Identification and characterization of umami peptides from enzymatic hydrolysates of cod skin based on sensory evaluation and molecular simulations

Cod skin possesses a pronounced savoury flavour yet remains underutilised as a processing by product. As a potential source of umami peptides, cod skin holds significant development potential. This study employed gel permeation chromatography (GPC), ultrafiltration (UF), sensory evaluation, high–performance liquid chromatography tandem mass spectrometry (LC–MS/MS), and virtual screening to isolate, purify, screen, and identify potential umami peptides from cod skin enzymatic hydrolysate (EHCS). Five potential umami peptides: GDRGFPGER, SSGDQGPAG, SSGPFGE, LPGADDDKF, and GLPGADDKF were screened. Their interactions with T1R1/T1R3 receptors and the stability of peptide–receptor complexes were investigated via molecular docking and molecular dynamics simulations. Ultimately, GDRGFPGER was identified as a potent umami peptide, while SSGDQGPAG and SSGPFGE exhibited umami enhancing characteristics. This study provides a screening and identification methodology for extracting umami peptides from cod skin, elucidates the molecular perception mechanism of umami peptides, and establishes a theoretical foundation and technical support for developing natural umami enhancers.