Plant extracts combined with vitamin E in PUFA-rich diets of cull cows protect processed beef against lipid oxidation

The effect of supplementing PUFA-rich cull cow diets with vitamin E (2.8 g/animal/day) or vitamin E plus plant extracts rich in polyphenols (PERP) (126 g/animal/day), for 101 +/- 3 days preceding slaughter, on the oxidative stability of longissimus thoracis (LT) and semitendinosus (ST) steaks was evaluated after ageing (for 12 d at 4 degrees C either in carcass or under-vacuum) and packaging (14 d under-vacuum (V), 4 d aerobic (A) and 7 d under modified atmosphere (70:30, O-2/CO2) (MA)). The ageing method had no effect on a beef lipid oxidation intensity marker (malondialdehyde (MDA)), whereas packaging systems containing O-2 (A and MA) significantly increased lipid oxidation intensity (5 and 13 times higher than under V. respectively). Adding antioxidants to diets of animals given a PUFA-rich diet significantly improved lipid stability in steaks; the combination of vitamin E and PERP was more efficient than vitamin E alone for the most deleterious beef packaging. (C) 2010 Elsevier Ltd. All rights reserved.