Thermo-Physical Properties of Farmed African Freshwater Catfish (Clarias gariepinus) Fillet for Process Design and Optimization

Abstract

The proximate composition of skinned farmed African freshwater catfish (Clarias gariepinus) fillet was determined and found to be moisture (77.2%), protein (17.12%), ash (1.53%), lipid (3.39%) and carbohydrate (0.75%). The density, specific heat, thermal conductivity, thermal  diffusivity and latent heat obtained as functions of the proximate  composition of the fillet were 1059 kgm^-3, 3.63 kJkg^-1K^-1, 0.525  Wm^-1K^-1, 1.2 x 10^-4m2s^-1 and 258.62 kJkg^-1 respectively. The thermo-physical values obtained were correlated with the proximate composition value, the specific heat, thermal conductivity and latent heat increased with increase in moisture content while thermal diffusivity decreased as  moisture content increased. The density had positive correlation with ash and carbohydrate contents but had inverse relation with protein, lipid and moisture contents. It also had weak inverse relation with thermal diffusivity and latent heat. Thermal conductivity had positive correlation with moisture content but had inverse relation with lipid content and weak relation with ash content. Heat may be transferred better along the fibres of the fillet than across the fibre.