Safflower oil, either high in linoleic acid or in oleic acid, has a tocopherol content dominated by α-tocopherol. α-Tocopherol is commonly known as vitamin E. It has a pivotal role in the body as a fat-soluble antioxidant but also possesses various other functions. However, other tocopherol forms, such as γ-tocopherol, enhance the oxidative stability of oils. This is crucial for high temperature applications, such as deep frying or lubrication, but also for biofuels.
María Ruiz-Méndez, Insituto de la Grasa, Sevilla, Spain, and colleagues investigated the oxidative stability of the oil from a genetically engineered safflower mutant. This oil was extracted by solvent extraction or cold press. The oil is characterized by a high oleic acid content and a γ-tocopherol fraction that makes up to 95 % of the total tocopherol content. The genetic replacement of α- by γ-tocopherol doubles the induction time for the safflower oil when cold press is used, and quadruples it when solvent extraction is used, thus showing that for solvent extraction the tocopherol extraction is more efficient.
This demonstrates that the natural antioxidant γ-tocopherol makes the oil less susceptible to oxidation and, hence, increases the range of possible applications.
- Novel safflower oil with high γ-tocopherol content has a high oxidative stability,
Álvaro Fernández-Cuesta, Leonardo Velasco, María Victoria Ruiz-Méndez,
Eur. J. Lipid Sci. Technol. 2014.