Enzymatically Hydrolyzed Porcine Blood Meal as a Potential Iron Source in Canine Diets: Effects on Digestibility and Antioxidant Properties.

Porcine blood meal is a protein and iron-rich animal by-product, but its use in companion animal diets is often limited by poor solubility and variable digestibility caused by thermal processing. This study evaluated whether enzymatic hydrolysis could improve the physicochemical properties, digestibility, iron-related characteristics, and antioxidant capacity of porcine blood meal for potential use in canine diets. Porcine blood meal was hydrolyzed using alcalase or pepsin under controlled conditions, and the resulting hydrolysates were characterized by degree of hydrolysis, electrophoretic peptide profiles, techno-functional properties, in vitro digestibility using a simulated canine gastrointestinal model, heme and non-heme iron fractions, and antioxidant activities. Alcalase treatment produced a higher degree of hydrolysis and more extensive peptide fragmentation than pepsin. Consistent with these structural changes, the alcalase hydrolysate exhibited significantly higher in vitro apparent digestibility. Enzymatic hydrolysis increased extractable heme iron while reducing ferrozine-reactive non-heme iron, suggesting changes in iron binding forms after proteolysis. Hydrolyzed samples also showed enhanced radical scavenging activity and ferric-reducing capacity, whereas superoxide dismutase (SOD)-like activity decreased following hydrolysis. These findings indicate that controlled enzymatic hydrolysis, particularly with alcalase, could improve apparent digestibility and non-enzymatic antioxidant capacity of porcine blood meal, supporting its potential as an iron-containing ingredient in canine diets. Further in vivo studies would be required to confirm iron availability and nutritional efficacy.