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1.
Saponins are surfactants that reduce the surface tension of aqueous solutions, besides having pharmacological actions. In order to extract and fractionate saponins from Pfaffia glomerata roots and Hebanthe eriantha roots using supercritical technology, fractionated extracts were obtained from a sequential process in fixed bed using supercritical CO2 (scCO2), ethanol, and water as solvents. All extractions were carried out in four sequential steps, at 50 °C and 300 bar. In the first step, pure scCO2 was used as solvent, while (a) scCO2/etanol (70:30, w/w); (b) ethanol, and (c) ethanol/water (70:30, v/v) were used as solvents in the three subsequent steps. The extracts were analyzed by thin layer chromatography (TLC) and surface tension. The extraction yields of the four steps were 0.16, 0.55, 1.00, and 6.90% for P. glomerata roots, and 0.17, 0.58, 0.89, and 28% for H. eriantha roots, showing a predominance of high polarity compounds in these species. TLC analysis showed that the extraction process was selective according to the polarity of the solvent, and provided extracts containing different saponins, except for scCO2 extraction. The extracts from the extraction using ethanol + scCO2 (Step 2) showed the greatest ability to reduce the surface tension of water from 72 mN m−1 (pure water) to 25 mN m−1, suggesting that this step was the best for extraction of less polar saponins in the extracts. The critical micelle concentration (CMC) values were approximately 2 and 8 g L−1 for P. glomerata and H. Eriantha, respectively. These results confirmed the efficacy of the extraction process under study. 相似文献
2.
The objective of this work was to determine the economic feasibility of large-scale operations of supercritical fluid extraction (SFE) for the recovery of phenolics using grape bagasse from Pisco residues. Experimental data were used to estimate the extraction kinetic parameters, as well as the cost of manufacturing the extracts. Experimental data were obtained using supercritical CO2 containing 10% ethanol (w/w) at 313 K and 20–35 MPa. The supercritical CO2/ethanol extraction process produced extracts with higher concentrations of phenolics than extracts produced using conventional techniques. The compounds identified in the extracts were syringic, vanillic, gallic, p-hydroxybenzoic, protocatechuic and p-coumaric acids, as well as quercetin. An evaluation of the economics of the process indicated the feasibility of an industrial SFE plant with a capacity of 0.5 m3 for producing an extract with an expected phenolics concentration of approximately 23 g/kg of extract at an estimated cost of manufacturing of US$ 133.16/kg. 相似文献
3.
With the goal of maximizing the extraction yield of phenolic compounds from pitanga leaves (Eugenia uniflora L.), a sequential extraction in fixed bed was carried out in three steps at 60 °C and 400 bar, using supercritical CO2 (non-polar) as solvent in a first step, followed by ethanol (polarity: 5.2) and water (polarity: 9.0) in a second and third steps, respectively. All extracts were evaluated for global extraction yield, concentration and yield of both polyphenols and total flavonoids and antioxidant activity by DPPH method (in terms of EC50). The nature of the solvent significantly influenced the process, since the extraction yield increased with solvent polarity. The aqueous extracts presented higher global extraction yield (22%), followed by ethanolic (16%) and supercritical extracts (5%). The study pointed out that the sequential extraction process is the most effective in terms of global extraction yield and yield of polyphenols and total flavonoids, because it produced the more concentrated extracts on phenolic compounds, since the supercritical ethanolic extract presented the highest phenolics content (240.5 mg GAE/g extract) and antioxidant capacity (EC50 = 9.15 μg/mL). The most volatile fraction from the supercritical extract, which is similar to the essential oils obtained by steam distillation or hydrodistillation, presented as major compounds the germacrenos D and B + bicyclogermacrene (40.75%), selina-1,3,7(11)-trien-8-one + selina-1,3,7(11)-trien-8-one epoxide (27.7%) and trans-caryophyllene (14.18%). 相似文献
4.
