Identification of saltiness-enhancing compounds in Zanthoxylum bungeanum essential oil chicken soup and molecular docking with transmembrane channel-like protein 4 (TMC4).

This study examines how adding Zanthoxylum bungeanum essential oil affects the sensory quality of chicken soup, focusing on identifying the mechanisms of saltiness-enhancing compounds. Sensory evaluation demonstrated that the essential oil significantly increased the soup's saltiness, umami and overall acceptance. Metabolomics and chemometrics identified unique (17 volatile and 27 non-volatile) and differential (11 volatile and 16 non-volatile) compounds with high expression levels in Z. bungeanum chicken soup as potential saltiness enhancers. Sensory evaluation and E-tongue analyses indicated that 13 volatile and 6 non-volatile compounds significantly boosted the saltiness of a 3 g/L NaCl. Molecular docking studies showed that volatile saltiness-enhancing compounds primarily interact with TMC4 through hydrophobic forces at key residues (Trp449, Phe243, Phe446 Tyr608, and Trp190), while non-volatile compounds bind at Leu618, Lys471, Cys207/475 and Tyr608. This research not only identified multiple novel saltiness-enhancing compounds but also partially revealed the potential of Z. bungeanum as a natural flavor enhancer.