100. Detection of storage-dependent hop oxidation by direct thermal desorption of hop solids for use with GC-FID and GC-MS

Brett Taubman (1), Layton Ashmore (1); (1) Appalachian State University, Boone, NC, U.S.A.

Analytical
Poster

The current accepted method for the analysis of hop essential oils involves the time- and energy-intensive process of steam distillation of hop matter. While steam distillation is an effective method of hop oil extraction, removal of the added processing step would considerably increase sampling efficiency, especially when running multiple samples. Expanding on previous work, this study uses direct application of hop solids to a stainless-steel GC liner with subsequent thermal desorption. Direct thermal desorption (DTD) requires small sample sizes, no sample processing, and can be performed on any standard GC without need for additional accessories. Initial results suggest that DTD agrees with results using traditional steam distillation. The development of this method will allow for rapid sampling with accurate results, which will aid in the study of hop aging as it relates to storage conditions. Prior studies have investigated oxidation of various hop essential oils and oxidation mechanisms have been described; however, a broad study of the formation of oxidation products over time in varying storage conditions of several hop varietals has yet to be conducted. This study will lead to a more comprehensive understanding of how hop flavor profile changes during storage. This information can be used to determine optimal storage time and conditions depending on hop varietal and beer style.

Brett Taubman is a faculty member of the A.R. Smith Department of Chemistry at Appalachian State University engaged in instruction and academic research within the chemistry and fermentation sciences. He has earned B.S. degrees in both finance and chemistry from the Pennsylvania State University and Montana State University, respectively, and a Ph.D. degree in analytical and environmental chemistry from the University of Maryland in 2004. Following his graduate studies, he worked as a postdoctoral research associate at the Pennsylvania State University before joining the chemistry faculty at Appalachian in 2007. Brett has successfully developed a pilot instructional brewing facility on the ASU campus and currently serves as president of Ivory Tower, Inc., a 501(c)(3) non-profit corporation with the mission of supporting research and education within fermentation sciences. He helped to develop the four-year degree program in fermentation sciences and shares time between that program and the Department of Chemistry. He has been brewing and teaching brewing science and technology for over 10 years and is a member of the American Chemical Society, the American Society of Brewing Chemists, Master Brewers Association of the Americas, and the Institute of Brewing and Distilling.