Comparative Study of Changes in Muscle Protein of Cultured and Wild Clarias gariepinus in Frozen Storage

Fish is valued for its nutritional qualities as a good source of protein, minerals and vitamins in the amount required for healthy human growth. African catfish, Clarias gariepinus is widely consumed in Nigeria but prone to spoilage after harvest. In this study, samples of both cultured and wild Clarias gariepinus (5kg/each) were subjected to frozen storage immediately after harvest to arrest spoilage after removing the slimes and blood clots from the skin, labeled as wild whole fish (WWF), and cultured whole fish (CWF) respectively. Proximate, minerals and biochemical analysis of fish samples were determined at fresh state, seven days and fourteen days of freezing respectively and the results obtained were analyzed using pie charts and t-test table mean of values (P < 0.05). The crude protein decreased steadily with increase in number of days of freezing in both WWF (59.37 ± 0.78 - 54.19 ± 2.36) and CWF (68.82±0.09- 61.92±0.11) respectively. Conversely, the free fatty acid (FFA %) values increased with the number of days of freezing in WWF (0.13±0.08-0.18±0.08) and CWF (0.12±0.07-0.22±0.07) respectively. Mineral analysis indicated high calcium levels in both fish samples. Assessment of biochemical indices related to lipids damaged in Clarias gariepinus after 14days frozen storage showed Total Volatile Basic Nitrogen (TVBN) value higher in CWF (26.47%) than WWF (7.46%), indicating higher perishability in cultured fish than the wild species.