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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

ObtenÃÃo de suco em pà prebiÃtico de tangerina atravÃs de secagem em leito de jorro / Getting juice powder probiotic tangerine by drying in spouted bed

Solane Alves Santos da Rocha 07 March 2013 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Os alimentos funcionais vÃm conquistando espaÃo como uma boa alternativa na prevenÃÃo de doenÃas, sendo a maioria destes encontrados no mercado na forma de produtos lÃcteos, inviabilizando o consumo por indivÃduos intolerantes à lactose. Dentro deste contexto, o presente trabalho objetivou a elaboraÃÃo de suco de tangerina contendo oligossacarÃdeos prÃ-bioticos e desidrataÃÃo do mesmo em leito de jorro. A sÃntese dos oligossacarÃdeos foi realizada seguindo um planejamento experimental utilizando a enzima dextrana-sacarase, obtida a partir do Leuconostoc mesenteroidesB512F, sendo selecionado o ensaio que apresentou uma concentraÃÃo de 61,28 g/L de oligossacarÃdeos. O processo de secagem por leito de jorro foi otimizado mediante a aplicaÃÃo de dois planejamentos sendo o primeiro um planejamento fatorial fracionado e o segundo um planejamento composto central. Para o primeiro planejamento foram consideradas variÃveis independentes a temperatura, concentraÃÃo de maltodextrina, massa de inerte e vazÃo de alimentaÃÃo; e as variÃveis resposta o rendimento do processo, atividade de Ãgua do pà obtido, tempo de reidrataÃÃo e umidade. O segundo planejamento considerou como variÃveis independentes a temperatura de secagem na entrada do equipamento e a concentraÃÃo de maltodextrina empregada, tendo como resposta a higroscopicidade, grau de caking, coordenada de cor b*, tempo de reidrataÃÃo e rendimento da produÃÃo do pÃ. Os pÃs obtidos foram considerados nÃo higroscÃpicos e, de acordo com estes resultados, foram selecionados como parÃmetros do processo o emprego de temperaturas de 73 ÂC e adiÃÃo de 11% de maltodextrina na secagem de sucos de tangerina com ou sem prÃ-biÃtico. NÃo houve diferenÃa significativa nos resultados de umidade, o grau de caking e solubilidade para os sucos de tangerina em pà com e sem prÃ-biÃtico, sendo que para a higroscopicidade os resultados foram considerados significativos a 5% de probabilidade, apresentando ainda maior luminosidade, coloraÃÃo mais clara e menor intensidade da cor amarela no suco prÃ-biÃtico em pÃ. / Functional foods have been taking more space as a good alternative in preventing diseases, but they are found as lactic products, and person with lactose intolerance cannot consuming them. The aim of this work was elaborate tangerine juice containing prebiotic oligosaccharides and their dehydration using spouted bed drying. Oligosaccharide synthesis was performed following a experimental design using the dextran-sucrase enzyme obtained by LeuconostocmesenteroidesB512F and the assay with oligosaccharide concentration of 61,28 g/L was selected. Fractioned Fatorial and Central Composite design was used to optimize the spouted bed drying. The first design was considered temperature, maltodextrin concentration, inert and feeding output as independent variables; process yield, powder water activity, rehydration time and moisture was dependent variables. The second design used inlet drying temperature and maltodextrin concentration as independent varibles, obtaining as responses higroscopicity, caking degree, b* color coordinate, rehydration time and powder production yield. Powders obtaining was no hygroscopicand, with this results, was selected as process parameters temperatures of 73 ÂC and maltodextrin concentration of 11 per cent on tangerine juice drying with or without prebiotic in. No significant difference was found for moisture, caking degree and solubility of tangerine juice powder with or without prebiotics. Hygroscopicity results was significant as 5% probability, showing high luminosity, lighter color and yellow less color at prebiotic powder juice.
2

