微波提取枸杞叶中总黄酮工艺及其不同采收期含量变化

Technical Study and Comparison of Total Flavonoids Extracted in Leaves of Lycium barbarum of Different Picked Time by Microwave-assisted

目的:优选微波辅助提取宁夏枸杞叶总黄酮的提取工艺并测定其不同采收期总黄酮含量。方法:分别考察乙醇体积分数、料液比、微波时间、微波电流强度4个单因素对提取效率的影响,并设计正交试验,所得结果采用方差分析。利用优选出的最佳微波提取工艺测定比较不同采收期枸杞叶中的总黄酮含量。结果:确定了最佳单因素水平,通过正交试验优选出微波辅助提取枸杞叶总黄酮的最佳工艺条件为乙醇体积分数55%、料液比1∶45、微波提取时间40 s、微波电流强度60 mA。结论:通过比较不同采收时期枸杞叶总黄酮的含量,结果为5月中旬含量最高。

Objective：To optimally select the extraction technology of total flavonoids of leaves of Lycium barbarum by microwave-assisted and to determine the content of total flavonoids of leaves of L.barbarum of different picked time.Method： The effects of four single-factors（including ethanol concentration,material-liquid rate,microwave irradiation time and current intensity） on the extraction of total flavonoids of leaves of L.barbarum have been studied.And the results of the orthogonal experiment were analyzed by variance analysis.The best extraction technology was used to determine the content of total flavonoids in leaves of L.barbarum at different picked times.Result： The best single factor was determined and the best extraction of total flavonoids of leaves of L.barbarum by microwave-assistant with orthogonal experiment was optimized.The best extraction technology was as follows： using 55% ethanol as extractor with the ratio of material to liquid at 1∶45 and extraction for 40 s in 60 mA current intensity.Conclusion： By comparing the content of total flavonoids in leaves of L.barbarum at different picked time,the content of total flavonoids in leaves was decreased with the leaves growing.It is conclude that the best picked time of leaves of L.barbarum is in the middle of May.