正交设计优选乌饭树叶中总黄酮的微波提取工艺研究

Study on Microwave Extraction Process of Total Flavonoids from Vaccinium Bracteatum Thunb. Leaves by Orthogonal Design

关键词:  乌饭树叶  总黄酮  微波提取  正交试验

Key words:  Vaccinium bracteatum Thunb. leaves  total flavonoids  microwave extraction  orthogonal experiment

摘要:

目的 探讨微波辅助提取乌饭树叶中总黄酮的最佳工艺。方法 利用紫外分光光度法测定乌饭树叶总黄酮的含量，采用单因素试验和L₉（3⁴）正交设计试验进行优化，以其总黄酮转移率为指标，考察提取温度、提取时间、乙醇浓度、粉碎程度和料液比对总黄酮转移率的影响，筛选最佳提取工艺。结果 微波提取乌饭树叶总黄酮的最佳工艺：取乌饭树叶粉碎过80目筛，加入40倍量70%乙醇于70℃下250 W微波提取10 min。经验证实验结果表明，此条件下总黄酮转移率达91.34%，纯度21.53%（RSD=0.75%，n=3）。结论 微波提取具有效率高、时间短、能耗低等优点，且优选的提取工艺稳定，为乌饭树叶的后续研究提供了一定的参考。

Abstract:

OBJECTIVE To optimize the microwave extraction process of total flavonoids in leaves of Vaccinium bracteatum Thunb.. METHODS Ultraviolet spectrophotometry was used to determine the total flavonoids in Vaccinium bracteatum Thunb. leaves. While the transferring rate of total flavonoids was taken as index, single factor and L₉(3⁴) orthogonal test was employed to optimize the microwave extraction process parameters including extraction temperature, extraction time, ethanol concentration, degree of pulverization and material liquid ratio. RESULTS The optimum of microwave extraction process was as followed:the Vaccinium bracteatum Thunb. leaves was smashed and filtrated through 80 mesh, then 70% ethanol was added at the material liquid ratio of 1:40; the microwave extraction process was performed at the temperature of 70℃ and microwave power of 250 W for 10 min. Under this condition, the verification test results showed that the transferring rate of the total flavonoids of Vaccinium bracteatum Thunb. leaves was 91.34% and the purity was 21.53%(RSD=0.75%, n=3). CONCLUSION Microwave extraction has the advantages of high efficiency, brief and low energy consumption, and the optimized extraction process is stable, which provides a reference for follow-up study of Vaccinium bracteatum Thunb. leaves.