Navegando por Orientadores "BRASIL, Davi do Socorro Barros"

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Acesso aberto (Open Access)
Aproveitamento de resíduos sólidos da mandiocaba (Manihot esculenta Crantz) para o desenvolvimento de bioadsorventes
(Universidade Federal do Pará, 2023-07-10) DIAS, Rafael Silva; MARTELLI, Marlice Cruz; http://lattes.cnpq.br/1213009262936026; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306
The chemical contamination of water by dyes resulting from the disposal of industrial effluents triggered the need to develop technologies to remove such pollutants. Occurring naturally in the Amazon region, cassava differs from other cassava varieties in that it has high humidity and low starch yield. As part of a project on cassava technologies, this study analyzed the best conditions for the production of activated carbon from cassava solid waste for the adsorption of methylene blue dye. The Box-Behnken experimental design was used to determine the optimal production conditions. First, a physical-chemical analysis of the precursors was carried out, then 30 coal samples were produced according to the experimental plan. The maximum adsorbed amount and percentage of removal were determined under finite bath conditions, at a concentration of 120 mg/L and with 0.01 g of coal sample. The best conditions of temperature, acid concentration and heat contact time were observed at 600 ºC, 25 % and 3 h for peel and 600 ºC, 10.2 % and 3 h for pulp. These samples were subjected to physical-chemical and morphological characterization analyzes using scanning electron microscopy and Fourier transform infrared. For the adsorption kinetics tests, the models that best fitted the experimental data were intraparticle diffusion for shell and pulp coals, and for the adsorption equilibrium tests, the Freundlich and Langmuir models best fitted the experimental data for shell and pulp, respectively. Analysis of the adsorbents reveals a lower concentration of functional groups, however, in the pulp adsorbent, the loss of functional groups related to groups containing oxygen can be observed, which may help explain the lower adsorption capacity observed for pulp adsorbents. The activated carbons produced from the solid residues of cassava roots (pulp and peel) showed that, under the conditions used in this work, they can be applied as effective bioadsorbents in the removal of methylene blue in aqueous solution.
Acesso aberto (Open Access)
Estudo de métodos de extração, quantificação dos polifenóis totais, avaliação das atividades antioxidantes e antimicrobianas da casca do caule de Croton palanostigma Klotzsch
(Universidade Federal do Pará, 2017-02-22) RODRIGUES, Cintya Cordovil; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306; FARIA, Lênio José Guerreiro de; http://lattes.cnpq.br/7428609361678173; https://orcid.org/0000-0002-9534-9998
The Croton palanostigma is popularly known as "dragon blood" and used in folk medicine for the treatment of inflammatory diseases and wound healing. This paper proposes a study between the methodologies of conventional mining and extraction in supercritical carbon dioxide of stem bark of C. palanostigma, aiming to evaluate the extracts obtained income, the amount of total polyphenols, activities, antioxidant and anti-microbial. For the extraction process was conventional used jacketed extractor glass, in addition to a factorial design experiment of three factors and three levels of type Box-Behnken, with the objective of determining which variables (temperature, the extraction time and the relationship between mass/solvent) could influence the process, extraction for quantification of total polyphenols was used the method of Folin-Ciocalteau, with some changes and using the chart acid as a standard of reference, to analyze the antioxidant activity, we used the method of IC50, which measures the concentration needed to reach 50%of decrease in absorbance of DPPH radical and to the analysis antibiological was used the method of microdilution, whose goal was the determination of the minimum inhibitory concentration (CIM) Of all the tests ahead of the bacterial and fungal studied. The extraction methods used were efficient to obtain the extracts, with some qualitative differences, such as for example: color, viscosity and flavor. Quantitatively, the technique of conventional extraction presented a higher yield in their tests, however the same demanded much more time to process and greater amount of material used, both as botanist of solvent, in addition to all the variables assessed in this study were considered significant for the process, while the extraction supercritical the time used was significantly lower, as well as a lesser amount of botanical material and the co-solvent used (ethyl alcohol). For the quantification of total polyphenols found that the conventional extraction test 9 (T=45ºC; t=30 min; g/mL=1:2) was less efficient than those obtained by extracting supercritical (Test 1; T=40ºC; P=100 bar and Test 3; T=60ºC; P=300 bar) and having significant variables for the analysis time and relationship between mass and solvent. For antioxidant activity the best result was to extract conventional (IC50=30.71%) in relation to the test 3 (T=60ºC; P=300 bar) to extract supercritical (IC50=52.36) and having the variables, time and temperature its favorable conditions for the process. To analyze microbial all extracts obtained with the conventional extraction showed, in at least one of their concentrations, inhibitory activity against at least one of the pathogenic strains used in the test. For the samples obtained from the extraction in supercritical carbon dioxide to test 2 (T:60 ºC; P:200bar) showed no inhibitory activity against any bacterial strain used in the test, strain, bacterial Enterobacter did not suffer disqualification for none of the samples of supercritical carbon dioxide at a temperature of 60°C and E. coli also did not inhibit forward samples of extraction supercritical except test 1(T=40ºC; P=100 bar).
