The Maillard reaction is a series of complex chemical reactions we observe daily in a variety of different foods and drinks

The Maillard reaction is a series of complex chemical reactions we observe daily in a variety of different foods and drinks. Roasted coffee, grilled chicken, and chocolate chip cookies are all examples of products that have experienced the Maillard reaction. More commonly known as the “browning” or “flavoring” reaction, it is the process that brings golden-brown colors, new aromas, and distinct flavors to different foods. The Maillard reaction is a large process that is comprised of a number of smaller reactions, all of which produce complex products. These products, however, all contribute to the final results of the Maillard process.
In 1912, French physician and chemist, Louis Camille Maillard, discovered that a reaction begins to occur in food when it reaches a temperature of about 150°C. However, Maillard’s studies did not greatly influence the relationship between the reaction and its impact on browning and flavor. It was not until several decades later that scientists would discover the mechanisms and contributions the reaction gave to the culinary world. One chemist, John Hodge, published a mechanism identifying three main stages of the reaction. He found that the first stage was a reaction between the sugar and the amino acid, that produced a sugar-amino acid-based compound called glycosylamine. The second stage rearranged this product to produce another sugar-amino acid compound called ketosamine. Finally, this compound reacts in several different ways to produce numerous compounds that react to form melanoidins.
Melanoidins are one of the end products of the reaction that give cooked food its brown color and distinct aromatic flavors. This compound is composed of long chains of amino-based molecules. Melanoidins are a key product in determining a food’s color, but they mostly regulate the flavor and aroma generated by reactants involved in initial steps of the reaction. The melanoidins are produced without enzymatic activity, which allows the Maillard to be called a non-enzymatic browning reaction. Other forms of browning, such as a banana turning brown, are the results of enzymatic browning, a much less desirable occurrence. Although melanoidin compounds play a significant role in the final flavor and odor of the product, many other factors, like heat and pH, also have an impact.
Even though the major product of the reaction creates enticing new colors and aromas, minor by-products can be damaging to human health. Acrylamides are an example of a harmful product that could be produced by the Maillard under certain conditions. If food that undergoes the Maillard process is exposed to high heat for an extended period of time, the levels of acrylamide, a carcinogenic compound, will rise. Despite the fact that this reaction produces a carcinogenic product in certain conditions, the concentration of acrylamide is extremely low and is simply a natural consequence of cooking.
The Maillard reaction is a complex process that allows any individual to apply chemistry to a common aspect of their daily life. Because of its complexity, however, there is also an abundance of information that we do not understand about the reaction. In turn, researchers are not able to understand how specifically factors like temperature and pH affect the final products of this reaction. Comprehending the basics of this process and its products can allow for major advancements in the food chemistry industry. Using this material can ultimately allow us to manipulate food to deceive our senses to create more delicious food.