Yeast diversity in artisanal cheeses: biotechnological applications

Padilla López, Beatriz 03 March 2014 (has links)
The impact of yeasts on food production, quality and safety is closely linked with their ecology and biological activities. Recently, as a consequence of the relationship between diet and health, yeasts are becoming relevant as new probiotics or for the production of bioactive compounds. In dairy products, yeasts play a key role in proteolysis, lipolysis and lactose fermentation during cheese ripening, promoting the development of sensory properties, particularly aroma. This thesis focuses on the yeast diversity in artisanal cheeses produced in the Natural Park Serra d¿Espadà (Castelló) from ewes¿ and goats¿ raw milk. Different molecular techniques have been employed in order to characterize yeast isolates. Moreover, the succession of species along the cheese ripening process was studied. The intraspecific variability of the most abundant identified species Debaryomyces hansenii and Kluyveromyces lactis was also assessed. Additionally, the potential of Kluyveromyces marxianus and K. lactis ß-galactosidases to synthetize prebiotic oligosaccharides from lactose and lactulose was tested. Finally, Kluyveromyces and Debaryomyces isolates were investigated for the production of cheese aromatic compounds. / Padilla López, B. (2014). Yeast diversity in artisanal cheeses: biotechnological applications [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/36065 / TESIS
3

ObtenÃÃo de oligosscarÃdeos prebiÃticos por processo fermentativo a partir do suco de caju clarificado in natura / Obtentioin of prebiotic oligosaccharides for fermentative process from the clarificado cashew juice in natura

Clarice Maria AraÃjo Chagas Vergara 27 March 2007 (has links)
OligossacarÃdeos prebiÃticos sÃo carboidratos capazes de chegar ao intestino grosso onde sÃo metabolizados pelas bidifidobactÃrias e lactobacilos ali presentes estimulando o seu crescimento. A importÃncia destes microrganismos està associada a sua relaÃÃo com a melhoria da intolerÃncia à lactose, melhora da funÃÃo intestinal, melhoria do sistema imunolÃgico, reduÃÃo de enzimas mutagÃnicas e sÃntese de vitaminas do complexo B. A enzima dextrana-sacarase pode ser facilmente obtida a partir da fermentaÃÃo do Leuconostoc mesenteroides em meio contendo sacarose como fonte de carbono. Esta enzima catalisa a formaÃÃo de dextrana em meio contendo sacarose como Ãnico substrato. Quando um aceptor està presente no meio de cultura, parte das unidades de glicose da sacarose sÃo desviadas da sÃntese de dextrana formando oligossacarÃdeos. A utilizaÃÃo do suco de caju, rico em glicose e frutose, visa o aproveitamento de excedentes agrÃcolas, reduzindo assim o custo do processo final. Este trabalho teve por objetivo estudar a sÃntese de oligossacarÃdeos prebiÃticos a partir da fermentaÃÃo de duas linhagens de Leuconostoc mesenteroides; B512F e B742, ambas nÃo patogÃnicas e seguras do ponto de vista alimentar. Com base nos resultados obtidos pode-se concluir que o processo fermentativo utilizando o suco de caju como substrato apresentou bons resultados, principalmente no que se refere ao crescimento microbiano, produÃÃo da enzima dextrana-sacarase e crescimento de Lactobacillus sendo sua utilizaÃÃo, portanto viÃvel. / Prebiotic oligosaccharides are carbohydrates able to reach the large intestine being metabolizated by bidifidobacterium and lactobacillus and stimulating their growth. The importance of these microorganisms is related with its improvement of the intolerance to the lactose, improvement of the intestinal function and the imunologic system, mutagenic enzyme reduction and vitamin synthesis of the complex B. The enzyme dextransucrase can be easily obtained through the fermentation of Leuconostoc mesenteroides in a medium containing sucrose as carbon source. This enzyme catalyzes the formation of dextran in a medium containing sucrose as the only substrate. When an acceptor is present in the culture medium, part of the glucose moieties from sucrose are deviated from the dextran synthesis forming prebiotic oligosaccharides. The use of the cashew juice, rich in glucose and fructose, aims to the use of an agriculture excess, reducing the cost of the final process. This work had as objective the study of synthesis of prebiotic oligosaccharides from the fermentation of Leuconostoc mesenteroides, B512F and B742, both non pathogenic and safe from the alimentary point of view. Based on the obtained results it can be concluded that the fermentative process using the cashew juice as substratum presented good results, mainly for the microbial growth, production of the enzyme dextransucrase and growth of Lactobacillus being its use, therefore viable.

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