Convection drying of pumpkin slices (cucurbita moschata duch)

Abstract

The drying kinetics and indicators of convection-dried pumpkin slices were evaluated. Convective drying of pumpkin slices at 50, 60 and 70 °C required 105, 90  and          55 min, respectively, to reduce the moisture content from 87,4% m/m to 5% m/m; with a performance of 13,88% m/m. Wang and Singh's model was the most suitable for modeling the drying kinetics of pumpkin slices. The effective diffusivity of water was 1,298 × 10⁻⁹, 1,460 × 10⁻⁹ and 2,110 × 10⁻⁹ m²/s, for 50, 60 and 70 °C, respectively. The activation energy of the drying process was 22,24 kJ/mol, which is in the range for food products. The moisture content, gross density, compacted density and cohesiveness of the powders were not affected by the drying temperature. The colorimetric parameters were affected by the drying temperature and show that the Maillard reaction occurs with the modification of the color of the product.