Liquid Chromatography-Mass Spectrometry Analysis of Hop-Derived Humulone and Isohumulone Constituents in Beer: The Bitter Truth of Hops Utilization During Brewing

The contribution of hops to the bitter flavours in beer is complicated by a number of factors, including the relative concentrations of humulone homologues in hops, the extraction of bittering compounds from hops, and the conversion of humulones to isohumulones during the brewing process.This article describes a rapid liquid chromatography-mass spectroscopy (LC-MS) method using electrospray ionization (ESI) coupled with selective ion monitoring mass spectroscopy (SIM-MS) for the analysis of humulone and isohumulone content in beer. Individual beer samples are monitored directly following filtration and decarbonization. Using multiple injections in a single experimental run (MISER), data were collected in as little as 7 min for each beer sample. Results were displayed as a single misergram, which allowed for the convenient analysis of relative concentrations of humulones and isohumulones or hops utilization in sets of in-house brewed beers and commercial samples.

Automated summary

This article introduces a rapid LC-MS method for analyzing the content of humulone and isohumulone in beer. The method allows for convenient analysis of the relative concentrations of these compounds or hops utilization in different beer samples.