响应面法优化提取紫花苜蓿叶总黄酮及其抗氧化活性研究

Optimization Ultrasonic Extraction of Total Flavonoids from Medicago sativa L.by Response Surface Methodology and Its Antioxidation in Vitro

目的:确定紫花苜蓿叶总黄酮超声辅助提取最佳工艺条件,并对其抗氧化活性进行评价。方法:以紫花苜蓿叶片为试验材料,以总黄酮提取率为指标,在单因素试验的基础上,应用响应面法优化其超声提取条件,并通过不同的抗氧化评价指标测定研究其抗氧化活性。结果:在试验范围内各因素对紫花苜蓿叶总黄酮提取率的影响程度从大到小依次为:超声时间>乙醇体积分数>提取温度;紫花苜蓿叶总黄酮的最佳提取工艺参数为乙醇体积分数65%、超声波功率100 MHz、提取温度67℃、提取时间40 min,在此工艺条件下,苜蓿叶中总黄酮的得率为5.29 mg/g;紫花苜蓿叶总黄酮具有一定的抗氧化能力,并与总黄酮质量浓度呈一定的正相关关系。结论:利用响应面法分析结果可靠,得到紫花苜蓿叶总黄酮超声辅助提取的最佳工艺条件。紫花苜蓿叶总黄酮具有一定的抗氧化活性。

To explore the optimal ultrasonic-assisted extraction conditions of total flavonoids from Medicago sativa L.leaves and evaluate the antioxidant activity. Taking Medicago sativa L. Leaves as material, based on the single-factor tests, the ultrasonic extraction conditions of total flavonoids from Medicago sativa L. leaves were optimized by response surface methodology（RSM） in order to increase the extraction rate of total flavonoids. Meanwhile, the antioxidant activity of total flavonoids was assessed using different assay model systems in vitro. The optimal extraction conditions of total flavonoids were ethanol concentration of 65%, ultrasonic power of 80 MHz, extraction temperature of 67 ℃ and extraction time of 40 min. Under the optimal conditions, the maximum extraction rate of total flavonoids was 5.29 mg/g. Extracted total flavonoids had some antioxidant capacity in a dose-dependent manner. Response surface methodology is applicable for the optimization of ultrasonic extraction of total flavonoids from Medicago sativa L. leaves. The total flavonoids from Medicago sativa L. leaves have some antioxidant capacity.