Characterization and evaluation of umami taste: A review

Umami, as an alimentary taste, is an indicator for the presence of valuable amino acids or oligopeptides. Umami substances, including free amino acids, nucleotides, peptides, organic acids and their derivatives, are widely distributed in foods. They usually improve the overall taste of food such as modulating sweet taste, enhancing salty taste and suppressing sourness and bitterness. Though umami receptors have been discovered, the evaluation of umami intensity with sensitivity and selectivity is nevertheless a challenge because of its multivariate taste characteristics in complex food matrix source. Based on the available literature, this review summarized the distribution traits in food sources, taste characteristics, evaluation approaches and the related investigations. In further studies, with advance in the field of materials, microfluidic and nano-technologies, new evaluation approaches should be designed with the advantages of fast, sensitive and selective, and allowing more structurally versatile umami (enhancing) ingredients would be elucidated from raw food materials.