Composition, Lipid Changes, and Sensory Evaluation of Two Sizes of Channel Catfish During Frozen Storage

Abstract

The effects of size of fish on composition and of time in storage at -18°C on lipid and sensory changes for channel catfish, Ictalurus punctatus, were investigated. Dressed large (1.0 kg) fish (LF) averaged 13.2% fat, while dressed small (0.3 kg) fish (SF) averaged 10.8% fat (P < 0.05). Moisture was lower (P < 0.05) for LF (68.1 vs. 70.8%). Thiobarbituric acid (TBA) values for LF increased during the first ten months and dropped during the 12th month, while TBA values reached their highest level after the 8th month for SF. Free fatty acids did not change for LF but increased (P < 0.05) throughout storage for SF. Lipids for both sizes of fish were 25% saturated, 58% monounsaturated, and 17% polyunsaturated fatty acids. C 14:0, C 18:0, and C 18:3 acids decreased after 12 months of frozen storage. LF were rated higher (P < 0.05) in flavor for the first four months but were not rated significantly different from SF thereafter. These results indicate that although LF contained more fat, they did not oxidize any more than did SF, and both sizes were acceptable to panelists throughout the study. Thus, if channel catfish is handled and stored properly regardless of size, it should be acceptable even after 12 months frozen storage.