Preparation of N-succinyl-L-tryptophan: investigating its sweetness-enhancing effects and mechanisms on sucrose and high-intensity sweeteners through sensory evaluation, electronic tongue, and molecular simulation.

The increasing demand for healthier, sugar-reduced products can be attributed to rising living standards. This study presented the synthesis of a novel sweetness enhancer, N-succinyl-L-tryptophan (N-Suc-Trp), achieved through direct heating, yielding 81.58 %. Sensory evaluation and electronic tongue analysis revealed that the addition of 0.5-1.5 mg/L N-Suc-Trp significantly enhanced the sweetness intensity of sucrose as well as high-intensity sweeteners, such as neotame (NTM) and neohesperidin dihydrochalcone (NHDC), while also extending the duration of their sweetness perception in the mouth. Molecular docking revealed that N-Suc-Trp increased the binding affinities and interaction forces between sweet compounds and the T1R2/T1R3 receptor system, thereby intensifying sweetness perception. Molecular dynamics simulations further indicated that N-Suc-Trp improved the stability of the complex formed between the sweet compounds and the T1R2/T1R3 receptors. These findings elucidated the mechanism by which N-Suc-Trp enhanced sweetness perception and provide valuable insights into strategies for reducing sucrose and sweetener intake.