Extraction of essential oil from Pimpinella anisum using supercritical carbon dioxide and comparison with hydrodistillation

Supercritical fluid extraction (SFE) of essential oil from Pimpinella anisum, using carbon dioxide as a solvent is presented in this work. An orthogonal array design OA9 (3(4)) was applied to select the optimum extraction condition. The effects of pressure, temperature, dynamic extraction time and methanol volume on the extraction efficiency were investigated by the three-level orthogonal array design. Results show that pressure has a significant effect on the extraction efficiency. The extract obtained from P. anisum by using supercritical fluid extraction was compared with the essential oil obtained by hydrodistillation, considering both quantity and quality of the product. SFE products were found to be of markedly different composition, compared with the corresponding hydrodistilated oil. The total amount of extractable substances obtained in SFE (7.5%) is higher than that obtained by hydrodistillation (3.1%) and SFE is faster than hydrodistillation method.     

Extraction of atabron residues from cabbage with supercritical carbon dioxide

Summary In this work we present a new procedure for extraction of Atabron residues from cabbage samples using supercritical carbon dioxide. The results obtained with this procedure were compared with those obtained using traditional extraction methods for Atabron residues. The extraction yields found by both procedures are similar but SFE has several advantages, especially higher speed, greater economy, better selectivity and greater reproducibility.     

薤白挥发油成分的超临界CO2萃取及GC-MS分析

采取超临界CO2萃取和水蒸气蒸馏两种方法提取薤白中的挥发油,比较了两种提取方法得到的挥发油的理化性质,并利用GC-MS对它们进行了定性、定量分析。两种方法的主要提取物均为含硫化合物,但超临界CO2萃取法得到的含硫化合物的数量和质量都高于水蒸气蒸馏法得到的提取物。采用水蒸气蒸馏法提取8 h得到的萃取率为1.72%。通过设计的超临界CO2萃取的正交实验,得到了最佳萃取工艺条件为:压力25 MPa,温度40℃,CO2流量为25L/h。最佳萃取时间为120 min,萃取率为4.41%,是水蒸气蒸馏法萃取率的2.8倍。实验结果表明,超临界CO2萃取法简单易行,可以较快速、有效地提取薤白中的挥发油。     

Isolation of the volatile oil from Satureja thymbra by supercritical carbon dioxide extraction: chemical composition and biological activity

Satureja thymbra L. is well known in Italy by the popular name of "Santoreggia sarda". It grows only in Sardinia and nowadays it is restricted to the slope of the Colle San Michele in Cagliari. The composition of the aromatic extracts obtained by supercritical CO2 and by hydrodistillation and their antifungal activity is reported. The collected extracts were analyzed by GC-FID and GC-MS methods. No significant differences were observed in the composition of the volatile extracts depending on the extraction method. The results showed the presence of thymol, gamma-terpinene, beta-caryophyllene, p-cymene, carvacrol and borneol as main components. The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oils against Candida albicans, C. tropicalis, C. krusei, C. guillermondii, C. parapsilosis, Cryptococcus neoformans, Trichophyton rubrum, T. mentagrophytes, T. mentagrophytes var. interdigitale, Trichophyton rubrum, T. verrucosum, Microsporum canis, M. gypseum, Epidermophyton floccosum, Aspergillus niger, A. fumigatus and A. flavus. The volatile extracts revealed a wide-spectrum antifungal activity. They were fungicidal and similarly potent against yeasts, dermatophyte and Aspergillus stains, with MICs ranging from 0.16 to 0.32 pL x mL(-1).     

