Peaks h–k were identified to be the mono-epoxides of OOO, POS, OOS, and SOS, respectively. In epoxides, the loss of an oxygen-con- taining functional group may produce extra unsaturation, as previ- ously proposed by Neff and Byrdwell (1998). These authors also identified an OOO epoxide during the auto-oxidation of triolein. In our studies we found that the POS epoxide and OOS epoxide were produced more in b-carotene than astaxanthin-containing samples at 14 h of thermal treatment in the Rancimat for 110 °C. In model TAGs (Zeb & Murkovic, 2010a) with a similar TAGs com- position, we identified nine oxidised species of different classes. With the exception of OOO-hydroperoxides, OOO and OOS epoxy epidioxides, and OOO mono-epoxide, all others were reported for the first time in the refined olive oil. All of the above discussed oxi- dised compounds were produced in the control as well as in the carotenoids-containing samples. However, the changes in their composition in the presence of carotenoids are highly correlated to the different activity of each carotenoid toward each TAG in the presence of other oil components.