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• RGT and SXT exhibit distinctive different sensory and volatile profiles. • A total of 12 odor-active compounds (OACs) with OAV > 1 are identified as key OACs. • Eight OACs are commonly shared between RGT and SXT, but with different contents. • The unique key OACs of RGT are (E) -linalool oxide and (Z) -jasmone. • The unique key OACs of SXT are β-cyclocitral and α-ionone. The distinctive fragrance of Wuyi Rock Tea (WRT) has garnered high attention in recent years. Herein, we conducted a comprehensive comparison of the sensory attributes and odor-active compounds (OACs) between two quintessential WRTs, namely Rougui (RGT) and Shuixian (SXT). Sensory analysis revealed that RGT exhibited a more pronounced fruity aroma, while SXT had a more complex and intricate sensory profile. By using gas chromatography-olfactory mass spectrometry (GC-O-MS) and two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF-MS) analyses, 26 OACs were identified. Among them, 12 compounds with odor activity values > 1 were recognized as key OACs. Noteworthily, eight compounds, including 6-methyl-5-hepten-2-one, 2-ethyl-3,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine, linalool, methyl salicylate, geraniol, (E) -β-ionone, and (E) -nerolidol, were shared by both teas. The unique compounds for RGT were (E) -linalool oxide and (Z) -jasmone, while those for SXT were β-cyclocitral and α-ionone. These findings offer valuable insights for better understanding the flavor differences between the two most important types of WRT. [ABSTRACT FROM AUTHOR]

• The most remarkable changes in volatiles of WRT occurred during roasting. • Flavanols were promptly oxidized and converted to heterogeneous oxidation products. • Flavonols, phenolic acids, and xanthine alkaloids remained stable during processing. • Central vacuole of tea leaf cells shrunk remarkably during withering. Wuyi Rock tea (WRT), a top-ranking oolong tea, possesses characteristic woody, floral, nutty flavor. WRT flavor is mainly formed during the manufacturing process. However, details regarding its formation process are not fully understood yet. In this study, the dynamics of volatile and phenolic components over the whole manufacturing process of WRT were investigated. During withering, despite minor changes in volatile and phenolic components, the central vacuole shrunk remarkably, which reduced the cell mechanical performance and facilitated the subsequent enzymatic fermentation. During fermentation, approximately 78% of flavan-3-ols in fresh tea leaves were oxidized and converted to a diverse mixture of highly heterogeneous oxidation products, such as theaflavins, whereas flavonols, phenolic acids, and xanthine alkaloids remained stable throughout the manufacturing process. Aldehydes, ketones, and heterocyclic compounds, imparting woody, floral, and nutty scent, were mainly formed during the roasting steps. This detailed information can expand our understanding on the formation of WRT flavor. [ABSTRACT FROM AUTHOR]