Maillard Reaction - Blog Posts

Everyday Phenomena: The Maillard Reaction

At first glance, steak, French fries, bread, milk caramel, and soy sauce don’t have very many similarities. However, the preparation of these foods all have one thing in common: browning that occurs via the Maillard (my-YAR) reaction.

The Maillard reaction was first discovered in 1912 by Louis-Camille Maillard, and refers to a long chain of reactions that ultimately leads to browning of food. This chain typically begins with the condensation of an amine (often the amino acid lysine) with a reducing sugar (containing an aldehyde); one example of this Amadori rearrangement is shown above with lysine and glucose.

This Amadori product can react in a variety of different ways, including dehydration and deamination to produce a diverse array of molecules that give browned food a distinctive flavor; a few of these compounds are shown above. At the end of the sequence of reactions that occur during browning is a class of polymeric compounds known as melanoidins, which lend a brown color to the food.

Below about 140°C (280°F), the Maillard reaction does not proceed at an appreciable rate, although alkaline conditions (such as the lye used to make pretzels) can accelerate the process. Without this reaction, many foods we enjoy now wouldn’t be nearly as tasty!

Further Reading: Hodge, J. E., J. Agric. Food Chem. 1953, 1 (15), 928-943 (Full text)