Abstract

The antioxidant effects of tocols (α-tocopherol and α-tocotrienol) and Rosa mosqueta shell extract added to antioxidant-stripped canola oil (TCO) were evaluated and compared with the non-stripped oil (CO) under the same conditions. Seven oil systems were subjected to thermal treatment at 180 °C for 18 h. Polar compounds formation, degradation of tocols and carotenoid pigments were studied. The addition of Rosa mosqueta shell extract gave a great stability to TCO, similar to CO, with a low polar compound formation and a high retention of α-tocopherol compared with other TCO samples, which suggested the protective action of the minor components present in the extract. Alpha-tocopherol showed a higher effectiveness than α-tocotrienol at high temperature. However, an increase in the level of α-tocopherol did not improve its action. © 2007 Elsevier Ltd. All rights reserved.