La Chimie des Arômes: Les Hétérocycles

Heterocyclic compounds are widely distributed in food flavours. They arise following two main ways: Ienzymatic and fermentation reactions from primary precursors (proteins, lipids, anthocyanines, polyphenols, carotenoids, ribonucleotides…). IInon-enzymatic browning reactions between reducing sugars and α-amino acids also called MAILLARD's reaction. The thermal degradation of food components: sugars, amino acids, vitamins, trigonelline… constitutes another important source of heterocyclic compounds. The various steps of the MAILLARD reaction as well as the formation of furans, pyrroles, thiophenes, oxazoles, thiazoles, imidazoles, pyridines, pyrazines, lactones in these reactions are described. Owing to the great complexity of natural flavouring mixtures and model systems, the computer assisted synthesis and the realization of a bank of mass spectra provide a valuable help to identify heterocyclic compounds in food flavours.