Mail·lard reaction | \ mə-ˈlärd- , -ˈyär- \
Definition of Maillard reaction
1. A nonenzymatic reaction between sugars and proteins that occurs upon heating and that produces browning of some foods (such as meat and bread)
2: The Maillard reaction (/maɪˈjɑːr/ my-YAR; French: [majaʁ]) is a chemical reaction between amino acids and reducing sugars that gives browned food its distinctive flavor. Seared steaks, fried dumplings, cookies and other kinds of biscuits, breads, toasted marshmallows, and many other foods undergo this reaction. It is named after French chemist Louis-Camille Maillard, who first described it in 1912 while attempting to reproduce biological protein synthesis.
The reaction is a form of non-enzymatic browning which typically proceeds rapidly from around 140 to 165 °C (280 to 330 °F). Many recipes call for an oven temperature high enough to ensure that a Maillard reaction occurs. At higher temperatures, caramelization (the browning of sugars, a distinct process) and subsequently pyrolysis (final breakdown leading to burning) become more pronounced.