Flavor modulation of braised He Bao carp (Cyprinus carpio) by natural plant spices: Insights from GC–MS, GC–IMS, E-nose, E-tongue, and molecular docking analyses

Spice use in traditional braised He Bao carp (Cyprinus carpio) remains empirical, and its flavor-modulating mechanisms lacks scientific elucidation. This study elucidated the differential flavor-modulating mechanisms of four natural spices—Perilla frutescens, dried tangerine peel (Citrus reticulata), lemongrass (Cymbopogon citratus), and orange peel (Citrus sinensis). Aroma-active and taste-active compounds were characterized by GC–MS, GC–IMS, E-nose, E-tongue, and molecular docking. A total of 129 volatiles were identified, including 16 shared core compounds (e.g., benzaldehyde, nonanal, geraniol). Lemongrass group yielded the highest volatile content (110.34 mg/kg) with dominant citral, geraniol, citronellol, and eugenol, while orange peel group exhibited abundant D-limonene (9.93 mg/kg, OAV > 200). Perilla frutescens group suppressed fishy odor by reducing 1-octen-3-ol, and dried tangerine peel group enriched thymol and γ-terpinene, enhancing herbal-citrus notes. Molecular docking revealed stronger binding of key pleasant odorants (–4.4 to –5.1 kcal/mol) to OR1D2 receptors than off-flavor compounds. In taste evaluation, dried tangerine peel group and lemongrass group enhanced umami perception via increased Glu (≈1.09 g/100 g) and 5′-IMP (up to 258.7 mg/100 g). Overall, natural spices distinctly modulated aroma and taste, with lemongrass group and orange peel group producing complex aromatic profiles and dried tangerine peel group improving taste balance. These findings provide mechanistic insight and practical guidance for enhancing the flavor and standardization of traditional Jiangxi cuisine.