Navegando por Assunto "Supercritical fluid extraction"

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Acesso aberto (Open Access)
Avaliação da composição química, atividade antioxidante e antimicrobiana do óleo de cipó-de-alho (Mansoa standleyi) (Steyerm.) A. H. Gentry (Bignoniaceae) obtido via extração supercítica
(Universidade Federal do Pará, 2019-05-31) URBINA, Glides Rafael Olivo; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580
Mansoa standleyi is popularly known as "cipó-de-alho" because of its characteristic garlic odor (Allium sativum). The plant has an inhibitory effect on bacteria and fungi growth. The objective of this work was to evaluate the chemical composition, antioxidant and antimicrobial activity of the oil obtained from M. standleyi leaves via supercritical fluid extraction (SFE) and conventional extraction (Hydrodistillation). The SFE tests were performed using supercritical CO2, static extraction time of 30 min and dynamic time of 180 min, CO2 flow of 2.5 L/min and raw material mass of 10 g. The temperature and pressure variables were selected in order to obtain a difference in the CO2 density (𝜌𝐶𝑂2) in the 35 and 45 ºC isotherms combined with the pressure values of 100, 200, 300, and 400 bar. The results obtained allow us to verify that the global yield values of SFE on dry basis show significant differences between them (p≤0.05), with values varying from 0.87 to 2.02%. The highest average found refers to 400 bar/35 ºC condition (𝜌𝐶𝑂2 = 972.26 kg/m3). However, in Hydrodistillation extraction the oil yield was 0.14%. The results of phytochemical screening by high performance thin layer chromatography (HPTLC) evidenced the presence of terpenes, fatty acids, phenolic compounds, and flavonoids. It was demonstrated the presence of substances with antioxidant activity for all oils obtained with SFE, being observed a better identification in the oils obtained at high pressures. In the quantitative analysis of chemical composition, it was observed that the values ranged from 31.87 to 72.06 mg EAG/g oil in the content of total phenolic compounds. In relation to the antioxidant activity, the values ranged from 457.64 to 2475.55 EC50 expressed in g of oil/g of DPPH, the best results being obtained in the condition of 400 bar/35 ºC. In the fatty acid profiles of M. standleyi oil obtained by SFE, the results indicated that there was a difference in the fatty acids qualitative composition detected, in function of the operational extraction condition, where the presence of linoleic (≅95%), palmitic (≅12%), and oleic (≅5%) acid was observed. The chemical constituents identified in the obtained oil by Hydrodistillation were identified as sulfur compounds, phenols, and alcohols. The antimicrobial activity in vitro analysis showed that the oil obtained by SFE presents an antibacterial action against Stapphylococcus aureus and Escherichia coli. Finally, M. standleyi oil represents an alternative for future use in the treatment of diseases caused by microorganisms.
Acesso aberto (Open Access)
Avaliação da influência da natureza da matriz sólida sobre a extração supercrítica de óleos vegetais
(Universidade Federal do Pará, 2013-05-10) COSTA, João Fernando Alves; FRANÇA, Luiz Ferreira de; http://lattes.cnpq.br/6545345391702172
The extraction of substances from solid substrates both low and high pressures involves at least two phases, a solid and another fluid. The content of the solute in each phase is expressed in terms of the volume of phase and / or volume of solvent. Then, by modeling the interfacial mass transfer it requires a partition coefficient. In general, the simplest way to address this problem is to model the phases separately. The mechanism predominant mass transfer can vary from system to system. For some substrates higher resistance may be in the solid phase and for others it is in the fluid phase. As the interface concentrations for each phase are represented by different variable, phases have to be modeled separately. However, depending on the system, there may be a transfer mechanism predominated over the other, and many effects can be discarded for simplification of the model. The utilization of simpler mathematical models requires a combination of variables for definition of parameters that can represent the phenomenon. In this work the extraction curves were fitted to a model which describes the interfacial mass transfer like a first order kinetics, since the constant of the extraction rate is the unique adjustment parameter. It has been proposed that the adjustment parameter depends on the solubility of solute in the supercritical solvent and on the solid substratum characteristics. To avail that, extraction experiments with babaçu, powder açaí and pupunha pulp using super-critic carbon dioxide at 20, 25 and 30 MPa and temperature of 50°C have been carried out. The results showed that the experimental data fit well to a model with a constant characteristic of each material, with values 4.1983 x 10-5 m/kg∙s to babaçu, 4.2258 x 10-5 m/kg∙s to pupunha pulp, to 10-5 m/kg∙s to powder açaí.
