| abstract |
Extn of hops or hops prods is effected using CO2 followed by vapourisation of the CO2 from the extract obtd. For extracting resins, tar oils and low mol wt. polyphenols, a temp range up to the CO2 critical temp. and a pressure range above the CO2 critical pressure during all the extrn. are used. The extract is either further extracted to obtain oestrogenically active cpds, or isomerised by mixing with absorbents and liquid CO2 at high temp and pressure to form isohumulane. The initial extract is used in brewing beer. The oestrogenically active cpds, are used in animal feeds as protein synthesising agent, or in the prepn. of cosmetic prods or bath additives. The process enables an extract contg. all the better cpds, the low M. W. polyphenols, and the hops oil cpds, avoiding the extrn of high M W polyphenols and chlorophyll obtd in previous CO2 extrn processes. |