从甜菊叶中提取和精制甜菊苷的方法

METHOD OF EXTRACTION AND PURIFICATION OF STEVIOSIDES FROM STEVIA LEAVES

本实验用１５００ｍ１８０℃热水从１００ｇ甜菊干叶中萃取甜菊苷，用Ｃａ（ＯＨ）２和聚合硫酸铁作絮凝剂，在８０℃温度下去除萃取液中的杂质和色素，再经吸附树脂处理后于９８％的乙醇中结晶提纯，可得８．９６ｇ纯度为９６．２％的甜菊苷．文中对影响提取和精制的因素如温度、水量、絮凝剂和树脂种类以及乙醇浓度等进行探讨．结果表明，本方法可大大提高结晶的收率和纯度．

Stevioside was extracted from l00g leaves of dry stevia in l500ml hot water(80℃).The impurity and pigmental materials were removed from the extract with the Ca(OH)2 and Solidpolyfer-ric Sulfate as flocculant. After treated with adsorbed resins,the stevioside was further pu-rified by crystallization with 98%ethanol.The 8.96g stevioside of 96.2%pure was obtained. Thefactors influenced the extraction and purification i,e.temperature,water volume, flocculant, thesort of resine, and concentration of ethanol etc ,were discussed. The results proved that themethod of extraction may increase the percentage of the pure product.