Effect of storage methods on the nutritional qualities of African Catfish Clarias gariepinus (Burchell, 1822)

Abstract

The aim of this study was to evaluate the effect of storage methods on the nutritional qualities of African Catfish (Clarias gariepinus). Fresh fish samples were obtained from Johnybeth Farm, Ilesa, Nigeria. Fish specimens were divided into two equal parts. One part was stored fresh in a freezer at -6°C the other was smoked at 65 ± 5°C until equilibrium moisture content was attained, and was further divided into two parts. One part of the smoked fish was stored in continuous heated environment at 40 ± 4°C while the second part was packaged in polyethylene bags and stored at -6°C. Samples were analyzed over a period of six weeks. Nutrients (protein, lipid and carbohydrate), non-nutritional (ash, fibre) and trace element (Ca, Fe, Zn,) content and spoilage parameters (peroxide, pH, TVN, PV, TBA and FFA) were determined using standard methods. The crude protein ranged between 40.53 and 74.00%, lipid 5.46 and 21.71%, ash 2.59 and 8.57%, fibre 0.0 and 2.36%, carbohydrate 0.15 and 38.86%. Peroxide value ranged between 4.60 and 16.02 meq, O2/kg FFA 0.17 and 1.92%, TVN 4.10 and 23.97 mgN/100g, TBA 0.18 and 1.42 mg MDA/g and pH 6.52 and 7.80. Ca ranged between 0.03 and 1.62, Fe 0.28 and 2.27, Zn 0.30 and 2.59, mgkg 1 respectively. There was significant reduction in the nutrient, non-nutrients and trace elements while spoilage parameters increased during the six weeks storage period at (P<0.05). However smoked fish stored in heated environment has less reduction in quality. Key words: Freezing, smoking, nutrients, quality indices, Clarias gariepinus