Abstract:Citronella essential oil has more than eighty components, of which the most important ones are citronellal, geranial and limonene. They are present at high concentrations in the oil and are responsible for the repellent properties of the oil. The oil was extracted using supercritical carbon dioxide due to the high selectivity of the solvent. The operational conditions studied varied from 313.15 to 353.15 K for the temperature and the applied pressures were 6.2, 10.0, 15.0 and 180.0 MPa. Better values of effici… Show more
“…Occasionally, it was necessary to use steam at a higher pressure to obtain a good yield. Silva et al (2011) mentioned that better extraction efficiency of citronella oil by supercritical CO 2 was obtained under high pressure. The best conditions were found to be 353.15 K and 18.0 MPa.…”
Section: Scanning Electron Microscopy (Sem) Analysismentioning
A proposed method for citronella oil extraction was developed with the application of ohmic heated hydro-distillation. The objective was to compare the performance of three different extraction methods, viz. ohmic heated hydro-distillation, hydro-distillation, and steam distillation. The maximum amount of extracted oil yield by ohmic heated hydrodistillation was 7.64 mL/kWh as compared to hydro-distillation and steam distillation methods that resulted oil yields of 3.87 mL/kWh and 1.69 mL/kWh, respectively. The kinetics of extraction followed a second-order model. Gas chromatography-mass spectrometry analysis found that the major constituents of citronella oil (GC-MS) for the different extraction methods were citronellal, citronellol, and geraniol. Scanning electron microscopy (SEM) of citronella grass provided evidence that the lignocellulosic sources of the extracted citronella oil were schizogenous cavities and cellular lignin. The citronella that had undergone ohmicheated hydro-distillation and steam distillation showed some microfractures and less cell wall degradation than hydro-distillation. The cell walls were less rigid using ohmic-heated hydro-distillation compared to steam distillation. However, the cell walls of the hydro-distillation sample were less dense and exhibited pronounced swelling, but did not show any microfractures.
“…Occasionally, it was necessary to use steam at a higher pressure to obtain a good yield. Silva et al (2011) mentioned that better extraction efficiency of citronella oil by supercritical CO 2 was obtained under high pressure. The best conditions were found to be 353.15 K and 18.0 MPa.…”
Section: Scanning Electron Microscopy (Sem) Analysismentioning
A proposed method for citronella oil extraction was developed with the application of ohmic heated hydro-distillation. The objective was to compare the performance of three different extraction methods, viz. ohmic heated hydro-distillation, hydro-distillation, and steam distillation. The maximum amount of extracted oil yield by ohmic heated hydrodistillation was 7.64 mL/kWh as compared to hydro-distillation and steam distillation methods that resulted oil yields of 3.87 mL/kWh and 1.69 mL/kWh, respectively. The kinetics of extraction followed a second-order model. Gas chromatography-mass spectrometry analysis found that the major constituents of citronella oil (GC-MS) for the different extraction methods were citronellal, citronellol, and geraniol. Scanning electron microscopy (SEM) of citronella grass provided evidence that the lignocellulosic sources of the extracted citronella oil were schizogenous cavities and cellular lignin. The citronella that had undergone ohmicheated hydro-distillation and steam distillation showed some microfractures and less cell wall degradation than hydro-distillation. The cell walls were less rigid using ohmic-heated hydro-distillation compared to steam distillation. However, the cell walls of the hydro-distillation sample were less dense and exhibited pronounced swelling, but did not show any microfractures.
