Recent Advances in Umami Peptides From Livestock and Poultry By-Products: Influencing Factors, Structural...

Livestock and poultry by-products (LPBP), owing to their abundant protein content and potential for value-added applications, have become important raw materials for developing umami peptides. In this context, this review for the first time systematically integrates the structural modification strategies of umami peptides derived from LPBP from a cross-modal sensory perspective and preliminarily explores their preparation, separation, and purification methods. Specifically, this review classifies existing strategies for umami peptide modification into biological, physical, and chemical categories. The biological strategies mainly include enzymatic hydrolysis and microbial fermentation; the physical strategies involve the application of physical fields to assist and enhance enzymatic hydrolysis; and the chemical strategies comprise chemical modification approaches such as the Maillard reaction, γ-glutamylation, the plastein reaction, and cyclization. Despite significant progress in these technologies in laboratory studies, the industrial application of umami peptides remains constrained by issues such as raw material instability, high production costs, challenges in separation and purification, and underdeveloped safety and regulatory frameworks. Meanwhile, consumer acceptance may influence the commercialization of umami peptides derived from LPBP, and the standardization of raw material selection and processing technologies is critical to ensuring safety. Therefore, future research needs to not only further optimize large-scale production processes but also to integrate regulatory considerations, consumer perception assessments, and modern computational tools such as artificial intelligence (AI), multi-omics, and molecular docking (MD) into a systematic framework to guide flavor improvement and product development. Through these combined efforts, umami peptides extracted from LPBP are expected to advance toward high quality, sustainability, and industrialization.