Abstract

Cholesterol is a molecule with a double bond in its structure, and therefore it is susceptible to oxidation leading to the formation of oxysterols. These oxidation products are found in many commonly consumed foods and are formed during their manufacture and/or processing. Concern about the consumption of oxysterols arises from the potentially cytotoxic, mutagenic, atherogenic, and possibly carcinogenic effects of some of them. Eggs and egg-derived products are the main dietary sources of oxysterols. Thermally processed milk and milk-derived products are also another source of oxysterols in our diet. Fried meats, and other miscellaneous foods, such as French fried potatoes, when prepared using vegetable/animal frying oil, are another important source of oxysterols in the western diet. Efforts to prevent or to reduce cholesterol oxidation are directed to the application of antioxidants of either synthetic or natural origin. Antioxidants cannot only inhibit triglyceride oxidation, but some of them can also inhibit cholesterol oxidation. Among synthetic antioxidants, 2, 6-di-tertiarybutyl-4-methylphenol (BHT) and tertiary butylhydroquinone (TBHQ), can efficiently inhibit the thermal-induced oxidation of cholesterol. Among natural antioxidants, alpha- and gamma-tocopherol, rosemary extracts, and flavonoid quercetin, show the strongest inhibitory action against cholesterol oxidation.