Antioxidant and Antimicrobial Activity of Porcine Liver Hydrolysates Using Flavourzyme

Oxidative stress is implicated in human diseases including cancer or neurodegenerative diseases. On the other hand, lipid and microbial spoilage are the main issues of food degradation. Bioactive peptides with antioxidant and antimicrobial activity could solve both problems and create an opportunity to improve the sustainability of the meat industry. Recently, meat by-products are subject of numerous studies to produce antioxidant peptides, highlighting pork liver as a potential source of hydrolysates. To achieve this purpose, pork liver was digested with Flavourzyme at four reaction times (4, 6, 8, and 10 h) and filtered with cut-offs of 5, 10, and 30-kDa molecular weight. Monitoring hydrolysis with SDS-PAGE showed that the reaction was almost complete. Free amino acid profile exhibited that aliphatic and aromatic amino acids were released in a higher amount at longer reaction times. Heat map analysis demonstrated that a hydrolysis time beyond 6 h, displayed a differential amino acid pattern enabling us to optimize the enzymatic reaction. Antioxidant activity was assessed using ABTS, DPPH, FRAP, and ORAC tests, while antimicrobial assay was carried out against Gram-positive and Gram-negative. ABTS and DPPH values revealed that hydrolysates showed a high antioxidant capacity, as well as an inhibition of growth of Brochothrix thermosphata particularly 30 kDa hydrolysates.