Phenolic compounds from Arrabidaea chica Verlot leaves, besides conferring staining properties to their extracts, also have various biological activities including anti-inflammatory and wound-healing properties. To evaluate new possibilities for obtaining extracts with differentiated yield and composition, sequential extractions in fixed bed were performed at 40 and 50 °C, and 300 and 400 bar, using as extracting solvents pure supercritical carbon dioxide (scCO2) in a first step, acidified ethanol in a second step and acidified water in a third extraction step. Four flavonoids of interest were investigated in the extracts, one of them being flavone (luteolin), and three anthocyanin compounds of type 3-desoxyanthocyanidins which were quantified by high performance liquid chromatography (HPLC). The extraction curves, the global yields and the concentration and yield of the compounds under study were evaluated. The results indicated that the cumulative total yields in the three steps ranged from 22% to 27% in all conditions of temperature and pressure, with the highest global yield at 50 °C and 300 bar. Although the lowest extraction yield was obtained using pure scCO2, this step was highly selective, since only carajurin in its aglycone form was extracted among the compounds of interest and this was confirmed by analysis of MS/MS. 相似文献
5.
Carob pulp kibbles, a by-product of carob been gum production, was studied as a source of bioactive agents. Firstly, the carob kibbles were submitted to an aqueous extraction to extract sugars, and supercritical fluid extraction (SFE) was applied to the solid residue of that aqueous extraction, by using compressed carbon dioxide (SC-CO2) as the solvent and a mixture of ethanol and water (80:20, v/v) as a co-solvent. Pressure and temperature were studied in the ranges 15–22 MPa, and 40–70 °C. Particle diameter, and co-solvent percentage in ranges of 0.27–1.07 mm, and 0–12.4%, respectively, were also studied, as well as the flow rate of SC-CO2 between 0.28 and 0.85 kg h−1, corresponding, respectively, to 0.0062 and 0.0210 cm s−1 of superficial velocity. The extracts were characterised in terms of antioxidant capacity by DPPH method, and total phenolics content by the Folin–Ciocalteu method. The central composite non-factorial design was used to optimise the extraction conditions, using the Statistica, version 6 software (Statsoft). The best results, in terms of yield and antioxidant capacity, were found at 22 MPa, 40 °C, 0.27 mm particle size, about 12.4% of co-solvent and a flow rate of 0.29 kg h−1 of SC-CO2. The phenolics profile of the extracts obtained at these conditions was qualitatively evaluated by HPLC-DAD. The solid residue of the supercritical extraction was also studied showing to be a dietary fiber, which can be compared to Caromax™, a carob fiber commercialised by Nutrinova Inc. 相似文献
6.
Near-supercritical and supercritical CO2 was used to extract low-molar-mass phenolics and lipophilic compounds from Pinus pinaster wood. Extraction of samples containing sapwood and knotwood was carried out at 1025 MPa and 3050 °C to assess the influence of the operational conditions on the yields of total extracts and phenolics, as well as on the radical scavenging capacity of extracts. The use of ethanol as a co-solvent increased both the extraction yields and the concentration of phenolics in extracts. Operating under selected conditions (25 MPa, 50 °C, 10% ethanol), the extraction yield accounted for 4.1 wt% of the oven-dry wood. The extracts contained up to 7.6 g of phenolic compounds (measured as gallic acid equivalents) per 100 g extract, and showed one third of the radical scavenging capacity of Trolox. Native resin acids accounted for about 24 g per 100 g extracts, whereas flavonoids, lignans, stilbenes and juvabiones were found at lower proportions. 相似文献
7.
