995 resultados para Oil extraction
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Deacidification of vegetable oils can be performed using liquid-liquid extraction as an alternative method to the classical chemical and physical refining processes. This paper reports experimental data for systems containing refined babassu oil, lauric acid, ethanol, and water at 303.2 K with different water mass fractions in the alcoholic solvent (0, 0.0557, 0.1045, 0.2029, and 0.2972). The dilution of solvent with water reduced the distribution coefficient values, which indicates a reduction in the loss of neutral oil. The experimental data were used to adjust the NRTL equation parameters. The global deviation between the observed and the estimated compositions was 0.0085, indicating that the model can accurately predict the behavior of the compounds at different levels of solvent hydration. (C) 2011 Elsevier Ltd. All rights reserved.
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Soybean oil can be deacidified by liquid-liquid extraction with ethanol. In the present paper, the liquid-liquid equilibria of systems composed of refined soybean oil, commercial linoleic acid, ethanol and water were investigated at 298.2 K. The experimental data set obtained from the present study (at 298.2 K) and the results of Mohsen-Nia et al. [1] (at 303.2 K) and Rodrigues et al. [2] (at 323.2 K) were correlated by applying the non-random two liquid (NRTL) model. The results of the present study indicated that the mutual solubility of the compounds decreased with an increase in the water content of the solvent and a decrease in the temperature of the solution. Among variables, the water content of the solvent had the strongest effect on the solubility of the components. The maximum deviation and average variance between the experimental and calculated compositions were 1.60% and 0.89%, indicating that the model could accurately predict the behavior of the compounds at different temperatures and degrees of hydration. (C) 2010 Elsevier B.V. All rights reserved.
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The catalytic ethanolysis of soybean oil with commercial immobilized lipase type B from Candida antarctica to yield ethyl esters (biodiesel) has been investigated. Transesterification was monitored with respect to the following parameters: quantity of biocatalyst, reaction time, amount of water added and turnover of lipase. The highest yields of biodiesel (87% by (1)H NMR; 82.9% by GC) were obtained after a reaction time of 24 h at 32 degrees C in the presence of lipase equivalent to 5.0% (w/w) of the amount of soybean oil present. The production of ethyl esters by enzymatic ethanolysis was not influenced by the addition of water up to 4.0% (v/v) of the alcohol indicating that it is possible to use hydrated ethanol in the production of biodiesel catalyzed by lipase. The immobilized enzyme showed high stability under moderate reaction conditions and retained its activity after five production cycles. The (1)H NMR methodology elaborated for the quantification of biodiesel in unpurified reaction mixtures showed good correlations between the signal areas of peaks associated with the alpha-methylene groups of the ethyl esters and those of the triacyl-glycerides in residual soybean oil. Monoacylglycerides, diacylglycerides and triglycerides could also be detected and quantified in the crude biodiesel using (1)H NMR spectroscopic and GC-FID chromatographic methods. The biodiesel production by enzymatic catalysis was promising. In this case, was produced a low concentration of glycerol (0.74%) and easily removed by water extraction. (C) 2010 Elsevier B.V. All rights reserved.
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Many factors can affect the quality of diesel oil, in particular the degradation processes that are directly related to some organosulfur compounds. During the degradation process, these compounds are oxidized into their corresponding sulfonic acids, generating a strong acid content during the process. p-Toluene sulfonic acid analysis was performed using the linear sweep voltammetry technique with a platinum ultramicroelectrode in aqueous solution containing 3 mol L(-1) potassium chloride. An extraction step was introduced prior to the voltammetric detection in order to avoid the adsorption of organic molecules, which inhibit the electrochemical response. The extraction step promoted the transference of sulfonic acid from the diesel oil to an aqueous phase. The method was accurate and reproducible, with detection and quantification limits of 5 ppm and 15 ppm, respectively. Recovery of sulfonic acid was around 90%.
