Pro-oxidant activity of oxidized triacylglycerols in olive oil and comparison with pro-oxidant action of polar triacylglycerol oligopolymers

An experimental investigation was carried out with the aim to evaluate the pro-oxidant activity of oxidized triacylglycerols and compare it with that observed for polar triacylglycerol oligopolymers. The research on these classes of substances, that form during processing and storage of fats and oils, has a great concern with the study of the effect of heat in technologic processes, such as vegetable oils refining, frying and cooking. Oxidized triacylglycerols and polar triacylglycerol oligopolymers, obtained in purity by preparative gel permeation chromatography, were added in amounts of 0.25-1 g/100 g both to a purified and an unpurified olive oil. Regarding the oxidized triacylglycerols, the accelerated oxidation tests showed that the induction times of both oils significantly decreased at increasing concentrations of these compounds, demonstrating their pro-oxidant effect. Moreover, the data showed that the pro-oxidant activity of oxidized triacylglycerols was greater than that of polar triacylglycerol oligopolymers.