Acesso aberto (Open Access)
Extração de Compostos Antioxidantes de Cissus sicyoides L. com Tecnologia Supercrítica e Determinação da Atividade Anti-inflamatória no Modelo de Lesão Medular
(Universidade Federal do Pará, 2023-05-11) RODRÍGUEZ SALAZAR, Marielba de Los Ángeles; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580
Cissus sicyoides L. or Cissus verticillata L., also known as vegetable insulin, is a plant that has a potent anti-inflammatory activity, due to its chemical composition, which stands out for the presence of compounds with high antioxidant activity. Supercritical technology is an appropriate alternative to extract antioxidant compounds from plant matrices. In this sense, the objective of this thesis was to perform the extraction of antioxidant compounds present in C. sicyoides through supercritical technology, using CO2 and EtOH as a co-solvent, and subsequently, in the supercritical extract, to evaluate the anti-inflammatory effect in the spinal cord injury model. For this, in the first experimental stage of the thesis, the identification of phenolic compounds by HPLC and the cytotoxic effect, on human red blood cells, of the extract of leaves and stems of C. sicyoides obtained by supercritical extraction was evaluated, in the operating condition of 50 °C/ 400 bar and 10 % EtOH (𝜌𝐶𝑂2+𝐸𝑡𝑂𝐻 = 953 kg/m3), compared to the extract obtained by conventional extraction (Soxhlet) and, finally, the antiinflammatory effect in the spinal cord injury model was evaluated. In the analysis of the extracts by HPLC, the UV/Visible spectral data revealed compounds with absorption bands at wavelengths characteristic of glycosylated flavonoids. The supercritical extract did not show a cytotoxic effect, as there was no disruption of red blood cell membranes. The in vivo assay demonstrated an apparent reduction in cell concentration in the area surrounding the lesion in the treated animals, suggesting an anti-inflammatory effect of the supercritical extract in the spinal cord injury model. In the second experimental stage of the thesis, the aim was to study the antioxidants present in each part of C. sicyoides (fruits, flowers, leaves and stems). Samples were evaluated for CFT content by the Folin-Ciocalteu method, which ranged from 9.30 to 141.04 mg GAE/g of sample, of FT by complexation with aluminum chloride from 1.03 to 44.02 mg QE /g of sample, its antioxidant activity by the DPPH method, the EC50 value varied between 162.83 to 453.25 g of sample/g of DPPH and by the FRAP method the values were 199.14 and 241.26 μM ferrous sulfate/ g sample. Thus, leaves and stems before and after SFE are rich in antioxidants, which justifies the high FT content, as well as the higher antioxidant activity by the tested methods. Finally, in the SFE process it was possible to obtain an extract with potential antioxidant activity, which can be used for biological applications.
