Comparison of the most odor-active compounds in fresh and dried hop cones (Humulus lupulus L. variety spalter select) based on GC-olfactometry and odor dilution techniques.
Application of aroma extract dilution analysis on the volatiles obtained from dried cones of Spalter Select hops grown in the German hop-growing area of Hallertau revealed 23 odorants in the flavor dilution (FD) factor range of 16-4096, 20 of which could be identified. On the basis of high FD factors, trans-4, 5-epoxy-(E)-2-decenal, linalool, and myrcene were identified as the most potent odorants, followed by ethyl 2-methylpropanoate, methyl 2-methylbutanoate, (Z)-1,5-octadien-3-one, nonanal, (E,Z)-1,3, 5-undecatriene, 1,3(E),5(Z),9-undecatetraene, propyl 2-methylbutanoate, 4-ethenyl-2-methoxyphenol, and 1-octen-3-one. Ten of the high-impact hop aroma compounds had previously not been identified as hop constituents and, in particular, 1,3(E),5(Z), 9-undecatetraene has not yet been reported as a food odorant. In an extract obtained from fresh hops, in addition to the odorants found in dry hops, (Z)-3-hexenal was characterized as a further key odorant rendering an additional green aroma note to the fresh material.
Steinhaus
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M
Deutsche Forschungsanstalt für Lebensmittelchemie and Institut für Lebensmittelchemie der Technischen Universität München, Lichtenbergstrasse 4, D-85748 Garching, Germany.
Schieberle
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P
D002849:Chromatography, Gas / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009812:Odorants / Q000032:analysis*; D019685:Rosales / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet