Green Extraction of Fennel and Anise Edible Oils Using Bio-based Solvent and Supercritical Fluid: Assessment of Chemical Composition, Antioxidant Property and Oxidative Stability

The aim of this study was to evaluate the replacement aspects of conventional methods (petroleum-based solvent and Folch assay) by alternative methods (bio-based and biodegradable solvent 2-methyltetrahydrofuran (MeTHF) and supercritical CO2 (SC-CO2)) for seed oil extraction from anise (Pimpinella anisum L.) and fennel (Foeniculum vulgare Mill.). Results showed that the highest oil yield of aniseeds was obtained by using Folch (24.07%) and MeTHF (23.65%) extraction methods whereas fennel seeds had 20.02% and 18.72%, respectively. Fatty acid composition of both seed oils obtained by the two green extraction methods was similar to the conventional ones with the predominance of petroselinic acid (54.22–61.25% in fennel and 42.39–48.97% in anise). Besides, SC-CO2 method allowed to obtain the maximum of sterol content in anise (3.85 mg/g of oil) and fennel (4.64 mg/g of oil) seed oils. Furthermore, anise and fennel seed oils extracted with MeTHF method significantly showed higher total phenolic content (2.43 and 1.32 mg GA/g oil, respectively), stronger antioxidant activity (9.23 and 5.04 μmol TEAC/g oil, respectively), and oxidative stability (8.23 and 10.15 h, respectively) than the other methods (p < 0.05). In conclusion, MeTHF appeared to be a good substitute to petroleum solvents for recovery of high oil quality from Pimpinella anisum and Foeniculum vulgare seeds.