Abstract
Polyunsaturated acids in lipids are easy to be oxidized during preservation, processing, and cooking of foods. Some lipid oxidation products deteriorate food quality. In soybean, hexanal, the main beany flavor compound, is produced via the oxidation of linoleic acid by lipoxygenase. Among three isozymes in soybean seeds, L-2 isozyme mainly contributes hexanal formation, but L-3 suppresses its formation. In fish, trimethylamine has been thought to be the main fishy compound. However, many carbonyl compounds, which were produced by oxidation of icosapentaenoic and docosahexaenoic acids, have various kinds of flavors and contributes fishy flavor rather than trimethylamine.
