Abstract: Medicago L.,an important medical and edible grass,is rich in natural bioactive substances.In order to make full use of flavonoids in M.sativa L.,the microwave-assisted flavonoid extraction process was studied by one-factor experiment of ethanol concentration,microwave power,ratio of solid to liquid,and processing time,and extraction times,respectively, and the orthogonal experiment based on the one-factor experiments.The results show that ratio of solid to liquid and microwave power were main factors and the others were minors.The parameters for optimized extraction process were ethanol concentration at 40%,ratio of solid to liquid at 1:30,microwave power at 500W,and radiation time at 60 seconds.The amount of flavonoids extracted from alfalfa was 4.88 mg/g under the optimized extraction process and similar to the theoretical content at 4.92 mg/g.

Key words: Microwave-assisted, Alfalfa(Medicago sativa L.), Flavonoid, Extraction process

摘要： 为充分利用紫花苜蓿(Medicago sativa L.)中的黄酮类物质,应用微波辅助提取技术,分别对影响其黄酮提取量的乙醇浓度、微波功率、固液比、提取时间和提取次数进行单因素试验,并在此基础上对各因素的互作效率进行正交试验。结果表明:固液比和乙醇浓度是影响提取量的主要因素,微波功率和其它因素影响较小;微波提取苜蓿黄酮的最佳工艺为:40%乙醇浓度,1:30固液比,微波500 W功率下作用60s;在此工艺条件下,黄酮提取量的理论值为4.92mg/g,接近于实际测定值4.88mg/g。

关键词: 微波辅助, 紫花苜蓿(Medicago sativa L.), 类黄酮, 提取方法