Effects of CaCl2 on chemical interactions and gel properties of surimi gels from two species of carps

Effects of CaCl2 on chemical interactions, textural properties and expressible moisture content of suwari and kamaboko gels from yellowcheek carp and grass carp were investigated. And the correlations between the contents of chemical interactions and physical properties of surimi gels were analyzed. The contents of chemical interactions, especially non-disulfide covalent bonds, disulfide bonds and hydrophobic interactions of suwari and kamaboko gels, varied with addition concentration of CaCl2 and fish species. Suwari and kamaboko gels from yellowcheek carp exhibited higher breaking force, deformation and gel strength than these from grass carp. Surimi gels (suwari and kamaboko gels) from yellowcheek carp and grass carp exhibited their maximum gel strength when 40 mmol/kg and 100 mmol/kg CaCl2 was added, respectively. Addition of CaCl2 at high concentration resulted in low water holding capacity of surimi gels. Correlation analysis indicated that the contents of nonspecific associations, ionic bonds, hydrophobic interactions and sulfhydryl groups exhibited significant correlation with breaking force of surimi gels from yellowcheek carp and grass carp. Additionally, the content of non-disulfide covalent bonds had significant positive correlations with breaking force and expressible moisture of surimi gel from yellowcheek carp.