Previous studies supposed that Amadori rearrangement products (ARPs) of peptides might have better umami-enhancing abilities. To confirm this, five ARPs (EP-ARP, AH-ARP, EE-ARP, β-AH-ARP, RFPHADF-ARP) were synthesized using a food-grade preparation method, and their chemical structures were clearly demonstrated by mass spectrometry and 1D/2D NMR. Sensory experiments showed that ARPs had better umami-enhancing abilities than the corresponding peptides in this research, though their enhancing performance varied. ARPs showed a synergistic effect with multiple umami substances (MSG and GMP), while their corresponding peptides did not. RFPHADF-ARP had good umami-enhancing capacity, despite that RFPHADF was a bitter peptide without any umami/umami-enhancing property. RFPHADF-ARP could bind to the T1R3, which is beneficial to the stability of the active conformation of the umami receptor. The introduction of glucose via the Maillard reaction increased the binding force of RFPHADF with the umami receptor by influencing the electron density distribution and offering more binding groups (hydroxide group).

中文翻译：

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新型肽糖缀合物的制备、感官表征和鲜味增强机制

先前的研究认为肽的 Amadori 重排产物 (ARPs) 可能具有更好的鲜味增强能力。为了证实这一点，使用食品级制备方法合成了五种 ARP（EP-ARP、AH-ARP、EE-ARP、β-AH-ARP、RFPHADF-ARP），并通过质谱和一维/二维核磁共振。感官实验表明，ARPs 比本研究中的相应肽具有更好的鲜味增强能力，尽管它们的增强性能各不相同。ARPs 与多种鲜味物质（MSG 和 GMP）显示出协同作用，而其相应的肽则没有。RFPHADF-ARP具有良好的鲜味增强能力，尽管RFPHADF是一种没有任何鲜味/鲜味增强特性的苦味肽。RFPHADF-ARP 可以与 T1R3 结合，有利于鲜味受体活性构象的稳定。通过美拉德反应引入葡萄糖通过影响电子密度分布和提供更多的结合基团（羟基）来增加 RFPHADF 与鲜味受体的结合力。