Caramelization is a process of browning of sugar used extensively in cooking for the resulting sweet nutty flavor and brown color. The brown colors are produced by three groups of polymers: caramelans, caramelens, and caramelins . As the process occurs, volatile chemicals such as diacetyl are released, producing the characteristic caramel flavor.
Like the Maillard reaction, caramelization is a type of non-enzymatic browning. Unlike the Maillard reaction, caramelization is pyrolytic, as opposed to being a reaction with amino acids.
When caramelization involves the disaccharide sucrose, it is broken down into the monosaccharides fructose and glucose.