Acta Scientiarum Polonorum Technologia Alimentaria

Background. Purple sweet potatoes were produced with a high yield annually. Applying the drying process to purple sweet potatoes could enhance the economic value of this material. Furthermore, energy consumption, as well as the change in the quality of the product, are the important characteristics that determine the product’s quality and effect on the environment.
Material and methods. This research examined the impact of various drying temperatures on kinetic behaviour, effective moisture diffusivity coefficient (Deff), activation energy (Ea), specific energy consumption (SEC), color, shrinkage and physicochemical characteristics of purple sweet potatoes. The final quality of the sample was also evaluated.
Results. Seven models were applied and fitted to actual data of the drying process. The two-term model showed the best fit with high R2, and low RMSE and Chi-square. The calculated Deff and Ea values were 1.58–2.67 m2/s and 17.95 kJ/mol, respectively. The energy consumption of drying purple sweet potatoes ranged from 107.92 to 119.01 kWh/kg. The quality of the product was maintained when a sample was dried at 60°C.
Conclusion. Temperature strongly affected the quality of dried purple sweet potatoes and energy consumption. The first report about the value of energy used during the drying process of sweet potatoes also provides more information about the effect of the drying process on carbon emissions to the environment. Therefore, research aimed at improving product quality and minimizing environmental impacts should be implemented in the future and concerned with ensuring sustainable agricultural production.