Studies on the Fermentation Control of Sake Mash (XVI)

Determination of Acetic Acid, Acetoin, and Ethyl Lactate with Gas Chromatography, and Their Changes in Fermentation

Abstract

1. A method of determining acetic acid, acetoin, and ethyl lactate in moromi mash with gas chromatography was studied. The mash was saturated with ammonium sulfate, and sodium chloride, and extracted with aceton. The aceton extract was dehydrated with magnesium sulfate, concentrated, and subjected to gas chromatography.
2. Large amounts of ethyl lactate and acetic acid were present in seed mash and abnormally fermented moromi mashes.
3. Acetic acid was produced in large amount in the growing stage of yeasts, and decreased as the fermentation proceeded. Its amount was larger, and its decreasing rate was loweras the pH of the mash became more acidic.
On the other hand, the amount of ethyl lactate formed was larger with larger amount of lactic acid present in the mash.