Thermal properties of some selected nigerian soups

Abstract

A preliminary investigation was carried out on the thermal properties of “Ewedu” (Corchorusolitorus), “Ila” (Hibiscus esculentus), “Ogbono” (Irvingia gabonensis) and ” Kuka” (Adansonia digitata) soups, because information on the thermal properties of these soups has not been established. The specific heat capacity, thermal conductivity and thermal diffusivity parameters were determined as a function of their proximate compositions by applying additivity principles. The proximate composition obtained for the soups were: ewedu (moisture content; 88.60 ± 0.14%, protein; 6.00 ± 0.01%, fat; 1.05 ± 0.05%, ash; 1.81 ± 0.01%, crude fiber; 1.47 ± 0.02%, carbohydrate; 1.05 ± 0.04% and energy 34.27 ± 1.89 k/cal/10 g), Ila (moisture content; 77.25 ± 0.35%, protein; 15.94 ± 0.08%, fat; 2.13 ± 0.04%, ash; 1.90 ± 0.14%, crude fiber; 1.15 ± 0.07%, carbohydrate; 1.48 ± 0.11% and energy 87.61 ± 3.31 k/cal/10 g), Ogbono (moisture content; 68.87 ± 0.14%, protein; 18.70 ± 0.42%, fat; 6.12 ± 0.11%, ash; 4.55 ± 021%, crude fiber; 1.04 ± 0.60%, carbohydrate; 1.90 ± 0.01% and energy; 133.08 ± 0.60 k/cal/10 g) and Kuka (moisture content; 78.54 ± 0.06%, protein; 8.80 ± 0.41%, fat; 2.29 ± 0.01%, ash; 2.09 ± 0.01%, crude fiber; 0.88 ± 0.02%, carbohydrate; 7.42 ± 0.08% and energy 85.64 ± 0.17 k/cal/10 g). The specific heat capacity, thermal conductivity and thermal diffusivity for the soups were; ewedu (3.851 kJ/ kg/K, 0.530 W/m/K and 1.358 x 10-7 m2/s), Ila (3.554 ± 0.01 kJ/kg/K, 0.483 W/m/K and 1.281 x 10-7 m2/s), ogbono (3.332 kJ/kg/K, 0.447 W/m/K and 1.220 x 10-7 m2/s) and kuka (3.586 kJ/kg/K, 0.494 W/m/K and 1.296 x 10-7 m2/s)respectively. The values obtained for the thermal properties showed that the soups can mildly retain or dissipate heat during canning and freezing.