Identification, saltiness-enhancing effect, and antioxidant properties of novel saltiness-enhancing peptides from peanut protein

In order to reduce the use of traditional salt (NaCl), this study aimed to rapidly identify novel peptides with salt-reducing effects from peanut protein. Four potential peptides were identified through virtual screening and molecular docking. The sensory evaluation and electronic tongue confirmed that the peptides SPDIY, DPSPR, QPGDY, and SPPGER had significant saltiness-enhancing effects, with saltiness enhancement thresholds ranging from 0.16 to 0.64 mmol L^-1. Among them, DPSPR exhibited the most pronounced effect in enhancing saltiness, capable of replacing approximately 56.7% of NaCl. Molecular docking and dynamics simulation studies indicated that amino acid residues Arg272, Glu161, Gln279, Arg168, and Ser165 were found to play key roles in ligand-receptor binding. Additionally, antioxidant activity assays demonstrated that the peptide QPGDY contributed to free radical scavenging in a dose-dependent manner through the hydrogen atom transfer mechanism. The combination of virtual screening technology and experimental validation greatly improved the efficiency and accuracy of peptide discovery and functional characterization, offering a promising strategy for the development of low-sodium foods with antioxidant properties.