Leaves of Arrabidaea chica (Humb. Bonpl.) Verlot are rich in anthocyanins and have been used as a medicinal plant in the Amazon region. In order to obtain different extracts from this plant, a sequential extraction in fixed bed was carried out at 40 °C and 300 bar, using supercritical carbon dioxide (scCO2) in a first step, and a mixture containing CO2/ethanol/water at mass ratios of approximately 80/20/0, 80/14/6 and 80/10/10 in a second extraction step. The residue from the second step was extracted with water at 40 °C and atmospheric pressure. Ethanolic, aqueous and hydroalcoholic (70:30, v:v) extracts were also obtained by conventional extraction methods at atmospheric pressure. All extracts were analyzed for global extraction yield, total phenolic content, total flavonoids, and carajurin content. High performance liquid chromatography (HPLC) was used both to quantify carajurin, which is the main anthocyanin component of A. chica, and to monitor qualitatively two other anthocyanin pigments found in that plant. The extraction yield in the first step was only 0.65% using pure scCO2, but this extraction was highly selective to extract carajurin from the three main anthocyanins. The accumulated global yield of the two steps ranged from 3% when the solvent ratio (80/20/0) was used in the second step to about 50% when 6 or 10% water was used, showing the highest yield when the extraction was done with water. The highest contents of total phenolic compounds (178 mg GAE/g extract) and total flavonoids (373 mg EC/g extract) were found in the process performed with the extraction mixture (80/20/0), and the highest carajurin content was obtained in the ethanolic extracts. 相似文献
8.
Microalgae represent diverse branch of microorganism that can produce a wide range of unique functional ingredients that can be used in food, cosmetics, pharmaceuticals, and energy. Among them, Haematococcus pluvialis is known for accumulating the highest levels of a potent natural antioxidant, astaxanthin, which has demonstrated positive health effects. Therefore, the aim of numerous studies has been to develop novel and efficient extraction techniques to produce high-quality (purity and antioxidant activity) extracts, while complying with the Green Chemistry Principles. Supercritical CO2 (scCO2) emerges as an alternative to organic solvents because of its high selectivity and bioactivity-preserving qualities. Nevertheless, astaxanthin is a large molecule with low solubility in scCO2 that usually requires long extractions at high pressures. Ethanol has been used as co-solvent to increase astaxanthin solubility in scCO2. In this work, a Box–Behnken experimental design was used to study the effects of operating pressure (20–35 MPa), temperature (40–70 °C), and ethanol content in scCO2 (0–13%, w/w) on the yield, astaxanthin content, and antioxidant activity of H. pluvialis extract. Results showed that ethanol content in CO2 has a more significant effect on all responses than pressure and temperature. These results lead us to investigate the effect of a further increase in ethanol content, up to the region of gas-expanded liquids. We studied the effects of temperature (30–60 °C) and ethanol content (50–70%, w/w) at a fixed pressure (7 MPa) on the same response variables using CO2-expanded ethanol (CXE). Results showed that temperature and ethanol content had a significant influence on astaxanthin yield and antioxidant activity. Also, the overall responses of CXE surpassed scCO2 extractions to match conventional extraction with acetone, maintaining high quality extracts, thus validating the use of this new type of green technology for extraction of high-value compounds. 相似文献
9.
《The Journal of Supercritical Fluids》2007,40(3):330-337
In this study, the extraction of jojoba seed oil obtained from jojoba seed using both supercritical CO2 and supercritical CO2+ethanol mixtures was investigated. The recovery of jojoba seed oil was performed in a green and high-tech separation process. The extraction operating was carried out at operating pressures of 25, 35 and 45 MPa, operating temperatures of 343 and 363 K, supercritical fluid flow rates of 3.33 × 10−8, 6.67 × 10−8 and 13.33 × 10−8 m3 s−1, entrainer concentrations of 2, 4 and 8 vol.%, and average particle diameters of 4.1 × 10−4, 6.1 × 10−4, 8.6 × 10−4 and 1.2 × 10−3 m. It was found that a green chemical modifier such as ethanol could enhance the solubilities, initial extraction rate and extraction yield of jojoba seed oil from the seed matrix as compared to supercritical CO2. In addition, it was found that the solubility, the initial extraction rate and the extraction yield depended on operating pressure and operating temperature, entrainer concentration, average particle size and supercritical solvent flow rate. The solubility of jojoba seed oil and initial extraction rate increased with temperature at the operating pressures of 35 and 45 MPa and decreased with increasing temperature at the operating pressure of 25 MPa. Furthermore, supercritical fluid extraction involved short extraction time and minimal usage of small amounts entrainer to the CO2. About 80% of the total jojoba seed oil was extracted during the constant rate period at the pressure of 35 and 45 MPa. 相似文献
10.
