Bond reactivity and antioxidant effect on the autoxidation of soybean oil

Soybean oil (SBO) contains many unsaturated fatty acids, so that it can be easily oxidized by air/oxygen. Therefore the autoxidation of soybean oil was performed to investigate the bond reactivities of allylic, bisallylic CH2, α-CH2, β-CH2, chain CH2 and CH2O of backbone in the presence and absence of phenolic and aniline antioxidants by means of iodometry and 500 MHz 1H NMR spectroscopy. From the active oxygen concentration, the inhibiting effect and by application of proton integration of each bond of pure and oxidized soybean oil to the first order rate equation, got firstly the orders of the reactivity of each C–H bond and inhibiting effect of antioxidants. In the presence of 2,6-di-t-butyl-4-cresol, three phenol adducts from oxidation product also firstly were identified by means of GC–MS spectroscopy.