In this study, the levels of bioactive compounds in tea leaves produced by fermenting fresh tea leaves in nitrogen gas are investigated. The fermentation was conducted at different temperatures: room temperature (28±2), 35, and 40ºC; and for each temperature setting, the fermentation times were 6, 9, 12, and 15 hours. The results show that the GABA content increased significantly with fermentation temperature. The most appropriate temperature and time for the anaerobic fermentation to produce GABA and other bioactive compounds were, respectively, 40ºC and 9 hours. Under these conditions, GABA content reached the maximum value ( mg/100 g of dry tea); that of total polyphenols was of dry matter (DM); caffeine was DM; and soluble solids were DM. | Effects of anaerobic fermentation in a nitrogen atmosphere on bioactive compound content in Vietnamese GABA tea
