EQA - Artigos Publicados em Periódicos
URI permanente para esta coleçãohttps://rihomolog.furg.br/handle/1/1611
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- ItemDevelopment and Characterization of Nanovesicles Containing Phenolic Compounds of Microalgae Spirulina Strain LEB-18 and Chlorella pyrenoidosa(2014) Assis, Letícia Marques de; Machado, Adriana Rodrigues; Motta, Amanda de Souza da; Costa, Jorge Alberto Vieira; Soares, Leonor Almeida de SouzaThe objective of this study was to elaborate liposomes, through the lipid film hydration methodology, to nanoen-capsulate phenolic compounds of Spirulina LEB-18 and Chlorella pyrenoidosa microalgae, and evaluate their physicochemical characteristics and storage stability for 21 days. The total phenolic compounds were evaluated using a calibration curve of gallic acid using methanol and ethanol as extraction solvents. The size and polydis-persity index of nanovesicles were determined by light scattering and the percentage encapsulation efficiency was determined by a centrifugation process. The stability of the liposomes at storage time was measured by zeta potential for 21 days. The methanol extracts from Spirulina had a higher content of phenolic compounds (2.62 mg gallic acid∙g−1 of microalgae) compared to the extracts of Chlorella. However, liposomes with ethanolic ex-tracts of the two algae showed higher encapsulation efficiency. The value was higher (96.40%) for Chlorella. All samples obtained nanometric size, with the highest value obtained for the liposome containing ethanol extract of Chlorella (239 nm) differing significantly (p ≤ 0.05) from the others. The liposomes containing extracts of Spiru-lina were more stable during the 21 days of storage, whereas, those consisting of ethanol extract showed no sig-nificant difference (p ≤ 0.05) throughout this period.
- ItemConteúdo lipídico e composição de ácidos graxos de microalgas expostas aos gases CO2, SO2 e NO(2008) Radmann, Elisangela Martha; Costa, Jorge Alberto VieiraThe objective of the present work was to verify the lipid content and the fatty acid composition of the microalgae Spirulina sp., Scenedesmus obliquus, Synechococcus nidulans and Chlorella vulgaris cultivated in a medium containing CO2, SO2 and NO. The microalga Scenedesmus obliquus presented the highest lipid content (6.18%). For the other microalgae the lipid content ranged from 4.56 to 5.97%. The major monounsaturated fatty acids content was 66.01% for S. obliquus. The PUFA were obtained in major amount by the microalgae Spirulina sp. (29.37%) and S. nidulans (29.54%). The palmitoleic acid was in larger amount, with 41.02% concentration (Spirulina sp.)
- ItemThe role of biochemical engineering in the production of biofuels from microalgae(2011) Costa, Jorge Alberto Vieira; Morais, Michele Greque deEnvironmental changes that have occurred due to the use of fossil fuels have driven the search for alternative sources that have a lower environmental impact. First-generation biofuels were derived from crops such as sugar cane, corn and soybean, which contribute to water scarcity and deforestation. Second-generation biofuels originated from lignocellulose agriculture and forest residues, however these needed large areas of land that could be used for food production. Based on technology projections, the third generation of biofuels will be derived from microalgae. Microalgae are considered to be an alternative energy source without the drawbacks of the first- and second-generation biofuels. Depending upon the growing conditions, microalgae can produce biocompounds that are easily converted into biofuels. The biofuels from microalgae are an alternative that can keep the development of human activity in harmony with the environment. This study aimed to present the main biofuels that can be derived from microalgae.
