This is the tanning reaction by reacting amino acids With reducing sugars how glucose and fructose, which creates new aromatic compounds. You mustn't go with that caramelize can be confused, but both reactions can occur together. It is named after the French physicist and chemist Louis Camille Maillard (1878-1936), who experimented with it around 1912. The reaction takes place in practically all foods that are heated, but also in the storage of dried fruits, in particular, at very low temperatures. It can be positively felt flavors how roasted (Bread crust, coffee ) caramel and malty, but also negative impressions like bitter. burnt or rancid arise. The lower the temperature, the finer, the higher the temperature, the coarser the aromas.
The phenomenon occurs when frying french fries, roasting coffee, toasting bread and roasting a steak, among other things. This reaction also occurs with wines. That is the formation of the amber color in old ones Trockenbeerenauslese, as well as the fine aroma formation sparkling wines by the reaction of the in the Dosage contained sugar with the at autolysis after bottle fermentation resulting amino acids.