Essential oil extraction from onion using ethanol and CO2 as an extraction fluid mixture

Abstract

Introduction: Essential oils are volatile chemical compounds, widely known by their fragrance, as well as by antimicrobial and antioxidant activities. These oils are generally extracted from aromatic plants in procedures using conventional solvents. Methods: In this study, essential oil was extracted from onion (previously chopped and dried) using a mixture of ethanol and CO2 as the extraction fluid. The essential oil obtained from the extraction was collected and purified and the mass was determined (by weighing) to evaluate the effect of CO2 flow on the yield. The essential oil extracted and purified was characterized to determine the acid and refraction indexes, viscosity, and specific mass. Results: The values obtained for refraction and acid indexes are within limits and similar to the average reported in literature. In all cases, when the CO2 was used, there was an increase the essential oil recovery. In terms of quality, the products from this process were characterized to determine the density, acid index and refraction index. The results obtained were similar to those published in the literature. Discussion: The proposed apparatus and CO2 methodology can be considered a good alternative to boost the extraction of essential oil aiming the obtaining of new products for use as raw materials in different industrial processes. Since this apparatus presents more than double extraction yield than Soxhlet experiment.

Potential of diallyl sulfide from bulbs of Allium parvum to inhibit the growth and biofilm formation in Malassezia furfur MTCC 1374

“…An equal volume of ethyl acetate was added to the filtrate, incubated for 30 minutes, and the ethyl acetate (organic) layer was separated using a separating funnel. The obtained extracts were concentrated under a vacuum and dissolved at 0.1% w/v in dimethyl sulfoxide (DMSO) solution for further assays (Dos Santos et al, 2021).…”

Extraction of Essential Oil from Onion (Allium cepa) using Hybrid Fluid Mixture (Ethanol and CO 2 ) as Solvent

“…In this study the onion (Allium Cepa) was used as the raw ma- Extraction procedure Dos Santos., et al [5] built an experimental apparatus that was adjusted and used in this study and that enabled the acquisition of data presented in this scientific work (Figure 4).…”

“…The apparatus built by Dos Santos., et al [5] was used and comprise three sections: a) section of mixture and heating of conventional and supercritical fluid; b) Section of extraction of essential oil; c) section of recovery the essential oil.…”

“…Commonly, the extraction processes use of an extractor and a conventional solvent or supercritical fluid, or both, known as a hybrid mixture, where the proportion can be adjusted to improve the extraction yield [5].…”

“…The concepts of mass transference in the interface between the solid-liquid or solid-gas phases can be used to measure the efficiency of those process. Dos Santos., et al [5] state that the extraction process based on knowledge of mass transference allows identified the procedures to enhance the quality and quantity of the products. In this way, Shakir [6] states that with the increase of the extraction temperature, the interaction between the phases in the system, that results in the increase the mass transference from solid to liquid phase.…”