Diagram of phospholipids concentrations relative to triacylglycerols. New information about these constituents of fat stems from improvements in the ability to analyze them and studies of their properties. Vitamin E . The tocopherols have a saturated hydrocarbon tail, whereas the tocotrienols are the farnesylated analogues having an unsaturated isoprenoid tail. Vegetable oils and the products made from them usually contain large amounts of tocopherol, especially the a , b and g isomers.
Carotenoids are highly unsaturated polyisoprene hydrocarbons that are lipid soluble.
Over 75 different carotenoids are known to occur in animal fats and vegetable oils. The carotenoids and their derivatives are generally responsible for the yellow to deep-red colour of fruits, vegetables, cereals and crude palm oil. Carotenoids are the precursors of vitamin A, with -carotene having the highest provitamin A activity. Vitamins A and D . A traditional source of vitamin A is butterfat.