The popularity of unsaturated vegetable oils continues to increase as more and more research links the possible risk of coronary disease with high dietary intake of saturated fats and trans unsaturated fats. Trans unsaturated fats are produced when vegetable oils are partially hydrogenated, causing them to become harder or more saturated.
Hydrogenation increases the melting point and oxidative stability of fat.
Without hydrogenation, antioxidants may be required in unsaturated vegetable oils to obtain acceptable oxidative stability and shelf life. With a wide variety of unsaturated vegetable oils available, it is important to know which antioxidant will be the best performer at increasing oxidative stability. An experiment was designed to compare all of the commonly used synthetic antioxidants in a wide range of vegetable oils. Tocopherols were not included in the experiment because adding them to unsaturated vegetable oils generally shows only limited increases in oxidative stability. Experiment Five vegetable oils ranging in iodine value from 85 to 131 were selected.