ABSTRACT
It has been known for many years that toxic heterocyclic compounds, such as furan, 5-hydroxymethylfurfural, and 4(5)-methylimidazole, are formed in Maillard reaction systems (Shibamoto, 1983). Accordingly, they are found in large numbers in heat-treated foods and beverages. For example, brewed coffee alone contains over 400 heterocyclic compounds (Flament, 2002). Some of them have been recognized as important avor chemicals, which give pleasant roasted or toasted avors to cooked foods. Figure 3.1 shows typical unsubstituted heterocyclic compounds and their physical and sensory properties (Arctander, 1969). Among heterocyclic avor chemicals shown in this gure, furan may be the only chemical which has both a characteristic desirable avor and an unacceptable level of toxicity.
