Modelling, extraction optimisation and phytochemical profile of essential oil from Moroccan endemic medicinal plant <i>Ballota hirsuta</i>

Abstract

The present study describes for the first time the optimisation of the extraction by hydrodistillation and chemical composition of the essential oil (EO) of Ballota hirsuta aerial parts using Gas chromatography (GC/FID) and GC-mass spectrometry (GC/MS) analysis. Single-factor experiments and response surface methodology (RSM) based on a central composite design (CCD) were used to optimise the EO extraction parameters including drying period (0–21 days), extraction time (60–240 min) and water/plant ratio (5–20 ml/g). The optimum conditions for obtaining the best yield (0.91%) are a drying period of 7 days, an extraction time of 120 min and a water/plant ratio of 10 ml/g. The findings suggest that the experimental and the predicted data are in reasonable agreement, showing that the quadratic model was the fittest for the optimisation of the extraction process Under these optimum condition, GC/FID and GC/MS enabled the identification of forty-three volatile components representing 82.3% of the total of EO. Germacrene-D (16%), Z-Phytol (7.7%), α – Cadinol (7.3%) and Carvacrol (6.7%) were the main constituents of this EO.