Analysis of the properties of physiologically active hydrolysates from animal by-products

The utilization of animal by-products for bioactive peptide production is a promising and sustainable approach in the food and nutrition industry. Meat by-products serve as a valuable raw material to produce high-value-added components, such as bioactive peptides, contributing to sustainability. In this study, porcine livers and hearts classified as third-category meat by-products, as well as edible meat by-products that showed no changes after veterinary postmortem examination, were selected. Hydrolysis was performed using pepsin and papain at three different time intervals: 3, 6, and 24 hours. The pH of the samples was determined using the EN ISO 2917:2002 standard technique. The optimal pH values for enzymatic hydrolysis were established for papain (pH = 6) and pepsin (pH = 2.5). When comparing hydrolysis times of 3 hours and 24 hours, the pH values of porcine hearts and livers (edible organs and category 3 meat by-products) treated with papain and pepsin enzymes showed a significant decrease (p < 0.05). However, no significant effect on pH was observed at 3 and 6 hours (p > 0.05). The influence of hydrolysis duration and enzyme type on the degree of hydrolysis (DH) was assessed. The highest DH value (33.56 ± 0.31) was observed in porcine hearts after 24 hours of hydrolysis with pepsin. The assessment of antiradical activity involved the quantification of DPPH• and ABTS•+. Porcine liver hydrolysates treated with papain for 24 hours exhibited the highest radical scavenging activity: ABTS•+ (97.2 ± 1.79%) and DPPH• (92.07 ± 2.23%) (p < 0.05). Peptides from porcine livers and hearts were identified and quantified using SWATH-MS technology. The most abundant peptides associated with antioxidant capacity were WGKVNVDEVGGEALGRL, WGKVNVDEVGGEAL, and GLWGKVNVDEVGGEALGRL from beta hemoglobin.