ANTIOXIDANT INHIBITION OF CHOLESTEROL OXIDATION IN A SPRAY-DRIED FOOD SYSTEM DURING ACCELERATED STORAGE

Spray-dried egg yolk was used to evaluate antioxidant inhibition of cholesterol oxidation during accelerated (Cu+2 and heat) storage. Liquid yolk was treated with equimolar amounts of BHA (0.01%, w/w of lipid), ascorbyl palmitate (0.023%), or a tocopherol blend (0.023%). Yolk batches were spray-dried, stored at 60 +/- 2 degrees C for up to 28 days, and analyzed for cholesterol oxidation products (COPs) using gas chromatography. COP levels generally increased during storage with 7-ketochholesterol predominant. Significant antioxidant effects were manifest in decreased levels of 7-ketocholesterol, 7 alpha- and 7 beta-hydroxycholesterol; while cholestane-triol and cholesterol-5,6-epoxide levels were not affected. All antioxidants showed significant inhibitive effects relative to the control, and tocopherols were more effective than ascorbyl palmitate.