Weibull Model for Thin-Layer Drying of Mango Slices at Different Maturity Stages

Application of Weibull model was investigated for describing the thin-layer drying of green and half-ripe mango slices and determining the water effective diffusion coefficient (De). The air-drying was carried out at 50, 60, 70 and 80C and air velocities of 1.80 and 1.91 m/s. The high regression coefficients (R2 > 0.99) and low reduced chi-square indicated the acceptability of Weibull model for predicting moisture content and determining De, respectively. Scale parameter at 1.80 m/s was the most temperature-sensitive (activation energy [Ea] = 18.9 kJ/mol for green mango and Ea = 10.4 kJ/mol for half-ripe mango), while that at 1.91 m/s was the least temperature sensitive (Ea = 12.6 kJ/mol for green mango and Ea = 9.8 kJ/mol for half-ripe mango). De values ranged from 1.76 × 10−10to 3.14 × 10−10 m2/s and from 2.30 × 10−10to 3.25 × 10−10 m2/s for green and half-ripe mango slices, respectively. PRACTICAL APPLICATIONS This work is intended to provide a model that allows describing the moisture content during the thin-layer drying of mango slices, and determining the water effective diffusion coefficient. So, we provide a significant tool for predicting the moisture content of the product at any time during drying process and for establishing the air-drying conditions in order to achieve given moisture content of mango slices. Also, the knowledge of moisture content and water diffusion coefficient during drying allows to optimize the design of drying process.