Navegando por Autor "Araújo, Jaciara Silva de"

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Exploiting films based on pectin extracted from yellow mombin (Spondias mombin L.) peel for active food packaging
(Springer Nature, 2021-01-30) Santos, Everaldo Silvino dos; Oliveira Júnior, Sérgio Dantas de; Araújo, Jaciara Silva de; Asevedo, Estefani Alves de; Medeiros, Fábio Gonçalves Macêdo de; Santos, Vinícius Silva dos; Sousa Júnior, Francisco Canindé de; Araújo, Nathália Kelly de
In this study, the potential of yellow mombin (Spondias mombin L.)–extracted pectin as a film-forming matrix for the elaboration of edible coatings was investigated. The films of chitosan, citric pectin, and carboxymethylcellulose (Sigma/USA) and natural pectin were prepared by casting. The film morphological characterization was performed by scanning electron microscopy (SME), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and atomic force microscopy (AFM). Additionally, total phenolic compounds (TPC), total antioxidant activity (TAC), DPPH scavenging capacity, and antimicrobial activity were assayed for the natural pectin–based films. The results showed that the film based on natural pectin presented a 46% degree of esterification that was higher than commercial (34%), showing its capacity of forming gels. The film formed by chitosan presented a very different behavior for loss of mass during TGA when compared to the other films, occurring a mass loss completely at 647.7 °C in 61 min. The value obtained from the concentration of total phenolics (mg GAE/100 g dried) found in the formulated film based on pectin was 3998.99 ± 42.64 and with solubility in water of almost 100%. Additionally, the scavenging of the DPPH radical with a value of 15.48 ± 1.48 μmol TE/g was found on the film based on natural pectin thus showing antioxidant capacity. Finally, this film showed less significant mechanical properties when compared to other films and a good pronounced antimicrobial effect against the gram-negative bacteria tested. Therefore, it could be potentially used for producing food-active packages
Produção de ramnolipídeos por Pseudomonas aeruginosa AP029-GLVIIA usando glicose como substrato e aplicações
(2018-02-26) Araújo, Jaciara Silva de; Santos, Everaldo Silvino dos; ; ; Almeida, Andrea Farias de; ; Barros Neto, Eduardo Lins de; ; Ferreira, Leandro de Santis;
Biossurfactantes são compostos anfifílicos de origem microbiana, os quais surgem como alternativa ao uso dos surfactantes químicos devido ao fato destes serem sintetizados a partir de derivados de petróleo, por conseguinte, bastante agressivos ao meio ambiente. Em contrapartida, os surfactantes biológicos além de possuírem propriedades semelhantes às dos surfactantes químicos, possuem também vantagens sobre eles: biodegradabilidade e estabilidade em condições drásticas de pH, temperatura e salinidade. Diante disso, vários estudos vêm se desenvolvendo a fim de tornar a produção dos biossurfactantes viável à sua comercialização. Grande parte das pesquisas tem como objetivo avaliar a produção desses compostos utilizando diferentes fontes renováveis e investigar suas propriedades surfactantes. Os ramnolipídeos, biossurfactantes produzidos por bactérias e pertencentes ao grupo dos glicolipídeos, são aplicados em diversas áreas industriais (petrolífera, agrícola, farmacêutica, etc.) devido às suas várias propriedades: emulsificante, solubilizante, molhante, dentre outras. Dessa forma, o presente trabalho tem como finalidade verificar a produção de ramnolipídeo por Pseudomonas aeruginosa AP029-GLVIIA, variando-se a concentração de substrato: glicose (10, 18 e 26 g/L) e a percentagem de inóculo (3, 10 e 17%) durante 72 horas de cultivo. Avaliou-se durante esse tempo o crescimento celular (X), a concentração de glicose consumida (S), o ramnolipídeo produzido (P), o pH do sistema e a produção de proteínas totais. Foram realizados cinco ensaios dos quais a melhor condição avaliada (26 g/L de glicose e 3% de inóculo) produziu 0,84 ± 0,06 g/L de ramnolipídeo em 24 horas, fator de conversão de biomassa em produto (YP/X) de 0,260 g/g, fator de conversão de substrato em produto (YP/S) de 0,034 g/g e produtividade em produto (PP) de 0,021 g/L∙h. Neste ensaio a biomassa alcançou o maior valor dentre todos os cultivos realizados (2,5 ± 0,041 g/L), o pH variou entre 5,8 e 8 e o consumo de substrato alcançou 82,45% ao fim do experimento. A partir do melhor resultado fez-se o estudo do índice de emulsificação e da atividade emulsificante avaliando seis solventes: querosene, hexadecano, tolueno, óleo de soja, de milho e de motor, dos quais o óleo de motor apresentou as melhores respostas: índice de emulsificação de 77,55% nas primeiras 24 horas e elevada estabilidade emulsificante, 2,23 U. Em seguida, a eficiência do biossurfactante na remoção de petróleo presente em areia foi avaliada em 16,8% e a atividade antimicrobiana do ramnolipídeo contra espécies fúngicas foi determinada, mostrando a sua capacidade em inibir fungos das espécies Candida tropicalis e Candida albicans. Deste modo, os resultados obtidos comprovam o potencial do ramnolipídeo produzido para aplicações biotecnológicas.
