Identification of 2-Ethyl-Hexanoic (2-Ethyl-Caproic) Acid in Beer. That Vinh, Gérard Schwartz, and Manfred Moll, TEPRAL, 2 Rue Gabriel Bour, F-54250, Champigneulles, France. J. Am. Soc. Brew. Chem. 39:0044, 1981.

Analysis of beer volatiles by gas-liquid chromatography in a high resolution capillary column revealed a number of compounds not separated from a carbon disulfide extract of beer on a packed column. Among these, 2-ethyl-hexanoic (2-ethyl-caproic) acid was identified in beer for the first time. Its identification was supported by the results of electron impact ionization and chemical ionization. The mass spectra were determined on the free acid and its methylated derivative. In sensorial analysis, the addition of this acid to beer at levels in the 1-50 mg/L range created a particularly harsh taste.

Keywords: Beer, Fatty acid, Flavor, Gas chromatography, Mass spectroscopy