As the most consumed tea in the world, all kinds of black tea are developed from Wuyi black tea. In this study, quality components, regulatory gene expression, and key enzyme activity during the processing were analyzed to illustrate the taste formation of WBT. Withering mainly affected the content of amino acids, while catechins and tea pigments were most influenced by rolling and the pre-metaphase of fermentation. Notably, regulatory gene expression was significantly down-regulated after withering except for polyphenoloxidase1, polyphenoloxidase2, leucoanthocyanidin dioxygenase, chalcone isomerase, and flavonoid 3′, 5′-hydroxylase. Co-expression of flavonoid pathway genes confirmed similar expression patterns of these genes in the same metabolic pathway. Interestingly, rolling and fermentation anaphase had a great effect on polyphenol oxidase, and fermentation pre-metaphase had the greatest effect on cellulase. Since gene regulation mainly occurs before picking, the influence of chemical reaction was greater during processing. It was speculated that polyphenol oxidase and cellulase, which promoted the transformation of quality components, were the key factors in the quality formation of WBT. The above results provide theoretical basis for the processing of WBT and the reference for producing high-quality black tea.

Laocong Shuixian (LCSX), a premium Wuyi rock tea derived from aged Shuixian tea trees, is valued by consumers for its distinctive “Cong flavor”—a unique aroma profile characterized by woody, bamboo leaf, and glutinous rice notes. However, the chemical basis and underlying mechanisms of this unique aroma remain unclear. Here, we assessed and established a professional sensory evaluation panel using the PanelCheck software, with significant F-value levels >5% confirming the panel’s discriminative capacity for key “Cong flavor” attributes. Combining a literature review and sensory analysis, we identified the descriptive terms associated with the “Cong flavor” of LCSX. Gas chromatography–olfactometry–mass spectrometry (GC–O–MS) analysis revealed 36 key aroma-active compounds, among which theaspirone (OAV = 500.05, ACI = 37%, R_woody = 0.82), δ-decalactone (OAV = 65.6, ACI = 4.3%, R_woody = 0.77), and 2-acetylpyrrole (OAV = 163, ACI = 9%, R_rice = 0.74) were identified as the contributors to the woody and rice-like notes of LCSX based on odor activity values and correlation analyses. Molecular docking results demonstrated that these compounds spontaneously bind to multiple olfactory receptors, with binding affinity ≤−5.0 kcal/mol, providing insights into their roles in human aroma perception: theaspirone to OR8D1; δ-decalactone to OR1E2, OR5M3, OR7D4, OR7G1, OR8D1 and OR8G1; and 2-acetylpyrrole to OR1E2, OR1G1, OR5M3, OR7D4, OR7G1, OR8D1, and OR8G1. This study enhances our understanding of the formation of distinctive aroma qualities in oolong tea and establishes a foundation for further research into its sensory and chemical properties.

L-theanine is a bioactive non-protein amino acid predominantly derived from tea plants (Camellia sinensis), widely recognized for its potential benefits in mood regulation and psychological health. Despite its promising neuropsychological profile, the specific molecular targets and mechanisms underlying its antidepressant activity remain incompletely understood. In the present study, an integrated network pharmacology strategy, combined with molecular docking and molecular dynamics (MD) simulations, was employed to systematically elucidate the potential antidepressant mechanisms of L-theanine. By intersecting predicted drug targets with depression-related genes, 40 potential targets were identified. Protein–protein interaction (PPI) network analysis subsequently pinpointed five hub targets: PRKACA, GRIA2, GRIN1, GRIA1, and HTR1A. Functional enrichment analyses (KEGG and GO) indicated that these targets are primarily implicated in critical pathological processes of depression, including neurotransmitter regulation, glutamatergic synaptic transmission, stress response signaling, and neurotrophin-related pathways. Molecular docking revealed favorable binding affinities between L-theanine and the key targets. Furthermore, MD simulations and binding free energy calculations corroborated the structural stability and thermodynamic favorability of these protein–ligand complexes. Overall, this study provides hypothesis-generating insights into the antidepressant mechanisms of L-theanine from a multi-target perspective, offering a theoretical foundation to guide future experimental validation in depression research.