EQA - Escola de Química e Alimentos
URI permanente desta comunidadehttps://rihomolog.furg.br/handle/1/1610
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27 resultados
Resultados da Pesquisa
- 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.
- ItemRevisão: microalgas: uma fonte alternativa na obtenção de ácidos gordos essenciais(2013) Ferreira, Shana Pires; Soares, Leonor Almeida de Souza; Costa, Jorge Alberto VieiraAs microalgas são micro-organismos fotossintetizantes de grande importância, uma vez que sintetizam biocompostos de alto valor agregado. Os ácidos gordos de microalgas podem ser produzidos tanto de forma autotrófica quanto heterotrófica e sua síntese ocorre no cloroplasto. O objetivo do presente trabalho é realizar uma breve revisão sobre os ácidos gordos poli-insaturados produzidos por microalgas, enfatizando a influência das condições de cultivo das microalgas, síntese e metabolismo para a produção de ácidos gordos. Esta revisão aborda alguns trabalhos desenvolvidos pelo grupo do LEB e, enfoca os seguintes itens: microalgas, conteúdo lipídico das microalgas, síntese e metabolismo de ácidos gordos, influência das condições de cultivo das microalgas na produção de lipídios e perfil de ácidos gordos.
- ItemKinetic studies on the biosorption of phenol by nanoparticles from Spirulina sp. LEB 18(2013) Dotto, Guilherme Luiz; Costa, Jorge Alberto Vieira; Pinto, Luiz Antonio de AlmeidaA kinetic study on the biosorption of phenol by nanoparticles from Spirulina sp. LEB 18 was carried out. The Spirulina sp. nanoparticles were prepared and characterized. Kinetic curves of phenol biosorption were obtained in batch system, being verified the effects of initial concentration (50, 150, 250 and 450 mg L 1) and stirring rate (50, 200 and 400 rpm). The models of pseudo-first order, pseudo-second order, Elovich, Bangham, general order and Weber–Morris were used for the kinetic interpretations. Spirulina sp. nanoparticles were stable, monodisperse, spherical with mean diameter of 230 nm. The phenol biosorption was a relatively fast process, being favored at higher values of initial concentration and stirring rate. Pseudo-second order and general order models showed satisfactory fit with the experimental data and the maximum biosorption capacity was around 101 mg g 1. From the Weber– Morris analysis, it was found that external mass transfer and intraparticle diffusion occurred during the phenol biosorption on Spirulina sp. nanoparticles. The externalmass transfer was faster at higher values of initial concentration and stirring rate, and the intraparticle diffusion was favored at high initial concentrations.
- ItemProdução de Biomassa de Spirulina sp. LEB 18 com Diferentes Difusores Para Injeção de CO2(2013) Cardias, Bruna Barcelos; Moraes, Luiza; Rosa, Gabriel Martins da; Santos, Lucielen Oliveira dos; Costa, Jorge Alberto VieiraCom a biofixação de CO2 por microalgas, além dos créditos de carbono, podem ser obtidos biomassa, biocombustíveis e outros bioprodutos de interesse comercial. O objetivo deste trabalho foi investigar a influência de diferentes configurações de difusores para a injeção do CO2 no crescimento da microalga Spirulina sp. LEB 18. Os cultivos foram realizados em fotobiorreatores tubulares verticais de 2 L, com fotoperíodo 12 h claro/escuro e 30°C. Na fase clara o ar foi enriquecido com 12% de CO2. A injeção do gás foi realizada com 4 difusores de configurações diferentes, denominados pedra sinterizada, madeira porosa, cortina porosa e anel perfurado.Com exceção da produtividade máxima, as demais respostas de crescimento avaliadas não apresentaram diferença significativa (p>0,05) entre as configurações de difusores empregadas. Assim, foi selecionada a cortina porosa como melhor configuração de difusor a ser empregado no cultivo de Spirulina, pois proporcionou superior produtividade máxima de biomassa (0,13 ± 0,0 g.L-1.d-1).
