Comparison of the composition and antioxidant activity of the chamomile essential oil (Matricaria chamomilla L.) obtained by supercritical fluids extraction and other green techniques

Abstract

The chemical composition and antioxidant activity of the chamomile essential oil (Matricaria chamomilla L.) obtained by supercritical fluids extraction (SFE) and other green techniques (steam stripping, AV; hydrodistillation, HD; steam-dragging distillation with simultaneous steam-extraction using an organic solvent, DES, and maceration (MC). We optimized the extraction process with supercritical fluids by checking the effect of temperature (35-65°C) and pressure (90-210 bar) on the extraction yield (% w/w) and we determined that the best extraction conditions (0.87% w / w) were at 65°C and 210 bar. We analyzed the chemical composition by gas chromatography-mass spectrometry (GC-MS) and identified the constituents based on their fragmentation patterns and Kovat’s index. We evaluated the antioxidant activity using the ABTS method. The main components were en-yn-dicycloeter, β-farnesene, and bisabolol oxide A. The results of the GC-MS analyses indicate that when using different extraction methods the composition and concentration of the essential oil changes, for example, the oils extracted by MC had en-yn-dicycloeter is their main component while for those extracted by HD it was β-farnesene, and by DES ii was bisabolol oxide A. The oil obtained by AV (27.56 μmol trolox/ml of oil) had a higher antioxidant activity compared to the other extraction methods, even when compared with SFE (15.25 μmol trolox/ml of oil).