Alteration of the lipid of red carp (Cyprinus carpio) during frozen storage

Lipid oxidation of red carp fish during frozen storage was assessed by FTIR method. Druring storage, peroxide acid increased, while unsaturated fatty acids and triglycerides contents decreased. these decreased the nutritional value of red carp.

Fish analysis

Abstract

The aim of this study was to determine the oxidative stability of oil extracted from red carp fish frozen up to 9 months at −18°C. To assess oil stability of red carp fish, the analytical indexes and Fourier transform infrared (FTIR) spectroscopy were used. These methodologies used provided similar conclusions. Before frozen storage, the composition of fatty acids showed that red carp oil is a good source of polyunsaturated fatty acids (PUFAs) such as linoleic acid (C18:2ω‐6: 5.29% of total fatty acid), linolenic acid (C18:3ω3: 3.53% of total fatty acid), arachidonic acid (C20:4ω6: 3.68% of total fatty acid), eicosapentaenoic acid (C20:5ω‐3, EPA: 4,06% of total fatty acid), and docosahexaenoic acid (C22:6ω‐3: 3.02% of total fatty acid). During frozen storage, the free fatty acid and peroxide value increased, respectively, from 1.35% to 8.06% in oleic acid and 3.77 to 18.62 meq O₂/kg in lipid, while the ratio of PUFA/SFA and polyene index decreased, respectively, from 0.58 to 0.25 and 0.30 to 0.09. The triglycerides also decreased with frozen duration. Therefore, for good fish quality, red carp fish must be stored for <3 months at −18°C.

https://onlinelibrary.wiley.com/doi/abs/10.1002/fsn3.971?af=R