超声提取枸杞叶总黄酮的工艺研究

目的：优选超声辅助提取枸杞叶总黄酮的提取工艺并探讨枸杞叶的合理采收时期。方法：分别研究乙醇浓度、乙醇用量、超声提取时间、超声时温度四个单因素对提取效果的影响，设计正交试验，所得结果采用方差分析。利用优选出的最佳超声提取工艺测定比较不同采收时期枸杞叶中的总黄酮含量。结果：确定了最佳单因素水平，通过正交试验法优选出超声辅助提取枸杞叶总黄酮的最佳工艺条件为乙醇浓度75％、乙醇用量1：40、超声提取时间30min、超声时温度50℃。结论：通过比较不同采收时期枸杞叶总黄酮的含量，发现总黄酮的含量随枸杞叶生长而下降，结合枸杞果园生产探讨得出枸杞叶合理采摘时期为4月上旬和11月中旬。

Technical Study of Total Flavonoids Extraction in Lycium Chinensis Leaves by Ultrasonography

Objective： To optimally select the extraction technology of total flavonoids of Lycium chinensis leaves by ultrasonography and to explore the reasonable picked time of Lycium chinensis leaves. Methods： The effects of four single-factors（including ethanol concentration, ethanol consumption, ultrasonic extraction time and temperature） on the extraction of total flavonoids of Lycium chinensis leaves have been studied .And the results of the orthogonal experiment were analyzed by variance analysis. Use the best extraction tech- nology to determine the contents of total flavonoids in leaves of Lycium chinensis at different picked times. Results： The best single factor was determined and the best extraction technology of total flavonoids of Lycium chinensis leaves by ultrasonography with orthogonal experiment was optimized. The best extraction technology were as follows： using 75%（V/V） ethanol as extractor with the ratio of material to liquid at 1：40 and extraction for 30min in 50℃. Conclusions： By comparing the contents of total flavonoids in leaves ofLycium chinensis at different picked time, the contents oftotaI flavonoids in leaves were decreased with the leaves growing. It is concluded that the best picked time of Lycium chinensis is first ten-day period of April and the middle of November.