Kokumi Peptides in Salt Reduction: Preparation, Evaluation Methods, Perceptual Mechanisms, and Prospects for Food Applications

Excessive dietary salt intake poses significant health risks and is closely associated with the pathogenesis of hypertension and cardiovascular diseases. Developing strategies that achieve salt reduction without compromising saltiness perception has become a major focus in food science and public health research. The study and application of kokumi peptides provide a novel approach to achieving "salt reduction without loss of saltiness." Although kokumi substances themselves are usually tasteless or only weakly flavored, they can markedly enhance the intensity and persistence of other taste modalities within complex food systems, thereby improving overall flavor perception. Kokumi peptides are widely derived from natural food sources and can effectively reduce sodium intake without sacrificing palatability, showing remarkable potential for food applications. This review systematically summarizes the primary preparation methods, sensory evaluation techniques, and molecular mechanisms underlying the salt-enhancing properties of kokumi peptides. Particular emphasis is placed on calcium-sensing receptor (CaSR)-mediated taste sensation and its potential crosstalk with key salt-taste transduction pathways, including the epithelial sodium channel (ENaC), transient receptor potential vanilloid 1 (TRPV1), and transmembrane channel-like protein 4 (TMC4). Moreover, the review discusses the potential applications of kokumi peptides in salt-reduced foods and seasonings, as well as their roles in flavor enhancement, physiological activity, and multisensory synergy. Finally, the current challenges in kokumi peptide research are identified, and promising prospects for health-oriented food innovation and salt-reduction strategy optimization are proposed.