响应面法优化苦荞壳中总黄酮的提取工艺

Optimization of technology for extracting total flavonoids from tartary buckwheat shell by response surface methodology

目的优化苦养壳中总黄酮提取工艺。方法用浸提法、恒温振荡提取法、索氏提取法、高压提取法、超声波提取法进行实验,以最大提取率及总黄酮含量为指标进行对比,优选出浸提法为最佳提取方法。采用响应面分析法对影响苦荞壳中总黄酮提取率的4个主要因素,乙醇浓度、提取温度、提取时间、料液比进行研究,并以Box-Behnken中心组合设计建立数学模型。结果浸提法最佳提取工艺为乙醇浓度45%、提取温度85℃、提取时间2.5 h、料液比1:40,此条件下总黄酮含量为15.7 mg/g,提取率为1.57%,回收率为98.2%,回归模型的预测值(16.4 mg/g)与实测值的相对误差为4.6%。结论以Box-Behnken设计结合响应面分析法能较好地预测苦荞壳中总黄酮的含量,该方法简便省时,是苦荞壳中提取总黄酮的有效途径。

Objective To optimize the extraction technology of total flavonoids from tartary buckwheat shell. Methods The maximum extraction rate and content of total flavonoids were compared by soak extrac-tion method, constant temperature oscillation extraction method, soxhlet extraction method, high-pressure ex-traction method, and ultrasonic wave extraction method. Soak extraction method was selected as the optimiza-tion extraction method. Effects of ethanol concentration, extraction temperature, extraction time and liquid to solid ratio on total flavonoids extraction rate were studied using response surface methodology, and the expe-riment mathematical model was established according to Box-Behnken central composite experimental design. Results The optimum extraction conditions are ethanol concentration 45%, extraction temperature85℃, ex-traction time 2.5 h, and the liquid to solid ratio 1:40. Under the optimum conditions, the flavonoids yield is 15.7 mg/g, the maximum extraction rate is 1.57%, close to predictive value16.4 mg/g. Conclusion The combination of Box-Behnken design and response surface analysis can well optimize the extraction technology of total flavonoids from tartary buckwheat shell.