Characterization of Novel Varietal Floral Hop Aromas by Headspace Solid Phase Microextraction and Gas Chromatography Mass Spectrometry/Olfactometry

In this study, headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were optimized and implemented to investigate the volatile composition of novel floral hop essences prepared from four German aroma hop varieties. In total, 91 different constituents were assigned, which were further grouped into monoterpene hydrocarbons, esters, ketones, aldehydes, furans, and oxygenated and nonoxygenated sesquiterpenes. Most volatiles belong to the ester group, whereas the monoterpene hydrocarbon beta-myrcene appears to be the predominant compound in all hop oil preparations investigated. Furthermore, as demonstrated by principal component analysis, varietal floral hop essences are clearly discriminated on the basis of their characteristic volatile composition. Via GC-olfactometry on the floral essence variety Spalter Select, beta-myrcene and 2-undecanone were identified as the most potent odorants. Several hop oil constituents were reported for the first time as impact odorants of hop aroma.