Acesso aberto (Open Access)
Extração e transesterificação do óleo de resíduo industrial de palmiste usando metanol supercrítico
(Universidade Federal do Pará, 2018-11-23) COSTA, Wanessa Almeida da; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748
Palm kernel is an oleaginous seed found in fruits of Elaeis guineensis Jacq. and which represents one of the main oils consumed in the world, with an mean production of 18,59 million tons. Its main process is the extraction by mechanical pressing that generates, in the world, approximately 9.6 x 109 tons of residue also called residual cake. Since this residue can still present about 12% of remaining oil, supercritical fluid extraction (SFE) is presented as an alternative to the recovery of this oil. Soxhlet extraction was also performed to be compared to the SFE. Pressures of 150, 250 and 350 bar and temperatures of 40, 60 and 80 °C were used in the experiments. The raw material was characterized before and after the SFE by moisture, ash, fibers, proteins and lipids contents and the extracts were characterized by gas chromatography/mass spectrometry (GC/MS). The kinetic data were compared to the Sovová (2012) model and the condition of highest yield was used in the transesterification experiments. Molar ratios of 1:24 and 1:42 (oil: methanol), temperatures of 250, 300 and 350 °C, constant pressure of 200 bar and reaction times of 5, 10, 15, 20 and 25 minutes were used. The products were also analyzed by GC/MS to verify the transformation of triacylglycerols into methyl esters. The main results of this study were: SFE does not alter the centesimal composition of the raw material; the condition of highest yield was 350 bar and 80 °C; Sovová's model had the best fit to the kinetic data; the condition 1:42, 350 ºC was the one that obtained the highest content of esters (99.81%) in only 5 minutes of reaction. The transesterification of palm kernel oil in a supercritical medium is a valid alternative and presents advantages over the conventional method, however a more in-depth analysis considering the technical and economic limitations of this method is necessary.
Acesso aberto (Open Access)
Modelagem e simulação do fracionamento de óleos vegetais e do produto líquido orgânico do processo de craqueamento termocatalítico do óleo de palma em colunas multiestágios em contracorrente
(Universidade Federal do Pará, 2016-10-03) COSTA, Elinéia Castro; ARAÚJO, Marilena Emmi; http://lattes.cnpq.br/8983914018546682; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065
In this work, a method was developed employing the commercial process simulator Aspen Hysys using a countercurrent multistage column to the fractioning/deacidification of vegetable oils applying processes such as liquid-liquid extraction, using ethanol as solvent, and supercritical fractioning, with CO2 as solvent. Palm and olive oil were used in the case study. Experimental equilibrium data of multicomponent systems published in the literature were correlated with both NRTL model and RK-Aspen models, the binary interaction parameters obtained from these correlations were used in the simulations. The same procedure was applied to the fractioning/deacidification process of the organic liquid products (OLP) from the thermal-catalytic cracking of palm oil, using supercritical CO2 as solvent. The correlation of liquid-liquid equilibrium data of the systems showed that the NRTL model was able to suitably fit the experimental data for all the studied systems with RMSD between 0.15 to 1.72%. For all the S/F ratios analyzed, simulation results demonstrated, on the 10 stage column, that only when a mixture water+ethanol (12.41%) was used as solvent, the maximum acceptable level of neutral oil loss for industrial physical refining (5%wt) was attained. Correlation of experimental equilibrium data at high pressures indicated that the RK-Aspen model was able to properly fit the equilibrium data for all studied systems, with RMSD from 3.0E-05% to 0.58% for the liquid phase and between 2.0E-06% to 0,02% for vapor phase, for each composition of free fatty acid in the feed. The absolute mean deviations between the supercritical fractioning process simulated with 10 stages using the olive oil model mixture and the experimental results of supercritical fractioning of olive oil in a pilot scale column at 313K, S/F=20, with varying pressure and different fatty acid composition in the feed, were 2.25% for the yield of raffinate stream and 0.15% for the fatty acid concentration in the raffinate stream. The simulations of supercritical fractioning of OLP, with 10-staged columns, showed that the CO2 was able to deacidificate the produced fractions. For both proposed process diagrams with the column 1 using S/F=17 or 19, column 2 for all the studied S/F ratios, presented top streams (extract) containing compositions characteristic of kerosene from petroleum, with lower olefin and oxygenated content compared to the experimental fraction distillated within the same temperature range of petroleum kerosene published in the literature.
