Unraveling the Chemical Composition of Caramel

Caramel is one of mankind's best known dietary materials obtained from carbohydrates by heating. Much effort has been expended toward the chemical characterization of the components of caramel but impeded by a lack of suitable analytical techniques sufficiently powerful for providing insight into an extraordinarily complex material. This paper reports the characterization of caramel formed by heating from glucose, fructose, and saccharose using a conceptually novel combination of mass spectrometrical techniques. The analytical strategy employed uses high-resolution mass spectrometry (MS) followed by targeted liquid chromatography tandem MS experiments. Caramel is composed from several thousand compounds formed by a small number of unselective and chemoselective reactions. Caramelization products include oligomers with up to six carbohydrate units formed through unselective glycosidic bond formation, dehydration products of oligomers losing up to a maximum of eight water molecules, hydration products of sugar oligomers, disproportionation products, and colored aromatic products.