NITROGEN OXIDE-INITIATED CHOLESTEROL OXIDATION AND CAROTENOID DEGRADATION IN AN EGG LIPID MODEL SYSTEM

The influence of nitrogen oxide (NOx) concentrations on the oxidation of cholesterol and carotenoids in an egg lipid model system was invest igated. The effects of dietary alpha-tocopherol supplementation on cho lesterol and carotenoid stability in egg lipids were also evaluated. T he rate constants for cholesterol oxidation and carotenoid degradation in egg lipids during storage at 40 degrees C were affected by both th e egg treatments and the level of exposure to NOx before storage. The presence of NOx greatly promoted the oxidation of cholesterol and caro tenoids. Dietary supplementation with (a)lpha-tocopherol greatly impro ved the stability of carotenoids and cholesterol in egg lipids exposed to NOx. The addition of carotenoids to egg lipids also protected chol esterol from NOx-initiated oxidation. The patterns of cholesterol oxid ation and carotenoid loss in this lipid model system were similar to t hose in egg powders processed by the direct gas-fired spray-dryer.