TEMPERATURE FACTOR AND SUNFLOWER OIL OXIDATION

Abstract

This article investigates the processes that take place during the forced thermo-oxidation of sunflower oil. The results obtained in the study showed a major impact of thermo-oxidation. The acidity index of fresh sunflower oil increased 13.7 times, with a value of 2.46 mg KOH·g-1 of fat for the thermo-oxidized oil compared to the initial value of 0.180 mg KOH·g-1 of fat. The thermo- oxidation of sunflower oil caused a significant decrease of the saponification index, which indicates a significant degree of polymerization and leads to viscosity increase of the studied sunflower oil. It was established that the applied treatment favoured both the formation of carbonyl secondary compounds and the simultaneous formation of hydroperoxides and triglycerides containing hydroxylated groups. The accumulation of hydroperoxides and triacylglycerides that have hydroxyl functions have facilitated the course of polymerization reactions, which are to increase the viscosity of thermo-oxidized studied sunflower oil.