High temperature and heating effect on the oxidative stability of dietary cholesterol in different real food systems arising from eggs Abstract 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, collectively called oxysterols. These compounds are increasingly considered of potential interest in the onset and development of vascular disease due to their ability to trigger irreversible damage of vascular cells with consequent activation of phagocytes, up-regulation of the expression and synthesis of adhesion molecules and inflammatory cytokines. The understanding of the conditions, in the presence of which the cholesterol oxidation occurs in foods, could certainly help to prevent the accumulation of oxysterols, allowing to avoid harmful effects on human health. The aim of this work was to verify the presence of 7-ketocholesterol, the most representative of oxysterols family, in eggs and derivative obtained through different procedures of cooking. In the light of our results, we confirmed that the temperature and the lipid nature of the food matrix are closely related to the oxidative stability of cholesterol in foodstuffs. In particular, we tested 7-ketocholesterol formation in the presence of palm oil, rich in saturated fatty acids, or soybean oil, rich in polyunsaturated compounds.