LIPID OXIDATION DETERMINATION IN BUTTER AND DAIRY SPREADS BY HPLC

Butter and daily spread were stored for 14 wk at 20 degrees C. Lipid h ydroperoxides were analyzed by HPLC. Two methods were tested with chem iluminescence detection based on a post-column reaction with cytochrom e c and luminol. One was for separation of neutral lipids and one for separation of phospholipids. Lipid oxidation in triacylglycerols and p hospholipids in both butter and dairy spread increased during storage. A linear relationship was observed between the chemiluminescence resp onse of oxidizes triacylglycerols and peroxide value. Correlation coef ficient was 0.97 for stored butter and 0.99 for stored dairy spread (P V-range 0.1-1.4 and 0.2-5.4 meq/kg, respectively). The method is sensi tive, fast and reliable: for detection of primary oxidation in dairy p roducts.