From mist to matter – Steering particle structure development during pilot-scale spray drying

Summary

Food powders are commonly produced using spray drying. During this process a liquid concentrate is atomized into tiny droplets and contacted with hot air to produce powder particles. Spray-dried powders are highly valued for their flowability and easy reconstitution in water. This can be attributed to the powder particle size and structure. When too small particles are present in a powder, it may need to be discarded, contributing to high energy use and food waste. Therefore, during spray drying smaller particles are agglomerated into larger particle clusters. The overall aim of this research was to formulate knowledge-based guidelines on steering particle structure formation to contribute to better-controlled agglomeration and thus achieve more sustainable spray drying processes. The research consisted of pilot-scale spray drying experiments supported by modelling and single droplet drying experiments, which supported development of these guidelines.