Is it possible to modulate the structure of skim milk particle through drying process and parameters?

• Spray drying parameters were investigated with a dimensionless approach on powder properties.
• Increasing temperature and pressure promoted more surface lactose, less surface proteins.
• Influence of process parameters were investigated: solid content, drying temperature or both.
• Three groups of functional properties, according to their dependency to process were identified.

The spray drying operation influences on skim milk powders properties were investigated. It was possible with the use of dimensional analysis to classify the powders into three groups of properties according to their dependency to process parameters. The first group of properties (D50, shape, tapped density) were mainly influenced by the concentrate solid content. On the opposite, the surface composition and surface hydrophobicity ratio were influenced by the drying temperature only. And finally, the third group of properties studied (humidity and water activity) were affected both by the total solid content and drying temperature.In this work, some fundamental key process parameters were identified such as the drying air inlet temperature and the nozzle pressure. Indeed, a clear tendency was highlighted when increasing temperature and pressure: more surface lactose, more surface mineral, less surface proteins, smaller particles, lower humidity and relative humidity.