Formation and Gelation Role of Serum Protein Aggregates during the Manufacture of Milk Powder

Abstract

AbstractThe aim of the present study was to investigate the effects of heat‐related processes during the production of milk powder on aggregation of milk proteins and consequent impacts on the coagulation properties. Compared with raw milk, preheating as well as concentration and subsequent dehydration greatly changed serum protein aggregates, sizes of casein micelles and calcium ion activity, and consequently influenced the textural properties of rennet and acid gels. Moreover, the diversities of these physicochemical and gelling properties were also observed among reconstituted milk powder due to the different preheating or concentration. However, the difference in spray‐drying parameters only affected the intensity of some protein aggregates. It was indicated that all these heat‐related processes should be paid attention during milk powder manufacture in order to control acid or rennet coagulation of reconstituted milk powder.Practical ApplicationsThis study demonstrated the differences in the gelling properties due to the heat‐related processes, i.e., preheating, concentration and spray drying, in the production of milk powder. The information on milk proteins and calcium ion activity would help in understanding their influences on rennet or acid coagulation. The research on the gelling properties of reconstituted milk powder would shed light on the technological application of milk powder such as modification of milk proteins, processing control of milk powder production and suitability of final yogurt or cheese products.