The effect of lutein (100, 200, 300μg/ml), sesamol (500, 1000, 2000μg/ml), ellagic acid (300, 600, 900μg/ml) and olive leaf extract (100, 200, 300μg/ml) on oxymyoglobin oxidation and lipid oxidation in bovine and porcine muscle model systems (25% M. longissimus thoracis et lumborum homogenates) was examined. Radical scavenging activity, using the DPPH assay, and iron-chelating activities of lutein, sesamol, ellagic acid and olive leaf extract were assessed at concentrations ranging from 200 to 1000ppm. The radical scavenging activity was of the order: ellagic acid>sesamol>olive leaf extract>lutein. None of the natural antioxidants examined exhibited iron chelating activity. Following induced lipid oxidation (FeCl(3)/sodium ascorbate addition), lipid oxidation and oxymyoglobin oxidation were measured after 24h at 4°C. In bovine and porcine muscle model systems, lipid oxidation decreased (P<0.001) following addition of each of the natural antioxidants relative to the control and antioxidant potency followed the order: sesamol>ellagic acid>olive leaf extract>lutein. Ellagic acid and olive leaf extract decreased oxymyoglobin oxidation (P<0.001) while sesamol increased oxymyoglobin oxidation in both systems. The natural antioxidants examined may have applications in the development of nutritional enhanced meat products with enhanced shelf-life characteristics.