Umami-enhancing effect of typical kokumi-active γ-glutamyl peptides evaluated via sensory analysis and molecular modeling approaches

Juan Yang; Yuran Huang; Chun Cui; Hao Dong; Xiaofang Zeng; Weidong Bai

doi:10.1016/j.foodchem.2020.128018

Umami-enhancing effect of typical kokumi-active γ-glutamyl peptides evaluated via sensory analysis and molecular modeling approaches

Food Chem. 2021 Feb 15:338:128018. doi: 10.1016/j.foodchem.2020.128018. Epub 2020 Sep 8.

Authors

Juan Yang¹, Yuran Huang², Chun Cui³, Hao Dong¹, Xiaofang Zeng⁴, Weidong Bai⁵

Affiliations

¹ College of Food Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China; Academy of Contemporary Agricultural Engineering Innovations, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.
² College of Food Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.
³ School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China.
⁴ College of Food Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China; Academy of Contemporary Agricultural Engineering Innovations, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China. Electronic address: xiaofang_zeng2015@163.com.
⁵ College of Food Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China; Academy of Contemporary Agricultural Engineering Innovations, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China. Electronic address: whitebai2001@163.com.

PMID: 32932086
DOI: 10.1016/j.foodchem.2020.128018

Abstract

The umami-enhancing effect of typical kokumi-active γ-glutamyl peptides was verified by sensory evaluation. To investigate the umami-enhancing molecular mechanism of the peptide on monosodium glutamate (MSG) taste, a novel hypothetical receptor, taste type 1 receptor 3 (T1R3)-MSG complex, was constructed. These peptides demonstrated strong interactions with T1R3-MSG. Moreover, four amino acid residues, Glu-301, Ala-302, Thr-305, and Ser-306, were critical in ligand-receptor interactions. In detail, γ-Glu-γ-Glu-Val (γ-E-γ-EV) readily interacts with T1R3 through hydrogen bonds and hydrophobic interactions. While γ-E-γ-EV did not bind to MSG, γ-Glu-Val (γ-EV) and γ-Glu-Leu (γ-EL) showed high binding affinity to MSG and interacted with T1R3 through hydrophobic bonds suggesting that the interactions between dipeptides and T1R3-MSG were weaker than tripeptides. These results demonstrated that kokumi-active γ-glutamyl peptides could enhance the umami taste of MSG, and exhibit synergistic effects in activating T1R3. This study provides a theoretical reference for interactions between the novel umami-enhancing substances and umami receptor.

Keywords: Molecular mechanism; T1R3; Umami-enhancing effect; γ-Glutamyl peptides.

MeSH terms

Adult
Amino Acids / chemistry
Amino Acids / metabolism
Dipeptides / chemistry
Dipeptides / metabolism*
Female
Flavoring Agents / chemistry
Flavoring Agents / pharmacology
Humans
Hydrogen Bonding
Male
Middle Aged
Models, Molecular
Molecular Docking Simulation
Receptors, G-Protein-Coupled / chemistry
Receptors, G-Protein-Coupled / metabolism*
Sodium Glutamate / chemistry
Sodium Glutamate / metabolism*
Sodium Glutamate / pharmacology
Taste* / drug effects

Substances

Amino Acids
Dipeptides
Flavoring Agents
Receptors, G-Protein-Coupled
gamma-glutamylvaline
taste receptors, type 1
gamma-glutamyl-leucine
Sodium Glutamate