Hop Aroma analysis in beer using PDMS-stir bar sorptive extraction-GC-MS

Analytical Session
Yanping L Qian, Oregon State University, Corvallis, OR 97331, USA
Co-author(s): Tom Shellhammer and Michael Qian, Oregon State University, Corvallis, OR, USA

ABSTRACT: The development of stir bar sorptive extraction (SBSE) allows for simple sample preparation to establish a volatile spectrum. Automated SBSE extraction coupled with gas chromatography-mass spectrometry (GC-MS) is a valuable technique to analyze a wide range of volatile aroma compounds in alcoholic beverages with minimum sample preparation. The PDMS phase is particularly useful to selectively extract hop aroma compounds in beer in the presence of a high concentration of alcohol with high sensitivity and reproducibility. Hop aroma compounds such as alpha-pinene, beta-pinene, myrcene, limonene, alpha-terpineol, linalool, alpha-humulene, and many other compounds can be reliably quantified at the ppb level or even lower. Simultaneous MS full scan and selective mass monitoring enabled quick identification and sensitive quantification. Comparison of beers using different hop varieties showed the Citra variety had the highest concentration of linalool.

Yanping Qian received her B.S. degree in agro-chemistry from Huazhong Agricultural University, M.S. degree in agro-chemistry from the University of Illinois, Ph.D. degree from the University of Minnesota, and MBA from Metropolitan State University (Minnesota). She has been working on many areas related to agriculture and agricultural products, natural resources, and environmental sciences. More recently, she has been working on the flavor chemistry of beer and hops.