Unraveling the Molecular Basis of Bitter Taste Formation in Stored Milk: A Comprehensive Approach Combining Peptidomics and Molecular Docking

Abstract

Flavor profile constitutes a pivotal determinant in milk product development and consumer acceptance. Extensive research has documented peptide profile variations in milk at diverse storage conditions, with particular emphasis on bitterness development. Nevertheless, the molecular mechanisms underlying bitter-active peptide formation and sensory manifestation during storage remain poorly characterized. This investigation employed an integrated analytical approach, combining peptidomics with chemometric characterization to identify and quantify bitter-active peptides generated under thermal storage. The analysis identified significant up-regulation of six and five distinct bitter-active peptides in full-fat and low-fat UHT milk, respectively, when stored at elevated temperatures. The molecular docking results revealed that lower CDOCKER energies were observed for the interaction of these peptides with the TAS2R14 receptor and was stabilized by hydrogen bonding. These findings provide novel mechanistic insights into the molecular basis of bitter taste development in thermally processed dairy products, establishing a theoretical framework for understanding flavor chemistry during storage.

Keywords: UHT milk, Protein degradation, Bitter active peptide, TAS2R14, Molecular docking