The Color and Flavor of Olive Oil

The result is an oil that’s green-gold from the presence of chlorophyll and carotenoid pigments (beta-carotene and lutein), more or less pungent from a variety of phenolic compounds and certain products of fat breakdown (hexanol), and aromatic from dozens of volatile molecules. These include flowery and citrusy terpenes, fruity esters, nutty and earthy and almondy and hay-like molecules; but above all there are the grassy, “green”-smelling fragments of fatty acids that are also characteristic of leaf and other green vegetables (artichokes), herbs, and apples. Most of these molecules are generated during the grinding and malaxation, when active enzymes from the damaged fruit cells come into contact with vulnerable polyunsaturated fatty acids in the green chloroplasts. (Leaves are sometimes included in the grinding to supply more chloroplasts.) The oil itself is predominantly monounsaturated (oleic acid) and less vulnerable to oxidation.