Cholesterol photosensitized oxidation in muscle foods

Cholesterol photoxidation can affect the nutritional quality of fresh meat and fish due to the formation of oxysterols (COPs), which exert a strong impact on the lipid metabolism and are involved in various chronic and degenerative diseases and disturbance of cell functionality. The evaluation of light sensitized cholesterol oxidation has been reviewed in beef, pork, horse, turkey and sardine meat. In the retail market, fresh slices of meat or fish are usually displayed in refrigerated vessels wrapped with plastic film and are exposed to a fluorescent light. Under these conditions, COPs can range from 8.5 μg/g of lipids (photoxidized pork meat) to more than 300 μg/g of lipids (photoxidized horse meat), corresponding to a maximum of 1.3% of oxidized cholesterol. The oxidative process can be reduced by feeding the animals with antioxidants, such as tocopherols, or by spraying the muscle food with lipid- or water-soluble antioxidants before packaging. However, the combined use of alternative protective packaging and lighting conditions during commercial retail storage, such as the use of red wrapping films, warm tone lamps and modified atmosphere with lower oxygen content, can efficiently prevent photoxidation without modifying the food product composition and sensory properties.