Enzymatic Hydrolysis Enhances Antioxidant Bioactive Sequences and Mineral Recovery from SC-CO2 Defatted Salmon Side Streams

Abstract

Efficient extraction methods are needed to maximize the recovery of high-added-value components for sustainable utilization. This study aimed to compare enzymatic hydrolysis (EH) with conventional extraction (CE) in recovering proteins, minerals, and antioxidant compounds from defatted salmon side streams after supercritical fluid extraction (SFE: 25.0 MPa, 40 °C, 75 min, 10.0 mL/min). Protein content, bioactive peptides, mineral composition, bioaccessibility, and total antioxidant capacity (TAC) were analyzed in solid matrices and liquid extracts from head, backbone, and viscera. EH-derived liquid extracts had significantly higher protein content than CE. Antioxidant activity was highest in solid matrices (head and backbone). Bioactive peptides with anti-inflammatory, immunomodulatory, and hypolipidemic properties were identified. The mineral content varied across the side streams, and the viscera showed the highest Fe, Cu, Zn, and Se levels. Mineral bioaccessibility ranged widely (0.1–100.0%), suggesting variability in bioavailability. EH outperforms CE in recovering essential nutrients and bioactive compounds, demonstrating its potential for valorizing salmon side streams. Further research should optimize EH conditions to enhance mineral bioavailability and explore industrial-scale applications for food, nutraceutical, or feed ingredients.