Wuyi rock teas of different storage duration have different flavor, bioactivity, and market value, Shuixian is a main variety of Wuyi rock tea. In this study, metabolites composition of Shuixian with different storage years were analyzed using Ultrahigh Performance Liquid Chromatography‐Quadrupole‐Time of Flight‐Mass Spectrometry (UPLC‐Q‐TOF‐MS). A total of 1201 compounds were identified, and 104 differential compounds (VIP > 1.5) were determined. Furthermore, the results showed that five compounds exhibited a positive correlation with storage time, such as alpha‐terpineol formate, carnosol, 2‐phenethyl‐D‐glucopyranoside, Ellagic acid, and D‐ribosyl nicotinic acid, while 24 compounds showed a negative correlation, such as Ethyl linoleate, leucocyanidin, cis‐3‐hexenyl acetate. In total, 29 signature compounds significantly correlated with storage time. These findings shed light on the patterns and mechanisms of changes in the composition of Wuyi rock tea during storage and provide a theoretical foundation for distinguishing the storage years.

This study enhanced the odor retention of instant black tea powder by utilizing ultrasonic-assisted extraction and β-cyclodextrin embedding technology. Through single-factor tests considering variables such as the tea-to-water ratio, extraction temperature, ultrasonic extraction duration, and β-cyclodextrin addition, the optimal extraction conditions were determined. The ideal parameters were identified as follows: β-cyclodextrin was added at a rate of 7.5%, the tea-to-water ratio was 1:16, the ultrasonic extraction temperature was 52 °C, and the extraction duration was 30 min, and then the extract was processed by freeze-drying to obtain instant tea powder. Electronic nose trials revealed that the primary volatile odor compounds distinguishing the 14 groups of instant black tea soups were sulfides, terpenes, nitrogen oxides, alkanes, and aromatic compounds. HS-SPME-GC-MS analysis identified 65 effective volatile compounds, among which 11 key odor compounds, including Benzyl alcohol, Phytol, phenylethyl alcohol, 1,6,10-Dodecatrien-3-ol,3,7,11-trimethyl-,(E)-, Benzeneacetaldehyde, Undecanoic acid, ethyl ester, Dodecanoic acid, ethyl ester, Tetradecane, 2,4-Di-tert-butylphenol, 2-Pentadecanone, 6,10,14-trimethyl-, and indole, were the main contributors to the odor profile of instant black tea. The instant black tea powder produced under these conditions exhibited high quality, providing a valuable reference for further research on the production process of instant black tea powder.

Wuyi rock tea Rougui produced consecutively from 2016 to 2025 were analyzed using UHPLC-QTOF-MS untargeted metabolomics combined with UHPLC-QqQ-MS/MS targeted quantification to characterize polyphenol variation. 17 catechin - gallic acid - related annotated features were retained, it suggesting that storage-related effects extend across a broad range of polyphenolic constituents. Targeted quantification of eight representative catechins and gallic acid revealing esterified and non-esterified catechins varied in both trend and magnitude across production years, without a consistent overall increase or decrease. Gallic acid content was notably higher in the samples with longer storage time, with increases of approximately 166.25% and 168.25% in RG16 and RG17 compared with RG25, respectively. Correlation analysis indicated strong positive associations between EGCG–GCG and ECG–CG, while GA showed non linear correlation with EGCG and GCG. These finding suggest that long - term storage of Rougui is characterized by polyphenol compositional remodeling involving catechin redistribution and gallic acid enrichment.

In this study, Wuyi rock tea Rougui produced consecutively from 2016 to 2025 were analyzed by UHPLC-QTOF-MS untargeted metabolomics combined with UHPLC-QqQ-MS/MS targeted quantification to characterize storage-associated changes in polyphenol composition. From the untargeted metabolic profiles, 17 catechin - gallic acid - related annotated features were retained, encompassing non-galloylated catechins, galloylated catechin derivatives, methylated gallates, theaflavin gallates, and prodelphinidin gallates, suggesting that storage-related effects extend across a broad range of polyphenolic constituents. Targeted quantification of eight representative catechins and gallic acid further revealed that esterified and non-esterified catechins varied in both trend and magnitude across production years, without a consistent overall increase or decrease. Gallic acid content was notably higher in the samples with longer storage time, with increases of approximately 166.25% and 168.25% in RG16 and RG17 compared with RG25, respectively. Correlation analysis indicated strong positive associations between EGCG–GCG and ECG–CG, while GA showed non linear correlation with EGCG and GCG. These findings suggest that long-term storage of Wuyi rock tea Rougui is associated with non-linear polyphenol compositional remodeling, primarily characterized by redistribution within the catechin pool and accumulation of gallic acid. This study will contribute to understanding the dynamic changes in the chemical components of Rougui during storage.