Enzymatic and Microwave Pretreatments and Supercritical CO2 Extraction for Improving Extraction Efficiency and Quality of Origanum vulgare L. spp. hirtum Extracts

Abstract

The goal of the study was to establish a procedure for improving the efficiency of supercritical carbon dioxide (scCO2) extraction of Origanum vulgare L. spp. hirtum (Greek oregano) and enhancing the quality of obtained extracts. Microwave and enzymatic pretreatments of the plant material were applied prior to the scCO2 extraction. It was determined that the microwave pretreatment with irradiation power 360 W during 2 min accelerated the extraction of lipophilic compounds and provided a twofold higher extraction yield compared to the control. Moreover, this pretreatment also led to an increase in oxygenated monoterpenes content and the most dominant component carvacrol, as well as the extracts’ antioxidant activity. The enzymatic pretreatment caused a significant increase in the extraction yield and the attainment of the extract with the most potent antioxidant properties. Coupling the pretreatments with scCO2 extraction improves the process of obtaining high value lipophilic products of oregano in terms of utilization of the plant material, acceleration of the extraction with the possibility to adjust its selectivity and quality of extracts, and enhancement of biological activity.

Essential Oil as Green Preservative Obtained by Ecofriendly Extraction Techniques

“…Vladić et al [35] incubated Origanum vulgare aerial parts with viscozyme at 8%, pH 4.9, 45°C for 60 min before extraction for 4 h increased EO yield to 6.59% compared to 3.39% that obtained by the control. The EAE led to an increase of oxygenated compounds in the extracted EO to 94.67% compared to the control (88.06%).…”

Supercritical CO2 Extract from Microalga Tetradesmus obliquus: The Effect of High-Pressure Pre-Treatment

“…Due to the structure of the microalgae cell wall, which consists of carbohydrates and glycoproteins, enzymatic pre-treatments showed promising effects [14]. However, these treatments require a long time and several steps, involving additional costs related to the production of enzymes [15]. Ansari et al applied microwave, sonication, autoclaving, and osmotic shock as treatments for the disruption of S. obliquus biomass before extraction with organic solvents (chloroformmethanol; 2:1, v/v) [16].…”

A new green approach for Lavandula stoechas aroma recovery and stabilization coupling supercritical CO2 and natural deep eutectic solvents

“…To overcome these shortcomings, supercritical carbon dioxide (CO 2 ) extraction was developed and its superiority over conventional methods was demonstrated 6 . Supercritical CO 2 extraction unifies several beneficial aspects and important preconditions for industrial implementation and remaining competitive on the market: (i) the environment—a more efficient utilization of natural raw materials is achieved and an environmentally-safe solvent is used; (ii) health—clean products without the presence of toxic organic solvents are obtained; (iii) profit—by optimizing processes, efficient utilization and maximal yield are achieved with the minimization of process expenses; the process conditions can be manipulated and varied according to the purpose, and fractioning can be conducted which can increase the utilization of the plant material 7 , 8 . Furthermore, supercritical CO 2 extraction lowers the possibility of degradation which can often occur, for instance, during steam distillation 9 .…”