Acesso aberto (Open Access)
Tecnologia supercrítica aplicada à extração do óleo de bacaba-de-leque (oenocarpus distichus), determinação de compostos bioativos e avaliação dos parâmetros de processo.
(Universidade Federal do Pará, 2021-07-08) CUNHA, Vânia Maria Borges; ARAÚJO, Marilena Emmi; http://lattes.cnpq.br/8983914018546682; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748
The Oenocarpus distichus species is a native palm from Brazilian Amazon biomes, popularly known as bacaba-de-leque. Its economic value is mainly based on the palm heart exploitation and the fruits pulp oil extraction, used for edible purposes. Despite this, there is little knowledge about this species, especially regarding its functional characteristics and its nutritional contribution to local populations and society in general. Therefore, in this thesis, three research manuscripts were produced in order to promote the valorization of the species in the industrial scenario. The studies were carried out by applying supercritical carbon dioxide (Sc-CO2) for the extraction of oil from the lyophilized bacaba-de-leque pulp under different process conditions. In the first article, the operating temperatures of 50 °C was applied, combined with pressures of 150, 220 and 350 bar, and 60 °C, combined with pressures of 190, 270 and 420 bar, to obtain the best oil yield. Its chemical composition was evaluated, as well as the bioactive compounds contents present in the pulp before and after extraction. The maximum oil yields were reached at 50 ºC/350 bar (45.23%) and 60 ºC/270 bar (45.90%). The oleic, palmitic, and linoleic acids, as well as the predicted triglycerides OLiO, PLiO, OOO, POP, and POO were predominant in the oil composition, independent of the extraction conditions, and presented excellent functional quality. There was an increase in phenolic compounds, total anthocyanins contents, and antioxidant capacity of the bacaba-deleque pulp extracts after the Sc-CO2 extraction. In the second article, the nutritional and physicochemical properties of the oil extracted by Sc-CO2 at 50 °C/350 bar were investigated, as well as its thermal stability, the presence of functional compounds and the cytotoxic effect. The extracted oil showed 21.36 μg/g oil of total carotenoids. The quality parameters evaluated, which define the physicochemical properties, presented values within the standards recommended by the legislation for crude vegetable oils, and were similar to those of edible oils marketed in Brazil and in other countries. The thermogravimetric profiles indicated relative thermal stability at 210 ºC. The spectral bands, determined by FTIR, showed that the extraction method and the operating conditions applied did not alter the characteristic functional group profile. The cytotoxicity tests revealed that the extracted oil had no cytotoxic effect. The third article consists of a study of the supercritical extraction kinetics of bacabade- leque oil in two extraction vessels (V1 and V2) at different solvent flows (𝑄𝐶𝑂2) at 50 °C/350 bar and 60 °C/270 bar. The experimental data were properly adjusted by modifying the Broken-and-Intact Cell (BIC) model, proposed in the literature. Lastly, experimental and predicted scale-up procedures were evaluated, correlating operational variables in different bed geometries. The operational parameters applied did not influence the final oil yields. However, the initial stages of extraction were visibly affected. The use of the correlation between bed height and diameter (Hb/Db) and 𝑄𝐶𝑂2 , for the same feed mass (F), was not enough to reproduce the experimental kinetic curves from V1 (5×10-5 m3) to V2 (10-4 m3). However, when expressed as a function of solvent consumption, the curves converged to the same line, showing that the total amount of CO2 consumed was responsible for the process efficiency. In predicting scale-up, the increase of F and 𝑄𝐶𝑂2 for the same Hb/Db proved to be adequate to reproduce the kinetic behavior of the experimental scale in larger scales. The results of these studies showed that bacaba-de-leque oil is presented as a high-quality product, which is attributed to its chemical composition and functional properties, and provide information that allows the improvement and technical feasibility of oil extraction for possible application on a commercial scale.