Particle size distribution and lipid composition of skim milk lipid material

Skim milk lipid material was characterized in terms of particle size distribution and lipid composition, and compared with other milk fat particle distributions. Whole milk, skim milk, large fat globules, small fat particles and skim milk lipid material were prepared using centrifugation and/or filtration, and the particle size distributions measured by laser diffraction. The lipid composition was determined using a combination of thin layer chromatography and gas chromatography–mass spectrometry. There were significant compositional differences between each fraction for both particle size distribution and fatty acid composition. The most distinguishing feature of the skim milk lipid material was the increased percentage of long chain sphingomyelin species compared with the other milk fat fractions.