Comparison of Tea Water Extraction and Ethanol-extraction Extracting Tea Polyphenols from Unfermented Pu-erh

The anhydrous ethanol,pure water,and different concentrations of aqueous ethanol solvent were used to extract tea polyphenols from Pu-erh tea( unfermented tea). Based on four factors( extraction temperature,extraction time,solid-liquid ratio and different concentrations of aqueous ethanol) single-factor test in orthogonal experiment,by orthogonal experiments and comparative analysis,the contribution rate on extraction of tea polyphenols and differences with the four factors were analyzed. The results showed that the mixed solvent to extraction method polyphenols was the highest( 31. 499 %),water as the solvent extraction method was second( 22. 556 %),and last one was anhydrous ethanol( 11. 520 %). The effect and difference of four factors to polyphenols extraction were different with different solvent.