Teses em Engenharia de Recursos Naturais da Amazônia (Doutorado) - PRODERNA/ITEC
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/4045
O Doutorado Acadêmico inicou-se em 2006 e pertence ao Programa de Pós-Graduação em Engenharia de Recursos Naturais da Amazônia (PRODERNA) do Instituto de Tecnologia da UFPA (ITEC) da Universidade Federal do Pará (UFPA).
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Item Acesso aberto (Open Access) Extração do óleo de tucumã-do-Pará (Astrocaryum vulgare) usando CO2 supercrítico visando o aumento de escala(Universidade Federal do Pará, 2022-04-04) MENEZES, Eduardo Gama Ortiz; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580With the growing worldwide demand for products and wealth generation, there is a need to invest in new sustainable processes and engineering practices for scale expansion. Thus, the objective of this work was to obtain β-carotene-rich tucumã-do-Pará (Astrocaryum vulgare) oil using supercritical CO2 and to verify the adequacy of two new scale-up equations. Therefore, two isotherms and three pressures (40°C, 60°C, 150bar, 250bar, 400bar) were used. In the condition that presented the highest oil and β-carotene extraction yield, a kinetic study was carried out, followed by the application of a new equation based on Buckingham's π theorem. The highest oil extraction yield (31.49±0.04%) was obtained at 60°C and 400bar with a high concentration of oleic acid, and this yield was similar to the value obtained by soxhlet, which was 32.73±0, 59% oil. The application of the Tukey test (p <0.05) shows that there is no significant difference between the extraction yield obtained in the isotherm of 40 °C and 60 °C in the pressure condition of 400bar. The highest concentration of β-carotene (1351.8±0.02 μg/g) was obtained at 40°C and 400bar, and the solvent density was considered the most significant variable with the greatest influence on β-carotene extraction. The kinetic study carried out with the application of a new mathematical proposal based on the correlation between operational variables (solvent flow, feed mass, height and diameter of the extraction bed), mass transfer mechanism and constancy of the inclination angle of the kinetic curves that , for a solvent flow rate of 10.93 g/min, on the larger scale, the diffusive step controlled the mass transfer mechanism.Item 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/5544305606838748Palm 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.Item Acesso aberto (Open Access) Obtenção de extratos com potencial bioativo a partir da polpa do piquiá (caryocar villosum (aubl.) pers.) utilizando dióxido de carbono no estado supercrítico(Universidade Federal do Pará, 2024-09-30) CORDEIRO, Renato Macedo; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580In a context of increasing demand for substances with health-beneficial properties, extracts from certain plant species found in the Amazon are a promising source of bioactive compounds. Caryocar villosum (Aubl.) Pers., a native fruit of the Amazon region commonly known as piquiá, is regarded as a source of bioactive compounds. This study investigated the supercritical extraction process of piquiá pulp to evaluate the process parameters, overall yield, extraction kinetics, fatty acid profile, α-tocopherol content, functional quality, and physicochemical characterization. The influence of extraction temperature, pressure, and solvent density on the extraction yield was considered. The quality of the obtained extracts was assessed in terms of fatty acid profile, functional quality indices, physicochemical characterization, and α-tocopherol content. A kinetic study of the piquiá extraction with supercritical fluid was conducted using experimental data and mathematical models. The extraction yield was found to increase with pressure at each isotherm, with the highest yield reaching 62.74% and the lowest at 44.01%. The kinetic mathematical models of Martinez and Barton demonstrated good performance in correlating the extraction process of piquiá pulp. The primary fatty acids observed in the extracts obtained under all operational conditions were oleic and palmitic acids. The extract obtained at the operational condition of 60 °C and 250 bar exhibited the highest α-tocopherol content compared to the other experimental conditions in this study. The results indicated that the extracts from piquiá pulp obtained through supercritical CO₂ extraction present significant potential for the industry due to their functional quality.Item Acesso aberto (Open Access) Obtenção do óleo e da polpa sem gordura do açaí (euterpe oleracea) por extração supercrítica: caracterização físico-química, estudo da citotoxicidade e vida de prateleira(Universidade Federal do Pará, 2025-01-06) SIQUEIRA, Letícia Maria Martins; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580Açaí is a very important product for the development of the state of Pará, for the bioeconomy and the market has been growing. And currently the majority of the state’s production is just fruit pulp, hence the importance of new products with added value and the need to invest in new sustainable processes for the region’s development. Therefore, the objective of this work was to obtain the oil and pulp without açaí fat by supercritical extraction, determine the main bioactive compounds, evaluate the possible cytotoxicity in MRC-5 and VERO cells in vitro and evaluate the shelf life of the products. The freezedried açaí pulp was subjected to extraction with supercritical CO2, under the conditions 323,15 K at 35 MPa, 333,15 K at 42 MPa and 343,15 K at 49 MPa. The highest yield (51,74 %), carotenoids (277,09 μg/g), DPPH (2,55 μmol TE/g), ABTS (2,60 μmol TE/g) and FRAP (15,25 μm ferrous sulfate/g) from oil and ABTS (644,23 μmol TE/g) from pulp without fat were found at 343,15 K at 49 MPa condition. The highest contents of phenolic compounds (150,20 mg GAE/g d.b.), DPPH (414,99 μmol TE/g d.b.) and FRAP (746,2 μm ferrous sulfate/g) from pulp without fat were found at 323,15 K at 35 MPa condition. The pulp without fat presented high levels of anthocyanins without significant variation. The products did not present cytotoxicity. The half-life of the freeze-dried pulp and the fat-free pulp in the presence of light (Becker) was shorter than that of the packaging materials. The sealed packaging achieved a longer half-life compared to vacuum-sealed packaging for the freeze-dried pulp. However, for the fat-free pulp, the vacuum-sealed packaging showed a longer half-life compared to the sealed one. The results of the stability of açaí oil qualify it as a table oil rather than a frying oil, as it degrades more rapidly at higher temperatures. The results demonstrated that the products have potential applications in the industry.