Supercritical CO Extraction of Lavandula angustifolia Mill. Flowers: Optimisation of Oxygenated Monoterpenes, Coumarin and Herniarin Content.

INTRODUCTION

Lavandula angustifolia is good source of oxygenated monoterpenes containing coumarins as well, which are all soluble in supercritical CO (SC-CO ).

OBJECTIVE

The study objective is to investigate SC-CO extraction parameters on: the total yield; GC-MS profile of the extracts; relative content of oxygenated monoterpenes; the amount of coumarin and herniarin; and to determine optimal SC-CO extraction conditions by response surface methodology (RSM).

METHODOLOGY

SC-CO extraction was performed under different pressure, temperature and CO flow rate determined by Box-Behnken design (BBD). The sample mass and the extraction time were kept constant. The chemical profiles and relative content of oxygenated monoterpenes (as coumarin equivalents, CE) were determined by GC-MS. Coumarin and herniarin concentrations were dosed by HPLC.

RESULTS

SC-CO extracts contained linalool (57.4-217.9 mg CE/100 g), camphor (10.6-154.4 mg CE/100 g), borneol (6.2-99.9 mg CE/100 g), 1,8-cineole (5.0-70.4 mg CE/100 g), linalyl acetate (86.1-267.9 mg CE/100 g), coumarin (0.95-18.16 mg/100 g), and herniarin (0.95-13.63 mg/100 g). The interaction between the pressure and CO flow rate as well as between the temperature and CO flow rate showed statistically significant influence on the extraction yield. Applying BBD, the optimum extraction conditions for higher monoterpenes and lower coumarin content were at 10 MPa, 41°C and CO flow rate 2.3 kg/h, and at 30 MPa, 50°C and CO flow rate 3 kg/h for higher monoterpenes and coumarin content.

CONCLUSION

SC-CO extraction is a viable technique for obtaining lavender extracts with desirable flavour components. The second-order model based on BBD predicts the results for SC-CO extraction quite satisfactorily. Copyright © 2017 John Wiley & Sons, Ltd.