INVESTIGATION OF THE OXIDATIVE STABILITY OF COLD PRESSED SUNFLOWER OIL OF HIGH-OLEIC TYPE SUBJECTED TO ELEVATED TEMPERATURE

In this paper the oxidative stability of cold pressed sunflower oil of high-oleic type was investigated, using Schaal-Oven test at elevated temperature (63 +/- 2 degrees C). At the same time samples of linoleic type oils, cold pressed and refined, were tested. The extent of oxidative changes was analyzed regarding the content of primary and secondary oxidation products during the period of 14 days. To especially expressed increase in oxidative values, with very high values of the coefficient of determination occurred in samples of linoleic type of oils, cold pressed and refined, whereas these changes were much less observed in the sample of cold pressed sunflower oil of high-oleic type (R-2 >= 0.99). The cold pressed oils of high-oleic and linoleic type, as well of refined sunflower oil of linoleic type were measured and the content of conjugated dienes and conjugated trienes. In the period of 14 days, the lowest increase in oxidative value and the lowest degree of conjugation into the conjugated diene and triene were determined in cold pressed sunflower oil of high-oleic type, indicating a significantly better oxidative stability of this type of oil compared to linoleic types.