枣叶黄酮微波-离子液体辅助提取工艺优化及其抗氧化活性研究

摘要

以枣叶为原料,枣叶黄酮提取率为指标,利用单因素分析结合正交试验的方法优化了枣叶黄酮的微波-离子液体辅助提取工艺条件,并研究了枣叶黄酮的抗氧化活性.结果表明:枣叶黄酮微波-离子液体辅助提取的最佳工艺条件为微波功率195 W、微波时间12 min,乙醇浓度60％、料液比1∶25 (g/mL)、离子液体1-辛基-3-甲基咪唑四氟硼酸盐的浓度为0.6 mol/L、提取次数2次.在该工艺条件下,黄酮提取率平均值为3.20％.抗氧化性研究显示,枣叶黄酮对DPPH自由基、羟自由基以及亚硝酸根离子均具有较强清除能力,IC50分别为0.181 mg/mL、0.080 mg/mL和0.039 mg/mL,表明枣叶黄酮具有较强的抗氧化活性.%Using Ziziphus jujuba Mill.Leaf as the material,extraction yield as the index,the extraction conditions of the flavonoids was optimized based on the single factor analysis and orthogonal experimental design,and the antioxidant activities were also studied.The results showed that the optimal extraction conditions of the flavonoids were as follows:microwave power 195 W,microwave time 12 min,ethanol concentration 60％,solid-liquid ratio 1:25 (g/mL),concentration of ionic liquid 1-hexyl-3-methylimidazolium tetrafluoroborate 0.6mol/L,extraction time 2 times.Under these conditions,the mean of flavonoids yield is 3.20％.The results of antioxidant activities were showed that the flavonoids had strong scavenging effects on DPPH radical,OH radical and nitrite ion.IC50 values were 0.181 mg/mL,0.080mg/mL,0.039mg/mL,respectively,which indicated that the flavonoids from Ziziphus jujuba Mill.Leaf has strong antioxidant activitiy.