<p>Techno-Economic Evaluation of Nigerian Stored Products Research Institute's Parabolic-Shaped Solar Dryer for Production of High-Quality Cassava Flour</p>

Cassava (Manihot esculenta) is a staple crop that plays a crucial role in food security and industrial applications. However, its high moisture content makes it highly perishable, necessitating immediate processing into stable products such as High-Quality Cassava Flour (HQCF). Traditional open sun-drying methods are inefficient due to contamination risks, weather dependency, and inconsistent drying rates, and fossil fuel-powered dryers are also costly to operate. This study evaluated the techno-economic performance of the Nigerian Stored Products Research Institute (NSPRI) Parabolic-Shaped Solar Dryer (PSSD) as an alternative drying method for HQCF production. Two different sizes (6.5 m × 4.2 m × 2.4 m with effective drying area of 17.85 m2) and (10 m × 6 m × 4 m with an effective drying area of 45.6 m2) of the NSPRI PSSDs installed at NSPRI Ibadan Zonal Office, Onireke and “STOP HUNGER” at Moniya, all in Ibadan, were evaluated in this study. This resulted in distinct drying performance and techno-economic outcomes. Sensory evaluation was also conducted on some value-added products solely from the HQCF composites, ensuring assessment of flour quality through its practical use (functional and organoleptic quality). Results from meteorological data indicate that the NSPRI PSSD maintained an average temperature of about 50℃ in the two dryers and effective air distribution that resulted in 17-21% reduction in relative humidity in the dryers. Furthermore, average drying rates of 0.0573-0.0727 and 0.0687-0.0701 kg/h were obtained from samples in the small and big PSSD, respectively. The dryers have loading capacity of 1.4 kg/m2 and batch capacity of 25.2 and 64.0 kg/batch for the small and big PSSD, respectively. Results of sensory evaluation indicates that the HQCF has potential for production of some value-added products at moderate substitution of up to 20%. The results show that the total revenue estimated from the market value of the dried product obtained, was N72,175.00, while the total cost, representing only the operational costs of the drying process, was N54,513.00. The fabrication cost of the dryer was excluded from the analysis. The net profit obtained was N17,662.00 with a benefit-to-cost ratio of 1.32. The economic analysis suggests that adoption of the PSSD can reduce energy costs, minimize postharvest losses, and improve profitability for small-scale cassava processors.