“…Another study in the extraction of Cymbopogon nardus essential oil using supercritical CO 2 , the operational parameters studied were from 313.15 to 353.15 K for the temperature and the applied pressures were 6.2, 10.0, 15.0 and 180.0 MPa. The best yield was 2.06% at 353.13K and 18.0 MPa of pressure [7]. Economic study should be conducted to further review this improved method which is ohmic heated hydro distillation in terms of costing such as labour, total operating cost and total cost of production for its application in small-scale industry.…”
Section: E Kinetics Of Oil Extractionmentioning
confidence: 99%
“…usage in traditional medication for antispasmodic, rubefacient, stimulant, insect repellant carminative, and diaphoretic. It also widely used in the perfume industry, soap manufacturing, cosmetics, flavoring industry and health purposes [5]- [7].…”
An improved method for essential oil extraction was developed with the application of ohmic heated hydro distillation. In this study the parameters affecting citronella oil extraction by ohmic heated hydro distillation such as power input, extraction time, solvent to solid ratio and chopping frequency were investigated to achieve maximum oil yield. The kinetics of extraction was assumed and verified based on a second-order mechanism. The initial extraction rate, the saturated extraction capacity and the rate constant of extraction were calculated using the second-order model. The optimum parameters were found at voltage input of 77 V up to boiling point and 50 V until the end of extraction, 120 minutes extraction time, solvent to solid ratio of 3:1 and once chopping frequency. The kinetics and mechanism of ohmic heated hydro distillation of citronella oil has proved follow second-order model. The initial extraction rate (h) was 0.134 gL-1 min-1 ; the extraction capacity (C s) was 5.787 gL-1 ; the second order extraction constant (k) was 0.004 Lg-1 min-1 and the coefficient of determination (R 2) was 0.976. Index Terms-Ohmic heating; hydro distillation; citronella oil; optimization; kinetics I. INTRODUCTION Citronella grass is native to India and Sri Lanka; whereby the plant can be found growing wild in most tropical Asian countries including Malaysia. Citronella belongs to the genus Cymbopogon, which very closely resembles and formerly was included in the genus Andropogon [1]. Cymbopogon, which is native to warm temperate and tropical regions of the Old World and Oceania, is a genus comprising about 180 species, subspecies, varieties and subvarieties [2]. The plant is also growing wild in most tropical Asian countries, America and Africa. There are two cultivated types of citronella grass, which are Ceylon (Mahapengiri) and Java (Lenabatu) citronella. Java citronella known as Cymbopogon winterianus Jowitt while Ceylon citronella known as Cymbopogon nardus (L) Rendle [3]. Normally, the plant is planted in the kitchen gardens in Malaysia. Recently, the plants are planted commercially by entrepreneurs for essential oils extraction [4]. The citronella oil is comparatively high demand due to its
“…This plant is well known as mosquito repellent and also has several pharmacological properties (Simic et al, 2008;Nurhanani and Othman, 2010;Istianto and Emilda, 2011;Kongkaew et al, 2011;Silva et al, 2011;Sritabutra et al, 2011). For food productivity, Lonkar et al (2013) analyzed the chemical constituents from leaves of six varieties of C. flexuosus for preparation as medicinal tea.…”
In this study, leaves, stalks and roots of Cymbopogon nardus were separately evaluated to determine the most active parts that contained the strong growth inhibitory activity. Each aqueous methanol extracts of Cymbopogon nardus were determined their allelopathic activity by using six test plant species; alfalfa (Medicago sativa L.), cress (Lepidum sativum L.), lettuce (Lactuca sativa L.), barnyard grass (Echinochloa crus-galli L.), Italian ryegrass (Lolium moltiflorum Lam.) and jungle rice (Echinochloa colonum (L.) P. Beauv.). Four extract concentrations (0.01, 0.03, 0.1 and 0.3 g dry weight equivalent extract/mL) were used for the bioassay. The results showed that these three extracts have inhibitory activity and the percent inhibition increased concentration dependently. However, the inhibitory activity of leaf and root extracts was more effective than stalk extract at 95% level of significance. Barnyard grass, Italian ryegrass and jungle rice were the most sensitive to the leaf, stalk and root extracts, respectively. The concentrations required for 50% growth inhibition of C. nardus leaf, stalk and root extracts on all test plants were 0.000-0.025, 0.009-0.077 and 0.003-0.023 g dry weight equivalent extract/mL, respectively. In addition, separation of these extracts through silica gel column indicated that root extract contained the most active fractions with strong growth inhibition. The present results suggest that C. nardus may have allelopathic compounds and the root extracts have the greatest inhibitory activity. Studies are in progress for the isolation and identification of allelopathic compounds in aqueous methanol extracts of C. nardus roots for the development of natural herbicides.
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