Iodometric Determination of the Peroxide Value of Edible Oils

Abstract The results of peroxide value determinations in soybean oils depend on the temperature at which the experiments were carried out. The effect of temperature on the values obtained was more pronounced in oils which contained higher amounts of peroxides. When the determinations were carried out in the presence of air, the peroxide values of fresh and oxidized oils to which Fe3+ (20 ppm) had been added were considerably higher than those which were obtained for the same oils without added Fe3+. In the presence of nitrogen, lower values than expected were obtained for oxidized oils with added Fe3+, whereas values which were obtained for unoxidized oils, with or without Fe3+, were similar.