Chemometric mapping of beer styles: Integration of hordenine into the beer composition fingerprint

The study developed a chemometric map of commercial beer brands of different fermentations (Ale & Lager), grouped into twelve styles, integrating hordenine into the beer fingerprint as a contributor to overall quality traits. Multivariate modeling was used to establish non-obvious relationships between beer ingredients and finished product characteristics such as physicochemical properties, isoalpha-acids, ethanol, and hordenine. Ale beers showed the highest hordenine levels, up to 11.82 mg·L^-1, whereas Lager light exhibited the lowest concentration (1.41 mg·L^-1). Unexpectedly, hordenine correlated with isoalpha-acids and bitterness (r = 0.69 and 0.71, respectively). Hence, the results indicated that bitterness measurements seem to include spectral contributions from isoalpha-acids and hordenine. Furthermore, beers with wheat malt transformed the Ale beers into a Lager-like chemical and theoretical sensory traits described in style guidelines. New knowledge of the chemistry behind IBUs as a beer quality biomarker seems relevant since bitterness is possibly beer's prominent sensory basic taste.