CHARACTERISTIC DRYING CURVE and MATHEMATICAL MODELING of THIN‐LAYER SOLAR DRYING of PRICKLY PEAR CLADODE (<i>OPUNTIA FICUS INDICA</i>)

Abstract

ABSTRACT Thin‐layer solar drying experiments were conducted for the prickly pear cladode grown in Marrakech, Morocco. the experimental drying curves obtained show only a falling rate period. the results verified, with good reproducibility, that the drying air temperature is the main factor in controlling the drying rate. the expression of the drying rate equation was determined empirically from the characteristic drying curve. Eight different drying models were compared according to their correlation coefficient (r 2 ) to estimate solar drying curves. the Page model could satisfactorily describe the solar drying curves of cladode with an r 2 of 0.9995. the coefficient of this model could be explained by the effect of drying air temperature with an r 2 of 1.0000.