Determination of Drying Characteristics of Tomato Using a Cabinet Solar Dryer in Katsina State

Post-harvest tomato losses in North West Nigeria represent one of the most significant sources of food waste in the agricultural sector, with estimates suggesting that up to 45 percent of fresh tomato produce is lost annually due to inadequate preservation infrastructure. This study investigates the drying characteristics of tomato slices subjected to cabinet solar drying under the climatic conditions of Katsina State during the dry harmattan season. A cabinet solar dryer with a flat-plate collector, a drying chamber, and a natural convection airflow arrangement was constructed using locally available materials. Tomato samples of uniform slice thickness were loaded into the drying chamber, and mass loss was measured at two-hour intervals throughout each drying session. Solar irradiance, dryer inlet and outlet air temperatures, and relative humidity were continuously monitored. Experimental drying curves were fitted to established thin-layer drying models including the Page, Henderson and Pabis, and Lewis models. Statistical goodness-of-fit parameters confirmed that the Page model best described the drying behaviour, with an R-squared value of 0.991 and a root mean square error of 0.013. The solar dryer achieved chamber temperatures 18 to 25 degrees Celsius above ambient and reduced tomato moisture content from 94 percent wet basis to below 10 percent within two days of drying. The study supports investment in community-scale solar drying infrastructure as a sustainable post-harvest loss reduction strategy. Keywords: solar cabinet dryer, tomato drying, drying kinetics, post-harvest losses, Katsina State.