Enzymatic synthesis and sensory evaluation of N-cinnamoyl-L-phenylalanine as a novel flavor enhancer: Impact on taste perception and mechanistic insights

N-Phenylpropenoyl-L-amino acids, naturally occurring in plants, are potential candidates for food flavor enhancement. This study optimized the enzymatic synthesis of N-cinnamoyl-L-phenylalanine (CiA-Phe) using trans-cinnamic acid and L-phenylalanine as raw materials, achieving a 7.93 % yield. The purified CiA-Phe exhibited over 98 % purity, confirmed by HPLC-MS/MS and NMR. Quantitative descriptive analysis demonstrated that CiA-Phe at concentrations from 1 to 100 mg/L significantly enhanced sourness and umami intensity in a dose-dependent manner. Electronic tongue test further confirmed the prolonged perception of saltiness and umami. Time-intensity analysis showed that samples with 100 mg/L CiA-Phe prolonged the duration of saltiness and umami by 113.33 % and 18.46 %, respectively. Molecular docking and dynamics simulations revealed that CiA-Phe exhibits significant binding affinity with key taste receptors (OTOP1, TMC4, T1R1 and T1R3), suggesting a potential mechanism underlying the enhancement of sourness, saltiness, and umami. These findings suggest that N-cinnamoyl-L-phenylalanine has potential as a natural flavor enhancer in food products.