抄録
Oxidation experiments of β-carotene were performed in a biphasic oil-water system having a definite interfacial area. An inert solvent, n-decane, and 0.01 M Tris-HCl buffer solutions were used as oil and water phases, respectively. The time for which α-tocopherol remained in the biphasic system was about 1.6 times longer than that in the single phase of n-decane. α-Tocopherol was consumed by its oxidation as well as the antioxidative protection of β-carotene. The peroxyl radical of α-tocopherol concerned with the chain oxidation was easily dissolved in the water. This phenomenon was considered to contribute the restrain of α-tocopherol consumption, resulting in the suppression of β-carotene oxidation. A kinetic model was constructed by considering the transfer of the α-tocopherol peroxyl radical into the water phase in addition to the oxidation and antioxidation mechanisms of β-carotene. The model quantitatively described the oxidation behavior of β-carotene in the biphasic system over wide ranges of temperature, initial α-tocopherol concentration, interfacial area and water phase volume.
