Effects of hot air and vacuum drying methods on drying kinetics and some quality characteristics of traditionally produced couscous in Turkey

Abstract

Drying kinetics and changes in some quality properties of couscous were studied to determine optimal drying method and drying temperature. Drying methods using hot air drying (HAD) and vacuum drying (VD) were applied and couscous samples were dried as thin layer at 55, 65 and 75 °C. Pressure was set at 0.98 bar for vacuum drying. Quality parameters of color values (L*, a*, b*, chroma) and water activity values were measured. Drying periods for VD and HAD at 65 °C were found to be similar. Lower color deviation (?E) and water activity values were also determined for vacuum-dried samples. The Midilli et al. model was found to be the most appropriate thin layer model for both HAD and VD methods. © 2019, College of Agriculture and Food Science, University of the Philippines Los Banos. All rights reserved.