Drying Characterization of Uganda’s Popular High Value Food Products

Food preservation in Uganda is critical due to high post-harvest losses resulting from inadequate storage and preservation techniques. Solar drying offers a sustainable solution, yet its performance for diverse high-value products remains under-characterized. This study aims to address this gap by investigating the drying behavior of pineapple, mango, cassava, banana, and beef, focusing on drying kinetics and system efficiency under Uganda’s wet and dry seasons. An indirect solar dryer equipped with a flat plate thermal collector was used to monitor key parameters, including ambient and dryer temperatures, ambient and dryer relative humidity, drying time and moisture content. Experiments conducted at Busitema University included two seasonal runs, with predictive models developed using Python. Results indicate that dryer temperatures peaked at 60˚C during the dry season, while humidity dropped significantly, enhancing drying efficiency. Mango exhibited the shortest drying time (7 h), followed by cassava (8 - 9 h), while pineapple required the longest (8 - 13 h), depending on the season. Peak drying rates were observed between 12:00 pm and 3:00 pm, coinciding with maximum solar irradiance. Predictive models for dryer conditions and moisture content showed strong conformity with experimental data (R2 > 0.7 in most cases). These findings underline the solar dryer’s capability to efficiently preserve high-value food products, although incorporation of thermal energy storage or auxiliary heat sources like biomass is necessary for consistent wet-season performance.