A vacuum drying model for mango pulp

Vacuum drying of mango pulp at varying conditions of pulp thickness (2, 3, and 4 mm) and vacuum chamber plate temperature (65, 70, and 75degreesC) was carried out under 30-50 mm of mercury absolute pressure. A model based on moisture diffusivity was found to give close prediction to moisture content of the pulp at different times of drying with correlation coefficient varying between 0.98-0.99 for pure mango pulp and pulp with ingredients. Color change of reconstituted pulp made from mango powder was found to depend more on pulp thickness than plate temperature. For getting low color change vacuum drying should be carried at maximum pulp thickness of 2.6 mm and vacuum chamber plate temperature of 72.3degreesC.