Production of Tomato Powder by Refractance Window Drying

Abstract

The aims of this work were to investigate the drying of tomato pulp by refractance window (RW) and the effects of process conditions on the drying rates and characteristics of the dry powder. Different heating water temperatures (65, 75, 85, and 95°C) and pulp thickness (2 and 3 mm) were studied for drying 4.8–5.2 °Brix pulps. The powder characteristics were assessed from its solubility, dispersion time, water sorption isotherm, and color. Shorter drying time (17 minutes) was observed to the lower pulp thickness and higher drying temperature. The solubility of tomato powders was approximately 80%, and the dispersion time was lower than one minute. The color change (ΔE) of rehydrated powder showed an increase with increasing process temperature. These results indicate that RW is an adequate procedure for the production of tomato powder.