Application of ultrasound technology in the washing process of surimi: improvement of meat yield and gel quality

Washing is a key process in surimi processing, whereby lipids, water-soluble proteins, pigments, and other factors that impede gel formation are separated from the fish. However, this process significantly reduces the meat yield of raw fish and destroys its nutrients, generating more organic wastewater. To enhance the process efficiency, ultrasound is used to assist washing process. This study aims to investigate the effects of ultrasound-assisted washing at different power levels (0 W, 150 W, 250 W, 350 W, and 450 W) on the quality, biochemical characteristics, protein conformation and gel-forming ability of surimi from silver carp. The results showed that ultrasound-assisted washing could increase yield by over 4% and reduce crude fat content by approximately 0.5% than control group. Protein secondary structure indicated that ultrasonic treatment of 250 W didn’t cause significant loss of α-helix. Moreover, the gel strength of 450 W group was roughly 17% more than that in control group. 250 W ultrasound-assisted washing was the most effective and significantly improved the productivity and quality of surimi.