MICROCALORIMETRIC АPPROACH TO DETERMINATION OF THE CONTENT OF ANTIOXIDANTS AND TOCOPHEROLS IN NATURAL OILS
NATALIA V. SIZOVA *
The Laboratory of Physicochemical Methods of Analysis, Institute of Petroleum Chemistry, SB RAS, 634055, Akademichesky Ave. 4, Tomsk, Russia.
*Author to whom correspondence should be addressed.
Abstract
Using a calorimetric approach, the content of antioxidants and tocopherols (vitamin E) in natural vegetable oils and fats is found. A model reaction of initiation of cumene (isopropylbenzene) oxidation, used as an example, showed that fatty oils inhibit the free-radical reaction, with an induction period proportional to the content of tocopherols in oils. It is shown that the amount of tocopherols is indicative of oil quality, so the method proposed for determination of tocopherols could be extended to monitor production, feed-stock quality and the presence of synthetic antioxidants. The content of tocopherol in oils manufactured by various technologies is determined from the experimental curves.
Keywords: Antioxidants, natural oils, kinetic method for determination of tocopherols (vitamin E)