Acesso aberto (Open Access)
Estudo de quantificação de compostos fenólicos, avaliação de atividades antioxidantes e modelagem molecular da croton pullei var. Glabrior lanj
(Universidade Federal do Pará, 2021-04-16) SOUZA, Alexandre Augusto Moraes de; COSTA, Renato Araújo da; http://lattes.cnpq.br/6578338979054891; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219
The study aimed to evaluate, from extracts, the yield (on a dry basis), quantify the total polyphenols, evaluate the antioxidant activity, perform a theoretical NMR research of the julocrotine, crotonimide A and crotonimide B structures, from Croton pullei VAR. glabrior LANJ. and evaluate these molecules in molecular docking against the enzymes Candida albicans (PDB ID: 1AI9), Staphylococcus aureus (PDB ID: 1DIM) and Salmonella thyphimurium (PDB ID: 4URM). A conventional extraction was performed using a stainless-steel extractor and three-factor planning (temperature, particle size and solid/liquid ratio) and three Box-Behnken levels, to determine which variables were influential in the responses. The quantification of total polyphenols was performed according to the Folin-Ciocalteu methodology. For the antioxidant analysis, the IC50 method was applied. And the theoretical NMR study was carried out via DFT, where the computational methods DFT/B3LYP/cc-pvDZ and DFT/B3LYP/6-31 G* were applied to obtain the chemical displacements (δH and δC), to compare to the experimental ones and thus provide which computational method is the most efficient. Yields vary between 5.57 and 10.61. In the quantification of total polyphenols, there was a variation between 101.33 and 308.84 mg EAG/g. The minimum and maximum antioxidant values were 94.74% and 98.97%. In general, the DFT/B3LYP/cc-pvDZ methodology was more efficient compared to the analyzed structures. The molecules showed hydrogen bonds with residues Lys 57 (A), Arg 56 (A), Cys37, Gly38, Asp62, Gly193, Tyr342, Gly56, Arg37, Tyr128, Arg56, Thr58 (A), Gly114 (A) and Thr 127.
Acesso aberto (Open Access)
Produção de batons a partir das oleaginosas amazônicas: açaí, andiroba, castanha-do-brasil, copaíba e tucumã
(Universidade Federal do Pará, 2023-02-28) OLIVEIRA, Jenniffer Rayane Alves de; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306
Several researches are being carried out for the elaboration of cosmetic products using Amazonian raw materials, due to their innumerable properties. Açaí oil (Euterpe Oleracea) extracted from the pulp of its fruits has a high content of antioxidant compounds. From the seeds of the andiroba tree (Carapa guianensis Aubl.) an oil with medicinal properties was extracted. The oil extracted from the almonds of the Brazil nut (Bertholletia excelsa) contains a high content of lipids, vitamins and minerals. From the tucumã almonds (Astrocaryum aculeatum) a butter is extracted, which has great potential for cosmetic and pharmaceutical use. Copaiba essential oil, extracted from the resin of the species (Copaifera Officinalis) has an exotic aroma and therapeutic properties. Thus, the objective of this study is the manufacture of lipsticks based on Amazonian ingredients mentioned above, in addition to other constituents present in their formulation. The oilseeds underwent physical-chemical analysis, proving their good quality for cosmetic application. The GC-MS result of the same identified their main fatty acids, signaling what would be the main applicability for each of the species. Tests of antioxidant activity by scavenging the ABTS free radical and of toxicity and in vitro cell recovery of oilseeds helped to measure their antioxidant and anti-inflammatory properties. The lipsticks produced from oilseeds underwent quality control tests, presenting compliant results for microbiology, spreadability, pH, colorimetry and melting point. Proving not only the feasibility of producing the cosmetic, but also its properties.
