Navegando por Assunto "Fatty acids"

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Acesso aberto (Open Access)
Aplicação de destilados provenientes do bio- óleo de pirólise de resíduos de gordura animal no asfalto diluído de petróleo
(Universidade Federal do Pará, 2024-08-12) VALENTE, Alex Lopes; MACHADO, Nélio Teixeira; http://lattes.cnpq.bhttp://lattes.cnpq.br/1500327307736428r/5698208558551065; https://orcid.org/0009-0002-4461-7611; BERNAR, Lucas Pinto
Waste animal fats (WAF) can be converted into distillate fractions similar to petroleum solvents and used as biofuels or in other applications through pyrolysis and fractional distillation. The distillate fractions from the pyrolysis of triglycerides exhibit adequate viscosity and volatility compared to petroleum-derived fuels but show acid values between 60-140 mg KOH/g, preventing their direct use as biofuels without considerable purification of the distilled fractions. Diluted petroleum asphalt (DPA), used for priming soil in the construction of flexible pavement, requires adequate viscosity, volatility, and penetration, and the distillate fractions from WAF pyrolysis oil can be used as partial or full substitutes for the standard solvent (kerosene) in DPA production. The aim of this study was to test the compliance of DPAs prepared by substituting kerosene with bio-oil fractions from WAF according to DPA standards. First, WAF is obtained from meat waste through the rendering process. Then, WAF is subjected to pyrolysis in a semi-batch fixed-bed reactor (2L), and the resulting bio-oil is fractionally distilled into gasoline, kerosene, and diesel fractions. The pyrolysis process is analyzed concerning the type of reactor used, with a focus on the influence of temperature and reaction time, as well as the distillation profile. The distilled fractions are characterized by density, viscosity, and acid value before being used in the preparation of DPAs by partial and/or total (0-40% by weight) substitution of standard kerosene. The mixtures were tested for kinematic and Saybolt-Furol viscosity, flash point, and penetration, according to road pavement standards. The results showed that the kerosene and diesel fractions from WAF can be adequately used in the preparation of DPAs as a total substitute for the petroleum kerosene typically used.
Acesso aberto (Open Access)
Aproveitamento de resíduos da indústria de óleos vegetais produzidos na Amazônia
(Universidade Federal do Pará, 2014-12-17) SANTOS, Marcio José Teixeira dos; CARVALHO JUNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; SILVA, Luiza Helena Meller da; http://lattes.cnpq.br/2311121099883170
The objective of this study was the use of açaí waste, cupuassu and Brazil nut resulting from mechanical pressing of oil. In this context, the physico-chemical analysis of pies were made, and were subsequently applied oil extraction methods. Extraction methods were used: bligh dyer, sohxlet and supercritical fluid. We evaluated the efficiency of the extraction, the fatty acid profile, physico-chemical properties and the oxidative stability of oils obtained. Evaluating the results obtained, it could be said that the pies are an important source of nutrients, especially lipids, protein and fiber. The profile of fatty acids obtained Brazil nut pie, cupuassu pie and blend Brazil nut - cupuassu had higher unsaturated fatty acids, however, these tests showed the lowest time of oxidative stability. The extraction of oil from cupuaçu pie, applying supercritical fluid extraction and bligh dyer, obtained a ratio (ω-3 / ω-6) more significant when compared to the other raw materials and for the three extraction methods. Oil samples showed elevated levels of acidity, up establishing the RDC n ° 270. Regarding the peroxide values, with the exception of oil açaí pie, cupuassu - açaí blend and blend Brazil nut - açaí, all other samples showed peroxide values below that establishes the resolution. The oils obtained from mixtures had higher oxidative stability than the pure oil extracted from the pie, as well as profiles of more balanced fatty acids. The oils obtained from mixtures had higher oxidative stability than the pure oil extracted from the pie, as well as profiles of more balanced fatty acids.
