Cholesterol is prone to oxidation, which results in the formation of cholesterol oxidation products (COPs). This occurs because it is a monounsaturated lipid with a double bond on C-5 position. Cholesterol in foods is mostly non-enzymatically oxidized by reactive oxygen species (ROS)-mediated auto-oxidative reaction. The COPs are found in many common foods of animal-origin and are formed during their manufacture process. The formation of COPs is mainly related to the temperature and the heating time the food is processed, storage condition, light exposure and level of activator present such as free radical. The level of COPs in processed foods could reach up to 1-10 % of the total cholesterol depending on the foods. The most predominant COPs in foods including meat, eggs, dairy products as well as other foods of animal origin were 7-ketocholesterol, 7 α-hydroxycholesterol (7α-OH), 7β-hydroxycholesterol (7β-OH), 5,6α-epoxycholesterol (5,6α -EP), 5,6β-epoxycholesterol (5,6β-EP), 25-hydoxycholesterol (25-OH), 20-hydroxycholesterol (20-OH) and cholestanetriol (triol). They are mainly formed non-enzymatically by cholesterol autoxidation. The COPs are known to be potentially more hazardous to human health than pure cholesterol. The procedure to block cholesterol oxidation in foods should be similar to that of lipid oxidation inhibition since both cholesterol and lipid oxidation go through the same free radical mechanism. The formation of COPs in foods can be stopped by decreasing heating time and temperature, controlling storage condition as well as adding antioxidants into food products. This review aims to present, discuss and respond to articles and studies published on the topics of the formation and inhibition of COPs in foods and key factors that might affect cholesterol oxidation. This review may be used as a basic guide to control the formation of COPs in the food industry.

Ham, sausage and bacon were treated with common household processing techniques including refrigerated storage(0, 14, 28 days) and cooking(pan-frying, microwaving, boiling). Lipid oxidation was evaluated by measuring fatty acid composition, malonaldehyde(MA), TBA values and by measuring fluorescent products. Major fatty acid composition were oleic acid and followed respectively palmitic acid, stearic acid, linoleic acid, linolenic acid. There was no significant difference in fatty acid composition by cooking method but there was a tendency of being increased of unsaturated fatty acid during 28days storage. Ma, TBA and fluorescent products showed a tendency of being increased continually according to storage days rather than cooking method.

The oxidation of cholesterol in tallow heated at three frying temperatures, 130, 150 and 180℃ was studied by assaying cholesterol oxidation products(COP) by GC-MS. The correlation between levels of COP and changes of physicochemical parameters (peroxide value, polymer, polar components and dielectric constant) in tallow heated were studied. As temperature increased, the amount of cholesterol was decreased proportionally with heating time. However, the levels of COP did not increase considerably with increased frying temperature. The rate of cholesterol disappearance was the greatest at 180℃ and the smallest at 130℃. Larger amounts of COP formed were found at 150℃ than at 180℃. The levels of COP formed in tallow heated showed highly correlation with(r=0.94, n=30, p$lt;0.01) polymer, polar components and dielectric constant, respectively.

가열우지중 콜레스테롤 산화안정성을 연구하기 위하여 130, 150 및 18 가열온도에서 일정시간 가열하였을 때 생성되는 각종 콜레스테롤 산화생성물을 TLC에 의하여 분리.확인하고, 지방산 조성의 변화를 측정하였다. 지방산 조성은 가열시간이 경과함에 따라 linoleic과 linolenic acid등의 불포화 지방산은 약간씩 감소한 반면 포화지방산의 함량은 다소 증가하는 경향이었고, 이러한 변화는 가열온도가 높을수록 심하였다. 추출한 비비누화물의