Occurence of glycosidically bound fl avour compounds in hops, hop products and beer

Glycosidically bound fl avour compounds of hops are considered to contribute to the hop fl avour in beer. Therefore, different hop varieties and hop products were analyzed for their glycoside content. During extraction with supercritical CO 2 almost all of the hop glycosides remain in spent hops. After ethanol extraction, glycosides could be detected in both the ethanol tannin extract and the ethanol pure resin extract. In all examined varieties an enrichment of the sensorially important glycosides of monoterpene alcohols (e.g. linalool) and nor-carotenoids could be observed in the ethanol pure resin extracts. Some of these glycosides could be detected in hopped beer, where they could act as precursors for the organoleptically active linalool. This could be confi rmed by a rise in free linalool in a stored beer brewed with a re-extracted ethanol pure resin extract containing linalyl glycoside, compared to a beer brewed with a glycoside-free hop preparation. The strongly fl avouractive s-damascenone could also be liberated from hop glycosides, but hops seem not to be the only source for this ketone.