Suppressive Effect of α-Tocopherol Complexed with β-Cyclodextrin on the Oxidation of Methyl Linoleate

alpha-Tocopherol complexed with beta-cyclodextrin was prepared, and its suppressive effect on the oxidation of methyl linoleate was kinetically examined using the Weibull model. The rate constant, k, of the Weibull equation, for cc-tocopherol oxidation of methyl linoleate was nearly equal to that observed with a mixture of alpha-tocopherol and beta-cyclodextrin. Doubling the amount of alpha-tocopherol further reduced the k value, but the extent of the reduction was not large. All k values with the inclusion complex were lower than those without it. As the amount of free alpha-tocopherol only slightly affected the suppressive activity, the inclusion complexing of alpha-tocopherol with beta-cyclodextrin contributes to lowering the k value. The suppressive effect of alpha-tocopherol complexed with beta-cyclodextrin on methyl linoleate oxidation is due to the protection of alpha-tocopherol by its inclusion in beta-cyclodextrin and the gradual release of alpha-tocopherol from the inclusion complex to the lipid phase.