Acesso aberto (Open Access)
Recobrimento de pimenta-do-reino (piper nigrum l.), em leito de jorro, com suspensão polimérica de amido de mandioca, plasticizada com etanol
(Universidade Federal do Pará, 2024-12-13) QUEIROZ, Nian Iury Ferrão; REGO, José de Arimatéia Rodrigues do; http://lattes.cnpq.br/4163468898377462; HTTPS://ORCID.ORG/0000-0003-0891-6438; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306
This study aimed to evaluate the black pepper coating technique using a fluidized bed, focusing on its applicability in the food industry. The research explored the optimization of operational parameters, such as suspension flow rate, temperature, and blower flow rate, using the response surface methodology within a Box-Behnken design. The goal was to improve the efficiency of the coating process, ensuring uniform distribution of the coating over the black pepper grains. This study investigated the fluid dynamic and physicochemical behavior of black pepper seeds coated with a cassava starch-based biofilm, applying the spouted bed process. The seeds were classified in group D of the Geldart classification, indicating good fluidization potential and excellent flowability, facilitating the coating process. The sphericity of the seeds (0,98) and their density (1,45 g/cm³) directly influenced their behavior in the bed, allowing minimal fluidization at a velocity of 38,32 cm/s and a pressure drop of 7,13 cmH2O. The molecular interaction between the starch and ethanol generated biofilms with flexibility and mechanical strength. However, ethanol's volatility requires control during the drying process to maintain the biofilm's quality. The spouted bed process proved efficient for coating application, and the desirability function analysis indicated that the established criteria were satisfactorily met. The results confirm the technical feasibility of applying biopolymer coatings to black pepper seeds, contributing to the development of biodegradable alternatives aligned with environmental demands
Acesso aberto (Open Access)
Uso do óleo de açaí (Euterpe oleracea) e amido de mandioca (Manihot esculenta) na obtenção de produtos bioativos
(Universidade Federal do Pará, 2023-10-30) OLIVEIRA, Sara Caroline Pacheco de; LAGO, Gleice Vasconcelos Pereira do; http://lattes.cnpq.br/7932392876332323; HTTPS://ORCID.ORG/0000-0002-9702-250X; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306
Cassava is found in abundance in nature, especially in the State of Pará, from them it is possible to extract starch, rich in amylose and amylopectin, components that help in the production of bioplastics. Furthermore, Pará is the largest producer of açaí, a raw material that is also natural and has antioxidant, phenolic and healing compounds. The oil extracted from açaí has the same characteristics found in the pulp, which makes it an excellent agent for incorporation into products added on polymers. The present study reports the characterization of cassava starch and evaluation of the biological characteristics of açaí oil, for the production of an active bioplastic, with the aim of incorporating the benefits found in the oil. To this end, some tests were carried out using plasticizers such as glycerol, ethylene glycol and sorbitol in the composition, to structure the bioplastic, where glycerol proved to be the most viable option. Cassava starch was dried at three temperatures: 45, 60 and 75°C, for the drying curve, and it wasobserved that starch dried at 45°C had better performance, without significant losses in its structure. The analyzes carried out were relevant to detect the potential of açaí oil on incorporating bioplastic. It is known that the characterization of the oil is essential to ensure its quality. Açaí oil was evaluated for 1H NMR, which was essential for quantifying iodine (67.05 I2/g) and saponification (109.06 mg KOH/g) levels. Furthermore, the oil also presented satisfactory results, with emphasis on the following activities: antioxidant (532.56 µM of Trolox/g), anticancer (with reduced metabolic activity and cell viability for the AGP01, SK19 and VERO lines, with IC50 75 .30; 80.15; 73.05 µg/ml, respectively), in addition to the promising result in anti-inflammatory activity that tested target gene TNF-α (tumor necrosis factor alpha) and detected that the samples analyzed with the oil presented anti-inflammatory effect even after 24 hours of exposure, which confirms its bioactivity. This highlights the gigantic potential of using açaí oil for improvement and application in new products, as it has proven to be a strong ally against infectious and cancerous diseases, with cell recovery capacity. Therefore, the oil was incorporated into a polymeric matrix based on cassava starch, which resulted in bioplastic with a thickness (0.157 mm), PVA (19.39 g.mm.KPa-1.d-1.m- 2), transparency (2.60), and one of the highlights was the colorimetric analysis that was able to detect shades of green in the sample, represented by values of -5.75 (a*) and 10.90 (b*), identifying the presence of chlorophyll from açaí oil. In this way, it was possible to note the relevance of using this oil for inclusion in products that bring benefits to the end consumer, in order to take advantage of the chemical and biological properties that this oil has in its composition, as is the case of bioplastic, which contributes to the pharmaceutical sector for presenting bioactivity, in addition to its possible use in the packaging sector and helping to reduce the use of plastics from petroleum, as it is a 100% biodegradable plastic.