A specific structured lipid was produced from sunflower oil and caprylic acid. The antioxidative effect of adding alpha-tocopherol, ascorbyl palmitate or citric acid (each in three different concentrations) was investigated before and after the purification process (short-path distillation), and was compared with a control without addition of antioxidant. The oxidative status and stability were characterized by peroxide and anisidine values, secondary volatile oxidation products and induction period. The antioxidants affected the oxidative status compared with the control: citric acid was prooxidative at low concentrations, but antioxidative at high concentrations. Addition of ascorbyl palmitate had an antioxidative effect at all concentrations employed. alpha-Tocopherol showed less antioxidative activity compared with ascorbyl palmitate and citric acid, and its efficacy was slightly decreased with increasing concentration. Combinations of citric acid with ascorbyl palmitate were tested in a later part of the study. No additive or synergistic effect was found between citric acid and ascorbyl palmitate.
Journal of Food Lipids, 2007, Vol 14, Issue 3, p. 244-262