Quality changes in the unwashed silver carp surimi during the immersion frozen storage

Abstract

Objective: To evaluate the effect of immersion frozen storage （IFS） on quality of the unwashed silver carp surimi. Methods: The surimi samples were immersed into liquid coolant non-contacted and stored at (-20±2) ℃ for 60 days, and changes in the Ca2+-ATPase activity, carbonyl content, thiobarbituric acid value （TBA）, as well as the strength, water holding capacity and structure of surimi gel during frozen storage were analyzed, using the traditional frozen storage （TFS） as a control. Results: The results were showed that surimi in IFS group passed through the maximum ice crystal formation zone in 10 min, which was much faster than that of surimi with TFS group （78 min）. The temperature fluctuation range during the whole storage period in IFS and TFS group was 0.72 ℃ and 1.43 ℃, respectively. With prolongation of frozen storage time, the Ca2+-ATPase activity, gel strength and water holding capacity of all samples gradually decreased, while protein carbonyl content and TBA value of all samples gradually increased, and the surimi gel network structure was gradually destroyed. However, changes of all the above indicators for IFS group were distinctly smaller than those for TFS group. Condusion: IFS could effectively alleviate the deterioration of surimi quality during storage, and was a potential low-temperature cold chain technique for food processing and preservation.

Keywords

• surimi
• supercooled liquid
• immersion frozen storage
• temperature fluctuation
• quality