Optimal Conditions for the Formation of Sotolon from .alpha.-Ketobutyric Acid in the French "Vin Jaune"

Sotolon (3-hydroxy-4,5-dimethyl-2(5H)-furanone) is a key flavor compound in the French flor-sherry Vin Jaune. Sotolon in Vin Jaune (120-268 microgram/L) is produced during the development of yeast film over a period of 6 years. In a synthetic medium resembling wine, the formation of sotolon was studied for different organic acids and acetaldehyde. Then, sotolon was quantified by HPLC on a Lichrospher 100 Diol column. Under the conditions of temperature, pH, and alcoholic content similar to the ageing of wine in barrels, sotolon was formed by a purely chemical mechanism from alpha-ketobutyric acid and acetaldehyde. The formation of sotolon increases by increasing temperature and decreasing p…