Novel insight into the effect of fermentation time on quality of Yunnan Congou black tea. (1st February 2022)

• Record Type: Journal Article
• Authors: Wang, Huajie; Shen, Shuai; Wang, Jinjin; Jiang, Yongwen; Li, Jia; Yang, Yanqin; Hua, Jinjie; Yuan, Haibo
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 155(2022)
• Publication Date: 2022-02-01
• Subjects: Yunnan congou black tea -- Fermentation time -- Catechins -- Theaflavins -- Volatile compounds; FT2 Dried tea sample fermented for 2 h -- FT3 Dried tea sample fermented for 3 h -- FT4 Dried tea sample fermented for 4 h -- FT5 Dried tea sample fermented for 5 h -- PLS-DA Partial least-squares discriminant analysis -- OAV Odor activity value -- SPME solid-phase microextraction technology -- GC-MS Gas chromatography-tandem mass spectrometry -- TSC Total simple catechin -- TETC Total ester catechins -- TAC Total all of catechins -- Sugar4 The sum of four sugar components -- 10TFRB The ratio of the sum of 10 TFs and TRs to TBs (quality index); Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2021.112939
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: Fermentation is a crucial process in black tea processing; however, the effect of fermentation time on the quality of Yunnan Congou black tea has never been assessed. This study aimed to evaluate the quality of Yunnan Congou black tea by detecting quality components, artificial sensory evaluation, and objective attributes under different fermentation times (2, 3, 4, and 5 h). Partial least squares discriminant, odor active value, and least-significant difference analyses were used to identify key differences in its compounds. Overall, 36 non-volatile and 142 volatile compounds were detected. We found that 3 h was the optimal fermentation time for retaining several simple catechins, allowing formation of theaflavins (TFs) and thearubigins (TRs) and promoting formation and conversion of sugars and degradation of flavonoid glycosides. The volatile compounds were most abundant, and sweet and umami comprehensive sensor responses were stronger in the 3 h-fermented samples with the best sensory quality. Nine non-volatile (including TFs, TRs, theabrownins, caffeine, and glucose) and eight volatile (including linalool, phenylacetaldehyde, methyl salicylate, benzaldehyde, 2-pentyl-furan, and trans -β-ionone) markers were identified using multivariate statistical analysis. This study provides technical guidance for directed and standardized production and lays a theoretical foundation for the in-depth study of Yunnan Congou black tea. Highlights: Fermentation time significantly influences the quality of Yunnan Congou black tea. Evaluation was done using sensory, objective attributes, and multivariate analyses. Thirty-six non-volatile and 142 volatile compounds were detected among tea samples. Fermentation for 3 h was determined as the optimum time for Yunnan congou black tea. Nine non-volatile and 8 volatile key differential compounds were identified.