraction of flavonoids from Chenopodium quinoa by ultrasonic-negative pressure was ultrasound time of 27 min,solid-liquid ratio of 1∶36(g/mL)and negative pressure of 0.059 MPa.The extraction rate(5.31±0.038)mg/g was close to the predicted extraction value of 5.28 mg/g.The factors affecting the extraction rate of flavonoids from Chenopodium quinoa were solid-liquid ratio>negative pressure>ultrasonic time.The antioxidant activity of flavonoids from Chenopodium quinoa was positively correlated with the concentration,and the greater the concentration,the stronger the antioxidant capacity.At a concentration of 0.25 mg/mL,the scavenging rate of the DPPH radical reached(89.5±0.430)%.