OXIDATIVE STABILITY OF SUNFLOWER OIL EXTRACTED WITH SUPERCRITICAL CARBON-DIOXIDE

Extraction of oilseeds with supercritical carbon dioxide (SC-CO2) is a promising technique to obtain vegetable oils. However, instability of such oils has been associated in the past with SC-CO2 extraction. The reasons underlying such instability were unclear. Results presented here suggest that oil instability may be related to the oxygen content of CO2. In fact, oil stability decreases sharply when refined oil (additive-free) is re-extracted with SC-CO2 and can be related to the oxygen content in the CO2. Nevertheless, oil stability could be improved to the level of conventionally extracted oil by adding trace amounts of ascorbic acid.