Many of us would agree that a toasted sandwich is more appealing than the same meal on un-toasted bread. Did you know that science agrees, as well?
The Maillard reaction, named after chemist Louis Camille-Maillard, is responsible for many colors, flavors, and aromas of some of our most beloved foods, particularly during the baking, frying, and roasting processes. Although this chemical reaction was first officially studied around 1910, it wasn't until the 1940s that people took notice of the connection between the "browning reaction" and the flavor of certain foods.
"World War II soldiers were complaining about their powdered eggs turning brown and developing unappealing flavors," Exploratorium writes. "After many studies done in laboratories, scientists figured out that the unappetizing tastes were coming from the browning reaction. Even though the eggs were stored at room temperature, the concentration of amino acids and sugars in the dehydrated mix was high enough to produce a reaction."
Nevertheless, the Maillard reaction is more frequently associated with pleasant smells and tastes. This reaction between the amino acids and simple sugars aides in differentiating foods that were boiled, poached, or steamed from those that were roasted, grilled, or cooked in ways that cause the surface of the food to dehydrate quickly.
The Science of Cooking explains:
Maillard reactions generally only begin to occur above 285°F ...
Like caramelization, it is a form of non-enzymatic browning. The reactive carbonyl group of the sugar interacts with the nucleophilic amino group of the amino acid, and interesting but poorly characterized odor and flavor molecules result. This process accelerates in an alkaline environment because the amino groups do not neutralize. This reaction is the basis of the flavoring industry, since the type of amino acid determines the resulting flavor.
While delicious, this reaction can occasionally be difficult to obtain in foods such as meat. It can be challenging to get the surface of the meat or food item dry and hot enough without simultaneously overcooking the part that is directly underneath.
"One strategy that works well is to remove as much water from the surface of the meat as possible before cooking it (via blotting or drying at low temperature)," advised Modernist Cuisine. "Fast heating using deep fryers, superhot griddles and grills, and even blowtorches are also helpful tactics, such as when we deep-fry chicken wings."