DOI: 10.36347/sjet

Pages: 693-700

The study investigated the air drying characteristics of aerial yam in a fabricated air dryer within a temperature range of 50 to 70°C. Prior to drying, the sample was divided into two portions; one part was boiled at 100°C for 20min and the other part left fresh. The drying data was fitted to twelve well-known thin layer drying models. Among the models used, the Midilli et al.,Verma et al., Diffusion Approach, Wang and Singh, Parabolic and Simplified Fick’s Diffusion models were found to be the best models to predict the moisture ratio values during the drying process with high capability. The effective moisture diffusivity was found to vary between the range of 1.401 ×10-10 m2/s to 6.720 x 10-10 m2/s for the fresh yam slabs and 7.223 x 10-11 m2/s and 2.306 x 10-10 m2/s for the boiled yam slabs over the temperature range of 50 to 70°C. The values for activation energy were 28.42kJ/mol, 30.33kJ/mol for fresh yam samples of thicknesses of 0.5cm and 1cm respectively, whereas the values for boiled yam were 6.77kJ/mol and 15.37kJ/mol for slabs of 1cm and 0.5cm thicknesses respectively. Pre-treating the aerial yam by boiling will be beneficial in the optimisation of processing method for the Dioscorea bulbifera.