Effect of Ice Glazing on the Lipid Stability of Litopenaeus vannamei During Frozen Storage

Abstract:

Lipid changes during the freezing process is the primary reason for the deteriorating quality of aquatic products. To explore the lipid changes in the shrimp Litopenaeus vannamei during frozen storage and the effect of ice coating on lipids, the glazed shrimp were stored at −20℃ for 180 d and sampled regularly for the analysis of the thawing loss rate, cooking loss rate, total fat content, lipid composition, acid value (AV), peroxide value (POV), and thiobarbituric acid reactive substances (TBARS). The results showed that the thawing and cooking loss rates of shrimp increased during frozen storage, which were significantly lower in the ice-coated group than in the control group (P<0.01), indicating that ice coating can improve the water holding capacity of shrimp meat in frozen storage. The total lipid content of the shrimp did not change substantially, but the lipid composition did. The concentrations of phospholipids and triglycerides decreased, free fatty acids increased, and cholesterol was relatively stable. The changes in the lipid oxidation indices of the two groups were similar. The AV and TBARS levels increased continuously. The POV first increased and then decreased until 60 d, and then slowly increased. However, the lipid oxidation indicators of the ice-coated group were lower than those of the control group, indicating that ice coating is helpful for maintaining the lipid stability of shrimp during frozen storage.