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.

White tea has been scientifically proven to exhibit positive biological effects in combating chronic diseases, including cancer, metabolic syndrome, etc. Nevertheless, the anti-aging activity and mechanism of white tea on organisms exposed to a high-fat diet remain unexplored. Herein, we prepared a white tea aqueous extract (WTAE) from white peony in Fuding and assessed its in vivo antioxidant and anti-aging effects by employing a Drosophila melanogaster senescence model induced by lard, delving into the underlying molecular mechanisms through which the WTAE contributes to lifespan improvement. Notably, the WTAE significantly extended the lifespan of Drosophila fed a high-fat diet and partially restored the climbing ability of Drosophila on a high-fat diet, accompanied by increased activities of copper-zinc superoxide dismutase, manganese-superoxide dismutase, and catalase and decreased lipid hydroperoxide levels in Drosophila. Furthermore, transcriptomic analysis indicated that the WTAE countered aging triggered by a high-fat diet via activating oxidative phosphorylation, neuroactive ligand–receptor interactions, and more pathways, as well as inhibiting circadian rhythm-fly, protein processing in the endoplasmic reticulum, and more pathways. Our findings suggest that WTAE exhibits excellent inhibitory activity against high-fat diet-induced senescence and holds promising potential as an anti-aging agent that can be further developed.

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.

White tea (WT) and Indocalamus latifolius leaves (ILLs) are valued for their distinctive aromas and bioactive properties. In this study, flavonoid extraction from ILLs was optimized using total flavonoid yield as the response variable through single-factor experiments and response surface methodology. The resulting Indocalamus latifolius leaf extract (ILLE) was vacuum-concentrated and sprayed onto WT to produce Indocalamus latifolius leaf–white tea (IT). The effects of spray ratio, spraying liquid temperature, and drying temperature on the sensory and chemical qualities of IT were further evaluated. Untargeted metabolomics was performed to compare the metabolite profiles of IT and WT. The optimal extraction conditions for ILLs’ flavonoids were 95 °C, 120 min, and a liquid-to-solid ratio of 60:1 mL/g, yielding 4.39 mg/g total flavonoids. The optimal processing parameters for IT were a spray ratio of 1:1.75 g/g, a spraying liquid temperature of 50 °C, and a drying temperature of 105 °C. Compared with WT, IT showed improved sensory and biochemical qualities, including a richer and more persistent ILLs aroma, a more refreshing and more layered taste, and significantly higher levels of water extracts, flavonoids, tea polyphenols, soluble sugars, and amino acids (p < 0.05). Metabolomic analysis revealed clear compositional differentiation between IT and WT, including the enrichment of several metabolites, some with potential functional relevance, as well as aroma-active compounds. These findings provide chemical and sensory evidence for the distinctive quality of IT and support further development of this novel specialty tea.