Skim milk powders with enhanced foaming and steam-frothing properties

摘要

The effects of citrate addition to milks on the stability of milk foams formed by two aeration processes, whipping at room temperature and by steam-frothing, were examined. Citrate addition (0.1-0.5 mol added citrate-kg~(-1) milk solids non-fat) improved the whipping properties of milks reconstituted from conventional low-heat (72 °C for 30 s) and high-heat (85 °C for 30 min) powders. This effect was attributed to the role of citrate in dissociating casein micelles. However, while citrate addition(0.1-0.2 mol added citrate-kg~(-1) milk solids non-fat) improved the steam-frothing properties of milks reconstituted from conventional low-heat milk powder it did not improve those of milks made from corresponding high-heat milk powders. Similar effectsof citrate addition on foaming and stream-frothing properties were obtained when the salts were added to skim milk concentrate prior to drying. The citrated milk powders are alternatives to physical blends of conventional skim milk powders and citrate salts for enhancing the foaming properties of milks at both low and high application temperatures.