The Effects of Temperature and Pressure on the Characteristics of the Extracts from High-Pressure CO₂ Extraction of Majorana hortensis Moench

The aim of this work is to assess the influence of temperature and pressure (solvent density) on the characteristics of the essential oil obtained from high-pressure carbon dioxide extraction of marjoram (commercial marjoram samples available in the free market and Majorana hortensis Moench, cultivated in South Brazil under rigorous agronomic conditions). The extracts were analyzed in terms of the liquid yield (extract/raw material, wt/wt) and distribution of volatile chemical components. The experiments were performed in a laboratory-scale unit using the dynamic method in the temperature range of 293.15-313.15 K, from 100 to 200 bar in pressure. Chemical analyses were carried out in a GC/MSD. Results show that an increase in temperature leads to a rise in the extract liquid yield despite large changes in solvent density. Chromatographic analyses permitted the identification of cis-sabinene hydrate, terpineol-4, alpha-terpineol, and cis-sabinene hydrate acetate as the main volatile compounds present in both commercial and cultivated samples.