Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-12-01T23:35:59Z No. of bitstreams: 1 EllisonMatheusDelioAlcantara_DISSERT.pdf: 1987085 bytes, checksum: 4511f07e0b4aeaea594ec88fad96b400 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-12-05T22:39:58Z (GMT) No. of bitstreams: 1 EllisonMatheusDelioAlcantara_DISSERT.pdf: 1987085 bytes, checksum: 4511f07e0b4aeaea594ec88fad96b400 (MD5) / Made available in DSpace on 2017-12-05T22:39:59Z (GMT). No. of bitstreams: 1 EllisonMatheusDelioAlcantara_DISSERT.pdf: 1987085 bytes, checksum: 4511f07e0b4aeaea594ec88fad96b400 (MD5) Previous issue date: 2017-11-27 / As preocupa??es ambientais v?m aumentando nos ?ltimos anos, principalmente devido ao uso de v?rios produtos derivados de petr?leo, os quais levam anos para se degradar na natureza. Para minimizar esse problema, v?rios estudos focam na utiliza??o de materiais naturais biodegrad?veis. Nesse contexto, verificou-se que a f?cula de mandioca pode ser aproveitada como mat?ria prima para produ??o de um biopol?mero que pode ser utilizado como isolante t?rmico. O biopol?mero foi produzido por um processo de expans?o t?rmica controlada com fra??es volum?tricas de 30% de ?gua e 70% de f?cula de mandioca. Foram analisadas as propriedades f?sicas e t?rmicas do material com intuito de obter dados sobre a viabilidade de seu uso como isolante t?rmico. O material apresentou uma condutividade t?rmica de 0,152 W/mK, podendo ser aplicado como isolante em sistemas quente de at? 270 ?C e um limite de resist?ncia a temperatura de 270?C observado pela an?lise termogravim?trica. O biopol?mero de f?cula de mandioca mostrou-se eficiente quanto ? isola??o t?rmica, devido possuir propriedades semelhantes ?s de isolantes t?rmicos dispon?veis comercialmente. Al?m disso, foram realizadas an?lises de inflamabilidade, a qual o material se apresentou como n?o inflam?vel. Al?m disso, analisou-se dureza caracterizando-o como um material duro. Diante disso, o material mostrou-se promissor a ser aplicado como isolante t?rmico. Essas an?lises foram fundamentadas em normas ABNT, ASTM e UL-94 e os resultados obtidos experimentalmente comprovam que o biopol?mero de f?cula de mandioca pode ser utilizado para fins de isolamento t?rmico. / Environmental concerns have been rising in recent years, mainly due to the use of various petroleum products, which take years to degrade in nature. To minimize this problem, several studies focus on the use of natural biodegradable materials. In this context, it has been found that manioc starch can be used as raw material for the production of a biopolymer that can be used as a thermal insulation. The biopolymer was produced by a controlled thermal expansion process with volumetric fractions of 30% water and 70% cassava starch. The physical and thermal properties of the material were analyzed in order to obtain data on the feasibility of its use as thermal insulation. The material had a thermal conductivity of 0.152 W / mK, and can be applied as an insulator in hot systems up to 270 ? C and a temperature resistance limit of 270 ? C observed by thermogravimetric analysis. Cassava starch biopolymer proved to be efficient in thermal insulation, due to its properties similar to those of commercially available thermal insulators. In addition, flammability analyzes were performed, to which the material presented as non-flammable. In addition, hardness was analyzed by characterizing it as a hard material. In view of this, the material proved promising to be applied as a thermal insulation. These analyzes were based on ABNT, ASTM and UL-94 standards and the results obtained experimentally prove that the biopolymer of cassava starch can be used for thermal insulation purposes.