Classification of Czech Hops According to their Contents of Prenylflavonoids
Keywords:hops, α-bitter acids, bioactive effects, prenylflavonoids, xanthohumol, desmethylxanthohumol, liquid chromatography, hop drying, hop aging
The prenylated flavonoids are hop components with the most beneficial health effects. Information about their content and the dynamics of their decrease during hops processing is necessary for the production of beer with an increased content of these substances. This study deals with the long-term monitoring of the prenylflavonoids and α-bitter acids contents and their ratios in the whole spectrum of domestic hop varieties as well as with changes in these parameters during storage and hop processing. It was confirmed that the newly cultivated Agnus and Vital varieties are the varieties with the highest contents of prenylated flavonoids. As a result, the Vital variety is particularly useful in non-brewing applications. Based on the monitoring of the decrease in the levels of these components during hop processing it was recognised that development of new gentler methods, particularly for the hop drying would be necessary. These methods should minimize the risk of thermal and oxidative degradation.