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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

Estabiliza??o de mol?culas bioativas presentes em suco de camucamu (Myrciaria d?bia (H.B.K) Mc Vaugh) pela integra??o dos processos de osmose inversa, evapora??o osm?tica e atomiza??o / Stabilization of bioactive molecules present in camucamu juice by means of interaction among the processes of reverse osmosis, osmotic evaporation and atomization

Souza, Andr? Luis Rodrigues 06 March 2012 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-04-27T13:51:34Z No. of bitstreams: 1 2012 - Andr? Luis R. de Souza.pdf: 1971622 bytes, checksum: 5237bc23d365c59e774d9f8776efabf1 (MD5) / Made available in DSpace on 2017-04-27T13:51:34Z (GMT). No. of bitstreams: 1 2012 - Andr? Luis R. de Souza.pdf: 1971622 bytes, checksum: 5237bc23d365c59e774d9f8776efabf1 (MD5) Previous issue date: 2012-03-06 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Camu-camu is a native fruit from the Amazonian region, cultivated in the margins of rivers, lakes and Amazonian creeks called igarap?s. It is known as one of the fruit with the highest content of vitamin C. Reverse osmosis is a membrane concentration process in which the applied pressure is higher than the juice osmotic pressure. Such process favors the solvent permeation from the region with the highest concentration to the one with the lowest. Osmotic evaporation is another membrane concentration process in which a porous hydrophobic membrane separates the solution that is going to be concentrated from a concentrate brine solution. Microencapsulation is the process in which an active agent is entrapped by means of a polymer cover. Such process promotes the release of these active agents under specific conditions. The aim of this work is to evaluate the use of membrane separation processes and microencapsulation for the processing of camu-camu fruits. The camu-camu pulp, which has been obtained through the depulping of camu-camu fruits, was first centrifuged, in order to decrease its suspended solids content, and clarified by microfiltration with polysulfone membranes. Six clarification processes have carried out at 2.5 bar transmembrane pressure and 45?C. The clarified juice was concentrated by reverse osmosis at 60 bar and 20 ?C. The avarage permeate flux has been of 11.3 L/hm2. The preconcentrated juice had 28.8?Brix and the concentration degree of the process was 3.8. The pre-concentrated juice has been concentrated by osmotic evaporation in a laboratorial system with polytetrafluoroethylene membrane. The process presented an average pemeate flux of 2.4 Kg/hm2. The soluble solids content of the concentrated juice was of 56.6 ?Brix, presenting a concentration degree of 1.98. The retentate fraction of the microfiltration process was microencapsulated in a spray dryer. Three encapsulation agents were evaluated: starch, maltodextrin and the mixture of both. The values presented for the physicochemical caracterization of the pre-concentrated and concentrated camu-camu juices indicate that there has been an increase both in the physical characteristics of the juice, such as soluble solids, total solids and acidity, and in the concentration of camu-camu bioactive compounds. The dehydrated camu-camu juice presented a high concentration of bioactive substances. Nevertheless, there has been no stability of such compounds during storage. Through the results obtained in the present work, it is possible to observe that the integration of membrane processes proved efficient in the concentration of camu-camu juice, with a final product of high nutritional value / O camu-camu ? um fruto nativo da regi?o amaz?nica, cultivado as margens de rios, lagos e igarap?s. ? reconhecido como um dos frutos com um dos maiores teores de vitamina C. Osmose inversa ? o processo de concentra??o por membranas onde a press?o aplicada ? maior que a press?o osm?tica do suco, favorecendo a permea??o do solvente da regi?o de maior concentra??o para regi?o de menor concentra??o. Evapora??o osm?tica ? um outro processo de concentra??o, onde uma membrana hidrof?bica porosa separa a solu??o que ser? concentrada e uma salmoura concentrada. A microencapsula??o ? o processo onde um agente ativo ? protegido por meio de uma cobertura de pol?meros, ocorrendo a libera??o desses agentes ativos em condi??es espec?ficas. O objetivo desta disserta??o foi avaliar o uso dos processos de separa??o com membranas e microencapsulamento para o processamento de suco de camu-camu. Os frutos de camu-camu foram despolpados, sendo o suco submetido a centrifuga??o, com o objetivo de reduzir os s?lidos em suspens?o, e posteriormente clarificado por microfiltra??o em um sistema de membranas de polissulfona. Foram realizados seis processos de clarifica??o a 2,5 bar e 45?C. O suco clarificado foi pr?-concentrado por osmose inversa a 60 bar e 20 ?C. O fluxo permeado m?dio foi de 11,3 L/hm2. O suco pr?-concentrado apresentou teor de s?lidos sol?veis de 28,8?Brix e grau de concentra??o de 3,8. O suco pr?-concentrado foi processado por evapora??o osm?tica em um sistema laboratorial constitu?do por membranas de politetrafluoretileno. O processo apresentou fluxo m?dio permeado de 2,4 kg/hm2. O teor de s?lidos sol?veis do suco concentrado foi de 56,6 ?Brix, apresentando um grau de concentra??o de 1,98. O processo de microencapsula??o da fra??o retida do suco de camucamu foi realizado em um spray dryer Buchi Modelo B-190. Foram realizados tr?s ensaios com tr?s formula??es diferentes: mistura entre amido e maltodextrina, somente amido e somente maltodextrina. Os valores apresentados para a caracteriza??o f?sico-qu?mica do suco de camu-camu pr?-concentrado e concentrado indicam que houve um aumento nos s?lidos sol?veis e totais e da acidez, bem como no teor das subst?ncias bioativas do camucamu. O suco de camu-camu desidratado apresentou alto teor de subst?ncias bioativas, onde a estabilidade desses compostos durante o per?odo de armazenamento n?o foi alcan?ada. Observa-se que a integra??o dos processos com membranas se mostrou eficaz na concentra??o do suco de camu-camu, obtendo um produto com alta qualidade nutricional.

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