Oxidative Stability of Cholesterol‐Free Egg Lipid Fractions

Abstract
Lipids were extracted from fresh egg yolk using hexane:isopropanol (3:2.v/v) and separated on a silicic acid column into triacylglycerol (TG), phospholipid (PL), cholesteryl ester and cholesterol fractions using hexane, ethyl acetate and methanol. TG and PL fractions were cholesterol‐free. Oxidative stability at 35° C of crude lipids, TG, PL and combined TG + PL was evaluated over 12 days by measuring conjugated dienes, conjugated trienes and thiobarbituric acid reactive substances. PL and TG exhibited significantly higher oxidation than the crude lipids (alpha = 0.01). Combined TG + PL was not significantly different than the crude lipids (alpha = 0.01), showing much higher stability than individual TG or PL fractions.