With the development of the food industry and the improvement of living standards, single-taste characteristics in food can no longer meet demands. Some flavors in food cannot be described as bitter, sour, salty, umami, or sweet; such thick, lingering, complex flavors, as well as a series of strong, overall well-rounded, and balanced sensations are known as “kokumi”. Kokumi substances have no inherent flavor, or have only a faint taste, but the addition of small amounts of kokumi substances to basic solutions can change their taste. This paper summarizes the classification, measurement methods, and isolation and identification methods of kokumi substances, and the composition and characteristics of peptide and non-peptide kokumi substances. Preliminary determination of the advantages and disadvantages of kokumi substances was conducted by comparing the results of sensory evaluation and calcium-sensing receptor (CaSR) assays. This paper also introduces methods for the isolation and identification of kokumi substances, such as ultra-filtration, gel permeation chromatography, preparative reversed-phase high-performance liquid chromatography, and time-of-flight mass spectrometry (TOF-MS). Domestic and international research on kokumi substances is summarized, and a theoretical basis for research on kokumi substances is provided.
