Enhancing skimmed milk powder functionalities through multicriteria optimization of outlet drying air temperature and spraying air pressure

This study investigated the effects of spraying air pressure and outlet air temperature on the physicochemical and functional properties of skimmed milk powder. Experimental design methodology showed that higher outlet air temperatures improved dry matter content, gelation ability, and flowability, but strengthened colour, moisture sensitivity, and favoured protein denaturation. Spraying air pressure primarily influenced particle size, affecting powder rheological properties and colour. This study highlights the importance of controlling drying parameters to optimize powder properties. The use of a genetic evolutionary algorithm in the optimization process allowed the simultaneous improvement of several functionalities of skimmed milk powder. The findings of this study can contribute to the development of enhanced powders with tailored properties for specific industrial applications. • Outlet air temperature directly affects shelf life, protein integrity and colour of the powder. • Adjusting spray air pressure modifies particle size, shaping powder behaviour and appearance. • Genetic algorithms optimize multifunctional optimization but are challenged by milk seasonality. • Lower whey protein content speeds gelation, improving firmness and water retention. • Better gelling is linked to a regular gel structure with smaller pores, as shown by SEM analysis.