Disappearance and Interrelationship of Tocopherol Analogues during Autoxidation of Corn Oil, and Synergistic Effect of L-Ascorbyl Palmitate with α-Tocopherol

Abstract

Disappearance and interrelationship of tocopherols on individual or mixed additi on was investigated during autoxidation of stripped corn oil. Futhermore, the synergisti c property of L-ascorbyl palmitate (L-AsA palmitate) with α-tocopherol was examined. For t he evaluation of autoxidative stability, AOM test was used. Each residual amount of tocopherols and L-AsA palmitate during autoxidation was determined by HPLC. (1) At 0.1, 0.05 and 0.02% of individually added tocopherols in corn oil, the antioxidative activities decreased with the rise of0.02% α-Toc and 0.02% γ-Toc or ς -Toc, the antioxidative activity showed the r tocopherol concentration. of 0.02% α-Toc and 0.02% γ-Toc or ς -Toc, the antioxidative activity showed the r emarkable increase compared to individual addition of each tocopherol. (3) At 0.05 and 0.02% of individually added tocopherols, a similar tendency between the POV and the resid ual amount of each tocopherol was observed. When the same oxidation level was performed, the consumed amounts of tocopherols were the order of ς -Toc> -Toc>α-Toc. (4) In mixed addition of a-Toc and γ-Toc or ς-Toc, α-Toc was consumed faster than γ-Toc or ς -Toc. It was shown that α-Toc acted as electron donor for γ-Toc or ς -Toc radical. (5) L-AsA palmitate showed the synergistic activity with α-Toc. At 2.5x10^-3M of L-AsA pal mitate and α-Toc in corn oil, their highest activities were observed, and theformer wa s consumed faster than the latter. It was confirmed that L-AsA palmitate acted as electron donor for α-Toc radical.