A Green Protocol for Microwave-Assisted Extraction of Volatile Oil Terpenes from Pterodon emarginatus Vogel. (Fabaceae)

Microwave-assisted extraction of volatile oils (MAE) potentially offers a more efficient and bio-sustainable method than conventional extraction by Clevenger apparatus (CE). This study aimed to optimise the MAE of the volatile oil from Pterodon emarginatus fruits and characterise the volatile compounds. A 2(3) full-factorial central composite design and response surface methodology were used to evaluate the effects of time (min), moisture (%) and microwave power (W) on the extraction yield. The process optimisation was based on the desirability function approach. The reaction time and moisture conditions were standardised in these analyses. The volatile oil composition was analysed by Gas Chromatography/Mass Spectrometry (GC/MS) in order to compare techniques extractions influences. Microwave irradiation showed excellent performance for extraction of the volatile oil from Pterodon emarginatus and there were some advantages in compare to conventional method with respect to the time (14 times), energy (6 times), reagents amounts and waste formation. About chemical composition presents significant differences with the type of extraction. Caryophyllene (25.65%) and trans-α-bisabolol (6.24%) were identified as major components in MAE sample while caryophyllene (6.75%) and γ-elemene (7.02%) are the components with higher relative percentage in CE samples. The microwaves assisted process shown an increase of economic interested compounds present in volatile oil.