Optimum brewing conditions for dissolving green tea polyphenols and components analysis

The purpose was to determine the optimum brewing conditions for a cup of green tea.According to single factor experiments, a mathematical model was established using Box-Behnken central composite experimental design with contents of tea polyphenols as the response.Temperature, liquid-solid ratio, time and frequency were found to be the principal factors as well as cup, whether covered and stirred were found to be the habitual factors.The results showed that the optimum process conditions of green tea were as follows:temperature 81℃, liquid-solid ratio 150:1 (mL/g) , time 7min, and verified value 112.80mg/g.Total catechins occupied about 57.29% of tea polyphenols.The contents of EGCG, ECG, EGC and caffeine were higher than the others in this condition.It could be improved the taste of tea infusion by the combined action of total catechins and caffeine and avoided the phenomenon of too bitter or too astringent.The effect of habitual factors can be used as a reference.