A comparative study of selected engineering properties of cashew kernels grown in Nigeria

Engineering properties aid in the design and construction of equipment for post processing of cashew kernels. In this study, the engineering properties of cashew kernels from different locations were evaluated. The physical, mechanical and thermal properties of the kernels at a moisture content of 5% (wet basis) were investigated. The samples used for the study were randomly selected from four different plantation locations across two basic agro-ecological zones of Nigeria. The experiments were carried out in three replicates for each of the properties examined in any location in order to get average values. The physical properties considered were length, width, sphericity, bulk density, true density and specific gravity while the mechanical properties evaluated were porosity, angle of repose, terminal velocity, coefficient of friction, compression force, stress and deformation. The thermal properties examined were specific heat capacity and thermal conductivity. The results showed no significant difference (p <0.05) in the physical and thermal properties. Similarly, there was no significant difference (p <0.05) on porosity, angle of repose and deformation while terminal velocity, coefficient of friction, compressive force and stress were significantly different (p <0.05). It can be concluded that a processing system developed using the property values of a particular variety of cashew kernel can be conveniently used with any other variety of the kernel. It is, however, recommended that varying force applications are to be used depending on variety of kernel. This is because there were significant differences (p<0.05) in the values of the mechanical properties examined and the end-product of the processing operationwill be the same due to the fact that deformation in all cases was significantly the same. Equally, the thermal response of the cashew kernel from different plantation locations will be the same since the thermal properties of the cashew kernels were significantly the same.