Acesso aberto (Open Access)
Caracterização de óleos e gorduras vegetais amazônicas: utilização de modelo para predizer viscosidade
(Universidade Federal do Pará, 2022-06-03) FREITAS, Joice Silva de; SILVA, Luiza Helena Meller da; http://lattes.cnpq.br/2311121099883170; https://orcid.org/0000-0002-6002-9425
The Amazon rainforest is rich in oilseed plant species, which have fruits that are attractive due to their economic potential and biological properties. Oils from oleaginous matrices have a unique composition with physicochemical and nutraceutical properties that attract attention as a source of fatty acids. The predictive model is based on the use of mathematical equations that are more comprehensive and less limited than simple linear or polynomial models, and are able to predict a certain property using one or more physicochemical parameters. Thus, this work aimed to use a predictive model to calculate the viscosity of Amazonian oils (açaí, bacaba, tucumã) and fats (cupuaçu, bacuri and tucumã). The samples were physicochemically characterized in terms of acidity index, density, oxidative stability, peroxide, melting point, iodine index, saponification index, fatty acid composition, triacylglycerol composition, solid fat content, atherogenicity index and heterogeneity. Two predictive models were used to obtain the viscosity values of oils and fats, the model using the profile of the mass fraction of polyunsaturated and monounsaturated fatty acids and the model using the iodine and saponification index.The results showed that the oils (patauá, pracaxi, bacaba, açaí, tucumã) had high levels of unsaturated fatty acids, especially oleic acid, which has good thermal stability, while the fats (cupuaçu, bacuri and tucumã) are composed of mainly by saturated fatty acids. The oxidative stability showed that at a temperature of 110 °C, pracaxi oil and cupuaçu fat presented the highest values, while bacaba oil presented a lower value, this low stability value indicates that this sample is more conducive to oxidation. Pracaxi oil showed the highest value for the ratio between hypocholesterolemic and hypercholesterolemic fatty acids (HH), indicating that it is more nutritionally adequate. The studies to predict the regularity of Amazonian oils and fats proposed in this work may contribute to simplifying the evaluation of the physicochemical properties of important regional oleaginous raw materials on which there are no studies, but with growing industrial interest in different areas, in addition of the food area.
Acesso aberto (Open Access)
Estudo cinético e das isotermas de adsorção dos óleos de palma (Elaes guineensis, Jacq.) e andiroba (Carapa guianensis, Aubl.) em y-alumina e modelagem da dessorção com dióxido de carbono supercrítico
(Universidade Federal do Pará, 2013-11-08) AMARAL, Anderson Rocha; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065
In this work, the variables of the batch adsorption process of palm (Elaeis guineensis, Jacq.) and andiroba (Carapa guianensis, Aubl.) vegetables oils on thermally activated alumina at 723,15 K and 923,15 K (y-alumina) has been investigated by analyzing the influence of temperature, time, mass of vegetable oil, mass of adsorbent on the adsorbent capacity. A kinetic model of second-order was proposed to modeling the adsorption capacity of free fatty acids (FFA). Capacity results of FFA of the crude palm oil on y-alumina AG.450 at 328.15 K and of the crude andiroba oil on y-alumina AG.650 at 323.15 K were obtained from the consecutive adsorption experiments and adjusted by isotherms of Langmuir e BET. The transfer mass model of TAN & LIOU (1989) was used to modeling the kinetic desorption of the palm oil from y-alumina AG.650 and of the andiroba oil on y-alumina AG.450 with supercritical carbon dioxide, evaluating the yields, errors, correlation coefficients and the residues of the desorbed oil mass versus predicted by the model.The study of the variables influence, over the adsorption capacity, presented negative correlation (with exponential behavior) to the variable mass of oil. The adsorbent mass influence, presented a positive correlation (with a linear behavior) and the temperature increase is favorable to the adsorption process. The total reduction of the FFA after three consecutive adsorptions of the crude palm oil on y-alumina AG.450 and after four consecutive adsorptions on -alumina AG.650 with andiroba oil, were 21.07 % and 40.29 %, respectively. The modeling of the FFA capacity to the palm oil with Langmuir model, presented a high experimental data prediction ability (R² = 0.9610), as well as to the andiroba oil with the BET model, which presented a high adjustment (R² = 0.9140). Tan & Liou model evidenced high prediction capacity of the desorption oil mass from γ-alumina for all experiments, minimum correlation coefficient of 0.9230 and magnitude residues of 10-1 grams. The yields, based on adsorbate initial mass, of the palm oil desorbed from y-alumina AG.650 at 20 MPa up to 30 MPa and 323.15 K up to 328.15 K were 28.880 % up to 34.563 %, while to the andiroba oil on y-alumina AG.450 at 15 MPa up to 25 MPa at 323.15 K were 14.108 % up to 27.972 %. The yields results shows that the increase of pressure and temperature are favorable to the supercritical desorption.