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Eugenol is the main volatile compound extracted oil from clove bud, Syzygium aromaticum L., and used in traditional medicine, as a bactericide, fungicide, anesthetic, and others. Its extraction was performed using hydrodistillation which is the most common extraction technique. Its components and thermal behavior were evaluated using gas chromatography (GC) and differential scanning calorimetry (DSC), which provide a better characterization of these natural compounds. This extracted product was compared to the standard eugenol results. The GC results suggested similar to 90% eugenol was found in the total extracted oil, and some of its boiling characteristics were 270.1 A degrees C for peak temperature and 244.1 J g(-1) for the enthalpy variation.
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Hop(HumuluslupulusL.,Cannabaceaefamily)isprizedforitsessentialoilcontents,usedin beer production and, more recently, in biological and pharmacological applications. In this work,a methodinvolvingheadspace solid-phase microextractionand gas chromatography– mass spectrometry was developed and optimized to establish the terpenoid (monoterpenes and sesquiterpenes) metabolomic pattern of hop-essential oil derived from Saaz variety as a mean to explore this matrix as a powerful biological source for newer, more selective, biodegradable and naturally produced antimicrobial and antioxidant compounds. Different parameters affecting terpenoid metabolites extraction by headspace solid-phase microextraction were considered and optimized: type of fiber coatings, extraction temperature, extraction time, ionic strength, and sample agitation. In the optimized method, analytes were extracted for 30 min at 40 C in the sample headspace with a 50/30 m divinylbenzene/carboxen/polydimethylsiloxane coating fiber. The methodology allowed the identification of a total of 27 terpenoid metabolites, representing 92.5% of the total Saaz hop-essential oil volatile terpenoid composition. The headspace composition was dominated by monoterpenes (56.1%, 13 compounds), sesquiterpenes (34.9%, 10), oxygenated monoterpenes (1.41%, 3), and hemiterpenes (0.04%, 1) some of which can probably contribute to the hop of Saaz variety aroma. Mass spectrometry analysis revealed that the main metabolites are the monoterpene -myrcene (53.0±1.1% of the total volatile fraction), and the cyclic sesquiterpenes, -humulene (16.6 ± 0.8%), and -caryophyllene (14.7 ± 0.4%), which together represent about 80% of the total volatile fraction from the hop-essential oil. Thesefindingssuggestthatthismatrixcanbeexploredasapowerfulbiosourceofterpenoid metabolites.
Molecular analysis of the bacterial diversity in a specialized consortium for diesel oil degradation
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Diesel oil is a compound derived from petroleum, consisting primarily of hydrocarbons. Poor conditions in transportation and storage of this product can contribute significantly to accidental spills causing serious ecological problems in soil and water and affecting the diversity of the microbial environment. The cloning and sequencing of the 16S rRNA gene is one of the molecular techniques that allows estimation and comparison of the microbial diversity in different environmental samples. The aim of this work was to estimate the diversity of microorganisms from the Bacteria domain in a consortium specialized in diesel oil degradation through partial sequencing of the 16S rRNA gene. After the extraction of DNA metagenomics, the material was amplified by PCR reaction using specific oligonucleotide primers for the 16S rRNA gene. The PCR products were cloned into a pGEM-T-Easy vector (Promega), and Escherichia coli was used as the host cell for recombinant DNAs. The partial clone sequencing was obtained using universal oligonucleotide primers from the vector. The genetic library obtained generated 431 clones. All the sequenced clones presented similarity to phylum Proteobacteria, with Gammaproteobacteria the most present group (49.8 % of the clones), followed by Alphaproteobacteira (44.8 %) and Betaproteobacteria (5.4 %). The Pseudomonas genus was the most abundant in the metagenomic library, followed by the Parvibaculum and the Sphingobium genus, respectively. After partial sequencing of the 16S rRNA, the diversity of the bacterial consortium was estimated using DOTUR software. When comparing these sequences to the database from the National Center for Biotechnology Information (NCBI), a strong correlation was found between the data generated by the software used and the data deposited in NCBI.
