珠状壳聚糖树脂对绿茶中茶多酚的吸附研究

本实验制备了珠状壳聚糖树脂，通过TG-DSC 对其热稳定性进行了表征，研究了珠状壳聚糖树脂对绿茶中茶多酚的吸附分离性能，探讨了其吸附条件，并就珠状壳聚糖树脂对茶多酚的吸附动力学进行了讨论。结果表明，珠状壳聚糖树脂在温度小于172℃条件下具有较好的热稳定性；珠状壳聚糖树脂对茶多酚较佳的吸附条件为：珠状壳聚糖湿树脂4.0g(干重0.22g)/ 茶多酚含量为1.573mg/ml 的25ml 茶汤、吸附时间2h、茶汤pH7.06、温度30℃。此条件下提取率可达74.1%，单位吸附量为136.1mg/g；珠状壳聚糖树脂对茶多酚的吸附动力学符合Langmuir 等温吸附公式，单位饱和吸附量为1116mg/g。

Study on Adsorption of Tea Polyphenols from Green Tea onto Beaded Chitosan Resin

Beaded chitosan resins were prepared, which show good thermostability when temperature is lower than 172 ℃. Tea polyphenols (TP) was separated from green tea via the absorption of the beaded chitosan resins. The conditions and the mechanism of adsorption and desorption of TP were discussed. The results showed that the optimum adsorption conditions of TP (1.573 mg/ ml) in 25 ml tea soup are as follows: the beaded chitosan resin 4.0 g ( dry weight 0.22 g ), adsorption time 2 h, pH of tea soup 7.06 and adsorption temperature 30 ℃. The extraction rate can reach 74.1% under the above conditions and the absorption capacity is 136.1 mg/g. Furthermore, the experimental results showed that the adsorption kinetics of the beaded chitosan resins to TP accords with the Langmuir formula, and the saturated adsorption capacity is 1116 mg/g.