The influence of diverse factors on the supercritical fluid extraction (SFE) with supercritical CO2 (scCO2) of galanthamine from bulbs of Narcissus pseudonarcissus cv. Carlton was investigated. The parameters that were studied were CO2 density (temperature and pressure), flow rate and plant material particle size and pre-treatment. The highest yield (303 μg/g) was achieved by extracting 53–1000 μm particle-size powdered dried bulb material moistened with NH4OH (25%, v/v) at 70 °C, 220 bar (690 kg/m3) for 3 h. Other N. pseudonarcissus alkaloids such as O-methyllycorenine and haemanthamine were also obtained. N. pseudonarcissus alkaloids as free bases are highly soluble in CO2 at a high pH as opposed to the slightly soluble salt form in which they are generally found in plants. Therefore, plant material pre-treatment with a base is an essential step for galanthamine extraction. Scanning electron microscope (SEM) results also revealed that the desorption of N. pseudonarcissus alkaloids from the plant material rather than the solubility of the alkaloids in the scCO2 plays a major role in this scCO2 extraction. This extraction method has a good potential for industrial application. 相似文献
11.
The low-quality black tea was extracted at 27 different conditions using a lab-scale supercritical fluid extraction system according to four factor, three level Box–Behnken design [pressure (150–450 bar), temperature (40–80 °C), modifier flow rate (0.5–1.0 ml/min), and ethanol concentration in aqueous solution (75–100%)] at constant CO2 flow rate (2 l/min). Response surface methodology was used in order to optimize the extraction conditions for obtaining minimum caffeine and maximum phenolic profiles of the decaffeinated black tea. The R2 values for caffeine and phenolics were 99.5 and 96.6%, respectively. The lowest caffeine and the highest phenolics were obtained at following conditions [pressure (300 bar), temperature (53 °C), modifier flow rate (0.70 ml/min), and ethanol concentration (87.5%)] for 1 h. Using these conditions, the average loss of caffeine and phenolics in the decaffeinated tea were 99.8 and 3.3%, respectively. The present work suggests that optimum extraction conditions found can be applied for a pilot or large-scale production of decaffeinated black tea. 相似文献
12.
Pressurized liquid extraction (PLE) of curcuminoids from deflavored turmeric rhizomes was optimized. The rhizomes were initially deflavored by extraction with supercritical CO2. Immediately after SFE, PLE process was performed using ethanol as the solvent and a static extraction time of 20 min, and the independent variables were the temperature (333–353 K) and pressure (10–35 MPa). The results indicate that the optimum extraction temperature and pressure were 333 K and 10 MPa, respectively. PLE required three and six times less extraction time than low-pressure solvent extraction and Soxhlet extraction, respectively, to produce similar extraction yields. The cost of manufacturing (COM) decreased from US$ 94.92 kg−1 to US$ 88.26 kg−1 when the capacity of the two-extractor system increased from 0.05 m3 to 0.5 m3 and from US$ 94.92 kg−1 to US$ 17.86 kg−1 when the cost of the raw materials decreased from US$ 7.91 kg−1 to US$ 0.85 kg−1 for a two 0.05 m3 extractor system. 相似文献
13.
