ABSTRACT

In addition to the rather nonpolar triacylglycerols (TAG; Chapter 2), several classes of relatively polar lipids are also present in food materials. The most important are the phospholipids, containing a phosphate or (rarely) a phosphonate group. Another class includes the glycolipids, which contain bound sugar. A large, physiologically important group contains sialic acid. Lipids containing sulfur are less frequent. Phenolic acids are bound in another group of polar lipids. Lipids containing sugars, sialic acid, or sulfates may also contain a phospho group. As their chemical structures are rather complicated, they are usually called by their trivial or semisystematic names, and very rarely by their systematic names.