EFFECT OF THE PHENOL ANTIOXIDANT TYPE ON THE KINETICS AND MECHANISM OF INHIBITED LIPID OXIDATION IN THE PRESENCE OF FATTY ALCOHOLS

A kinetic analysis of inhibited lipid autoxidation in the presence of a phenol antioxidant and a hydroxy compound is proposed. It is based o n studies of the dependence of the W-inh(ROH)/W-inh ratio (between the inhibited oxidation rates in presence and absence of a hydroxy compou nd) on the hydroxy compound concentration. This analysis permits estab lishing the mechanism of action of the hydroxy compound in the presenc e of different types of phenol antioxidants during inhibited lipid oxi dation. The kinetic analysis has been applied to the oxidation at 80 d egrees C of triacylglycerols of sunflower oil (TGSO) inhibited by 0.1 mM hydroquinone, butylated hydroxytoluene (BHT) or alpha-tocopherol in the presence of different concentrations of 1-tetradecanol (1-TD) and 1-octadecanol (1-OD). A linear character of this dependence is establ ished during hydroquinone-inhibited oxidation of triacylglycerols of s unflower oil in presence of 1-TD. In the case of alpha-tocopherol this dependence is linear for both 1-TD and 1-OD. The equilibrium constant of interaction between the phenol antioxidant and the fatty alcohols is determined by the angle coefficient of the linear dependence. The h ydroquinone-inhibited autoxidation of TGSO in the presence of 1-OD has shown a non-linear character of the dependence under consideration. A kinetic model describing simultaneous participation of 1-OD in reacti on with both the phenol antioxidant and the lipid hydroperoxides is de duced. Studying the kinetics of BHT-inhibited autoxidation of TGSO in the presence of 1-OD, it has been shown that due to steric reasons the re is no interaction between 1-OD and BHT, 1-OD participating in the p rocess only by accelerating the decomposition of the lipid hydroperoxi des.