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-X 8 (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 (5 H)-furanone and its structure was also confirmed by synthesis. It was suggested that this compound was formed by the condensation of α-ketobutyric acid with acetaldehyde which occurred from degradation of threonine.
