Synergism of phosphatidylcholine on the antioxidant properties of α‐tocopherol in corn oils under different relative humidity

The effects of phosphatidylcholine on the antioxidant properties of α‐tocopherol (84 ppm) were determined in stripped corn oil with various moisture contents at 60 °C. The degree of oxidation in the oils was determined by analysing headspace oxygen content and conjugated dienoic acids (CDA). Generally, phosphatidylcholine acted as an antioxidant in stripped corn oils, whereas it accelerated the rate of lipid oxidation in nonstripped corn oils. As the relative humidity and moisture content increased, the antioxidant properties of phosphatidylcholine increased significantly (P < 0.05). Strong synergistic antioxidant effects were observed in samples containing both phosphatidylcholine and α‐tocopherol compared to samples with only phosphatidylcholine or α‐tocopherol. Oils containing phosphatidylcholine or α‐tocopherol under different moisture contents had different oxidative stabilities.