微波功率对黄芪提取的影响及其固化作用

THE EFFECT OF MICROWAVE POWER ON EXTRACTION OF EFFECTIVE COMPOSITION FROM ASTRAGULUS SLICES AND IT'S SOLIDIFICATION

为探讨微波场强化药用植物溶剂提取的作用机制,选择黄芪饮片为研究对象,通过对比实验分析了不同微波功率对黄芪水提液分子量分布特征的影响,并同步利用扫描电子显微技术对药材形态结构及其变化特征进行了表征.结果表明,当微波功率为200～900 W,提取时间均为20 min,相比较600 W更有利于分子尺度<4000 Dalton的小分子物质的浸出;900 W使药材内部产生微波固化现象,导致微小导管等通道凝固闭塞,阻碍了药材内部可溶性成分的浸出.因此,合适的微波功率有利于保持药材内部输导组织和薄壁组织的通透性,促进提取过程中有效成分的快速溶出.

To discuss the enhancement mechanism of microwave field on medicinal herb solvent extraction, the water extraction experiments of Astragalus slices were carried out to analyze the effect of the microwave power level on the characteristics of molecular weight distributing of solute in Astragalus water extracts, while the micro-structure and variable features of matrix materials were characterized by using scanning electron microscopy technology. Results show that with the microwave power 200 to 900 W range, and the extraction time 20 minutes, comparatively, 600 W is more benefit to the extraction of small molecular substances less than 4000 Dalton, and 900 W leads to solidification of plant tissues and also cause the coagulation and blockage of tiny trachea, which is un-benefited to the further leaching of soluble components in materials. Therefore, a suitable microwave power level is helpful for maintaining or improving the permeability of transportation tissue in materials and promoting the fast dissolution of effective components during the extraction process of medicinal herb.