Drying Kinetics of the Leaves From Three Varieties of Cassava ( Manihot esculenta Crantz)

ABSTRACT This study investigated the convective drying kinetics of cassava ( Manihot esculenta Crantz) leaves from three varieties ( Manipeba —M1, Tareza 1 —M2, and Folha fina —M8). Drying experiments were conducted in a tray dryer with forced air circulation at temperatures ranging from 40°C to 80°C, and the process was monitored until the sample mass reached equilibrium. The results highlighted that temperatures above 50°C (60°C, 70°C, and 80°C) significantly enhance water diffusion in cassava leaves, leading to reduced drying times. The effective diffusivity (D eff ) of M1 (1.15–6.32 × 10 −9 ), M2 (1.67–7.73 × 10 −9 ), and M8 (1.77–7.97 × 10 −9 m 2 /s) increased with temperature. The higher activation energy (E a ) of sample M1 (39.33 kJ/mol) suggests greater temperature sensitivity of water diffusivity compared with samples M2 (35.71 kJ/mol) and M8 (36.50 kJ/mol). Nine mathematical models were fitted to the drying experimental data, and the Page and Midilli models best described the drying curves ( R 2 > 0.99, RMSE < 0.05). The findings contribute to understanding the drying behavior of cassava leaves and define conditions for the drying process.