Preparation and Analysis of Liquid CO₂ Hop Extracts¹

1 Presented at the 46th Annual Meeting, Minneapolis, MN, May 1980.

Abstract

Hop extracts were prepared from several hop varieties grown in Europe, America, and Australia, using liquid CO₂ as the extracting solvent. Significantly less of the soft resin fraction was extracted by liquid CO₂ than by either n-hexane or methylene chloride. However, approximately 95% of the α-acids and 95–100% of the β-acids were extracted by liquid CO₂ in all cases. The composition of the essential oil fractions isolated by vacuum steam distillation of the extract and the hops from which the extract was derived were found to be very similar. None of the hard resin fraction was extracted by liquid CO₂. Selected liquid CO₂ extracts were compared analytically with commercial solvent extracts prepared from the same hop variety.

• α-Acids
• β-Acids
• Hop extract
• Hop oil
• Liquid CO₂