响应面法优化微波萃取黄芪多糖工艺的研究

Optimizing microwave-assisted extraction technology of Astragalus polysaccharides with response surface methodology

用微波萃取技术从内蒙古黄芪[Astragalus membranaceus(Fisch.)Bunge var.mongholious(Bunge)Hsiao]的干燥根中提取黄芪多糖。依据响应面法(RSM,Response surface methodology)原理,使用Design Expert(Static Made Easy,Minneapolis,MN,USA.version6.0.5,2001)软件的中心组合设计建立试验数学模型,对微波萃取黄芪多糖的提取时间、加热温度、提取溶液pH值及液料比进行优化组合。得到最优回归方程:Y=1.14+1·258E-003X1+0.16X2-0.027X3+0.15X4+0.032X11-0.047X22+0.025X33-0.047X22+0.025X33+0.029X44+0.043X1X2-0.018X1X3-0.059X1X4-0.027X2X3+2.263E-003X2X4+0.012X3X4。确定最优操作工艺参数为:微波加热时间20min、加热温度120℃、液料比8∶1、pH值10。粗多糖得率为32%,纯度为44.4%。测定值与预测值相关系数r为0.976。

The microwave - assisted extraction technology was used to extract Astragalus polysaccharides （APS） from the dried roots of Astragalus membranaceus Bunge vat. mongholicus （Bunge） Hsiao. The extracting duration, heating temperature, pH value of extracting solution and the ratio of liquid to solid were optimized according to the mathematic model built by Central Composite Design in Design Expert Software（Static Made Easy, Minneapolis, MN, USA. Version 6. O. 5, 2001 ）on the rationale of response surface methodology, The optimum regression equation was Y =1. 14 ＋ 1. 258E - 0.03X1 ＋ 0. 16X2 - 0. 027X3 ＋ 0. 15X4 ＋ 0.032X11 - 0. 047X22 ＋0. 025X33 - 0. 047X22 ＋ 0. 025X33 ＋ 0. 029X44 ＋ 0. 043X1X2 - 0. 018X1X3 - 0. 059X1X4 - 0. 027X2X3 ＋ 2. 263E -0.03X2X4 ＋ 0. 012X3 X4. The optimum microwave -assisted extraction technology is as follows： the extracting duration is 20 min, the heating temperature is 120 ℃ , pH value of extracting solution is 10 and the ratio of liquid to solid is 8： 1. The yield of crude APS is 32% with a content of 44.4%. The result was verified and the correlation coefficient of measured value and predictive value was 0. 976.