- ItemVertical tubular photobioreactor for semicontinuous culture of Cyanobium sp(2011) Henrard, Adriano Seizi Arruda; Morais, Michele Greque de; Costa, Jorge Alberto VieiraWe evaluated the kinetic culture characteristics of the microalgae Cyanobium sp. grown in vertical tubular photobioreactor in semicontinuous mode. Cultivation was carried out in vertical tubular photobioreactor for 2 L, in 57 d, at 30 °C, 3200 Lux, and 12 h light/dark photoperiod. The maximum specific growth rate was found as 0.127 d−1, when the culture had blend concentration of 1.0 g L−1, renewal rate of 50%, and sodium bicarbonate concentration of 1.0 g L−1. The maximum values of productivity (0.071 g L−1 d−1) and number of cycles (10) were observed in blend concentration of 1.0 g L−1, renewal rate of 30%, and bicarbonate concentration of 1.0 g L−1. The results showed the potential of semicontinuous cultivation of Cyanobium sp. in closed tubular bioreactor, combining factors such as blend concentration, renewal rate, and sodium bicarbonate concentration
- ItemCompostos fenólicos totais, atividade antioxidante e antifúngica demultimisturas enriquecidas com a microalga Spirulina platensis(2009) Bierhals, Vânia da Silva; Machado, Vanessa Goulart; Echevenguá, Walesca Oliveira; Costa, Jorge Alberto Vieira; Furlong, Eliana BadialeCom o objetivo de avaliar o conteúdo fenólico e as atividades antioxidantes e antifúngicas de multimisturas enriquecidas com Spirulina platensis, foram formuladas quatro multimisturas com farelo de arroz ou trigo, duas contendo Spirulina platensis e duas com sementes de girassol. Os compostos fenólicos foram estimados pela técnica de Folin-Ciocalteau. A atividade antioxidante foi avaliada por meio de inibição do radical livre DPPH e a atividade antifúngica foi analisada por meio de ensaio de inibição do halo de crescimento de Aspergillus orizae. O conteúdo de compostos fenólicos totais e a atividade antioxidante nas multimisturas contendo farelo de arroz foram em média 0,6 vezes superiores aos encontrados nas multimisturas contendo farelo de trigo. As multimisturas formuladas com 1% da microalga não apresentaram diferença signifi cativa (α=0,05) quanto ao conteúdo fenólico, quando comparadas às multimisturas padrão. A multimistura contendo farelo de arroz e Spirulina platensis apresentou maior atividade antioxidante, em comparação à multimistura padrão com o mesmo farelo, ao contrário do observado nas multimisturas contendo farelo de trigo, o que indica que a associação do farelo de arroz com a microalga é mais efi ciente do que a formulação com farelo de trigo quanto à proteção contra processos oxidantes. Quanto à atividade antifúngica, as multimisturas com farelo de trigo apresentaram 28% de inibição, comparado a 21% das multimisturas contendo farelo de arroz.
- ItemBiscoitos de chocolate enriquecidos com spirulina platensis: características físicoquímicas,sensoriais e digestibilidade(2006) Morais, Michele Greque de; Miranda, Martha Zavariz de; Costa, Jorge Alberto VieiraAs microalgas, como Spirulina, podem ser fonte de proteínas para alimentação humana, com a possibilidade de obter outros produtos como biopigmentos,vitaminas e lipídios. A biomassa obtida pode ser introduzida diretamente na dieta podendo auxiliar em casos de desnutrição. O objetivo deste trabalho foi avaliar as características físico-química, sensorial e digestibilidade de biscoitos de chocolate enriquecidos com a microalga Spirulina platensis. Foram elaborados quatro biscoitos de chocolate: controle (sem Spirulina) e biscoitos contendo 1,0;3,0 e 5,0% de Spirulina platensis. O biscoito com adição de 5,0% de Spirulina platensis apresentou o conteúdo protéico 7,7% maior que o controle. Os biscoitos com adição de 1,0% de S. platensis apresentaram maior digestibilidade (86,9%)que os demais. Volume específico, espessura e fator de expansão não foram alterados pela adição de Spirulina. Não houve diferença significativa entre o biscoito controle e os biscoitos com adição de 5,0% nos atributos cor, crocância, mastigabilidade e maciez. Na avaliação questionamento de intenção de compra, comparando os biscoitos com adição de S. platensis, a amostra com maior aceitação pelos julgadores foi com 1,0% de S. platensis.
- ItemConteúdo lipídico e composição de ácidos graxos de microalgas expostas aos gases CO2, SO 2 e NO(2008) Radmann, Elisangela Martha; Costa, Jorge Alberto VieiraThe objective of the present work was to verify the lipid content and the fatty acid composition of the microalgae Spirulina sp., Scenedesmus obliquus, Synechococcus nidulans and Chlorella vulgaris cultivated in a medium containing CO2, SO2 and NO. The microalga Scenedesmus obliquus presented the highest lipid content (6.18%). For the other microalgae the lipid content ranged from 4.56 to 5.97%. The major monounsaturated fatty acids content was 66.01% for S. obliquus. The PUFA were obtained in major amount by the microalgae Spirulina sp. (29.37%) and S. nidulans (29.54%). The palmitoleic acid was in larger amount, with 41.02% concentration (Spirulina sp.)
- ItemBioprocessos para remoção de dióxido de carbono e óxido de nitrogênio por microalgas(2008) Morais, Michele Greque de; Costa, Jorge Alberto VieiraThe aim of this work was to study the removal of CO2 and NO by microalgae and to evaluate the kinetic characteristics of the cultures. Spirulina sp. showed μmax and Xmax (0.11 d-1, 1.11 g L-1 d-1) when treated with CO2 and NaNO3. The maximum CO2 removal was 22.97% for S. obliquus treated with KNO3 and atmospheric CO2. The S. obliquus showed maximum NO removal (21.30%) when treated with NO and CO2. Coupling the cultivation of these microalgae with the removal of CO2 and NO has the potential not only to reduce the costs of culture media but also to offset carbon and nitrogen emissions.