VIEW ARTICLE    http://dx.doi.org/10.1094/ASBCJ-2013-0123-01

Investigation of Volatile Constituents of Beer, using Resin Adsorption and GC/MS, and Correlation of 2-(3H)-Benzoxazolone with Wheat Malt. Eleni Pothou, Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, and Faculty of Chemistry, University of Athens, Panepistimiopolis Zografou, 15771, Athens, Greece; Eleni Melliou and Alexios-Leandros Skaltsounis, Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, University of Athens; Maria Liouni, Faculty of Chemistry, University of Athens; and Prokopios Magiatis (1), Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, University of Athens. (1) Corresponding author. E-mail: <magiatis@pharm.uoa.gr> J. Am. Soc. Brew. Chem. 71(1):35-40, 2013.

The volatile constituents of 22 samples of commercial beers (lager, ale, and lambic) were isolated using adsorption resin XAD-4 and analyzed by gas chromatography, using mass-spectrometric detection. The presence of 63 volatile components was examined in each sample. Major common compounds identified in all of the studied samples were 2-methylpropanol (0.77–12.9%), 3-methylbutanol (32.0–55.5%), phenylethanol (18.7–58.8%), and tyrosol (0.69–5.82%), expressed as TIC percent. Most other components were found in various concentrations but their presence was not uniformly distributed in all the studied beers. One of the minor volatile compounds, 2-(3H)-benzoxazolone, was found only in beers made with wheat malt. Additionally, for the first time, tryptophol acetate was identified as beer constituent. Finally, principal component analysis of the volatile compounds was able to discriminate the group of beers containing wheat. Keywords: Adsorption resin, Gas chromatography–mass spectrometry, 2(3H)-benzoxazolone, Tryptophol acetate, Wheat malt, Volatiles

Los constituyentes volátiles de 22 muestras de cervezas comerciales (lager, ale, y lambic) se aislaron utilizando resina de adsorción XAD-4 y se analizó por cromatografía de gases, utilizando espectrometría de masas de detección. La presencia de 63 componentes volátiles se examinó en cada muestra. Los principales compuestos comunes identificados en todas las muestras estudiadas fueron 2-metilpropanol (0.77–12.9%), 3-metilbutanol (32.0–55.5%), feniletanol (18.7–58.8%), y tirosol (0.69–5.82%), expresado como TIC (cromatograma total de iones) por ciento. La mayoría de los componentes se encontraron otros en varias concentraciones, pero su presencia no se distribuyen de manera uniforme en todas las cervezas estudiadas. Uno de los compuestos volátiles menores, 2-(3H)-benzoxazolona, se encontró sólo en las cervezas hecha con malta de trigo. Además, por primera vez, acetato de triptofol fue identificado como componente de la cerveza. Por último, el análisis de componentes principales de los compuestos volátiles fue capaz de discriminar el grupo de cervezas de trigo que contiene. Palabras claves: Acetato de triptofol, Cromatografía de gases-espectrometría de masas, 2-(3H)-benzoxazolona, Los compuestos volátiles, Malta de trigo, Resina de adsorción