Analysis of flavors and fragrances in beers by the liquid-nitrogen trapping GC/FT-IR technique.

Powell, J.R. and Compton, S.V.

Abstract
The liquid nitrogen cold trapping gas chromatography/Fourier transform infrared spectroscopy (GC/FT-IR) method of analysis is described together with its use in the determination of trace volatile compounds in 5 different beer brands. These volatile aroma/flavour constituents were chromatographically separated, then deposited on a nitrogen chilled window where their infrared spectra were recorded in real time. By this means, all the eluants were characterized and identified. The relationships of some of these constituents to the respective characteristics of the individual beers, which differed greatly in their ingredients and brewing methods, are discussed.
Keywords : analysis aroma beer cooling flavour gas chromatography infrared radiation nitrogen spectroscopy volatile compound