AbstractThe stability of a northern sunflower oil was evaluated against a corn oil. The sunflower oil was tested before and after winteriza‐tion, as well as with and without the addition of methyl silicone and antioxidants. The corn oil was tested after winterization with and without the addition of methyl silicone and antioxidants. Under normal use conditions at room temperature and 35 C, in the pres‐ence of air in the headspace gas, sunflower oil samples developed peroxides more rapidly than corn oil. However, these higher perox‐ide numbers did not seem to affect their organoleptic scores. Starch chunks, deep‐fat fried in corn oil, had better flavor stability than those fried in sunflower oil. The peroxide values of the corn‐oil‐fried starch chunks were consistently lower than the sunflower‐oil‐fried starch chunks at various stages of aging. The chemical and physical changes of the corn oil and sunflower oil samples during simulated deep‐fat frying were compared. The stability of the corn oil was approximately the same as that of the sunflower oil.