MICROSTRUCTURE OF WHEY-PROTEIN ANHYDROUS MILKFAT EMULSIONS

Research has been undertaken in order to determine the microstructure of emulsions consisting of whey proteins and anhydrous milk fat. The r esults revealed that whey protein films were formed at oil/water inter faces. Scanning electron microscopy (SEM) analysis of chemically fixed specimens, and cryo-SEM analysis of partially etched, frozen specimen s revealed that the adsorbed protein layer (coating the fat droplets) had a granular, aggregated appearance. Emulsions with a high fat load prepared under high homogenization pressure exhibited a bimodal partic le-size distribution. Clustering of the protein-coated droplets, and s haring phenomena at the oil/protein interfaces were evident in these e mulsions. The structural analysis indicated that the bimodal distribut ion could be attributed to clustering of protein-coated fat droplets r ather than to coalescence.