The Chemistry of the Most Important Maillard Flavor Compounds of Bread and Cooked Rice

The Maillard reaction i.e. the non-enzymatic browning reaction of proteins or amino acids and reducing sugars, produces a variety of azaheterocyclic compounds, which have a major impact on the flavor profile of foodstuffs. This overview covers the chemistry and flavor characteristics of cracker-like flavors, such as 6-acetyl-1,2,3,4-tetrahydropyridine and 2-acetyl-1-pyrroline. Focus will be given to the mechanism of formation, their instability, and the synthesis of these most important Maillard flavor compounds. The so-called Hodge mechanism on the generation of the major bread flavor component will be critically evaluated. Finally, the formation of these flavors by fermentation processes will be discussed.