In this work it was studied experimentally the kinetics of drying of carrot and pumpkin under vacuum drying in nature and pre-treatment by freezing and bleaching. The experimental runs were driven in a dryer under vacuum, at pressures of 5, 15 and 25 kPa and temperatures of 50, 60 and 70°C. The influences on the drying kinetics of the pressures and temperature were studied, as well as the effect of adopting pre-treatment. It was observed that the best values were obtained at the temperature of 70°C and pressure of 5 kPa for the samples pretreatment by freezing. As concerns to the raw material employed, pumpkin presented higher drying speeds than the one shown by carrot, independently of the treatment received and of the operational condition of drying. The experimental curves of drying were adjusted to the difusional model of Fick for an infinite slab.
vacuum drying; carrot; pumpkin; effective diffusivity
