Identification, taste characterization, and molecular docking study of a novel microbiota-derived umami peptide

• Published in: Food chemistry Vol. 404; p. 134583
• Main Authors: An, Feiyu, Cao, Kaixin, Ji, Shuaiqi, Wang, Yusheng, Pan, Guoyang, Ma, Yuanyuan, Zhao, Yue, Wu, Junrui, Wu, Rina
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.03.2023
• Subjects: Molecular docking; Taste characteristics; Tetragenococcus halophilus; Umami peptide; Umami peptide; Taste characteristics; Tetragenococcus halophilus; Molecular docking
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2022.134583

•A novel microbiota-derived umami and umami-enhancing peptide DFE was identified.•DFE can help improve the overall taste of complex food systems.•DFE binding to receptors was studied by molecular docking.•DFE binds to T1R1/T1R3 through hydrogen bonding and electrostatic interactions. Umami peptides are an important taste substance in fermented foods. However, in the absence of known microbiota-derived umami peptides, the understanding of the umami mechanism remains unclear. Tetragenococcus halophilus, a dominant fermentation bacteria, may be an important source of umami peptides. Accordingly, T. halophilus fermentation broth was fractioned by ethanol precipitation, gel chromatography, and reverse phase-high performance liquid chromatography. The isolated peptide fraction with the most intense umami taste was screened by amino acid composition and sensory analyses. Finally, three novel microbiota-derived peptides (DFE, LAGE, and QLQ) were identified, synthesized, and characterized for taste. Among them, only DFE had umami and umami-enhancing abilities improving multiple tastes. Molecular docking studies indicated that DEF binds to T1R1/T1R3 receptors through hydrogen bonding and electrostatic interactions involving receptor residues Ser332, Ser256, ASN41, His125, etc. This study highlights the critical role of microbiota-derived peptides in the umami taste of fermented foods.