Abstract:

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.

Key words: chitosan, tea polyphenol, adsorption, green tea