Simultaneous determination of E-2-nonenal and beta-damascenone in beer by reversed-phase liquid chromatography with UV detection.

L F Guido, J R Carneiro, J R Santos, P J Almeida, J A Rodrigues, A A Barros

Index: J. Chromatogr. A. 1032(1-2) , 17-22, (2004)

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Abstract

A method for the simultaneous determination of E-2-nonenal and beta-damascenone in beer by reversed-phase liquid chromatography using UV detection is presented. The method consists of beer steam distillation, followed by an extraction/concentration step using Sep-Pak Plus C18 RP cartridges and determination by HPLC at 226 nm UV-absorption maximum. The identity of the compounds was confirmed by GC analysis with MS detection of the isolated fractions. A recovery factor of approximately 80% was obtained for beta-damascenone with a R.S.D. of 3%. E-2-Nonenal and beta-damascenone were monitored in a comparative study of fresh and either naturally and forced aged beer. The results obtained show that both compounds have a similar behaviour through an extended storage of beer and consequently can be used as good analytical markers of beer ageing. Nevertheless, the use of beta-damascenone seems to be more convenient because this compound appears in beer in higher concentrations than E-2-nonenal, thus making it easier to measure.