Flavor contribution and formation of heterocyclic oxygen-containing key aroma compounds in thermally processed foods

The biogeneration of oxygen-containing compounds is mainly based on the introduction of carbon dioxide into organic molecules by photo oxidation in plants. In addition, water and molecular oxygen can be enzymatically introduced. Although oxygen is also inserted into unsaturated compounds by auto oxidation, the generation of aroma compounds during food processing and storage is mainly characterized by losses of oxygen from oxygen rich molecules, primarily as water. In particular, carbohydrates are important precursors of oxygen-containing heterocyclic compounds, such as furanones and pyranones. In the present paper, the contribution of compounds like 4-hydroxy-2,5-dimethyl-3(2H)-furanone or 3-hydroxy-4,5-dimethyl-2(5H)-furanone to the flavors of processed foods are briefly discussed. New results on the formation pathways of 3(2H)-and 2(5H)-furanones and Maltol are presented.