FUNCTIONALITY OF MILK-FAT IN FOAM FORMATION AND STABILITY

The objectives of this study were to investigate the functional proper ties of different fats emulsified in food foams. Quantitative descript ions of the formation and subsequent stability of food foams containin g a dispersed lipid phase were generated to examine the effects of fat phase plasticity on foam dynamics. Formation and stability of foamed oil in water emulsions of vegetable oil, milk fat, or milk fat fractio ns separated by crystallization were characterized. Foams were generat ed in a sparging apparatus utilizing magnetic resonance imaging as a m easurement probe. Whole anhydrous milk fat was fractionated by melt cr ystallization. Milk fat fractions derived from crystallization separat ion possessed distinct functional characteristics that were due primar ily to the presence of long-chain saturated triglycerides in the hard fraction. The increased plasticity of the hard fraction affected the f ormation of foams and their subsequent stability. The stratification o f foam density from top to bottom, determined by magnetic resonance im aging, varied inversely with increasing lipid hardness. Composition an d physical state of the dispersed lipid particles contribute to foam f ormation and stability.