The present invention relates to a method for the production of a hop
extract which is enriched in 8-prenylnaringenin with respect to
6-prenylnaringenin, which method comprises the steps of subjecting a hop
product to (1) an isomerisation reaction in the presence of water as a
solvent and in the presence of an amount of a base and (2) to at least
one extraction. In that way a hop extract may be extract is obtained
which contains 6-prenylnaringenin and 8-prenylinaringening in a ratio
(8-prenylnaringenin .times.100%)/(8-prenylnaringenin+6-prenylnaringenin)
of at least 50%. The extract preferably also contains xanthohumol, the
weight ratio of xanthohumol to 8-prenylnaringenin being at least 10.