The four major lipid classes: triacylglycerols (TG); phosphatidylethan
olamines (PE); phosphatidylcholines (PC); and sphingomyelins (SM), wer
e quantified in skim milk, whey and buttermilk by liquid chromatograph
y (HPLC) with a light-scattering-detector (LSD) on a Lichrospher Si 60
column using two elution gradients. Calibrations were performed with
triolein, purified milk TG and commercial standards for PE, PC and SM.
LSD's response factors in the linear range of calibration were in the
ratio 1, 2 and 3 for SM, glycerophospholipids and TG respectively. Th
ey were unrelated with fatty acid composition in TG and glycerophospho
lipid classes, but varied widely depending on SM sources.