Insights into the flavonoid composition and antioxidant activity of Jeramon, a novel Korean lemon cultivar

'Jeramon' is a newly developed Korean lemon cultivar bred from Citrus limon 'Frost Lisbon' × 'Meyer'. This study provides the first comprehensive phytochemical and functional characterization of 'Jeramon' across ripening stages. DPPH and ABTS assays consistently showed stronger antioxidant activity in peel than in flesh, corresponding to higher phytochemical contents. LC-MS/MS and HPLC/PDA analyses identified a distinctive flavonoid profile enriched in eriocitrin, rutin, and hesperidin, with hesperidin remaining stable during maturation. Unlike many citrus varieties, total phenolic and flavonoid levels remained relatively constant throughout ripening. The yellow peel accumulated the highest total concentration of the three key flavonoids. Correlation analysis indicated eriocitrin as a major contributor to antioxidant capacity. A dual antioxidant mechanism is proposed, involving direct radical scavenging and indirect modulation of carbonic anhydrase 4, supported by strong in silico binding of hesperidin. These findings highlight 'Jeramon' as a metabolically stable, high-value cultivar and a promising natural antioxidant source.