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Study of sensory-active compounds of hops in dry-hopped beers
Zlochová, Tereza ; Sobotníková, Jana (advisor) ; Jelínek, Ivan (referee)
Study of sensory-active compounds of hops in dry-hopped beers Key words: hop, hop oils, dry-hopping, beer, beer-aging, beer sensory analysis Nowadays, dry-hopping is a widely used method of beer making, with its pros and cons. The main purpose of dry-hopping is to derive specific hop aroma to beer in its very unchanged form. The essential part of this work consists of a study of hop essential oils, as the main providers of desired hop aroma. Firstly, the validation of methods for isolating essential oils from hop material and beer is carried out. Secondly, the transfer of these volatiles in process of dry-hopping is studied and the impact on beer aroma profile is discussed. Subsequently, changes of essential oils profile during beer-aging are observed and evaluated with a valuable tool, the sensory analysis. This study was realized on beer samples from Brewers' Choice program, thanks to the Research Institute of Brewing and Malting and Lenka Strakova, the Pilsner Urquell brewer.
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Determination of sensory active compounds in hops using GC-MS
Zlochová, Tereza ; Sobotníková, Jana (advisor) ; Čejka, Pavel (referee)
Determination of sensory active compounds in hops using GC-MS Abstract The goal of this thesis was to determine sensory active compounds from a sample of hops by gas chromatographic-mass spectrometric detection. Hop oils were selected for this determination which, despite its low representation in hops, contain up to several hundred components. Hop oils were exctracted using a new method based on fluidized-bed extraction. An integral part of this work was identifying the yield of the method that has become an instrument to defining the content of hop oils in different hop varieties. A comparsion of the obtained extracts with the literature was made and a search was done for the link between chemical structure of the hop oils and their representation in the hops sample with regard to its age. Keywords: exctraction, hops, hop oil, gas chromatography, mass spectrometry
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