Introduction: The increasing popularity of immortelle (Helichrysum italicum (Roth) G. Don) and its products, particularly in the cosmetic industry, is evident nowadays. This plant is a source of coumarins, especially scopoletin, which are highly soluble in supercritical CO2 .
Objective: The objective of this study was to perform the supercritical CO2 extraction process of Helichrysum italicum flowers at different values of pressure and temperature and to optimise the extraction process using response surface methodology in terms of obtaining the highest extraction yield and yield of extracted scopoletin.
Methodology: Extraction was performed in a supercritical extraction system under different extraction conditions of pressure and temperature determined by central composite rotatable design. The mass of flowers in the extractor of 40 g, extraction time of 90 min and CO2 mass flow rate of 1.94 kg/h were kept constant during experiments. Antioxidant activity was determined using the DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging assay method. Scopoletin concentration was determined by HPLC.
Results: Changes in extraction conditions affect the extracting results remarkably. The greatest extraction yield (6.31%) and the highest yield of scopoletin (1.933 mg/100 g) were obtained under extraction conditions of 20 MPa and 40°C. Extracts have also proven to possess antioxidant activity (44.0-58.1% DPPH scavenging activity) influenced by both temperature and pressure applied within the investigated parameters.
Conclusion: The extraction conditions, especially pressure, exhibited significant influence on the extraction yield as well as the yield of extracted scopoletin and antioxidant activity of extracts. Copyright © 2016 John Wiley & Sons, Ltd.
Copyright © 2016 John Wiley & Sons, Ltd.