@Camel:
You are mixing up a couple of different things, Esters and Hydrogenated Oils are not one and the same: (1) Esters generally do not require an antioxidant unless there is a component of the chemical structure that contains unsaturated C-C double bonds. The Ester component is an alkylated hydroxyl group that has nothing to do with unsaturated C-C double bonds, the structure is generically C-O-R where R is any alkyl group. (2) Hydrogenated Oils are oils in which the C-C double bond has been “hydrogenated” … the C-C double bonds have been converted to a C-C single bond by the addition of Hydrogen atoms to each carbon of the C-C double bond. The C-C double bond is what makes oils more susceptible to oxidation with benefits from the addition of an antioxidant.