Review details structural modification strategies for umami peptides from livestock by-products, addressing off-flavor and bitterness.

The valorization of livestock and poultry by-products (LPBP) presents a significant opportunity due to their abundant protein content. These by-products are a promising source for developing umami peptides, which can enhance flavor and potentially offer nutritional benefits. However, challenges such as raw material instability, high production costs, and issues with off-flavors and bitterness currently limit their industrial application. This review addresses the need for systematic approaches to optimize the production and sensory profiles of these peptides.

This comprehensive review systematically integrated existing literature on the structural modification strategies for umami peptides derived from livestock and poultry by-products. Researchers classified these strategies into three main categories: biological, physical, and chemical. The review also preliminarily explored various preparation, separation, and purification methods, examining their effectiveness in enhancing umami taste and controlling undesirable sensory attributes like off-flavor and bitterness. The scope covered laboratory advancements and identified key barriers to industrial translation.

The review identified three primary categories for umami peptide modification: biological, physical, and chemical strategies. Biological methods primarily involve enzymatic hydrolysis and microbial fermentation. Physical strategies focus on applying physical fields to assist and enhance enzymatic hydrolysis processes. Chemical strategies encompass approaches such as the Maillard reaction, γ-glutamylation, the plastein reaction, and cyclization. Despite significant progress in laboratory settings, the industrial application of these peptides faces substantial hurdles. Key issues include raw material instability, high production costs, and complex separation and purification challenges. Regulatory frameworks and consumer acceptance also significantly influence commercialization. > Future research must optimize large-scale production, integrate regulatory considerations, assess consumer perception, and leverage computational tools like AI, multi-omics, and molecular docking to guide flavor improvement and product development.