超临界CO2萃取柚子叶挥发油的研究及GC-MS分析

采用超临界CO2萃取技术提取柚子叶的挥发性成分,以挥发油得率为衡量工艺参数的指标,通过正交试验法考察超临界CO2萃取过程中萃取温度、萃取压力、CO2的流量及萃取时间4个因素对柚子叶挥发油得率的影响。结果表明20MPa、萃取温度45℃、CO2流量7kg·h-1、萃取时间120min为最佳工艺。通过GC-MS对挥发油进行分析,从柚子叶挥发油中分离出144个组分,鉴定了61种成分,占化合物检出总量的90.4%。     

超临界CO_2萃取甾醇的研究(1)

本文用超临界ＣＯ＿２对高酸价麦胚油进行选择住萃取，结果表明，萃取温度和压力不同时，萃取物中甾醇的含量不同．且甾醇混合物主要为β－谷甾醇和菜籽甾醇。萃取物的酸价也明显高于高酸价麦胚油。     

Extraction of Lepidium apetalum seed oil using supercritical carbon dioxide and anti-oxidant activity of the extracted oil

The supercritical fluid extraction (SFE) of Lepidium apetalum seed oil and its anti-oxidant activity were studied. The SFE process was optimized using response surface methodology (RSM) with a central composite design (CCD). Independent variables, namely operating pressure, temperature, time and flow rate were evaluated. The maximum extraction of Lepidium apetalum seed oil by SFE-CO? (about 36.3%) was obtained when SFE-CO? extraction was carried out under the optimal conditions of 30.0 MPa of pressure, 70 °C of temperature, 120 min of extraction time and 25.95 L/h of flow rate. GC-MS analysis showed the presence of four fatty acids in Lepidium apetalum seed oil, with a high content (91.0%) of unsaturated fatty acid. The anti-oxidant activity of the oil was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay and 2,2'-azino- bis(3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS) test. Lepidium apetalum seed oil possessed a notable concentration-dependent antioxidant activity, with IC?? values of 1.00 and 3.75 mg/mL, respectively.     

Seed oil extraction with supercritical carbon dioxide modified with pentane

Chromatographia - Soybean, wheat germ, sunflower and peanut oils were extracted with supercritical carbon dioxide modified with pentane. The extractions were optimized by chemometric methods using...     

Isolation of Crithmum maritimum L. volatile oil by supercritical carbon dioxide extraction and biological assays

The chemical composition of the volatile concentrate obtained by supercritical CO2 extraction of aerial parts of Crithmum maritimum L. growing spontaneously in one area of Mediterranean coast (Buggerru, Sardinia Island, Italy) and in two areas of the Atlantic coast (Figueira da Foz and S. Pedro de Moel, Portugal) was investigated by GC and GC-MS. The major oil components identified were p-cymene, beta-phellandrene, gamma-terpinene, thymol methyl ether and dillapiole. The results showed the presence of two chemotypes of C. maritimum with different dillapiole contents, ranging from 0.2 to 64.2% in Portuguese and Italian plants, respectively. The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oils against yeasts and dermatophyte strains. All the oils exhibited significant antifungal activity against dermatophyte strains. The oil with the higher amount of dillapiole (64.2%) was the most active with MIC values ranging from 0.08-0.32 microL mL(-1).     

Extraction of carotenoids and chlorophyll from microalgae with supercritical carbon dioxide and ethanol as cosolvent

The extraction of carotenoids and chlorophylls using carbon dioxide modified with ethanol as a cosolvent is an alternative to solvent extraction because it provides a high-speed extraction process. In the study described here, carotenoid and chlorophyll extraction with supercritical CO(2 )+ ethanol was explored using freeze-dried powders of three microalgae (Nannochloropsis gaditana, Synechococcus sp. and Dunaliella salina) as the raw materials. The operation conditions were as follows: pressures of 200, 300, 400 and 500 bar, temperatures of 40, 50 and 60 degrees C. Analysis of the extracts was performed by measuring the absorbance and by using empirical correlations. The results demonstrate that it is necessary to work at a temperature of 50-60 degrees C and a pressure range of 300-500 bar, depending on the type of microalgae, in order to obtain the highest yield of pigments. The best carotenoid/chlorophyll ratios were obtained by using supercritical fluid extraction + cosolvent instead of using conventional extraction. The higher selectivity of the former process should facilitate the separation and purification of the two extracted pigments.     

