Preparation, Sensory Characterization, and Umami-Enhancing Mechanism of Novel Peptide Glycoconjugates

Previous studies supposed that Amadori rearrangement products (ARPs) of peptides might have better umamienhancing abilities. To confirm this, five ARPs (EP-ARP, AH-ARP, EE-ARP, beta-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).

Automated summary

This study confirmed the better umami-enhancing abilities of Amadori rearrangement products (ARPs) of peptides through synthesis and sensory experiments. ARPs showed a synergistic effect with umami substances and had a stronger umami-enhancing capacity compared to the corresponding peptides. RFPHADF-ARP, despite being a bitter peptide initially, exhibited good umami-enhancing properties.