A proteomic approach to detect lactosylation and other chemical changes in stored milk protein concentrate

► Milk protein concentrate powder was examined by proteomic techniques. ► Dramatic alterations in 2-D electrophoresis spot patterns were observed. ► MALDI-TOF-MS confirmed lactosylation caused distinct patterns of whey protein spots. ► Image analysis was used to quantify lactosylation of α-lactalbumin. ► Proteomic techniques could be broadly applied in analysis of food proteins.