Supercritical Fluid Extraction (SFE) was used to obtain myrtle leaf extracts, and to study the antioxidant capacity (AOC) and in vitro antimicrobial activity of those extracts. To optimize the SFE operational conditions, the response surface methodology (RSM) was adopted. The parameters studied were: pressure (P), within the range 10 to 30 MPa; temperature (T), between 35 °C and 60 °C and supercritical carbon dioxide (SCCO2) flow rate (Q) within the range 0.15 to 0.45 kg h−1. The results show a good fit to the proposed model and the optimal conditions obtained (23 MPa, 45 °C, and SCCO2 flow rate of 0.3 kg h−1) were within the experimental range. The predicted values agreed with experimental ones, thus indicating the suitability of the RSM model for the optimization of the extraction conditions being investigated. With those values remaining constant, ethanol as a co-solvent was then studied. There was an observed rise in AOC as the amount of ethanol increased, within the range studied (0–30 wt% ethanol). The extract with the highest AOC was tested for its antimicrobial activity against gram-positive and gram-negative bacteria. The minimum inhibitory concentration (MIC) values obtained showed significant inhibitory effect against gram-positive bacteria. 相似文献
14.
Main objective of this work was to investigate the influence of pre-treatments of Satureja montana herbal material on supercritical extraction process, in terms: influence on extraction yield, composition and antioxidant activity of extracts. Four different pretreatments were investigated: water pre-treatment, ethanol pre-treatment, ultrasound and high pressure pre-treatment. Extraction yields were in the range from 1.68 to 2.35 g/100 g. Pre-treatments with water and ethanol increase the yield of extraction for 25% and 17%, respectively. According to GC/MS results the main compound of obtained extracts was carvacrol. Analyses confirmed that carvacrol content in extracts can be significantly increased by application of pre-treatments. Ultrasound pre-treatment and high pressure pre-treatment yielded highest concentration of carvacrol in extracts (around 66%). Using these two pre-treatments of herbal material, concentration of carvacrol, in extracts obtained by supercritical carbon dioxide extraction, could be increased for around 25%. Antioxidant activity of all extract was very high and in the range of well-known antioxidants. 相似文献
15.
The present work describes a sensitive procedure for extraction and determination of three sulfonylurea herbicides (metsulfuron-methyl, bensulfuron-methyl and chlorsulfuron) in water samples using supramolecular solvent microextraction. A supramolecular solvent with a nano structure made up of decanoic acid assemblies dispersed in tetrahydrofuran and water was proposed. Also, a supercritical fluid extraction coupled with supramolecular solvent microextraction was applied for extraction and determination of ultra-trace amounts of sulfonylurea herbicides in soil samples. A Taguchi orthogonal array experimental design with an OA16 (45) matrix was employed to optimize the supercritical fluid extraction conditions. In supercritical fluid extraction–supramolecular solvent microextraction procedure, a mixture of decanoic acid and the SFE collecting solvent (tetrahydrofuran) was added to water for supramolecular solvent formation. The effective parameters on the supramolecular solvent microextraction efficiency were studied and optimized using two different optimization methods: one variable at a time and face centered design. Under the optimum conditions, linear dynamic ranges varied within 0.1–5 mg kg−1 (0.9978 ≤ R2 ≤ 0.9987) and 0.5–100 μg L−1 (0.9973 ≤ R2 ≤ 0.9995) for all of the sulfonylurea herbicides in the supercritical fluid extraction–supramolecular solvent microextraction and supramolecular solvent microextraction, respectively. The intraday (n = 5) and interday standard deviations were calculated by extracting the SUHs from water and soil samples through supramolecular solvent microextraction and supercritical fluid extraction–supramolecular solvent microextraction. Interday RSDs% lower than 7.1% and intraday RSDs% lower than 3.8% were obtained. Limits of detection, based on a S/N ratio of 3, were 0.5 μg L−1 and 0.7 mg kg−1 for supramolecular solvent microextraction and supercritical fluid extraction–supramolecular solvent microextraction, respectively. 相似文献
16.
