Antioxidant Effects of Tocopherols on Palm Oil by Frying Tests

Abstract

Antioxidant efficiencies of α-, γ- and δ-tocopherols (Toc) in vegetable oils were investigated by a storage test of potato chips fried with palm oil. (1) In addition to palm oil in freshly use, α-, γ- and δ-Tocs showed no effects on the autoxidation of the potato chips in continuous frying. (2) In addition to palm oil in continuously use, γ- and δ-Tocs showed considerable effects. The effect of δ-Toc was higher than that of γ-Toc. The effects became higher with an increase of the added amounts and lower with an increase of the frying times. (3) α-Toc in the palm oil was markedly consumed in the continuous frying, but the most of γ- and δ-Tocs remained. The similar trend had observed in the oven or AOM tests. (4) The residual amounts of tocotrienol (Toc-3) which contained inherently in the palm oil was the highest in δ-Toc-3, followed by γ-Toc-3 and α-Toc-3. The trend of Toc-3 was similar to that of Toc.