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 anti-free radical and
antibacterial agents in the biological systems.