Acesso aberto (Open Access)
Extratos de sementes de gergelim preto (Sesamum indicum L) obtidos via CO2 supercrítico: isotermas de rendimento global, dados cinéticos e ajustes, ácidos graxos totais, fitosteróis e efeitos neuroprotetores
(Universidade Federal do Pará, 2013-12-17) BOTELHO, José Rafael Santos; ARAUJO, Marilena Emmi; http://lattes.cnpq.br/8983914018546682; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748
In Brazilian folk medicine, black sesame (Sesamum indicum L) seeds is one of the most important ingredients present in the tea used to treat encephalic stroke victims. Nevertheless, isolation of black sesame extracts to medicinal finality using supercritical fluid technology has not been performed. The objective of this work was to investigate some process variables of supercritical fluid extraction in black sesame to generate extracts applicable in stroke research. Two isothermal (40 and 60 °C) were explored, combined with pressures that ranged from 200-400 bar, at a constant CO2 mass flow rate of 5,9 x 10-5 kg/s. The global yields ranged from 37-53% in dry basis. The highest mass yield was obtained at 60 °C and 400 bar. The fatty acid composition comprised a high unsaturated/saturated ratio. Chromatographic analysis of phytosterol content in the high global yield extract revealed higher amounts of β-sitosterol + sitostanol, cholesterol, campesterol + campestanol + 24-methylene cholesterol, Δ-5 avenasterol and stigmasterol, while lower levels of Δ-5,24 stigmastadienol, brassicasterol, clerosterol + Δ-5-23 stigmastadienol, Δ-7 avenasterol, eritrodiol and Δ-7 stigmastenol were present in the black sesame extract. Overall extraction curves from the supercritical fluid extraction in lower and higher global yields (200 e 400 bar at 60 °C) fitted the Tan and Liou (1989), Martinez et al. (2003), Esquível et al. (1999), Goto et al. (1993) e Sovová models (1994 and 2012). The models of Tan and Liou (1989), Goto et al. (1993) and Sovová (1994 and 2012) presented the best residual sum of squares values. Pilot experiments suggest that black sesame extract is neuroprotective following endothelin-1 induced focal ischemia into the motor cortex of male adult rat, observing indications that a prejudicial cell form for the stroke`s status was inhibited by the treatment.
