Oxidation and Thermal Degradation of Oil during Frying: A Review of Natural Antioxidant Use

Frying foods in hot vegetable oil is an efficient and convenient method for food preparation that imbues the product with qualities that are desirable to consumers. During the process of frying, the heated oil cooks the food, but the high temperatures also promote the damaging oxidation and degradation reactions that decrease oil quality over time. In order to prevent these reactions, antioxidants have been added to fryer oil to extend its life. Synthetic antioxidants are typically added to fryer oil, however there is growing concern about their long-term effects on human health. Therefore, finding natural alternatives is an important area of research. This paper reviews the current research around using natural antioxidants to delay the decrease of oil quality under frying conditions.