| 摘要 |
Hop extract containing a high proportion of a desired constituent, hop oil, alpha -acids or beta -acids, is formed by extracting hops with pressurized fluid carbon dioxide, collecting separate fractions of the extract obtained at different times, and selecting the fraction having a high proportion of the desired constituent. Fractions containing (a) at least 70% of the available hop oil at at least 10% concentration, and (b) at least 25% of the available alpha -acids at at least 55% concentration, may be obtained in a single process by extracting initially at a lower temperature in the range 0 DEG C. to -57 DEG C. and subsequently at a higher temperature in the range -5 DEG C. to 31 DEG C. |
