石榴皮多糖提取过程的动力学分析

Dynamics analysis of the extraction of polysaccharides from Granati Pericarpium

目的以动力学模型分析热水浸提石榴皮多糖的参数值。方法石榴皮石油醚脱脂后不同温度条件下进行恒温提取多糖,以总糖和还原糖为检测指标,求解提取动力学的速率常数k、相对萃余率、表面扩散系数DS、表观活化能Ea和半衰期t1/2等数值。结果石榴皮多糖提取过程的动力学基本符合一级动力学方程。提取系统温度越高,石榴皮多糖质量浓度达到平衡所需要的时间越短,k值和DS值呈现逐渐增大的趋势,相对剩余量下降越快,Ea值大体上呈现下降趋势,t1/2值均随之减小。结论所得石榴皮多糖提取动力学参数值提示溶质的内扩散为浸提过程的关键控制步骤。

AIM To obtain the parameters for hot water extraction of polysaccharides from Granati Pericarpium based on dynamic mathematical model. METHODS Polysaccharides were extracted thermostaticlly in different temperatures after Granati Pericarpium being defatted by petroleum ether. With the total sugar and reducing sugar as indice,extraction parameters,such as kinetic rate constant k,the relative rates of raffinate,surface diffusion coefficient DS,the apparent activation energy Ea,half-life values t1 /2,were thus obtained. RESULTS The dynamic extraction process fitted the first order reaction equation. The higher the temperature for extraction,the shorter time for polysaccharides from Granati Pericarpium concentration to reach the required balanced state,k values and DSvalues intended to increase gradually,but with a relative rapid decline of raffinate,and both Eavalues and t1 /2values generally presented to decrease. CONCLUSION The extraction kinetics parameters for polysaccharides from Granati Pericarpium suggest that the critical procedure may lie in the inner diffusion of the solvent during maceration.