- ItemEstimating microalgae Synechococcus nidulans daily biomass concentration using neuro-fuzzy network(2013) Furlong, Vitor Badiale; Pereira Filho, Renato Dutra; Margarites, Ana Cláudia Freitas; Goularte, Pâmela Guder; Costa, Jorge Alberto VieiraIn this study, a neuro-fuzzy estimator was developed for the estimation of biomass concentration of the microalgae Synechococcus nidulans from initial batch concentrations, aiming to predict daily productivity. Nine replica experiments were performed. The growth was monitored daily through the culture medium optic density and kept constant up to the end of the exponential phase. The network training followed a full 3³ factorial design, in which the factors were the number of days in the entry vector (3,5 and 7 days), number of clusters (10, 30 and 50 clusters) and internal weight softening parameter (Sigma) (0.30, 0.45 and 0.60). These factors were confronted with the sum of the quadratic error in the validations. The validations had 24 (A) and 18 (B) days of culture growth. The validations demonstrated that in long-term experiments (Validation A) the use of a few clusters and high Sigma is necessary. However, in short-term experiments (Validation B), Sigma did not influence the result. The optimum point occurred within 3 days in the entry vector, 10 clusters and 0.60 Sigma and the mean determination coefficient was 0.95. The neuro-fuzzy estimator proved a credible alternative to predict the microalgae growth.
- ItemUtilisation Of Spirulinasp. And Chlorellapyrenoidosa Biomass For The Productionof Enzymatic Protein Hydrolysates(2014) Lisboa, Cristiane Reinaldo; Pereira, Aline; Ferreira, Shana Pires; Costa, Jorge Alberto VieiraThis aim of this study was to assess the hydrolysis reaction of the biomass of Chlorella pyrenoidosaandSpirulinasp. LEB 18,using commercial proteases that act in different pH ranges, to obtain protein hydrolysates with promising application in food or food supplement, improving functional and nutritional food properties. Threecentral composite study designs were carried out for each microalga (Chlorella and Spirulina). The 23 type central composite design was utilized with three replications at the central point, varying the enzyme concentration (5 to 10 U.mL-1), the concentrationof substrate (5 to 10 %) and reaction time (60 to 240 min), for a total of 11 experiments per planning. The highestdegrees of hydrolysis (52.9% and 55.31%) forSpirulinaand Chlorella,respectively, were obtained with 4 h of reaction. The results show that it is possible to obtain enzymatic protein hydrolysates with different DH from microalgae biomass.
- ItemHydrolysis of Insoluble Fish Protein Residue from Whitemouth croaker (Micropogonias furnieri) by Fungi(2014) Martins, Vilásia Guimarães; Palezi, Simone Canabarro; Costa, Jorge Alberto Vieira; Prentice-Hernández, CarlosA significant amount of insoluble fibrous protein, in the form of feather, hair, scales, skin and others are available as co-products of agro industrial processing. These wastes are rich in keratin and collagen. This study evaluated different fungi for the hydrolysis of insoluble fish protein residues. Proteins resulting from Micropogonias furnieri wastes through pH-shifting process were dried and milled for fermentation for 96 h. This resulted the production of keratinolytic enzymes in the medium. Trichoderma sp. on alkaline substrate (28.99 U mL-1) and Penicillium sp. on acidic substrate (31.20 U mL-1) showed the highest proteolytic activities. Penicillium sp. showed the largest free amino acid solubilization (0.146 mg mL-1) and Fusarium sp. the highest protein solubilization (6.17 mg mL-1).
- ItemAnalytical modeling and numerical optimization of the biosurfactants production in solid-state fermentation by Aspergillus fumigatus(2014) Castiglioni, Gabriel Luis; Stanescu, George; Rocha, Luiz Alberto Oliveira; Costa, Jorge Alberto VieiraThis is an experimental, analytical and numerical study to optimize the biosurfactants production in solid-state fermentation of a medium containing rice straw and minced rice bran inoculated with Aspergillus fumigatus. The goal of this work was to analytically model the biosurfactants production in solid-state fermentation into a column fixed bed bioreactor. The Least-Squares Method was used to adjust the emulsification activity experimental values to a quadratic function semi-empirical model. Control variables were nutritional conditions, the fermentation time and the aeration. The mathematical model is validated against experimental results and then used to predict the maximum emulsification activity for different nutritional conditions and aerations. Based on the semi-empirical model the maximum emulsification activity with no additional hydrocarbon sources was 8.16 UE·g-1 for 112 h. When diesel oil was used the predicted maximum emulsification activity was 8.10 UE·g-1 for 108 h.
