Parallel Extraction of Sulfated polysaccharides and Protein Hydrolysate from Skipjack Tuna Head and Their Bioactive and Functional Properties

Journal article, 2023

A new process for parallel extraction of sulfated polysaccharides (SPs) and fish protein hydrolysate (FPH) from tuna head was developed. The effect of type of enzymes (Alcalase, Protamex, and Pancreatin) on the structural, functional, and bioactivity of both SPs and FPHs was also investigated. Initially, SPs were extracted, then the remaining ethanol from polysaccharide precipitation was used to obtain hydrolyzed proteins. Protamex produced SPs with the highest carbohydrate content (50.17%) while Alcalase prompted the highest content of uronic acid/sulfate. The degree of hydrolysis of the FPHs varied by the used enzyme but their amino acid composition fulfilled human requirements. Both SPs and FPHs had antioxidant activity but their efficiency was governed by the type of enzyme and oxidation mechanism. SPs had good metal chelation while FPHs showed good radical scavenging. Recovered FPHs had substantially higher antibacterial activity than the SPs and showed the highest inhibition against E. coli in concentration of 1 mg/mL. Altogether, parallel extraction of SPs and FPHs could be a promising biorefinery approach for more efficient utilization of tuna head.