Absorbance readings of TBA reaction products from the oxidation of linoleic acid in Tween-20-stabilized emulsions. Samples were held at 30 °C, in the dark, for up to 72 h. Data are the average of two trials: (♦) linoleic acid emulsion (control); (■) linoleic acid emulsion with MPC solution (10 mg·L⁻¹ protein); (▲) linoleic acid emulsion with 1 mmol·L⁻¹ free ferrous ions; and (●) linoleic acid emulsion with MPC-iron complex. Each point is the average of determinations on two separate samples. Bars indicate standard errors.