Abstract:To explore the effects of withering and baking factors on the antioxidant biological activity of flat green tea, based on single factor analysis, it was found that the withering temperature should be controlled at 190~210 ℃ and the withering time should be 5~7 minutes to preserve the antioxidant activity of green tea; Baking time is 30~40 minutes. Additionally moreover, the optimal process for preserving the antioxidant activity of green tea was as follow: fixing at 190 ℃ for 5~9 min, along with roating at 150 ℃ for 30 min; the suboptimal process was: fixing at 210 ℃ for 5 or 9 min, along with roasting at 150 ℃ for 30 min; fixing at 230 ℃ for 3.5 min along with shaping at 165 ℃ for 3.5 min, followed by roasting at 150 ℃ for 30 min. Correlation analysis showed that the correlation between the mass concentration of tea polyphenols in green tea solution and its in vitro and in vivo antioxidant activities was relatively low. However, the results of the antioxidant activity characterization via the targeted adsorption and removal of tea polyphenols in green tea solution, and the gradient differential recombination of tea polyphenols and the tea polyphenols in green tea solution showed that the mass concentration of tea polyphenols was extremely strong and significantly correlated with the tea’s antioxidant activity. Therefore, it is speculated that there might be other interfering factors that still require further research. The results indicate that the antioxidant activity of flat shaped green tea is influenced by different processes such as fixation temperature and time, and roasting time, and combined processing processes should be preferentially selected in order to preserve the activity of green tea. The results provide scientific basis for the optimization of green tea processing technology.
