Non-Volatile Metabolic Reprogramming and Sensory Evolution of Anhua Qianliang Tea During Long-Term Storage

Anhua Qianliang tea, a traditionally crafted dark tea, is highly prized for its unique sensory properties that develop and improve during long-term aging. To elucidate the material basis driving the quality transformation of Anhua Qianliang tea during prolonged storage, samples aged for 2 to 25 years were investigated using physicochemical analysis, untargeted metabolomics, and sensory evaluation. Prolonged storage reduced total polyphenols, free amino acids, and most catechins, whereas alkaloids remained relatively stable. Phenylpropanoids and polyketides, organic acids and derivatives, and lipids and lipid-like molecules were the main metabolite classes contributing to storage-stage discrimination, accompanied by extensive remodeling of flavonoid, phenylpropanoid, amino acid-related, and central carbon metabolism. Sensory evolution was closely associated with coordinated changes in catechins, polyphenols, phenolic acids, amino acid-related compounds, and storage-responsive metabolites. These insights significantly deepen the understanding of dark tea maturation and offer new perspectives for scientific evaluation and industrial standardization.