Cholesterol and lipid oxidation products in cooked meat as affected by raw-meat packaging and irradiation and by cooked-meat packaging and storage time

Aerobic packaging significantly increased cholesterol oxidation products (COPs) and thiobarbituric acid reactive substances (TBARS) in cooked turkey, pork, and beef patties after 7-d storage, but vacuum packaging was very effective in preventing cholesterol and lipid oxidation. Packaging of meat after cooking had a much stronger effect on COPs formation than before cooking, and irradiation had only a minor effect. The amount of total COPs correlated well with TBARS in cooked meat. Turkey had the highest rates of COPs and TBARS formation and beef had the lowest rates after 7-d storage, which were closely related to the fatty acid composition of meats. 7 alpha -hydroxycholesterol, 7 beta -hydroxycholesterol, and 7-ketocholesterol were the major COPs detected in all 3 cooked meat patties.