Extraction of Lantana camara essential oil by supercritical carbon dioxide: influence of the grinding and biological activity

The aim of this study was to produce Lantana camara essential oil by SFE and to study the effect of matrix grinding on the yield and/or composition of the extract. Experiments were carried out on grinding matrices (G) and on not grinding matrices (NG). The extracts were analyzed by GC-MS. A comparison with the oil obtained by hydrodistillation is also given. Finally, the antibacterial and antifungal activity of the various extracts has been assayed.     

Equilibrium solubilities of spearmint oil components in supercritical carbon dioxide

The equilibrium solubilities of l-carvone and l-limonene in the binary (l-carvone–CO₂ and l-limonene–CO₂) and ternary (l-carvone–l-limonene–CO₂) systems were obtained at 39°C and 49°C and at pressures ranging from 6 to 10 MPa. The solubilities of these components increased with a pressure increase or a temperature decrease. The solubility of l-limonene was higher than that of l-carvone at the same temperature and pressure. The correlation of the solubilities using Chrastil equation revealed that the solubilities of both components were strongly dependent on the density of CO₂. In the ternary system simulating the actual spearmint oil composition, the solubility of l-carvone was similar but the solubility of l-limonene was lower as compared to their solubilities in the binary systems.     

Extraction of polychlorinated biphenyl with supercritical carbon dioxide, sulfur hexafluoride and subcritical water

In the extraction of spiked PCB from soil, three extracting fluids were investigated: supercritical carbon dioxide (CO2), supercritical sulfur hexafluoride (SF6) and subcritical water. Among the tested fluids SF6 appeared to be appropriate especially for the extraction of low polar PCB. CO2 and water were found to be suitable for the quantitative extraction of all PCB. Water was judged as the best because of its low price, good availability and environmental safety.     

Extraction of polychlorinated biphenyl with supercritical carbon dioxide, sulfur hexafluoride and subcritical water

In the extraction of spiked PCB from soil, three extracting fluids were investigated: supercritical carbon dioxide (CO₂), supercritical sulfur hexafluoride (SF₆) and subcritical water. Among the tested fluids SF₆ appeared to be appropriate especially for the extraction of low polar PCB. CO₂ and water were found to be suitable for the quantitative extraction of all PCB. Water was judged as the best because of its low price, good availability and environmental safety.     

Comparative studies of volatile oil composition of Rhododendron anthopogon by hydrodistillation, supercritical carbon dioxide extraction and head space analysis

Volatile oil composition of the leaves of Rhododendron anthopogon (Ericaceae) growing wild in alpine Western Himalaya was studied using different extraction techniques including SC-CO(2) extraction and hydrodistillation (HD). Results from different extraction methodologies were compared with headspace analysis (HS) and evaluated for the effectiveness of techniques in characterisation of various terpene categories and to assess their influence on the yield and composition of volatiles. Variability in constituents and in quantitative yields was observed. The results varied with different extraction methods. A total of 27 constituents in SC-CO(2) extraction, 31 in HD and 17 in HS analysis were identified. Constituents in SC-CO(2) and HD oils were identified by gas chromatography mass spectrometry analysis. SC-CO(2) extraction was carried out at 40°C and 140 bar pressure and the oil represented by major constituents as β-caryophyllene (5.96%), α-humulene (4.06%) and p-menthadiene-2,9-diol (7.28%); in HD, oil limonene (11.26%), β-caryophyllene (11.62%), α-humulene (7.22%), and E-nerolidol (5.83%) dominated the oil and in HS analysis, limonene (24.14%), γ-terpinene (40.73%), α-terpinene (4.92%), β-phellandrene (3.44%) and β-ocimene (7.15%) were present as major constituents.     

Mathematical modelling for extraction of oil from Dracocephalum kotschyi seeds in supercritical carbon dioxide

Extraction of oil from Dracocephalum kotschyi Boiss seeds using supercritical carbon dioxide was designed using central composite design to evaluate the effect of various operating parameters including pressure, temperature, particle size and extraction time on the oil yield. Maximum extraction yield predicted from response surface method was 71.53% under the process conditions with pressure of 220 bar, temperature of 35 °C, particle diameter of 0.61 mm and extraction time of 130 min. Furthermore, broken and intact cells model was utilised to consider mass transfer kinetics of extracted natural materials. The results revealed that the model had a good agreement with the experimental data. The oil samples obtained via supercritical and solvent extraction methods were analysed by gas chromatography. The most abundant acid was linolenic acid. The results analysis showed that there was no significant difference between the fatty acid contents of the oils obtained by the supercritical and solvent extraction techniques.     

