INFLUENCE OF FREE-RADICALS AND OTHER FACTORS ON FORMATION OF CHOLESTEROL OXIDATION-PRODUCTS IN SPRAY-DRIED WHOLE EGG

Factors influencing formation of cholesterol oxidation products (COPS) in spray-dried whole eggs, particularly free radicals generated durin g the combustion process, were investigated. Total COPS formed in prod ucts dried in the presence of free radicals (by using a gas burner or addition of prooxidants into an electric heating system) were approxim ately 2-5 times greater than those in powders processed by an electric heating system. Addition of antioxidants (tertiary butylhydroquinone and oleoresin rosemary) did not significantly affect (P < 0.05) the fo rmation of COPS in eggs spray-dried with direct gas-fired heating duri ng processing and/or storage. Room temperature storage significantly p romoted (P < 0.05) further formation of COPS regardless of the initial content of COPS in the egg powders. The pathway of cholesterol oxidat ion initiated by oxides of nitrogen appeared to be similar to the hydr operoxide-induced free radical reaction.