α‐Tocopherol and Ascorbate Delay Oxymyoglobin and Phospholipid Oxidation In Vitro

An oxymyoglobin liposome model was used to study the effects of α‐tocopherol and/or ascorbate upon oxymyoglobin and lipid oxidation. Both oxidations were delayed (P<0.05) by increased concentrations of α‐tocopherol alone and α‐tocopherol/ascorbate relative to controls. The 14 μ Mα‐tocopherol/140 μM ascorbate treatment resulted in greatest delay in both oxymyoglobin and lipid oxidation. Ascorbate alone delayed oxymyoglobin oxidation; effectiveness diminished as ascorbate increased. Ascorbate showed a prooxidant effect toward lipid oxidation which was unchanged in the presence of EDTA. Results support the hypothesis that α‐tocopherol retards lipid oxidation directly and OxyMb oxidation indirectly.