Rhamno lipids biosurfactants from pseudomonas aeruginosa - A Review
(Oriental Scientific Publishing Company, 2018-12) Santos, Everaldo Silvino dos; Araújo, Jaciara Silva de; Rocha, Juliene da Câmara; Oliveira Filho, Marcos Antonio; Matias, Stephanie Caroline Bivar; Oliveira Júnior, Sérgio Dantas de; Padilha, Carlos Eduardo de Araújo
Studies addressing for ecological compatible products have been increased along time, especially, on biosurfactant field. Biosurfactants are extracellular amphiphilic compound that are mainly produced by microorganisms and are classified into five main groups, including the glycolipids one. Rhamnolipids are included in the latter and are anionic biosurfactants produced predominantly by Pseudomonas aeruginosabeing classified as mono- and di-rhamnolipids. In addition, their production may occur from different carbon sources, which may be obtained from renewable and low-cost residue. Therefore, it is possible to reduce the rhamnolipids production cost, since this has been the main bottleneck for replacing the chemical surfactants. In addition, to meeting a bona fideindustrial application some limitations such as low productivity as well as recovery and/or purification that represent from 60 to 80% of total production cost should be improved. Therefore, this review covers different ways for producing rhamnolipids covering their application in many fields such as pharmaceutical, agricultural, petrochemical and so on; demonstrating the versatility of these biological compounds
Separation and concentration of bioactive phenolic compounds by solvent sublation using three-liquid-phase system
(Elsevier, 2020-03) Santos, Everaldo Silvino dos; Padilha, Carlos Eduardo de Araújo; Nogueira, Cleitiane da Costa; Hanna Nóbrega Almeida, Hanna Nóbrega; Medeiros, Waleska Rayane Dantas Bezerra de; Oliveira Filho, Marcos Antônio; Araújo, Jaciara Silva de
The present work investigated the SS performance with focus on the addition of second collecting phase to intensify the separation of vanillin and eugenol. First, experiments were performed with only n-octanol as the only collecting phase and the effects of solutes concentration and pH of the bottom phase were evaluated on the separation efficiency (E%). Then,the SS process was performed in a three-liquid-phase system formed by n-octanol/PEG 400/(NH4)2SO4 and the results were evaluated based on E%, distribution coefficient (D) and vanillin selectivity (RVAN/EUG) values. When compared to single component experiments, the presence of another solute had little effect on the E% values of vanillin and eugenol, regardless of the range of the initial concentration. Moreover, in SS with n-octanol/acetate buffer it was possible to reach the highest values of E% for vanillin (53.83%) and eugenol (85.37%) in experiments with pH equal to 4.5. On the other hand, the three-liquid-phase system achieved selectivity at least twice as high as two-liquid-phase systems and D values higher than 25 for vanillin in the PEG 400-rich phase. Thus, SS using three-liquid-phase system appears as an alternative to solve multicomponent separation problems involving bioactive compounds

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Navegando por Autor "Araújo, Jaciara Silva de"