posted on 2018-02-19, 00:00authored byBenjamin L. Schulz, Toan K. Phung, Michele Bruschi, Agnieszka Janusz, Jeff Stewart, John Meehan, Peter Healy, Amanda S. Nouwens, Glen P. Fox, Claudia E. Vickers
Modern beer production is a complex
industrial process. However, some of its biochemical details remain
unclear. Using mass spectrometry proteomics, we have performed a global
untargeted analysis of the proteins present across time during nanoscale
beer production. Samples included sweet wort produced by a high temperature
infusion mash, hopped wort, and bright beer. This analysis identified
over 200 unique proteins from barley and yeast, emphasizing the complexity
of the process and product. We then used data independent SWATH-MS
to quantitatively compare the relative abundance of these proteins
throughout the process. This identified large and significant changes
in the proteome at each process step. These changes described enrichment
of proteins by their biophysical properties, and identified the appearance
of dominant yeast proteins during fermentation. Altered levels of
malt modification also quantitatively changed the proteomes throughout
the process. Detailed inspection of the proteomic data revealed that
many proteins were modified by protease digestion, glycation, or oxidation
during the processing steps. This work demonstrates the opportunities
offered by modern mass spectrometry proteomics in understanding the
ancient process of beer production.