Modelling the drying of a twig of “yerba maté” considering as a composite material

Moisture diffusion coefficient value was used to fit the developed model. This parameter was found to be dependent on temperature, moisture content and twig diameter. Moisture diffusion coefficients for xylem were greater than those found for bark. Their values varied between 1.7 × 10−10 and 8.3 × 10−9 m2/s for xylem and 8.7 × 10−12 and 4.7 × 10−9 m2/s for bark. Minor values of mean percent error were obtained dividing experiences in two groups: below and above 100 °C.