ANTIOXIDANT ACTIVITY OF A NOVEL PHOSPHATIDYL DERIVATIVE OF VITAMIN-E IN LARD AND ITS MODEL SYSTEM

The antioxidant activity of a novel phosphatidyl derivative of vitamin E [1,2-diacyl-sn-glycero-3-phospho-2'-(hydroxyethyl)-2',5',7',8'-tetramethyl-6'-hydroxychroman; PCh] was investigated. The induction period with PCh was longer than that with the mixture of vitamin E and phosphatidylcholine (PC) when lard was allowed to autoxidize at 60 degrees C in the dark. There was little difference in the antioxidant activities between vitamin E and PCh in an azo compound-induced radical chain reaction of the mixture of methyl linoleate and methyl laurate. However, PCh suppressed the occurrence of ferric ion-induced oxidation of this model oil more efficiently than vitamin E. Therefore; the inhibition of iron-mediated oxidation is likely to be responsible for the superiority of PCh in lard. It is also suggested that the synergistic effect of PC is related to the elevation of vitamin E activity for iron-mediated oxidation.