Enzymatic synthesis of N-succinyl-L-phenylalanine and exploration of its potential as a novel taste enhancer

N-succinyl-L-phenylalanine (SP) has been identified as a taste-active contributor in an array of foods. Despite its recognized importance, the understanding of its synthesis and taste enhancement properties remains rudimentary. The study examined the enzymatic synthesis of SP with 45.58 ± 1.95% yield. This was achieved under optimized conditions: 0.3 mol/L L-phenylalanine, 0.9 mol/L succinic acid, 30,000 U/L of the AY 50C, pH 4 and 55 °C for 24 h. Sensory evaluation and electronic tongue revealed that the incorporation of a mere 1 mg/L SP substantially increased the kokumi, umami, and saltiness intensities, indicating the potential of SP as a potent taste enhancer. Moreover, time-intensity (TI) results demonstrated a significant increase of umami duration in samples containing 1 mg/L of SP (210.0 ± 0 s), a significant extension compared to the control group (150.0 ± 0 s). Notably, the intensity of umami and saltiness in the SP sample were consistently higher than that of control group. The sigmoid curve analysis further confirmed that SP exhibited a synergistic effect on umami and saltiness perceptions. Moreover, the study also illuminated interaction of SP with T1R1, T1R3, TMC4, TRPV1, and CaSR receptors, resulting in significant enhancement in umami, saltiness, and kokumi.