Competition of microwave-assisted hydro-distillation in highlighting volatile phytochemicals of Anacyclus clavatus species

Abstract

The microwave-assisted hydro-distillation (MAHD) technique has recently gained considerable attention in the field of essential oil extraction. MAHD was applied as a green technology for the extraction of essence from leaves and stems of Anacyclus clavatus, generally used as a digestive herb. Results from qualitative and statistical analysis were compared with those obtained by the classic hydro-distillation (HD) method. An extraction time of 80 minutes with MAHD provided yields of 0.015 ± 0.004% (w/w) vs. 0.018 ± 0.001% (w/w) reached after 3 hours by HD. Extracts were analyzed by gas chromatography–flame ionization detector (GC–FID) and GC–mass spectrometry (GC–MS). Despite the common main family and the two major constituents, germacrene D followed by δ-elemene in both extracts, chemical compositions were different. The oxygenated fraction represented 42.7% in MAHD extract vs. 36.1% in HD oil. MAHD offers advantages over HD in terms of energy savings, extraction time and product quality, namely in the high contribution of oxygenated compounds in the fragrance of the essence.