莞香茶总黄酮的提取工艺优化及其亚硝酸盐清除效果

Optimization of extraction process and nitrite-scavenging ability of total flavones from Guanxiang Tea

关键词:  莞香茶  总黄酮  响应面法  提取工艺优化  亚硝酸盐清除率

Key words:  Guanxiang Tea  total flavonoids  response surface methodology  extraction process optimization  nitrite removal rate

摘要:

目的 优化莞香茶总黄酮的超声波辅助提取工艺和评价莞香茶总黄酮清除亚硝酸盐的效果。方法 以莞香茶为试样，乙醇为溶剂，用响应面法确定总黄酮的最佳超声提取工艺；同时比较莞香茶、新鲜莞香叶和其他常 见发酵茶总黄酮含量及其清除亚硝酸盐的能力。结果 响应面法预测的最佳提取条件为：乙醇体积分数 61.98%， 超声温度 57.92 ℃，超声时间 3.47 h，提取率预测值为 2.76%，与实测值 2.74% 基本一致。在最佳提取条件下测得 3 个品牌莞香茶和新鲜莞香叶总黄酮提取率分别为2.48%、2.69%、2.79%和2.54%。不同茶叶中的总黄酮清除亚硝酸 盐效率由高到低排序为莞香茶 3（72.85%）、莞香茶 2（71.06%）、乌龙茶 1（70.93%）、新鲜莞香叶（70.35%）、乌龙茶 2 （大红袍）（69.39%）、红茶 2（69.38%）、普洱茶（68.87%）、莞香茶 1（67.14%）、红茶 1（40.38%）。结论 莞香茶在乙醇 体积分数61.98%、超声温度57.92 ℃、超声时间3.47 h时提取总黄酮的效率好，清除亚硝酸盐的效果佳。

Abstract:

Objective To optimize the ultrasonic-assisted extraction technology and evaluate the nitrite-scavenging ability of total flavonoids from Guanxiang Tea. Methods The paper took Guanxiang Tea into the ethanol, used response surface methodology to determine the optimal ultrasonic extraction technology for total flavonoids. At the same time, the total flavonoid content and nitrite-scavenging ability of Guanxiang Tea, fresh Guanxiang leaves and other common fermented teas were compared. Results The results showed that the optimal extraction conditions predicted by the response surface experiment were: ethanol concentration of 61.98%, ultrasonic temperature of 57.92 °C, ultrasonic time of 3.47 h, the predicted extraction rate of 2.76%, which was in agreement with the measured value of 2.74%. Under the optimal extraction conditions, the extraction rates of total flavonoids from three brands of Guanxiang Tea and fresh Guanxiang leaves were 2.48%, 2.69%, 2.79%, and 2.54%. The removal efficiency of total flavonoids in different tea from high to low was as follows: Guanxiang tea NO.3 (72.85%), Guanxiang tea NO.2 (71.06%), Oolong tea NO.1 (70.93%), fresh Guanxiang leaves (70.35%), Oolong tea NO.2 (Dahongpo) (69.39%), black tea NO.2 (69.38%), Puer tea (68.87%), Guanxiang tea NO.1 (67.14%) and black tea NO.1 (40.38%). Conclusion At ethanol concentration of 61.98%, ultrasonic temperature of 57.92 ℃ and ultrasonic time of 3.47 h, the extraction efficiency of total flavonoids was good, and the removal of nitrite was good.