Supercritical Extraction of Essential Oil from Aniseed (Pimpinella anisum L) Using CO2: Solubility, Kinetics, and Composition Data

Abstract

Supercritical fluid extraction (SFE) from aniseed using carbon dioxide was performed at 30 °C and pressures of 80−180 bar. The chemical composition of the SFE extract was determined by GC-MS; the quantitative analysis was done by GC-FID and TLC. The total amount of extractable substances or global yield (mass of extract/mass of feed) for the SFE process varied from 3.13 to 10.67% (mass). The solubilities of the anise essential oil in CO₂ were 0.0110, 0.0277, 0.0143, and 0.0182 kg of solute/kg of CO₂ at 80, 100, 140, and 180 bar, respectively. The major compounds identified and quantified in the extracts were anethole (∼90%), γ-himachalene (2−4%), p-anisaldehyde (cis-pseudoisoeugenyl 2-methylbutyrate (∼3%), and trans-pseudoisoeugenyl 2-methylbutyrate (∼1.3%). The Sovová model described quite well the experimental overall extraction curves. Keywords: Aniseed; chemical composition; Pimpinella anisum; mass transfer rate; solubility; supercritical extraction