Date of Award
Master of Science
Dr. Andre Venter
Dr. Sherine Obare
Dr. Steve Bertman
Dr. Todd Barkman
Masters Thesis-Open Access
The objective of this research is to develop a new and innovative method of hops analysis, which is much faster than standard testing methods, as well as reduce the amount of consumables and solvent used. A detailed discussion on the development of an ambient ionization mass spectrometry method called paper spray (PS-MS) and leaf spray (LS-MS) mass spectrometry will be presented. This research investigates the use of PS-MS and LS-MS techniques to determine the α- and β- acids present in hops. PS-MS and LS-MS provide a fast way to analyze hops samples by delivering data as rapidly as a UV-Vis measurement while providing information similar to lengthy liquid chromatographic separations.
The preliminary results shown here indicate that PS-MS could be used to determine cohumulone and α/β ratios. A low cohumulone ratio is desirable for brewers to prevent a harsh bitterness in beer flavor. The α/β ratio is also important for brewers because during the aging process of hops, the bittering potential of α- acids decreases while it increases for β- acids. Leaf spray suffers from low reproducibility and poor quantitative performance but should prove useful for rapid qualitative analysis.
A separate aspect of this research involves investigating if hops varieties could be typified using PCA analysis of PS-MS or LS-MS data. Good grouping of hops varieties were observed for samples of the same variety from different sources and in different stages of processing. An attempt was made to develop a fingerprint database of PS-MS and LS-MS data to provide an alternative approach for differentiating and identifying hops varieties
Blain, Kari, "Direct Analysis of Hops by Leaf Spray and Paper Spray Mass Spectrometry" (2012). Master's Theses. 100.