Evaluation of Drying Kinetics of Mango Pulp using Vacuum and Tray Drying Approaches

This study presents a comparative evaluation of the drying kinetics of Alphonso mango pulp (Mangifera indica L.) using a laboratory-scale tray dryer and vacuum dryer at 70 °C. Mango pulp layers of 2, 3, and 4 mm thickness were dried to a final moisture content of less than 8% (wb). Drying time was shorter under vacuum conditions (270, 330, and 430 minutes for 2, 3, and 4 mm, respectively) compared to tray drying (380, 440, and 520 minutes), indicating the efficiency of vacuum drying in accelerating moisture removal. In both methods, drying occurred entirely in the falling-rate period, confirming that internal diffusion governed moisture transport. Experimental moisture ratio data were fitted to five thin-layer drying models: Lewis, Page, Henderson & Pabis, Logarithmic, and Two-Term. For vacuum drying, the Page model provided the best fit (R² = 0.9899–0.9974, lowest RMSE and χ²), whereas for tray drying, the Two-Term model showed superior performance (R² = 0.999 across all thicknesses), followed by the Logarithmic and Page models. These results demonstrate that while both drying methods effectively reduced the moisture content of mango pulp to safe storage levels, vacuum drying achieved faster drying, and tray drying was better characterized by multi-parameter models.