What is the Difference between Maillard Browning and Caramelization (Sugar Browning)?

Much confusion exists between Maillard browning and sugar browning or caramelization.

Both a sugar molecule’s carbonyl group and a protein molecule’s amino group must be present if Maillard browning, also known as sugar-amine browning, is to take place. Heat accelerates the Maillard browning reactions, but they can take place at temperatures as low as

122°F (50°C). The reactions can even proceed slowly at room temperature, such as when foods turn brown from age.

In contradistinction, the browning of pure sugar or other carbohydrates at temperatures higher than about 250°F (120°C) , in the absence of an amino acid or other nitrogen containing compound, takes place by a completely different set of complex chemical reactions, called caramelization.

Many chefs seem to love the world caramelize, and use it indiscriminately to describe any food that turns brown upon being cooked. But meat, poultry, fish, vegetables, and other protein-containing foods do not caramelize. They simply brown. Not as fancy a word, perhaps, but accurate.

A third kind of food browning, enzymatic browning, is caused by enzymes in the food. The surface of a cut apple or pear turns brown because of the release of enzymes from the fruit’s ruptured cells.