Effects of Citric Acid and Iron Levels on the Flavor Quality of Oil

A factorial design of four levels of added iron (0, 0.1,1 and 5 ppm) and five levels of citric acid (CA) (0, 10, 50, 100, 150 ppm) was used to study interaction effects of citric acid and added iron on flavor quality of oils containing 0.1 ppm iron. Flavor qualities were evaluated by measurement of dissolved free oxygen disappearance and flavor compound formation in oils. When oils contained 0 or 0.1 ppm added iron, the five levels of CA did not affect flavor quality. But, when the oils contained 1 ppm of added iron, increasing the content of CA, rate of oxygen disappearance decreased and smaller concentrations of flavor compounds formed. Results also showed that as the iron content was increased, the rate of dissolved oxygen disappearance increased and the larger concentrations of flavor compounds formed in the oil.