| Popis: |
The spray drying of maltodextrin/water/soybean oil mixtures is studied, with the aim of developing design and operating rules. The results of an extensive series of pilot-scale spray drying experiments are presented. The influence of process conditions, for example air outlet temperature, feed composition, pressure nozzle type, etc. on quality related properties of the dried product are studied. A drying model, based on the diffusion equation, is used to predict drying histories of hollow particles; a simple heuristic free fat model enables the estimation of the free fat content, which relates strongly to stickiness phenomena. Approaches are presented on how to evaluate composition dependent sorption isotherms and moisture diffusion coefficients, both properties being needed as input for the drying model. By combining theoretical modeling and empirical data a better qualitative and semi-quantitative understanding of the drying process is achieved. |