Measurement and prediction of the solubilities of aromatic polyimide monomers in supercritical carbon dioxide with acetone

The solubilities of 4,4′-diaminodiphenyl ether (ODA) and pyromellitic dianhydride (PMDA), which are the representative monomers for an aromatic polyimide, were measured in supercritical carbon dioxide (scCO₂) using the semi-batch flow method to clarify the entrainer effect of acetone. The investigations were carried out at 323 K and 20.0 MPa with concentrations of acetone as high as approximately 20 mol%. Although the solubilities of both ODA and PMDA increased with increasing acetone concentrations, the entrainer effects of acetone on both monomer solubilities in scCO₂ were lower than those of N,N-dimethylformamide, which was investigated in previous work. However, the addition of about 10 mol% of acetone increased the solubilities of ODA and PMDA by approximately 10- and 20-fold, respectively, compared with their solubilities in pure scCO₂. Moreover, the solubilities were predicted using the Peng–Robinson equation of state.     

Extraction of brominated flame retardants from polymeric waste material using different solvents and supercritical carbon dioxide

Different procedures were examined to extract pure and high concentrations of a series of brominated flame retardants from various polymer materials. These procedures include supercritical carbon dioxide (sc-CO₂), modified sc-CO₂, solvent and soxhlet extraction. Extraction with sc-CO₂ gave low extraction efficiencies (between 6 and 20%) probably due to the low pressure of sc-CO₂ used. The use of toluene, acetonitrile and THF as modifier in sc-CO₂ raised the extraction efficiencies for many flame retardants. High extraction efficiencies were achieved for tetrabromobisphenol A (TBBPA), TBBPA-bis-(2,3-dibromopropylether) (TBBPA-dbp), TBBPA-carbonatoligomer (TBBPA-co) and decabromodiphenylether (DECA) (between 93 and 100%) by using 1-propanol as solvent during soxhlet extraction. Toluene instead of 1-propanol was used where insufficient extraction of the flame retardant occurred. The materials (before and after extraction) were analysed with energy dispersive X-ray fluorescence analysis (EDXRF), high performance liquid chromatography with ultraviolet detection (HPLC/UV), gas chromatography/mass spectrometry (GC/MS) and infrared spectroscopy (IR) techniques. The properties of the extracted flame retardants such as TBBPA, TBBPA-dbp and 1,2-bis(tribromophenoxy)-ethane (TBPE) are in good agreement with those of standard reference materials.     

Isolation of Seseli bocconi Guss., subsp. praecox Gamisans (Apiaceae) volatile oil by supercritical carbon dioxide extraction

Isolation of the volatile concentrate from dried leaves of Seseli bocconi Guss. subsp. praecox Gamisans were obtained by supercritical fluid extraction (SFE) with carbon dioxide. Leaves from different zones of Sardinia (Italy) were collected and treated. Compositions of samples were analyzed by GC-MS. The volatile concentrate of S. bocconi from Buggerru was found to contain: himachalol (16.4%), sabinene (14.8%), beta-phellandrene (8.1%), cis-sabinene hydrate (4.5%). beta-Phellandrene (29.2%), undecane (9.6%), alpha-pinene (6.1%) and beta-guaiene (5.7%) were the main constituents of the volatile extract of S. bocconi from Carloforte. The volatile concentrate of S. bocconi of Ogliastra inland, was composed chiefly by alpha-humulene (17.7%), gamma-himachalene (9.3%), beta-phellandrene (8.0) and bicyclogermacrene (7.7%). The yields of extraction were in the range (0.13-0.60%). A comparison with the hydrodistilled oil revealed in each case a remarkable difference in composition.