Comparative analysis of sensory properties, chemical composition, and antioxidant activity in aqueous extracts from medicinal and edible citrus resources: Electronic tongue, UPLC-Q-TOF-MS/MS, antioxidant capacity, and molecular docking.

Medicinal and edible citrus resources are widely utilized in traditional Chinese medicine and daily diets due to their abundant health-promoting properties. However, systematic comparative studies on their sensory characteristics, phytochemical profiles, and biological activities remain insufficient, particularly among different varieties. In this study, electronic tongue analysis, UPLC-Q-TOF-MS/MS, spectrophotometry, and molecular docking were employed to evaluate the sensory attributes, chemical composition, and antioxidant activity of five medicinal and edible citrus resources. Electronic tongue analysis indicated that the Citri sarcodactylis fruct (CSF) exhibits the strongest sourness and bitterness. Citri exocarpium rubrum (CER), Citri grandis exocarpium (CGE), and Guangchenpi (GCP) exhibited strong antioxidant activity, while CSF showed the lowest activity. The ethanol precipitation supernatant (HTAPS) fraction exhibited significantly stronger antioxidant activity than the ethanol precipitation (HTAP). Furthermore, a total of 75 compounds were tentatively identified from five citrus resources, and multivariate analysis revealed key differential metabolites, including polymethoxyflavones, flavanones, and limonoids. Limonin, naringin, hesperidin, hesperetin, apiin, and isosinensetin exhibited strong binding affinity with Keap1 (PDB ID: 4IQK) protein. This study provides a multidimensional basis for the high-value utilization of medicinal and edible citrus resources in functional foods and health products.