- ItemSpirulina as a protein source in the nutritional recovery of wistar rats(2013) Moreira, Lidiane Muniz; Behling, Bruna del Sacramento; Rodrigues, Rosane da Silva; Costa, Jorge Alberto Vieira; Soares, Leonor Almeida de SouzaThis study was aimed at evaluating the effects of Spirulina (Arthrospira) as a protein source in the nutritional recovery of rats subjected to protein malnutrition. In order to understand such effects, responses of the developing body, serum biochemical profile, and blood count of animals were analyzed. A total of, 23 Wistar Rattus norvegicus were given a proteic diet (AIN-93G adapted) in malnutrition phase (phase I) for 10 days. After this period, the rats were separated into four groups according to the protein source (recovery phase): Control (C), casein 12%; Spirulina level I (S1), Spirulina 8.8% + casein 5.0%; Spirulina level II (S2), Spirulina 17.6% + casein 0.15%, and Spirulina level III (S3), Spirulina 26.4%. Recovery phase (phase II) lasted 30 days. In both the phases, the consumption and body weight of the rats were monitored daily and weekly, respectively. The S1 treatment showed the highest values of Feed Efficiency Ratio (FER) and Quotient of Protein Efficiency Ratio (QPE) (p≤0.05). Significant differences among the treatments were found mainly in the levels of serum lipids, and S2 diet caused an increase in such responses (p≤0.05). These results demonstrated that the nutritional recovery of animals was enabled by different concentrations of Spirulina.
- ItemAvaliação da rotulagem e qualidade físico-química de geleias de uva comercializadas na cidade do Rio Grande-RS(2013) Moro, Gisele Medianeira Barbieri; Rodrigues, Rosane da Silva; Costa, Jorge Alberto Vieira; Machado, Whallans Raphael Couto; Pizato, SandrianeO objetivo deste trabalho foi avaliar a qualidade físico-química e as informações contidas nos rótulos das embalagens de geleias de uva comercializadas na cidade do Rio Grande, RS. Geleias de uva produzidas industrialmente foram adquiridas no comércio local do Rio Grande, totalizando oito amostras, sendo seis geleias tradicionais e duas geleias light. As informações contidas nos rótulos foram avaliadas segundo a legislação brasileira vigente. As geleias foram analisadas quanto ao pH, teor de sólidos solúveis, acidez titulável e cor. Todas as marcas de geleias estudadas apresentaram informações nutricionais no rótulo. No entanto, quanto à rotulagem geral, todas apresentaram inconformidades. Uma das amostras analisadas apresentou massa inferior ao permitido pela legislação. Quanto à análise de sólidos solúveis, 62,5% das amostras do produto na versão tradicional apresentaram mínimo de 65ºBrix. A acidez titulável apresentou variação de 0,44+0,10 a 0,70+0,15% de ácido cítrico e o pH ficou na faixa entre 3,18+0,01 a 3,64+0,05. As geleias light apresentaram menor luminosidade (L*). Desta forma, as geleias de uva analisadas apresentaram alguma inconformidade em relação à rotulagem geral considerando-se a legislação brasileira para este tema. No entanto, todas as marcas estudadas apresentaram informações nutricionais no rótulo. Verificou-se enquadramento do produto dentro dos limites aceitáveis para sólidos solúveis e para acidez titulável embora a maioria das amostras tenha apresentado pH superior ao indicado como ideal à formação do gel. As geleias com redução calórica apresentaram menor luminosidade que as tradicionais, mas à exceção de uma, apresentou igualmente predomínio da cor vermelha.
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