Taste‐Active Peptides: Sensation Mechanisms and Structure–Taste Relationships

ABSTRACT Taste‐active peptides (TAPs) are food‐derived molecules that elicit taste sensations through coordinated effects on taste bud cells, taste receptors, and peripheral neuronal projections. This review synthesizes recent progress in how TAPs influence sensation and the structure–taste relationships they exhibit, framing these findings within gustatory neuroscience. We begin by describing how Type I, II, III, and IV taste bud cells contribute to peptide‐evoked taste coding via transmitter clearance, receptor activation, synaptic signaling, and cellular renewal. Although sour peptides are recognized, their receptor‐level mechanisms remain poorly characterized. Therefore, we focus on umami, sweet, bitter, kokumi, and saltiness‐enhancing peptides. Specifically, we examine TAPs targeting umami (T1R1/T1R3), sweet (T1R2/T1R3), bitter (TAS2Rs), kokumi (calcium‐sensing receptor, CaSR), and saltiness‐enhancing (ENaC and TMC4) receptors. We further highlight structural determinants that govern receptor compatibility and signal initiation, including acidity, terminal hydrophobic residues, γ‐glutamyl motifs, stereochemistry, propeptides to peptide conversion, and other modifications. Finally, we review the principal methodologies commonly used to characterize these peptides, ranging from sensory evaluation and cell‐based assays to molecular simulations and machine learning approaches. Overall, this review aims to forge direct links between peptide chemistry, taste‐cell physiology, and neural transduction, offering a new perspective on the role of TAPs in peripheral gustatory coding.