Slaughter blood-derived bioactive peptides: structure-function relationships, species-specific bioactivities, gastrointestinal stability, and sustainable applications in food systems.

This is a comprehensive review focusing on the utilization of slaughter blood proteins as sources of bioactive peptides for functional food applications. Despite significant advances in bioactive peptide research, critical knowledge gaps remain regarding species-specific variations in peptide bioactivity and the complex interplay between processing methods and functional properties. Enzymatic hydrolysis using various proteases generates peptides with diverse bioactivities, including antioxidant, anti-inflammatory, ACE-inhibitory, and DPP-IV inhibitory effects. This review uniquely integrates proteolytic mechanisms with in-depth molecular characterization across multiple animal sources, addressing the previously fragmented understanding of structure-function relationships. Notably, gastrointestinal stability is significantly enhanced by proline residues and hydrophobic amino acids, offering a novel structural insight for predicting peptide bioavailability. Hemoglobin decolorization methods enable broader food industry applications. Recent innovations in processing technologies and delivery systems position blood-derived peptides as valuable functional ingredients for sustainable food systems.