抄録
The effects of added tocopherol (Toc) and silicon oil (dimethyl polysiloxane KF 96) on the thermal oxidation of oils and methyl oleate were investigated. Addition of Toc to oils (soybean, hardened soybean, olive and high oleic safflower oils) and methyl oleate were carried out before heating and after heating 1,3,5,10 and 20 h at 180°C, respectively. Oils and methyl oleate containing Toc were heated at 180°C for 30 h (soybean and hardened soybean oils),10 h (olive and high safflower oils)and 5 h (methyl oleate), and Toc content, anisidine and carbonyl values of heated oils were determined by HPLC and JOGS official method 2.4.26-81,2.4.22-73, respectively. The ratio of preventive effects against the thermal oxidation of heated lightly hardened soybean oil increased according to the amount of Toc added. The thermal oxidation of each oil was greatly depending on addition of Toc at the initial stage after heating. The order of suppression of the thermal oxidation of methyl oleate by each Toc was as follows: γ-Toc>mixed Toc>α-Toc. Anisidine and carbonyl values of methyl oleate with mixture of Toc and silicon oil were markedly lower than in those containing only Toc and silicon oil.
