壳聚糖-聚酰胺法组合纯化甜叶菊废渣中黄酮

Process of purifying the flavonoids by chitosan and polyamide from waste residue of Stevia rebaudiana

采用壳聚糖絮凝与聚酰胺吸附相结合的方法纯化甜叶菊废渣乙醇提取液中的黄酮,并优化该工艺的条件。以黄酮纯度为主要考查指标,通过单因素及正交试验进行分析,确立壳聚糖絮凝沉淀法纯化的最佳条件;通过研究聚酰胺粉对甜叶菊废渣黄酮的吸附解吸性能、吸附动力学及等温线、上样浓度、过柱的流速、乙醇洗脱浓度及流速等,建立聚酰胺柱层析纯化法的最佳条件。实验表明:壳聚糖絮凝温度35℃,p H=5,搅拌时间15 min,壳聚糖溶液加入量1.0 m L。聚酰胺吸附的上样浓度约为0.2 mg/m L,流速为1.5 m L/min,洗脱液为体积分数60%乙醇,流速为1.5 m L/min,最终黄酮纯度达到53.42%,为醇提物的6倍以上。

The purification and extraction of flavonoids by chitosan and polyamide from waste residue of Stevia rebaudiana ethanol solution and optimization of purification were studied. With flavonoids purity as the index, we analyzed the chitosan flocculation by single test and orthogonal test. The polyamide purification process was studied by the properties of the adsorption, desorption, the adsorption kinetics and isotherm. The optimum condition was obtained by comparing the different sample concentration, absorption velocity, ethanol concentration and velocity for desorption. The results showed that the appropriate conditions of the process were as follow： the sample was stirred for 15 min with 1.0 mL chitosan solution at 35 ℃ and pH 5. The sample concentration for absorption by polyamide was about 0.2 mg/ mL and the velocity was 1.5 mL/min. The desorption was 60% ethanol at 1.5 mL/min. The purity were 53.42% , increased about more than 5 times. This progress solve the problem of hard to reuse polyamide, reduce the cost greatly, and can be used to pure the flavonoids extracted from Stevia Rebaudiana waste residue.