Current progress in umami peptides from blue foods: Preparation, screening, evaluation, synergistic effects, and taste mechanism

Blue foods, usually called aquatic foods, are animals, plants, and algae which are cultivated or caught from freshwater or marine habitats. Blue foods are expected to become a sustainable source of human consumption, reducing the threat posed by population growth and land resource reduction to food security. Blue foods offer a potential substrate for the production of umami peptides, which have important effects on food flavour. This article presents the structure-activity relationship and factors affecting the umami taste of peptides. Several methods can be applied to prepare and synthesize umami peptides, including thermal degradation, enzymatic hydrolysis, fermentation, gene expression, and solid-phase synthesis. Furthermore, in this work we aim to review evaluation methods for the umami taste of peptides, focusing on sensory evaluation, electronic tongue, biosensors, etc. Molecular docking and machine learning are effective methods for quickly screening umami peptides. It is necessary to prepare and identify novel umami peptides from blue foods, as this can lead to improved utilization and production of umami substances in blue foods. Moreover, both internal and external factors greatly contribute to the taste attributes of umami peptides. Therefore, the synergistic effects and mechanism of umami peptides and other taste compounds should be considered in future research.