RESUMO
Objective To screen the macroporous adsorption resin suitable for the separation and purification of total polyphenols from purple tea and establish the purification process parameters to prepare high-purity total polyphenols from purple tea. Methods The static adsorption-elution test was used to screen macroporous adsorption resin for the purification of total polyphenols from purple tea. Based on the single factor test, the comprehensive score of adsorption rate was used as the index to investigate the effects of different factors on the purification process and identify the optimal parameters for the purification process. Those factors included sample concentration, the pH value of the sample solution, the ratio of column diameter to height, sample size, ethanol percentage in the eluent, eluent volume and elution flow rate. Results The best process parameters for purification of total polyphenols from purple tea by AB-8 macroporous adsorption resin were as following. The sample concentration was 375 μg/ml with flow rate 2 ml/min. The sample volume was 3 BV. The sample solution pH was 2. The ratio of colume diameter to height was 1∶6. The impurities were removed first by water 3 BV. 50% ethanol 4 BV was used for elution with flow rate 2 ml/min. Conclusion AB-8 macroporous resin was selected for the purification of polyphenols from purple tea under the optimized technological conditions. The mass fraction of total polyphenols increased from 40.2% to an average of 69.8%. The solid content decreased from 56.0 mg to 29.9 mg. The established purification process has good stability and feasibility. It can be used as a purification process for total polyphenols from purple tea.