Dark chocolate is produced by adding fat and sugar to the cacao mixture. The U.S. Food and Drug Administration calls this "sweet chocolate", and requires a 15% concentration of chocolate liquor. European rules specify a minimum of 35% cocoa solids.Dark chocolate, with its high cocoa content, is a rich source of epicatechin and gallic acid, which are thought to possess cardioprotective properties. Dark chocolate has also been said to reduce the possibility of a heart attack when consumed regularly in small amounts.Semisweet chocolate is a dark chocolate with a low sugar content. chocolate is chocolate liquor to which some sugar, more cocoa butter, vanilla, and sometimes lecithin have been added. It has less sugar and more liquor than semisweet chocolate, but the two are interchangeable in baking.