Study on extracting tea polyphenols from green tea by microwave assisted aqueous two-phase systems

Tea polyphenols were extracted from green tea by the method of microwave assisted ethanol-dipotassium hydrogen phosphate aqueous two-phase system. The effects of factors such as the alcohol amount, the amount of dipotassium hydrogen phosphate, the extraction time, the ratio of solvent and material, and the microwave power on extraction of tea polyphenols were investigated and optimized.The results showed that the optimum conditions were as follows: volume fraction of ethanol 50%, the ratio of solvent and material 50 m L·g^-1, the microwave power 370 W, the extraction time 30 s.Under the optimized conditions, the yield of tea polyphenols was 38.98%.The research result can be applied to the extraction of tea polyphenols in green tea and green tea quality analysis.