Acesso aberto (Open Access)
Obtenção de gordura das sementes de Ucuúba (Virola surinamensis) por meio de extração com CO2 em estado supercrítico: rendimento global, dados cinéticos, ácidos graxos totais e atividade antimicrobiana
(Universidade Federal do Pará, 2015-09-28) CORDEIRO, Renato Macedo; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748
The Virola surinamensis, popularly known as ucuúba, is a typical tree found in floodplain habitats and along rivers in the Amazon region. The fat extracted from the seeds has a high melting point and is a product appreciated by the cosmetic industry. The objective of this work was to study the extraction of ucuúba seed fat using supercritical fluid and compare, in terms of process yield and composition of the extracts, with those obtained from the organic solvent extraction technique (via soxhlet). The extraction technique Supercritical Fluid Extraction (SFE) was used because it is regarded as a clean technology, economically attractive, and environmentally safe, avoiding the consumption of large amounts of organic solvents, which are often expensive and potentially harmful. The supercritical extracts of ucuúba seeds were obtained at temperatures of 40, 60 and 80 °C, combined with a pressure of 350 bar, the solvent density varied between 789.2 and 935.6 kg / m3, and a flow of 2.7 L / min. The highest yield obtained using supercritical CO2 was 64.39% for the extraction condition of 350 bar and 80 °C. The yield for the extraction via soxhlet was 61.38%. The mass transfer models of Goto et al. (1993), Esquivel et al. (1999), Tan and Lio (1989), Barton (1991) and Martinez et al. (2003) were employed to describe the extraction kinetics using supercritical fluid. The models that best described the extraction kinetics, with low average deviations, were the models of Martinez et al. (2003) and Goto et al. (1991). The fatty acid profile analysis showed that the ucuúba fat is composed predominantly of saturated fatty acids, mainly of myristic and lauric acids. The antimicrobial activity of the fats obtained was tested on the following organisms: Candida albicans, Staphylococcus aureus and Escherichia coli. Only the bacterium Staphylococcus aureus showed zone of inhibition, ranging from 10 to 11 mm.
Acesso aberto (Open Access)
Obtenção, avaliação e aplicabilidade de filmes biodegradáveis de proteínas de pescada amarela (cinoscyon acoupa), amido de mandioca (manihot esculenta c.) e ácidos graxos em frutos pós- colheita
(Universidade Federal do Pará, 2020-12-07) LAGO, Gleice Vasconcelos Pereira do; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; JOELE, Maria Regina Sarkis Peixoto; http://lattes.cnpq.br/2618640380469195
The general objective of this thesis is “Obtaining, evaluating and applicability of biodegradable films of yellow hake (Cinoscyon acoupa), cassava starch (Manihot esculenta C.) and fatty acids in post-harvest fruits” and presents three interconnected articles. The first one entitled “Influence of the addition of glycerol and fatty acids on the rheological and technological properties of films composed of Cynoscion acoupa”, and deals with the study carried out with films of lyophilized myofibrillar proteins (PML) and fatty acids (stearic (PE), palmitic (PP) and caproic (PC)). The addition of PE and PP acids and glycerol significantly increased the viscosity of film-forming solutions (SF). The films named PE (1% PML (w/v) and 0.5% stearic acid (w/w)) and PP (1% PML (w/v) and 0.5% palmitic acid (w/w)) showed better water vapor permeability (PVA) and solubility properties, with more ordered structures (crystalline) and better thermal resistance when compared to the other films. The second article “Rheological and technological properties of composite films obtained with myofibrillar proteins from yellow hake (Cynoscion acoupa) and cassava starch (Manihot esculenta C.)”, evaluated the influence of different concentrations of proteins and starch on the rheological properties of SF and film technologies. Starch had a significant influence on SF. The analyzes indicated that the interaction between these biopolymers is positive for the production of packaging for different types of food, and the composite film F4 (1% PML (w/v), 2% starch (w/v) and 30% glycerol (w/w)) showed better PVA, solubility, mechanics and thermal resistance. The third “Evaluation of the biodegradation of films composed of proteins from yellow hake(Cynoscion acoupa), palmitic acid and starch (Manihot esculenta C.) and its application as a coating on post-harvest fruits”, evaluated the biodegradation of the films in soil and the behavior of papaya fruits coated with F1 film (commercial film - PVC polyvinyl chloride), and coatings F2 (1% PML (w/v) and 0.5% palmitic acid (w/w)) and F3 (1% PML (w/v), 2% starch (w/v) and 30% glycerol (w/w)), using the uncoated fruit as a control. Biodegradation indicated that the F2 and F3 films were considered biodegradable and as expected the F1 did not degrade, however, the F2 was considered the most suitable to be applied as a coating when compared to the others, as it increased its shelf life by 6 days of the fruits. ..