Effect of Ultrasound Pre-Treatment Prior to Enzymatic Hydrolysis on Physicochemical Parameters of Fish Protein Hydrolysates Extracted from Side Streams of Atlantic Mackerel

The study examined the effects of ultrasound pre-treatment on fish protein hydrolysates (FPH) from Atlantic mackerel side streams, using power levels of 300 W, 450 W, and 600 W. Ultrasound treatment improved the physicochemical properties of FPH, making them lighter, less reddish, and less bitter due to reduced hydrophobic free amino acids. It also increased protein solubility and the degree of hydrolysis, attributed to smaller peptide particle sizes. The 450 W treatment was most effective, enhancing protein solubility, hydrolysis, and essential amino acid content. Overall, ultrasound pre-treatment, particularly at 450 W, significantly improved FPH quality, offering a sustainable method for utilizing fish side streams.