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-10-03T00:21:48Z No. of bitstreams: 1 MayraKerollySalesMonteiro_DISSERT.pdf: 5097719 bytes, checksum: 8a31b93e5438ec081f424997340a4eb4 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-10-09T22:11:42Z (GMT) No. of bitstreams: 1 MayraKerollySalesMonteiro_DISSERT.pdf: 5097719 bytes, checksum: 8a31b93e5438ec081f424997340a4eb4 (MD5) / Made available in DSpace on 2017-10-09T22:11:42Z (GMT). No. of bitstreams: 1 MayraKerollySalesMonteiro_DISSERT.pdf: 5097719 bytes, checksum: 8a31b93e5438ec081f424997340a4eb4 (MD5) Previous issue date: 2017-07-28 / Biofilmes e revestimentos comest?veis s?o camadas finas de materiais biodegrad?veis aplicados sobre produtos alimentares que desempenham um papel importante na sua preserva??o, distribui??o e comercializa??o. A f?cula de mandioca ? um dos melhores candidatos ? prepara??o de revestimentos comest?veis, por ser um pol?mero completamente biodegrad?vel no solo e na ?gua e de f?cil obten??o. No entanto, a f?cula possui limita??es em suas propriedades f?sico-qu?micas quando comparada aos pol?meros sint?ticos. Por sua vez, o melhoramento destas propriedades foi proposto neste estudo a partir da adi??o de 5%, em massa, de argila em rela??o ? massa seca de biopol?mero. A compatibiliza??o superficial da argila com a matriz biopolim?rica foi realizada por modifica??o superficial na presen?a de tr?s tipos de tensoativos (brometo de cetiltrimetil am?nio, dodecil sulfato de s?dio e ?lcool laur?lico etoxilado). O efeito de tr?s modifica??es sequenciais e cumulativas na argila foi caracterizado por Difra??o de Raios X (DRX), Transformada de Fourier por Radia??o Infravermelha (FTIR), Microscopia Eletr?nica de Varredura (MEV), Espectroscopia de Energia Dispersiva de Raios X (EDS), ?ngulo de Contato (AC), Potencial Zeta (ZETA) e An?lise Termogravim?trica (TGA). A argila modificada sinergicamente na presenta dos tr?s tensoativos evidenciou o maior distanciamento basal entre as camadas de silicato, cerca de 10 nm a mais em rela??o ? argila natural. Os filmes de f?cula de mandioca com argila natural e modificada foram caracterizados como bionanocomp?sito intercalado ou esfoliado atrav?s das an?lises de Microscopia de For?a At?mica (AFM), Microscopia ?ptica (MO), DRX, FTIR, MEV e AC. A influ?ncia da argila modificada e da natural na mudan?a das propriedades f?sico-qu?micas dos filmes de f?cula original foi investigada quanto ? permeabilidade ao vapor d??gua, ductibilidade, opacidade, estabilidade t?rmica e solubilidade em ?gua. Por fim, a argila modificada sinergicamente na presenta dos tr?s tensoativos foi o material de refor?o que mais contribuiu para o melhoramento das propriedades f?sico-qu?micas do filme de f?cula controle, dentre as quais reduziu 90,6% da permeabilidade ao vapor d??gua, bem como 77,43% da dissolu??o m?xima. / Biofilms and edible coatings are thin layers of biodegradable materials applied to food products that play an important role in their preservation, distribution and commercialization. Cassava starch is one of the best candidates for the preparation of edible coatings, because it is a completely biodegradable polymer in soil and water and easy to obtain. However, the starch has limitations in its physical-chemical properties when compared to the synthetic polymers. In turn, the improvement of these properties was proposed in this research from the addition of 5%, by mass, of clay in relation to the dry mass of biopolymer. The surface compatibilization of the clay with the biopolymer matrix was performed by surface modification in the presence of three types of surfactants (cetyltrimethyl ammonium bromide, sodium dodecyl sulfate and ethoxylated lauryl alcohol). The effect of three sequential modifications on the clay was characterized by X-ray Diffraction (XRD), Fourier Transform by Infrared Radiation (FTIR), Scanning Electron Microscopy (SEM), Dispersive Lightning Spectroscopy (DLS), Contact Angle (AC), Zeta Potential (ZETA) and Thermogravimetric Analysis (TGA). The clay modified synergistically in the presence of the three surfactants showed the greatest basal space between the silicate layers, about 10 nm more than the natural clay. The cassava starch films with natural and modified clay were characterized as bionanocomposite intercalated or exfoliated through Atomic Force Microscopy (AFM), Optical Microscopy (MO), XRD, FTIR, SEM and AC analyzes. The influence of modified and natural clay on the change in the physical-chemical properties of the original starch films was investigated for water vapor permeability, ductility, opacity, thermal stability and water solubility. Finally, the synergistically modified clay in the presence of the three surfactants was the reinforcing material that contributed the most to the physical-chemical properties of the control starch film, among which it reduced the permeability to water vapor by 90.6%, as well as 77.43% of the maximum dissolution.

