Isolation and identification of key bitter substances in Chrysanthemum morifolium (Chuju) and their interaction mechanism with bitter taste receptors using HPLC-Q-TOF-MS and molecular docking

Chrysanthemum morifolium (Chuju), a plant with both medicinal and edible importance, has limited applications in food and pharmaceuticals due to its bitter taste. This study aimed to identify the key bitter substances in Chuju by combining sensory evaluation (including both human sensory assessment and electronic tongue analysis) with solvent extraction, silica gel column chromatography, and HPLC-Q-TOF-MS. The relative contribution of each bitter substance was evaluated using the Dose-Over-Threshold (DoT) factor. Three compounds with high bitterness contribution were identified: Vitexin, Orientin, and Kaempferol. In human sensory evaluation, their DoT factors were 8.77, 2.73, and 0.40, respectively, while in electronic tongue analysis, the values were 136.62, 1.51, and 2.59. Molecular docking was further employed to investigate the interaction between these bitter substances and the bitterness receptor TAS2R14. All three compounds exhibited docking scores lower than -5 kcal/mol, indicating strong binding affinity to the bitterness receptor. This study identifies the key bitter substances in Chuju and provides a reference for its broader application and bitterness reduction in the future.