Abstract: The optimal conditions for the extraction of Kuding tea polyphenols for achieving maximum extraction yield were determined by response surface methodology to be ethanol concentration of 52%, material/liquid ratio of 1:24 (g/mL), microwave power of 291 W, and microwave treatment time of 62 s. The extraction rate of polyphenols was 114.82 mg/g under the optimal extraction conditions. The IC50 values of the obtained extract against DPPH, hydroxyl, superoxide anion ion free radicals and lipid peroxidation were 29.24, 34.14, 872.3 mg/L and 11.48 mg/L, respectively, suggesting that Kuding tea polyphenols have a remarkable antioxidant effect.

Key words: Kuding tea, polyphenols, extraction, response surface analysis, antioxidant