| Abstract: | A burnt flavoring compound, which imparts to aged sake its characteristic and dominant flavor, was isolated by Diaion HP–20, silicic acid and Dowex 1–X8 (CH3COO?) column chromatography and chloroform extraction. Based on thin-layer and gas liquid chromatography, UV and GC–MS spectral data, it was identified as 3-hydroxy-4,5-dimethyl-2 (5H)-furanone and its structure was also confirmed by synthesis. It was suggested that this compound was formed by the condensation of a-ketobutyric acid with acetaldehyde which occurred from degradation of threonine. |
