荷叶总黄酮提取工艺优化及其抑菌活性评价

Optimization of Extraction Technology of Total Flavonoids from Lotus Leaf and Antibacterial Activity Assessment

采用响应面法优化荷叶总黄酮浸提工艺,并考察其抑菌活性,为荷叶黄酮的提取开发提供参考。通过回流法提取荷叶中总黄酮,以总黄酮得率为考察指标,在单因素试验的基础之上建立乙醇浓度、料液比和温度的三因素回归模型,以响应面法优化总黄酮提取工艺参数为乙醇浓度68%、料液比1∶37、提取温度74℃,在此条件下的总黄酮得率为8.60%,而预测值为8.51%。各因素对总黄酮得率的影响为料液比>乙醇浓度>提取温度。通过生长曲线分析发现,荷叶总黄酮提取物能有效抑制金黄色葡萄球菌和假单胞菌的生长,且适宜的抑菌浓度分别为30μg/m L和40μg/m L。采用回流法提取荷叶总黄酮不仅得率较高,而且提取物表现出较强的抑菌活性,作为天然防腐剂具有良好的开发应用前景。

Extraction technology of total flavonoids from lotus leaf was optimized and it＇ s antibacterial activity was studied,so as to provide a reference for the extraction and development of lotus leaf flavonoids.Total flavonoids from lotus leaf were extracted by ultrasonic extracting.Total flavonoids extraction yield was used as optimizing index.Material-to-solvent ratio, ethanol volume percent and extraction temperature were selected to establish regression mathematical models based on single factor experiments, and the optimized conditions were then confirmed.The parameters of technology optimized by the model of total flavonoids extraction yield were as follows ： ethanol volume percent was 68%, material-to-solvent ratio was 1： 37 ,extraction temperature was 74 ℃ ,and total flavonoids extraction yield was 8.60% ,but the predicted value was 8.51%.The effects of experimental factors on total flavonoids extraction yield could be ordered as material-to-solvent ratio 〉ethanol volume percent 〉extraction temperature.The antibacterial activity of lotus leaves flavonoids to two bacteria was studied by Biosreen automatic growth curve determination apparatus.It was shown that the appropriate inhibition concentration of lotus leaves flavonoids to Staphylococcus aureus Rosenbach and Pseudomonas were 30 μg/mL and 40 μg/ mL.The ultrasonic extraction has the advantage of high extraction yield and strong antibacterial activity,which has good development prospect as natural preservative flavonoids.