A team led by researchers from the University of Queensland, Brisbane in Australia sought to further understand the ancient, yet complex process of brewing beer in a deeper level—down to its protein profile. As it turns out, the multistep process of brewing directly affects the proteome, which can influence the brew's properties, including its flavor and foaminess. The team’s findings are published in the Journal of Proteome Research.
The team performed a global untargeted analysis of a small mug’s worth of beer at different stages during production. The samples, including sweet wort, hopped wort, and bright beer, were analyzed by liquid chromatography-tandem mass spectrometry (LC−MS/MS). The team identified over 200 unique proteins from barley and yeast.
A complementary and data-independent analytical method called SWATH-MS (Sequential Window Acquisition Of All Theoretical Mass Spectra) then quantitatively compared the relative abundance of these proteins throughout the process. The team found large and significant proteome changes at different stages of brewing, also revealing many protein modifications by protease digestion, glycation, or oxidation. The appearance of dominant yeast proteins during fermentation were also identified.
Through their work, the team demonstrates how modern mass spectrometry proteomics can be used to understand beer production. Future work will focus next on how the identified proteins may control the flavor, consistency, and quality of beer.
Image: Schematic of beer production and mass spectrometric analysis of the proteome. Image courtesy of Claudia Vickers and ACS Publications.