Thin layer drying models for sweet potato in tray dryer

Sweet potato is increasingly becoming important and popular as food stuff all over the world. Therefore investigation of thin layer drying of sweet potato slices in three different dimensions was carried out between 50oC and 80oC in tray dryer using hot air at a flow rate of 2.5 m/s and 10% relative humidity. Eight thin-layer drying kinetic models were assessed on blanched and unblanched sweet potato slices presented in three different dimensions. The drying rate was observed to decrease with thickness and mass at a constant drying temperature. Also, the drying rate was found to increase with temperature and the blanched slices dried faster than unblanched slices. The eight models investigated fitted the experimental data of the six sweet potato samples between 50oC and 80oC adequately. However, Page model was found to be the best for all the samples. The results obtained are comparable to some of the reported works. Keywords: sweet potato, thin-layer drying models, page model, tray dryer, diffusion mechanis