Formation of cholesterol oxidation products (COPs) in animal products

The cholesterol oxidation products (COPs) are related to processing temperature, heating time, storage conditions, level of activator present, packaging and most of the COPs found in foods were subjected to processing conditions or exposure to heat. The hydroperoxides of polyunsaturated fatty acid formed during lipid oxidation may be necessary to initiate cholesterol oxidation. The amount of COPs in foods could frequently reach 1% of total cholesterol and occasionally 10% or more. The most predominant oxidized cholesterol detected was 7-ketocholesterol, as well as β-epoxycholesterol and α-epoxycholesterol. COPs have been known to be more injurious to arterial cells than pure cholesterol and are more directly connected to the development of atherosclerosis and coronary heart disease, and the lipid oxidation has been associated with quality deterioration caused by the development of off-flavors and off-odors during storage. Prevention of cholesterol oxidation in processed foods should be similar to procedures to prevent lipid oxidation. Overall, the formation of COPs in animal products can be minimized by the application of low processing temperatures, that is through minimal processing, by the use of oxygen-proof packaging and a protective atmosphere as well as by low-temperature and light-free storage, by the dietary antioxidants to animals or antioxidants addition to foods.