Changes in Quality of Congou Black Tea During the Fermentation Process

【Objective】 To provide a scientific basis for congou black tea fermentation time,effects of fermentation time on sensory quality and main biochemical components were investigated.【Method】 Effects of fermentation time on tea quality were studied by taking pictures and measuring main biochemical components during the fermentation process.【Results】 The cord did not vary with fermentation time but appearance and liquor colors became red gradually.Additionally,the taste was not bitter;the aroma became sweet from grass swell and total score was increased.Compared with 0 h(F1),tea polyphenols and caffeine were decreased by 2.56% and 0.66%,respectively,by fermentation 3.5 h.Moreover,amino acids,thearubigins were increased respectively by 0.48%,1.31%,while teaflavin and theabrownine had no significance change.【Conclusion】 Under the conditions of fermentation temperature 30 ℃,relative humidity of fermentation leaf 90%,air relative humidity 60% and fermentation time 3.5 h,the quality of congou black tea was the best.The quality will be affected negatively when the fermentation time was too short or long.