板蓝根多糖的提取与脱蛋白工艺优化

Optimization of extraction and protein removal of polysaccharides from indigowood root( Isatisindigotica Fort. )

通过Box-Behnken组合实验设计,考察了料液比、提取温度及提取时间对板蓝根多糖提取率的影响。利用响应面分析方法,模拟得到二次多项式回归方程的预测模型,并确定最佳提取条件为:料液比为1∶55,提取温度80℃,提取时间3.5 h。在此条件下,板蓝根多糖的提取率为3.55%。以蛋白脱除率和多糖损失率为指标,比较了Sevag法、三氯乙酸法和胃/胰蛋白酶法对粗多糖中蛋白质的脱除效果。结果表明:采用胃/胰蛋白酶脱蛋白工艺,蛋白脱除率较高,分别可达63.5%和52.9%,多糖损失较少,且操作简便,无污染,是较好的脱蛋白方法。

To optimize the extracting procedure of polysaccharides from Indigowood Root （Isatisindigotica Fort. ） and protein removal conditions. The Box-Behnken design was used to investigate the effects of processing parameters of extraction from Indigowood Root onthe yield of polysaccharides. Three independent variables such as solid to solvent radio, extraction temperature and extraction time were studied. The optimal conditions were determined and three-dimensional response surfaces wereplotted from the mathematical models. Considering the efficiency, the optimum conditions of polysaccharides extraction were solid to solvent radio of 1 ： 55, extraction temperature of 80% , and extraction time of 3.5 h. Under optimized conditions, the experimental yield of 3.55% agreed closely with the predicted yield. Furthermore, four methods of Sevag, TCA, pepsin and trypsin for removing protein in crude polysaccharides extracted from Indigowood Root were evaluatedand compared based on deproteination efficiency and polysaccharide loss. The resuits indicated that the pepsin and trypsin methods were better than the othertwo methodswith protein removal rate of 63.5% and 52.9% respectively, and with less polysaccharide loss. Theenzymic methods were simple, pollution-free- and suitable to remove protein in crude polysaccharides from Indigowood Root.