Processing of skim milk powder made using sonicated milk concentrates: A study of physicochemical, functional, powder flow and microbiological characteristics

The impact of sonication treatment (0, 5, 15, 30, and 60 min) of skim milk concentrates on physicochemical, functional, powder flow behaviour, and microbiological properties of milk powders was investigated. Sonication resulted in higher firmness and consistency of concentrates with increasing treatment time. In milk powders, higher L∗ and a∗ values were observed in sonicated samples. D[4,3] parameter of milk powders was between 8.1 and 255.0 μm, and sonication for 60 min decreased this value. Sonication significantly decreased the caking, cohesion, and compaction properties of samples. The flow stability of sonicated samples was higher than that of the control. Sonication can result in improved flow characteristics of milk powders in terms of caking, cohesion, and compaction. These observations could relate to effects of sonication on casein micelle, whey proteins denaturation, whey/whey or casein/whey aggregation. Sonication of milk concentrates was also effective in reducing the microbial counts of milk powders.