Supercritical CO2 extraction
Supercritical CO2 extraction entails treating a botanic natural aromatic raw material with CO2 in the supercritical state. In this state, CO2 has the viscosity of a gas and the density of a liquid, which makes it an effective solvent. Supercritical CO2 carries the odor molecules into a separator. The pressure is then lowered to separate the CO2 from the extract. The CO2 then becomes gaseous and recirculates until the aromatic raw material is completely extracted. The odor molecules precipitate at the bottom of the separator and are subsequently collected. This technique preserves the organoleptic qualities of the natural raw material, as the separation of the extract from the supercritical CO2 is performed at room temperature. It is an environmentally friendly technique, because it does not produce greenhouse gases or pollutants. CO2-extracted pink peppercorn essence is an example of product obtained using this technique.