Taste Characteristic Evaluation and Molecular Mechanism Analysis of Umami Peptides Based on Combination of ‘Electronic Tongue- Molecular Interaction-Molecular Docking’ Technology(基于电子舌、分子互作与分子对接联用技术的鲜味肽呈味特征评价及分子机制解析)

To investigate taste characteristics of the umami properties and their interaction mechanisms with umami receptors, five Stropharia rugosoannulata umami peptides (EP-6, SG-7, PH-5, SE-6, ES-7) were taken as the research objects, and the combined technology of sensory evaluation, electronic tongue analysis, surface plasmon resonance (SPR) molecular interaction technology, and molecular docking were used to systematically evaluate the umami intensity of the five umami peptides and analyze the molecular action mechanism with umami receptors. Sensory scoring (0-10) and taste dilution analysis revealed that EP-6 and ES-7 exhibited the highest umami intensity (6.90±0.88 and 6.70±0.95, respectively), with detection thresholds of 0.178mmol/L and 0.167mmol/L, significantly lower than the threshold (1.774mmol/L) of 0.3mg/mL monosodium glutamate (MSG). Principal component analysis of electronic tongue data (cumulative contribution rate reached 91.8% for first two components) demonstrated that the umami strength of EP-6 and ES-7 was comparable to 0.1% MSG, consistent with sensory evaluation. SPR kinetic analysis indicated that ES-7 showed the strongest binding affinity with T1R3-VFD receptor (KD=1.471×10-6mol/L), characterized by binding and dissociation rates of fast on and fast off. Molecular docking revealed that EP-6 and SG-7 achieved the lowest docking energies (-436.52kJ/mol and -397.81kJ/mol, respectively), stabilized by hydrogen bonds and hydrophobic interactions with key residues (ASN68, GLU45, HIS278). Notably, sulfur-containing amino acids Cys prolonged umami perception through thiol-mediated interactions, corroborating the kokumi features observed in sensory evaluation. This study established a comprehensive and rapid evaluation system for umami peptides through combination of electronic tongue-molecular interaction-molecular docking technology, overcoming the subjective limitations of traditional sensory methods. The identification of core binding sites in umami receptor domains and elucidation of sulfur-containing amino acids' regulatory role in taste persistence provided molecular insights for rational design and high-value application of natural umami enhancers. These findings advanced the development of precision flavor modulation technologies with significant implications for food science applications.(为探究鲜味多肽呈味特征及其与鲜味受体相互作用机制,以5种大球盖菇鲜味肽(EP-6、SG-7、PH-5、SE-6、ES-7)为研究对象,采用感官评定、电子舌分析、表面等离子体共振(SPR)分子互作技术及分子对接联用技术,系统评价了5种鲜味肽的鲜味强度并解析其与鲜味受体分子的作用机理。通过感官评分(0~10)与滋味稀释分析发现,EP-6与ES-7鲜味评分最高,分别为6.90±0.88、6.70±0.95,阈值分别为0.178mmol/L和0.167mmol/L,低于0.3mg/mL谷氨酸钠(MSG)的阈值(1.774mmol/L)。电子舌主成分分析结果显示,前两个主成分累积贡献率达91.8%,EP-6与ES-7鲜味强度接近质量分数为0.1%的MSG的鲜味强度,且与感官评定结果一致。SPR动力学分析表明,ES-7与T1R3-VFD受体结合亲和力最强(KD=1.471×10-6mol/L),结合解离速率呈“快上快下”特征；分子对接结果进一步揭示,EP-6与SG-7的对接能量最低,分别为-436.52、-397.81kJ/mol,其稳定性依赖于ASN68、GLU45、HIS278等关键残基的氢键与疏水作用。此外, 含硫氨基酸Cys等通过巯基作用延长鲜味感知,与感官评定的味感绵长特征相印证。通过电子舌、 分子互作与分子对接多技术联用构建鲜味肽综合快速评价体系,可突破传统感官评定主观局限,明确鲜味受体结合域核心结合位点,并揭示含硫氨基酸对鲜味持久性的调控作用。研究旨在为天然鲜味增强剂的理性设计与高值化应用,以及食品风味精准调控技术的开发提供分子层面的理论依据。)