An Enzyme-Mediated Strategy for Diminishing Bitterness-Contributing Peptides of Pea (Pisum sativum) Protein Isolates

To improve the applicability of pea protein isolate (PPI), this work demonstrated that enzymatic hydrolysis effectively mitigates its bitterness, which is primarily driven by specific bitter peptides. Five peptides were validated with low recognition thresholds (0.171-0.586 mmol/L), ranking within the top 30% of reported bitter peptides. Among them, LN-9, VF-5, and VN-10 contribute substantially to PPI bitterness. Molecular docking indicated that hydrophobic interactions and hydrogen bonds primarily mediate peptide binding to bitter taste receptors (TAS2Rs). Critically, in vitro calcium flux assays revealed that the activation of TAS2R14 and TAS2R39, as well as TAS2R4, strongly correlates with perceived sensory bitterness. This work provides an integrated strategy to identify key bitter peptides and pinpoints specific TAS2Rs as primary targets for debittering, offering a robust scientific basis for enhancing the palatability of plant-based proteins in the food industry.