The influence of nitrogen and carbon dioxide on the oxidative stability of fully refined rapeseed oil

The aim of this research was to assess the effect of nitrogen and carbon dioxide as well as of two methods of their application, i.e. the gas blanket method and the flushing method on the oxidation rate of the fully refined rapeseed oil. Both gases effectively reduced the oxidative changes in the tested rapeseed oil, however, carbon dioxide proved to be more effective in protecting the oil against oxidation compared to nitrogen. The peroxide values obtained in the Schaal oven test and the long-term storage test were, in both methods, significantly lower when using carbon dioxide than when using nitrogen. In the long storing test, carbon dioxide significantly reduced the p-anisidine value compared to nitrogen, regardless of the method used. The continuous flushing of oil with nitrogen or carbon dioxide protected the oil against oxidation almost completely, even at high temperatures (120°C). The oxygen dissolved in oil does not have any impact on oil oxidation.