Cholesterol Oxidation: Presence of 7-ketocholesterol in Different Food Products

Cholesterol, a monounsaturated sterol present in food of animal origin, can be oxidized during food processing and storage, thus generating a series of oxidation products, which are well known for their negative biological effects. The presence of 7-ketocholesterol (7-k), one of the main cholesterol oxidation products (COPs), was evaluated in biscuits, snacks, grated cheese, egg noodles, whole egg powder, whole milk powder, salami, raw and cooked meat. The content of 7-k varied depending on the type of matrix. Most food products showed a 7-k level lower than 2.0 ppm (expressed on sample basis), except for the beef meat (⩽3.5 ppm) and the whole egg powder (⩽4.6 ppm). In addition, beef meat and the meat products showed a higher percent ratio of cholesterol oxidation (⩽0.5%) as compared to the rest of the samples (⩽0.2%).