Exploring novel antifungal peptides from peptic hydrolysis of chicken cruor protein via regression-based machine learning approach

There is a growing interest in natural preservatives driven by consumer demand for clean-label products. In Canada, approximately 48 million liters of blood are produced annually during chicken slaughter, offering an opportunity to valorize cruor, the solid blood component rich in hemoglobin, for use in food preservation. This study investigated the hydrolysis of chicken cruor with pepsin at pH 2, 3, 4, and 5 for 180 min to produce antimicrobial peptides. The highest degree of hydrolysis (11.70 ± 0.77 %) was observed at pH 2, similar to pH 3 where the enzyme exhibited a zipper mechanism. Hydrolysates at pH 2 and 3 inhibited fungal strains (Paecilomyces spp., Rhodotorula mucilaginosa, and Mucor racemosus) with MIC: 0.63 mM, while no antibacterial activity was observed. Partial Least Square-Discriminant Analysis (PLS-DA) allowed the identification of 31 antifungal peptides, including LARKYH, active against R. mucilaginosa (MIC: 0.63 mM), highlighting chicken cruor's potential as a source of bio-preservatives.