The change of thermal gelation properties of horse mackerel mince led by protein denaturation occurring in frozen storage and consequential air floatation wash

This study investigated the protein deformation of horse mackerel muscle after frozen storage and consequential air-floatation wash (AFW) and its effect on thermal gelation property change. As frozen storage period of whole fish increased, the rigidity and gel strength of surimi products decrease, and longer washing time was needed for surimi products to gel. The reactive sulfhydryl group decreased with frozen storage time but increased with AFW time. Moreover, the addition of reducing agent (NaHSO3), which was able to reduce disulfide bond, could effectively improve the gelling ability of surimi made of the muscle with long term frozen storage but not significantly of the one made of unfrozen AFW treated mince. The chemical bonding behavior and the thermal analysis results indicated that the myosin rod was unfolded after AFW to interact with other protein, unlike the effect of frozen storage which resulted in denaturation and oxidative disulfide bond formation.