Ancient tea plants black tea taste determinants and their changes over manufacturing processes

Ancient tea plants black tea (ATBT) has outstanding sweet-mellow taste, but what contributes to its quality remains unclear. We tested 36 freeze and 9 finished tea sampled from five processing stages for ATBT by electronic tongue (ET), high performance liquid chromatography, and gas chromatography-tandem mass spectrometry. ET and chromatographic data revealed variation of sensory characteristics and chemical compounds among the five processing steps of ATBT. Through the correlation analysis and principal component analysis, it was concluded that ester-catechins and soluble sugars content in tea leaves had significant effect with the bitterness and sweetness in tea infusions (p < 0.05). Catechins, theaflavins, soluble sugars, and ET signals was considered an important information for determining the processing steps, and it had an impact on the taste of the tea infusions. These findings indicated that accurate processing control is effective approach to maintaining chemical constituents of contributes to taste quality in ATBT.