Potential of green tea-type processed tea from Eurya alata Kobuski leaves: a comprehensive analysis of major...

Lingmu tea, produced from Eurya alata Kobuski leaves, is a traditional non-Camellia sinensis tea, yet the chemical basis underlying its quality formation during green tea-type processing remains unclear. This study systematically investigated the effects of processing on sensory quality, chemical composition, and antioxidant capacity of Lingmu tea. Processed tea exhibited a bright orange-yellow infusion, a mellow and umami-dominant taste, and a mature, harmonious aroma characterized by chestnut-like, sweet, woody, and floral notes. Green tea-type processing increased total phenolic content from 183.20 to 224.59 mg/g and total flavonoid content from 87.31 to 120.11 mg/g. Metabolomic analysis revealed significant remodeling of non-volatile metabolites, characterized by flavonoid enrichment and catechin reduction. The major aroma contributors (ROAV > 1), included linalool, 1-octen-3-one, dimethyl sulfide, nonanal, and ethanol, with their dominant contributors differing markedly between fresh leaves and processed tea. Antioxidant capacity was functionally redistributed after processing: DPPH and superoxide anion scavenging activities decreased, whereas total antioxidant capacity increased substantially (from 208.31 to 346.77 μmol/g), while hydroxyl radical scavenging activity showed no significant difference. Overall, this study elucidates the chemical basis of quality formation in Lingmu tea and supports its evaluation, development, and standardization as a functional specialty tea.