Drying Kinetics of Plantain (Musa paradisiaca) in a Parabolic-Shaped Solar Dryer Developed by the Nigerian Stored Products Research Institute

Drying is an essential post-harvest process for preserving plantains, reducing waste, and ensuring year-round availability. A Parabolic-Shaped Solar Dryer (PSSD) developed by the Nigerian Stored Products Research Institute offers a promising sustainable option for drying agricultural produce. This study investigated the drying kinetics of plantain (Musa paradisiaca) slices using the dryer under natural solar operating conditions. Experimental moisture ratio data were fitted to selected thin-layer drying models, including Midili et al., Page, Newton, Logarithmic, and Wang and Singh models, to determine the most suitable predictive model for plantain drying behavior. The Page and Midili et al. models emerged as the best fit, exhibiting R² values of 0.999 and root mean square error values of 0.00, confirming their suitability for describing the drying characteristics of plantain. The drying process was primarily governed by the falling rate period, with moisture diffusion playing a dominant role in moisture removal. At an average temperature of 44.55 ℃ and relative humidity of 61.8%, the PSSD was able to reduce the plantain moisture level from 66 to 12.59% within 22 hours. The economic analysis of the PSSD operation for plantain drying showed a gross margin of ₦ 25,650, a net profit of ₦ 22,617, and a return on investment ratio of 1.20. This study provides insights into the drying behavior of plantain in a solar drying system and supports the application of thin-layer models for predicting drying kinetics under natural conditions.