乙醇加热回流法提取构树叶总黄酮工艺优化研究

本试验旨在研究加热回流法提取构树叶总黄酮的最优提取工艺。采用单因素试验设计研究加热回流法提取构树叶总黄酮的适宜反应时间、反应温度、液料比和乙醇浓度,上述4个因素均分别设置为5个水平,以总黄酮提取量为评价指标筛选最佳反应条件;在此基础上采用正交试验设计研究最优提取工艺,对筛选确定的最佳提取工艺进一步进行重复验证试验和工艺放大验证试验。结果表明：单因素试验筛选获得最佳乙醇浓度为70%,最佳反应时间为2.5 h,最佳料液比为1:30,最佳反应温度为70℃;正交试验确定加热回流法提取构树叶总黄酮的最优提取工艺为：乙醇浓度70%、反应时间2.5 h,料液比1:30,反应温度80℃;重复验证试验和工艺放大验证试验得率分别为23.11 mg/g和23.13 mg/g。本工艺稳定性和可操作性良好,适用于构树叶总黄酮的提取。

Optimization of the Extraction Process of Total Flavonoids from Broussonetia papyrifera Leaves by Ethanol Heating Reflux Method

The aim of this experiment is to study the optimum extraction technique of total flavonoids from leaves of Broussonetia papyrifera by using the method of heating reflux. A single factor experimental design was used to study the optimum reaction time, reaction temperature, liquid to solid ratio and ethanol concentration of the extraction of total flavonoids from leaves of the tree. The above four factors were set at five levels, respectively. The extraction amount of total flavonoids was used as the evaluation index to screen the optimal reaction condition. On this basis, orthogonal experiment was used to design the optimal extraction process, and the optimal extraction process was further verified by repeated validation test and process amplification test. The results showed that the optimum ethanol concentration was 70%, reaction time was 2.5 h, solid-liquid ratio was 1:30 and reaction temperature was 70℃. The optimum extraction condition was determined by orthogonal test as follows: ethanol concentration of 70%, reaction time of 2.5 h, solid-liquid ratio of 1:30, and reaction temperature of 80℃. The yield was 23.11 mg/g in repeated validation test and 23.13 mg/g in process amplification test, respectively. This process has good stability and operability, and is suitable for the extraction of total flavonoids from leaves.