Biochemical property and gel-forming ability of mackerel ( Auxis thazard ) surimi prepared by ultrasonic assisted washing.

A low gel-forming ability is needed to be encountered using the dark-fleshed fish as a raw material. Optimal washing process can be a principled way of improving the gelling properties because washing is the most important step for surimi production. This study aimed to investigate the effect of ultrasonic-assisted washing (UAW) on the biochemical properties and gel-forming ability of frigate mackerel ( Auxis thazard ) surimi. Unwashed mince and conventional washing (CW) with 3-cycle of water (10 min per cycle) were compared to UAW for 5 and 10 min per cycle. UAW tended to improve the lipid removal, reduce the TCA-soluble peptide, and increase the surface hydrophobicity of surimi, but it had no influence on the Ca 2+ -ATPase activity, reactive sulfhydryl content, haem protein content, and lipid oxidation. UAW for 5 min per cycle rendered the surimi with the highest gel strength, whiteness, and water holding capacity as well as a regular aggregated network. With this method, the washing time can be reduced to 50% compared to the CW. Therefore, UAW for 5 min per cycle was an alternative approach for the production of mackerel surimi.