Key Metabolites Influencing Astringency and Bitterness in Yinghong 9 Large-Leaf Dark Tea Before and After
Shuai Wen1,2, Silei Bai1,2,3,4, Ran An5
1Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China.
Journal of Agricultural and Food Chemistry
|November 27, 2024
Summary
Pile-fermentation of dark tea (DT) reduces astringency and slightly increases bitterness. Key metabolites like rutin and EGCG lower astringency, while caffeine increases bitterness, influenced by microbial enzymes.
Area of Science:
- Food Science
- Agricultural Chemistry
- Metabolomics
Background:
- Large-leaf dark tea (DT), specifically Yinghong 9 DT, has been developed.
- The impact of pile-fermentation on the taste quality of this large-leaf DT requires systematic study.
Purpose of the Study:
- To investigate how pile-fermentation influences the taste profile of Yinghong 9 DT.
- To identify key metabolites responsible for taste alterations during fermentation.
Main Methods:
- Sensory taste evaluations were conducted.
- Untargeted metabolomic analysis was employed to identify metabolites.
- Dose-over-threshold values were analyzed for specific compounds.
Main Results:
- Pile-fermentation decreased astringency and slightly increased bitterness in dark tea.
- Sixteen key metabolites were identified, correlating with taste changes.
- Rutin, isoquercetin, myricetin 3-galactoside, epigallocatechin gallate (EGCG), DL-catechin (DL-C), and epicatechin gallate (ECG) reduced astringency.
- Caffeine was linked to the increased bitterness.
Conclusions:
- Pile-fermentation significantly alters dark tea taste by modulating specific metabolites.
- Microbial extracellular enzymes play a crucial role in these metabolic transformations.
- Findings provide a scientific basis for understanding and controlling dark tea flavor profiles.
