Modelling spray drying processes for dairy products

NIZO food research (The Netherlands) has been working for the food industry, the dairy industry in particular, for over 50 years. During the past 15 years NIZO food research has put a lot of effort into developing predictive computer models for the food industry. Nowadays the main challenges in the production of powders are the development of specialities (having a high added value) and the reduction of processing costs. For this, the production capacity of available installations is maximised and the process conditions are directed towards minimal fouling of equipment, minimal product losses and reduction of energy consumption. On-line product quality control is implemented as far as possible. For these purposes predictive computer models have proven to be very helpful. These models also reduce the number of costly and time-consuming production trials needed for the development of new products or processes. In this article an overview is given of various industrial applications of predictive computer models for spray drying of dairy products. New applications in the field of computational fluid dynamics (CFD) and developments in model predictive control are also discussed. It is expected that these new applications will make it possible to adjust drying equipment more quickly to new products and will reduce variations in product properties to a large extent.