响应面法优化超声波辅助提取甘草多糖工艺

Optimization of Ultrasound-assisted Extraction of Polysaccharides from Radix Glycyrrhiza Using Response Surface Analysis

研究乌拉尔甘草多糖的超声波辅助提取工艺。在单因素试验的基础上,选定超声波功率、提取时间和提取温度3因素的3个水平进行中心组合试验,建立甘草多糖提取率和纯度的二次回归方程,其决定系数分别为98.98%和91.67%。通过响应面分析及岭嵴分析得到优化提取工艺条件为超声功率580W、提取时间64.5min、提取温度64.6℃,该条件下多糖提取率预测值为9.62%,验证值为9.56%,是传统水浴浸提法提取率的3倍多;多糖纯度预测值为71.36%,验证值为65.65%。红外光谱检测结果显示,超声波提取法与传统浸提法所得甘草粗多糖基本构成相同。

A three-level Box-Behnken design, combined with canonical and ridge analyses, was employed to optimize some process parameters for the ultrasound-assisted extraction of polysaccharides from Radix Glycyrrhiza, one of the most valued traditional Chinese medicines. The most critical factors affecting the extraction of polysaccharides from Radix Glycyrrhiza, were determined to be ultrasound power, length of extraction and extraction temperature. Using multiple regression analysis, the Box-Behnken experimental results were fitted into two quadratic polynomial models describing Radix Glycyrrhiza ploysacchride yield or purity as a function of the 3 above-mentioned factors, with determination coefficients of 98.98% and 91.67%, respectively. The canonical analysis of the established models revealed that three eigenvalues had different signs, indicating a saddle stationary surface. The optimal conditions for the extraction of polysaccharides from Radix Glycyrrhiza were determined using the ridge analysis to be： extraction time, 64.5 min; extraction temperature, 64.6 ℃; and ultrasound power 580 W. Under these conditions, the predicted and experimental values of Radix Glycyrrhiza ploysacchride yield were 9.62% and 9.56%, and those of Radix Glycyrrhiza ploysacchride purity were 71.36% and 65.65%, respectively. The Radix Glycyrrhiza ploysacchride yield given by conventional waterbath extraction for 1 h at 65 ℃ was only the first three of that given by optimized ultrasound-assisted extraction for 1 h at the same extraction temperature. According to infrared spectrometric analysis, the structure of Radix Glycyrrhiza polysaccharides obtained by the two methods were basically identical.