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In this work, experimental data for the system Lippia alba + CO2 is presented. The major constituents of the L. alba volatile oil are limonene and carvone. Thus, literature data for the systems limonene + CO2 and carvone + CO2, and the Peng-Robinson equation of state (PR-EOS) were used to select the operating temperature and pressure, which maximize the global yield in L. alba extract. Global yields were determined at 80, 100, and 120 bar and 40, 45, and 50 degrees C. L. alba extracts were also obtained by conventional processes (hydrodistillation, low-pressure ethanol extraction and Soxhlet ethanol). The chemical compositions of the extracts were determined by gas and thin layer chromatography (TLC). The secretor structures of L. alba were observed by scanning electron microscopy (SEM) before and after supercritical extraction. The largest yield (similar to 7%, mass of extract/mass of dry solid) of the CO2-extract was obtained at 318 K and 100 bar. The chemical compositions of the CO2-extracts were different from those of the extracts obtained by Soxhlet and low-pressure solvent extraction (LPSE) because of the co-extraction of heavy substances by ethanol. The operating conditions that maximized the carvone and limomene yields were 80 bar and 323 K (80 mass%) and 120 bar and 323 K (17 mass%), respectively. (c) 2004 Elsevier B.V All rights reserved.
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The aim of this work was to characterize the yellow melon seeds, hybrid variety, as for their proximate composition, and to evaluate the antioxidant potential of extracts of seed in soybean oil. The extract of melon seeds (EM), obtained by extraction using ethanol: water (95:5), was applied in soybean oil at three different concentrations (500; 750 and 1000 mg kg(-1)) and submitted to Shaal oven method at 60 degrees C for 20 days. Oil samples were evaluated for peroxic a value in periods of five days. The antioxidant activity of the extract was compared to the BHT (butyl-hydroxytoluene) activity. The melon seeds showed a high nutrition value, containing high percentages of lipids (25.2%), proteins (20.1%) and fiber (30.0%). All these treatments retarded lipid oxidation in soybean oil; however the natural extracts were less effective than BHT after 10 days in the oven. The antioxidant activities of different treatments tested in this study followed the order: BHT > EM 1000 mg kg(-1) = EM 750 mg kg(-1) > EM 500 mg kg(-1)> control.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The jeriva is a well-known fruit, which belongs to the Arecaceae family, Syagrus romanzoffiana species frequently found in Brazil. Extraction of the jeriva oil was carried out, and the fatty acid profile of this oil indicates the linoleic and oleic acid presence, around 29.35 and 28.89%, respectively. Thermogravimetry (TG), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC) were used to characterize this oil. Additionally, this oil was evaluated by DSC from 25 to -80 A degrees C, and the crystallization behavior was verified. Details concerning the thermal behavior as well as data of kinetic parameters of these stages have been described here. The obtained data were evaluated, and the values were plotted in activation energy (E (a)/kJ mol(-1)) in function of the conversion degree (alpha).
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Lithraea molleoides(Vell.) (Anacardiaceae) é uma árvore encontrada no Brasil, Paraguai, Bolívia, Uruguai, Argentina e Chile. É popularmente usada na forma de extrato alcoólico, decocção e infusão para o tratamento de tosse, bronquite, artrite, doenças do sistema digestivo, como diurético, tranqüilizante, hemostático e tônico. O objetivo do presente estudo foi a extração do óleo essencial dos frutos maduros, folhas e outras partes aéreas da planta e o rendimento do mesmo; a identificação e quantificação dos principais componentes e a determinação da atividade antimicrobiana. O rendimento do óleo essencial dos frutos maduros foi de 1%, entretanto, não foi encontrado óleo essencial nas partes aéreas da planta. A análise do óleo essencial por cromatografia gasosa com espectrometria de massa, mostrou a presença de limoneno (89,89%), alfa-pineno (3,48%), beta-pineno (2,63%), alfa-terpineol (1.27%), mirceno (0,64%), sabineno (0,54%), 4-terpineol (0,28%), canfeno (0,22%) e delta-3-careno (0,13%). O óleo essencial foi ativo contra algumas bactérias Gram positivas e leveduras testadas e não apresentou atividade contra bactérias Gram negativas.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)