Marinating beef with South African red wine may protect against lipid peroxidation during cooking

Dietary peroxidised lipids may be harmful to the cardiovascular system. Meat, a complex food, undergoes significant biochemical changes, including lipid peroxidation, during cooking. Wine is often used as an ingredient in the marinating of meat. This study determined whether marinating red meat overnight in red wine has a protective influence against cooking-induced lipid peroxidation in beef. Standardized portions of beef were marinated in red wine. Samples of marinated and unmarinated meat, raw and cooked (microwaved), were analysed for lipid peroxidation products: conjugated dienes (CD), lipid hydroperoxides (LOOH) and thiobarbituric acid reactive substances (TBARS). The antioxidant capacity of the wine was determined. The oxygen radical absorbance capacity (ORAC) value of the wines was 16.8±10.2 mmol/L trolox equivalents. There was great variability in the baseline peroxidation status of the meat samples. Marinating did not significantly alter the CD, LOOH or TBARS in raw meat. Expressed as changes of the mean values, cooking increased the TBARS in unmarinated meat by 17% (P = 0.039). Compared with unmarinated meat, marinating displayed a trend to lower the CD in cooked meat by 20%, (P = 0.084). More studies are required to examine the oxidative status of lipids in meat before and after cooking and to establish a beneficial role for marinating meat with wine.       Key words: Conjugated dienes, oxygen radical absorbance capacity (ORAC), polyunsaturated fatty acids, red meat, wine, thiobarbituric acid reactive substances (TBARS).