The impregnation of organic compounds in polymeric materials using supercritical carbon dioxide (scCO2) is a well-known technique, which is currently used in drug/polymer formulation. In this work, near critical and supercritical impregnation of thymol in linear low-density polyethylene (LLDPE) films was done in order to develop a new technique for preparation of active polymers to be used as food packages. The properties of thymol as a natural antimicrobial and antioxidant agent have motivated this study about the assessment of its migration from the polymer to different food simulant. Impregnation assays of thymol in LLDPE films were done in a high-pressure cell, where pure thymol was solubilized in supercritical carbon dioxide at 313 K and pressures varying from 7 to 12 MPa. This procedure allowed the preparation of plastic films with thymol concentrations ranged between 5100 and 13,200 ppm. Migration tests showed that the pressure applied during the impregnation procedure is a key parameter that affects the content of the active compound into the polymer, since thymol solubility in scCO2 and absorption phenomena in the polymer increased with the pressure. The correlation between experimental data and a phenomenological transfer model allowed the estimation of the diffusion coefficient of thymol in LLDPE, which was ranged from 7.5 × 10−13 to 3.0 × 10−12 m2 s−1. 相似文献
17.
18.
The work described here is a continuation of a previous study centered on the extraction, using supercritical carbon dioxide, of bioactive substances from sunflower leaves of the Helianthus annuus L. variety Arianna. In this study the addition of 9% of ethanol as co-solvent was analyzed. The extraction was carried out (P = 100/400 bar, T = 35/55 °C, ethanol = 9%) in order to analyze the influence of pressure, temperature and sample pre-treatment on the extraction yield and bioactivity of the extracts. The addition of 9% of ethanol to the supercritical solvent enhanced both the extraction yield and the biological activity of the extracts. The best conditions were a pressure of 400 bar and a temperature of 55 °C. In an effort to improve the bioactivity of the extract, a cascade fractionation of the extracts was carried out and this gave different results in terms of biological activities and extraction yields. The phytochemical compositions of the extracts were analyzed by thin layer chromatography. The fractionation that gave the best results was carried out at 90 bar and 40 °C in the first separator. Finally, the effect of extracts on the growth of seeds from different plants was analyzed. 相似文献
19.
The reported work aimed at the optimization of operating conditions of the supercritical fluid extraction (SFE) of spent coffee grounds (SCG) using pure or modified CO2, with particular emphasis on oil enrichment with diterpenes like kahweol, cafestol and 16-O-methylcafestol. The analysis comprised the application of Box–Behnken design of experiments and response surface methodology, and involved three operating variables: pressure (140–190 bar), temperature (40–70 °C) and cosolvent (ethanol) addition (0–5 wt.%). The best conditions to maximize total extraction yield are 190 bar/55 °C/5 wt.% EtOH, leading to 11.97% (goil/100 gSCG). In terms of the concentration of diterpenic compounds in the supercritical extracts, the best operating conditions are 140 bar/40 °C/0 wt.% EtOH, providing 102.90 mg g−1oil. The measurement of extraction curves near optimized conditions (140 bar/55 °C/0 wt.% EtOH and 190 bar/55 °C/0 wt.% EtOH) confirmed the trends of the statistical analysis and revealed that SFE enhances diterpenes concentration by 212–410% at the expenses of reducing the extraction yield between 39% and 79% in comparison to n-hexane extraction. 相似文献
20.
The objective of this study was to select a variety of pepper with high concentration of capsaicin and subject it to supercritical fluid extraction (SFE), in order to determine the best conditions of temperature (40, 50 and 60 °C) and pressure (15, 25 and 35 MPa) in terms of global yield (X0) and capsaicinoids content of the extracts. The influence of drying process (freeze and oven drying) on X0, capsaicin (C) and dihydrocapsaicin (DHC) contents and total phenolics was also analyzed. Capsicum frutescens showed the highest levels of capsaicinoids (1516 μg/g fresh fruit). For the responses C and DHC, the extraction conditions of 15 MPa and 40 °C provided the highest concentrations (C 42 mg/g extract and DHC 18.5 mg/g extract). The freeze drying process resulted in extracts with the highest concentration of capsaicinoids (61 mg/g extract), but in contrast, the phenolics were less susceptible to different drying processes, with a mean concentration of 35 mg GAE/g extract. The kinetics experiments indicated that the extraction rate of oleoresin was slightly slower than that of capsaicinoids at the operation conditions (40 °C and 15 MPa). 相似文献