凹凸棒黏土对甜叶菊水提液吸附絮凝作用研究

Adsorption and Flocculation Effect of Attapulgite on Water Extract of Stevia Leaves

摘要: 目的研究凹凸棒黏土(凹土)对甜叶菊水提液的吸附絮凝作用。方法采用单因素和正交实验，考察了吸附絮凝温度、水提液pH值、凹土加入量以及水提液浓度对吸附絮凝效果的影响。结果凹土吸附絮凝法的最佳吸附条件为在pH 8的30 mL甜叶菊水提液中加入0.4 g凹土于60 ℃时所得澄清效果最佳，凹土吸附絮凝法对水提液中莱鲍迪A苷(RA苷)保留率和固形物保留率分别为92.2%和70.5%，明显优于化学絮凝法的62.6%，57.3%。结论凹土可以作为一种新型吸附絮凝剂应用于中药提取液的分离纯化。

Abstract: OBJECTIVE To study the adsorption and flocculation effect of attapulgite(ATP) on water extract of stevia leaves. METHODS The factors influencing adsorptive and flocculate properties of ATP such as the temperature, pH value, the concentration of the water extract of stevia leaves and the amount of ATP addition were investigated by single factor experiment and orthogonal experiment. RESULTS The optimum condition abtained were 60 ℃ temperature and pH 8, respectively, and the addition of ATP was 0.4 g for 30 mL water extract. The adsorption method of ATP showed the higher retention rate of rebaudioside A (92.2%) and solids (70.5%) than the chemical ones (62.6% and 57.3%, respectively). CONCLUSION ATP can be used as a new flocculant for isolation and purification of Chinese herb extracts.