Computer modeling of sugar crystallization during drying of thin sugar films

A computer model was developed to predict drying and crystallization during processing of thin sugar films under the conditions of importance for sugar-coated cereals. The three-dimensional model analyzed simultaneous heat and moisture transfer, accounting for shrinkage, with temperature and moisture-dependent transport properties. Crystal growth was evaluated from crystallization kinetics based on supersaturation and temperature. The influence of growth on the solution concentration and drying were taken into account. Concentration profiles around the growing crystals during drying of the thin films were evaluated. The model! predicts a concentration reduction around the growing crystals, and film temperatures that are higher than the drying temperature las a result of the release of fusion heat). A phenomenon of case hardening was observed for dried films with a high density of seeds on surface. (C) 1999 Elsevier Science B.V. All rights reserved.