Characterizing Humulone Content in Beer Using Differential Mobility Spectrometry

Abstract

Beer is a complex fermented beverage and several hundreds of components have been identified erenow. Hops are extremely important to beer’s organoleptic qualities, especially bitterness. Bitterness, a distinguishing component of beer’s taste, is of concern for many beer brewing companies. Chemically, the bitterness of beers is associated with the content of iso-humulone, an isomerization product of tasteless natural humulone present in hops. Thus, it is vital to characterize humulone concentration profiles because brewers can utilize these to adjust desired beer properties. However, until now, there are some uncertainties of the quantitative relation between particular hop-derived compounds and sensory bitterness. In this research, the possibility of differential mobility spectrometry (DMS) technique being employed to separate and identify different humulone isomers has been explored. Results are compared against the UV-Vis spectrometry method, which is the conventional analytical technique used to determine the bitterness level of beer. Influence of external factors on the humulone isomerization and decomposition are also studied with rationalization from theoretical calculations.