What is the Maillard Reaction?
The Maillard reaction is an organic chemical reaction in which reducing sugars react with amino acids to form a complex mixture of compounds. This reaction is responsible for the characteristic flavour and aroma of browned food. The Maillard reaction is named after the French chemist Louis Camille Maillard.
This reaction can be classified as a non-enzymatic browning reaction. The optimum temperature for this reaction ranges from 140oC to 165oC. It is important to note that caramelization is not a Maillard reaction (it proceeds at higher temperatures and involves the pyrolysis of sugars).
Several flavour compounds are formed during the Maillard reaction. These compounds can break down to yield other flavour compounds. Therefore, different types of food produce different flavour compounds while undergoing the Maillard reaction.
Mechanism of the Maillard Reaction
- The Maillard reaction mechanism begins with the formation of an N-substituted glycosamine (along with water) from the reaction between the amino group of the amino acid and the carbonyl group of the reducing sugar.
- Now, the glycosamine is transformed into ketosamines via Amadori rearrangement.
- These ketosamines undergo further reaction via several pathways and can form reductones, butanedione, methylglyoxal, and several other products of short-chain hydrolytic fission.
- The ketosamines can also go on to form melanoidins and other brown nitrogenous polymers. This imparts the characteristic brown colour to the food.
An illustration detailing the mechanism of the Maillard reaction is provided above. It is important to note that the Maillard reaction between amino acids and reducing sugars can result in the formation of Acrylamide (which is a possible carcinogen in humans). This compound is formed from the reaction between asparagine and dicarbonyl.
To learn more about the Maillard reaction and other important named reactions in organic chemistry, such as the Friedel-Crafts alkylation and acylation reactions, register with BYJU’S and download the mobile application on your smartphone.