Three novel umami peptides from watermelon soybean paste and the revelation of the umami mechanism through molecular docking with T1R1/T1R3

Abstract

Watermelon soybean paste is a condiment popular in Henan, Shandong and Anhui provinces of China for the strong umami taste. This work used ultrafiltration and gel filtration chromatography to separate three novel umami peptides from watermelon soybean paste aqueous extract with sequences of AKEKFD, LAELK and LTFVER. The three peptides were all determined to be umami peptides by sensory evaluation and electronic tongue. Through molecular docking with umami receptor T1R1/T1R3, the umami taste mechanisms of the three umami peptides were revealed. The charged side chains in the umami peptides and T1R1/T1R3 played a key role in the perception of umami, and the primary factors of the interaction between umami peptides and T1R1/T1R3 were van der Waals forces and hydrogen bonds, which mainly contributed to the umami mechanism. This study will supplement the umami peptide database and offered a theoretical framework for further investigation on umami peptide.