Effects of washing with oxidising agents on the gel-forming ability and physicochemical properties of surimi produced from bigeye snapper ( Priacanthus tayenus)

Abstract

The effects of washing with hydrogen peroxide (H 2O 2) and sodium hypochlorite (NaOCl) solutions on the gel-forming ability and physicochemical properties of surimi produced from bigeye snapper ( Priacanthus tayenus), stored in ice for up to 14 days, were investigated. Generally, pH and the trichloroacetic acid (TCA)-soluble peptide content of washed mince varied, depending on the type of oxidizing agent and storage time of the fish. With increasing time of storage, the pHs of water- and H 2O 2-washed mince were lower than that of NaOCl-washed mince ( P < 0.05). However, no differences in the TCA-soluble peptide contents of the resulting mince washed with any media were observed ( P > 0.05). Washing with 20 ppm NaOCl resulted in the highest increase in both the breaking force and the deformation of mince from fish stored in ice for all the times studied ( P < 0.05). Natural actomyosin (NAM) extracted from NaOCl-washed mince had higher surface hydrophobicity and disulfide bond (SS) content than that of water-washed mince ( P < 0.05). With no effect on Ca 2+-, Mg 2+-, or Mg 2+–Ca 2+-ATPase activities, NaOCl washing resulted in an increase in Mg 2+–EGTA-ATPase activity of NAM ( P < 0.05). The results suggested that washing mince with the appropriate type and concentration of oxidizing agent can improve the gelling ability of surimi, particularly from low quality fish.