Preliminary study on the pro-oxidant activity of polar triglyceride oligopolymers in edible oils

The pro-oxidant activity played by oxidised lipids in edible oils has already been reported in literature. However, it is still unknown whether all the classes of compounds due to oxidation and polimerisation, present in the oxidised fraction of a fat, have an equivalent pro-oxidant activity or if this activity is mainly performed by some of them. The aim of this research was that of evaluating the pro-oxidant effect of one of these classes, always present in refined oils, represented by the oligopolymers of oxidised triglycerides. Silica gel column chromatography was used to obtain the polar compounds (PC) from a thermo-oxidised oil, while preparative gel permeation chromatography of PC was carried out for separating and collecting the oligopolymers of oxidised triglycerides. A purified oil (not containing products of oxidation and hydrolytic degradation as well as free of pigments and substances having antioxidant activity) was prepared in laboratory with the aim to evaluate the pro-oxidant effect without interferences. The addition to the purified oil of variable percentages of polar triglyceride oligopolymers, in a range comprised between 0.25 and 1.0 %, fully evidenced the pro-oxidant activity of this class of compounds