Effectiveness of ice structuring protein on the myofibrillar protein from mirror carp (Cyprinus carpio L.) during cryopreservation: Reduction of aggregation and improvement of emulsifying properties

Tracking aggregation behaviour and changes in emulsifying properties of myofibrillar protein from mirror carp (Cyprinus carpio L.) induced by its oxidation during frozen storage under the effect of ice structuring protein were investigated. Solubility, net charge, emulsion properties of the sample without ice structuring protein decreased, meanwhile carbonyl, turbidity, the mean diameter in volume and the mean diameter in surface increased during frozen storage. As ice structuring protein addition increased, water-holding capacity and emulsifying properties of samples showed a trend of first increasing and then decreasing, while the tendency of oxidation and aggregation was opposite. Ice structuring protein of 2.0 (g/L) caused the most significant results (P < 0.05). Carbonyl, solubility and emulsion activity index of samples with 2.0 g/L ice structuring protein were decreased by 10.0%, 14.3% and 34.6% after 180 d, respectively. Results suggested that ice structuring protein could effectively prevent moisture loss from flesh, inhibit myofibrillar protein oxidation, and improve emulsion stability during frozen storage.