Identification, taste properties and molecular docking of novel umami peptides from Butyriboletus roseoflavus

To better understand the delicious taste characteristics of Butyriboletus roseoflavus, the aqueous extract was separated and combined with sensory analysis. Four novel umami peptides, GSAQA, ISKEK, LPKERLYV, and VENQQLAL were isolated and identified by Gel chromatography, RP-HPLC, and Nano-LC-MS/MS. Umami peptides were synthesized to verify their taste characteristics, and sensory evaluation revealed that they could elicit umami and umami enhancement, among them VENQQLAL performing best. The umami thresholds of those peptides range from 0.20 to 0.60 mg/mL. Moreover, the four peptides possessed the potential to enhance salty and sweet taste. Molecular docking showed that all the peptides were embedded in the ligand-binding domain of the umami receptor T1R1/T1R3, and binding sites Lys155, Asn150, and Thr179 may be important in the interaction of umami peptides with T1R3 subunits. Hydrogen bonding and hydrophobic interactions were the most prominent ligand-receptor interaction forces.