Influence of protein content and profile on the processing characteristics and physical properties of model infant formula powders

Formulas were designed and produced with protein contents of 10, 14 and 18 g/100 g and whey protein:casein ratios of 60:40, 40:60 and 20:80. Protein content and whey protein:casein ratio did not significantly affect the volume mean diameter (D[4,3]) of milk fat globules during processing; however, increasing protein content and decreasing whey protein:casein ratio resulted in increased viscosity during processing. The free fat content of the powders decreased with increasing protein content. Particle and bulk densities of powders with whey protein:casein ratio of 20:80 were higher than that of powders with whey protein:casein ratio of 60:40.