Target profiling of beer styles by their iso-α-acid and phenolic content using liquid chromatography-quadrupole time-of-flight-mass spectrometry

Beer styles show wide variation in color, flavor, and clarity, due to differences in their chemical content. Some of the major flavor compounds in beer are isomerized alpha acids and phenolic compounds. These were investigated as potentially discerning features between beer styles. A selection of 32 American beers covering five styles was analyzed using liquid chromatography quadrupole time-of-flight mass spectrometry, which resulted in high mass accuracy chromatograms of the studied analytes. Distinctions between the presence or relative concentrations of certain compounds were observed and related back to brewing ingredients and procedures. For example, vanillin was only observed in stout beers due to the use of roasted barley malts for brewing, while chlorogenic acid isomers were found in two sours at relatively high concentrations (189 and 34 mg/L) because of the fruits used to flavor the beers. Distinctions were further confirmed using multivariate analysis techniques, which separated three of the five beer styles (India pale ales, stouts, and sours).

Automated summary

Beer styles exhibit wide variations in color, flavor, and clarity due to differences in their chemical content. In a study analyzing 32 American beers covering five styles, specific compounds such as vanillin and chlorogenic acid isomers were found to be distinguishing features. Using liquid chromatography quadrupole time-of-flight mass spectrometry, distinctions were observed between different beer styles, with multivariate analysis confirming separations between India pale ales, stouts, and sours.