Enhancement of Mass Transfer Intensification for Essential Oil Release from Lavandula pubescence Using Integrated Ultrasonic-Microwave Technique and Enzymatic Pretreatment

This work was designed to utilize the integration of ultrasonic-microwave assisted preceded by enzymolysis pretreatment to enhance the extraction efficiency of essential oil (EO) from wild Lavandula pubescens (Lp). Cellulase (C-ase), hemicellulase (H-ase), and mixed enzymes (C-ase/H-ase) were used at 10 mg/100 mL of the liquid phase. Gas chromatography-mass spectrometry (GC-MS) system was used for chemical composition analyses of Lavandula pubescens essential oil (Lp-EO). C-ase pretreatment achieved the highest yield (0.50%) of EO and highest ratio of carvacrol (29.22%) as the main compound in comparison to other treatments. Changes in the morphological structure of Lp tissues were tracked using scanning electron microscopy (SEM). Free radical-scavenging activity was assessed using DPPH•-SA and ABTS•+-SA assays. The optimal extraction conditions were enzyme concentration of 14.82 mg/100 mL, sonication time of 38.18 min, and microwave power at 333 W. At these conditions, the maximum % yield, % DPPH•-SA, and ABTS•+SA were 0.67%, 65.40%, and 0.025 (as mM Trolox), respectively. Results exhibited that the isolated Lp-EO could be used as antifree radical and antibacterial agents in the biological systems.