Effects of Four Kinds of Antioxidants on the Oxidative Stability of Xanthoceras sorbifolia Bunge Oil and Analysis of Its Fatty Acid Compositions

Taking cold-press Xanthoceras sorbifolia Bunge oil as material, the effects of antioxidants on the oxidation stability were studied by Schaal oven test according to peroxide value(POV), acid value(AV) and carbonyl value. The oxidation kinetic model were established with the POV determination, the effects of four antioxidants on the fatty acid compositions of Xanthoceras sorbifolia Bunge oil at 180 ℃ were studied. The results showed that the antioxidant effects of rosemary extract(RE), ascorbal palmitate(AP) and tert butyl hydroquinone (TBHQ) were in the order of TBHQ>RE>AP, and antioxidant effect of vitamin E(V_E) was not significant. The fitted kinetic equation model showed that the oxidation of Xanthoceras sorbifolia Bunge oil with blank and V_E group accorded with the first-order kinetic reaction, and the addition of RE, AP and TBHQ accorded with the zero order kinetic reaction. According to the fitting equation, the shelf life of blank Xanthoceras sorbifolia Bunge oil was 177 d, and that of antioxidants V_E, RE, AP and TBHQ were 178, 346, 341 and 425 d respectively. When Xanthoceras sorbifolia Bunge oil was treated at 180 ℃, RE, AP and TBHQ inhibited the increasing of low carbon chain fatty acids, saturated fatty acids and trans fatty acids in the initial stage. However, the inhibitory effect disappeared after 30 hours, and there was no significant difference compared with the blank group. Unsaturated fatty acid, especially linoleic were enriched in Xanthoceras sorbifolia Bunge oil, it was easy to be oxidized. This study would provide certain data support for the storage and utilization of Xanthoceras sorbifolia Bunge oil.