Changes in Chemical Properties of Three Types of Fats Used for Deep Fat Frying

Use of deep fat frying as a cooking method has increased significantly over the years due to short cooking times and the development of a unique flavor, odor and color in the final product. Reactions of fat with many constituents of the food being fried cause desirable changes in fried foods : however, prolonged heating of oils at high temperatures in the presence of moisture and oxygen results in oxidation of oils. These oxidation products including volatile carbonyls, hydroxy acids, keto acids and epoxy acids cause unpleasant flavours and darkening of the oil.