Evaluation of the Physicochemical Parameters of a Variety of Okra: Clemson Spineless

Significant quantities of okra rot during harvest periods due to a lack of appropriate technology for processing and preserving these products. To remedy this, this article proposes a CPC (cylindrical parabolic collector) solar dryer for drying a variety of okra (Clemson Spineless). This solar equipment consists of two parts: the drying chamber and the reflector concentrator unit. The coaxial tubular reflector is wrapped in small pieces of transparent glass that are opaque to infrared rays, limiting enormous radiative and convective losses. The greenhouse effect this creates helps to increase the air temperature, both in the receiver and inside the drying chamber, thus promoting natural air flow. Firstly, thanks to the root mean square error (RMSE = 4.5 °C), indicating good agreement between the numerical and experimental temperatures of the heat transfer air passing through the receiver, the thermal performance of this dryer seems evident. Then, experimental tests carried out on the dryer, both empty and loaded, using Clemson Spineless okra, made it possible to determine a hot air temperature level (40 °C - 60 °C) recommended for drying okra without denaturing its trace elements. Thus, the influence of the shapes (cylindrical and longitudinal) and sizes (1 cm, 1.5 cm, and 2 cm) of the dried okra pieces was noted. Also, the diffusion coefficient values (16.49 - 22.72) × 10⁻¹⁰ m².s⁻¹ and (6.24 - 15.59) × 10⁻¹⁰ m².s⁻¹ for the cylindrical and longitudinal slices, respectively, and the drying rate quantifying the water lost in these slices yielded promising results. Finally, observations were made on the appearance of the dried okra pieces, including their color retention, properties, and dryness. Tasting a delicious and appetizing sauce made with okra dried using the new dryer also indicated satisfaction with the performance of the CPC dryer.