Exploring the neural processing mechanisms of umami peptides: Insights from high-temporal-resolution electroencephalogram (EEG) analysis.

This study used electroencephalography to characterize brain responses to the umami peptide RPIEK (0.75, 1.50, and 3.00 mg/mL) and matched monosodium glutamate solutions (0.10, 0.50, and 1.00 mg/mL), focusing on oscillatory dynamics, cortical regions, and spatiotemporal response profiles. The results demonstrated that RPIEK significantly increased (P < 0.05) area under the curve of the power spectral density, with delta and theta band activity principally encoding umami information. Brain can distinguish between umami stimuli matched for perceptual intensity based on differences in the temporal sequence of regional activation, and implicated the frontal lobe as a critical contributor to umami perception. Significant differences in rhythmic oscillatory activity, temporal activation windows, and spatial distribution across brain regions were observed between RPIEK and monosodium glutamate. Umami peptides elicited stronger activation in cortical regions associated with higher-order cognitive, emotional, and reward processing. This study is expected to elucidate the neurophysiological mechanisms of umami peptide perception.