Evaluation of Thermal Conductivities of Some Selected Powdered Food Products and Their Mixtures

This paper reports on the experimental determination of the thermal conductivities of some selected powdered food stuffs and their mixtures. The foodstuffs considered are: guinea corn flour, rice flour, maize flour, beans flour, cassava flour and yam flour. One to one mixtures of these foodstuffs were made in equal ratios to give mixtures of rice and beans flour, cassava and guinea corn flour and yam and cassava flour. Lee’s Disc Apparatus was used for this investigation and the average thermal conductivities (‘k’ values) of the foodstuff samples are 0.2766 W/m C, 0.2873 W/mC, 0.3112W/mC, 0.3410W/mC, 0.3491W/mC and 0.3526W/mC respectively. The results obtained for the mixtures are 0.2706 W/mC, 0.2964 W/mC and 0.3112 W/mC respectively. It is observed that the thermal conductivity of finer particle flours is higher than the coarse flours and the ‘k’ values of the mixtures are characteristically lower compared to that of the individual constituents of these mixtures.