Made available in DSpace on 2016-04-28T14:59:00Z (GMT). No. of bitstreams: 1 2009 - Ariane Castricini.pdf: 2010336 bytes, checksum: 05cebf92245d2829733f92cab21a0901 (MD5) Previous issue date: 2009-02-16 / Funda??o Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / This study was conducted in UFRRJ (physico, chemical and microbiological analysis) and Embrapa Agroind?stria de Alimentos (sensory evaluation), with the general objective of assessing the influence of modified atmosphere by coating of starch (cassava starch and modified starch) on the ripening and conservation of papayas (Carica papaya L.) Golden , stored in refrigerated environment. The coating were used in concentrations of 1%, 3% and 5%. The concentrations of cassava starch to 3 and 5% provided better results as ripening: it s delayed the development of color yellow skin but without total development of yellow color and the fruits remained firm for a longer time, during the experimental period. The respiratory rates were lower as higher as the concentration of the coating. The coating of 1% was sufficient to reduce the respiratory rate of fruits, but not positively influenced by other variables. The coatings favored greater integrity of cell walls, demonstrated the proper structure and organization of the same view as the middle lamella. Coatings of modified starch were not effective in preventing ripeness. It did not cause distinct changes in titratable acidity, the content of ascorbic acid and total soluble solids. The results were similar those of uncoated fruits. The respiratory rates were lower in fruits coated film for the 3 and 5%, but not enough to slow the ripening process during storage. The microscopic visualization of cell walls showed good integrity in fruits coated film by the 1 and 5% and evidence of destruction when coated to 3%. The coatings of cassava starch and modified starch affect more the attributes of appearance that the taste of fruits. The coating of cassava starch at 5% was suitable for coating fruits, whereas the majority of the attributes of appearance studied. However, the stripping evidenced by the lower integrity of it, was considered unfavorable. The coating of modified starch and cassava starch at 1% formed intact film, without peeling. The taste was somewhat influenced by the coatings, but the coating of modified starch and 5% changed the characteristic flavor of papaya, evidenced by the bitter taste perceived at 12 and 14 days of storage. The coating of cassava starch with and without sanitary treatment plant favored the development of post-harvest decay, for the film of modified starch. But the largest areas affected by the lesions were observed only in fruits coated by concentrations of 3 and 5% of cassava starch after sanitary treatment plant. The oil inhibited the growth of Colletotrichum gloeosporioides in vitro, but when added to the coatings were not effective in controlling decay. For the sake of strong smell of garlic and cinnamon bark oils left in the fruits, beyond stains caused by concentrations of 1 and 0.5% oil of cinnamon, these products were improper to post-harvest use. / O presente trabalho foi conduzido na UFRRJ (avalia??es f?sicas, qu?micas e microbiol?gicas) e na Embrapa Agroind?stria de Alimentos (an?lise sensorial), com o objetivo geral de avaliar a influ?ncia de atmosfera modificada por revestimentos de amido (f?cula de mandioca e amido modificado) sobre o amadurecimento e conserva??o de mam?es (Carica papaya L.) Golden , armazenados em ambiente refrigerado. Os revestimentos foram utilizados nas concentra??es de 1%, 3% e 5%. As concentra??es de f?cula de mandioca a 3 e 5% proporcionaram melhores resultados, quanto ao amadurecimento. Retardaram o desenvolvimento da colora??o amarela da casca, por?m n?o permitiu o desenvolvimento total da mesma e mantiveram os frutos firmes por mais tempo, durante o per?odo experimental. As taxas respirat?rias foram menores quanto maior a concentra??o dos revestimentos. O revestimento a 1% foi suficiente para reduzir as taxas respirat?rias dos frutos, mas n?o influenciou positivamente nas demais vari?veis estudadas. Os revestimentos favoreceram maior integridade das paredes celulares, evidenciada pela boa estrutura??o e organiza??o das mesmas assim como visualiza??o da lamela m?dia. J? aqueles de amido modificado n?o foram eficientes na preven??o do amadurecimento. Os resultados de acidez total titul?vel, teor de ?cido asc?rbico e s?lidos sol?veis totais foram semelhantes aqueles dos frutos n?o revestidos. As taxas respirat?rias foram menores nos frutos revestidos pelas pel?culas a 3 e 5%, mas n?o o suficiente para desacelerar o processo de amadurecimento, durante o armazenamento. A visualiza??o microsc?pica das paredes celulares revelaram boa integridade nos frutos com pel?culas revestimentos a 1 e 5% e evidenciou desestrutura??o quando revestidos a 3%. Os revestimentos de f?cula de mandioca e amido modificado afetaram mais os atributos de apar?ncia que o sabor dos frutos. A pel?cula de f?cula de mandioca a 5% foi mais adequada para o revestimento dos frutos, considerando a maioria dos atributos de apar?ncia estudados. Por?m, o descascamento evidenciado pela menor integridade da mesma, foi considerado desfavor?vel. O revestimento por amido modificado e f?cula de mandioca a 1% formaram pel?culas ?ntegras, ou seja, sem descascamento. O sabor foi pouco influenciado pelos revestimentos, mas o revestimento de amido modificado a 5% alterou o sabor caracter?stico de mam?o, evidenciado pelo gosto amargo percebido aos 12 e 14? dias de armazenamento. Os revestimentos de f?cula de mandioca com e sem tratamento fitossanit?rio favoreceram o desenvolvimento das podrid?es p?s-colheita, em rela??o ?s pel?culas de amido modificado. Por?m as maiores ?reas afetadas pelas les?es foi observada somente nos frutos revestidos pelas concentra??es de 3 e 5% de f?cula de mandioca ap?s o tratamento fitossanit?rio. Embora os ?leos tenham inibido o crescimento de Colletotrichum gloeosporioides in vitro , n?o foram eficientes no controle quando adicionados aos revestimentos. Devido ao cheiro forte do ?leo de bulbilho de alho e casca de canela deixaram no fruto, al?m das manchas do ?leo de canela, tornam-se esses produtos inadequados para uso em p?s-colheita.