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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

Frutos de Schinus terebinthifolius Raddi: extra??o ativa, estudo fitoqu?mico e incorpora??o em filmes bioativos de pectina

Santos, Calila Teixeira 31 March 2017 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2018-01-31T22:05:14Z No. of bitstreams: 1 Calila Teixeira Santos-Tese.pdf: 4768163 bytes, checksum: d983e00648de308f628e91544b43f14c (MD5) / Made available in DSpace on 2018-01-31T22:05:14Z (GMT). No. of bitstreams: 1 Calila Teixeira Santos-Tese.pdf: 4768163 bytes, checksum: d983e00648de308f628e91544b43f14c (MD5) Previous issue date: 2017-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The present study had as main objective to obtain bioactive extracts of the fruits of Schinus terebinthifolius Raddi (STF), with antioxidant and antimicrobial action, for incorporation in a bioactive package for foods, besides inhibition of acetylcholinesterase. The extraction process performed by focussed microwave (EAMF) and ultrasound (UAE). The comparison between extraction methods was monitored by the biological activities of these extracts. The results showed that for the yield there was no significant difference. For the EAMF assays, the best value of phenolic (5950 ? 1.4 mgGAE / g) and total flavonoids (1750 ? 3.2 mgEQ / g) was at the extraction time of 25 minutes at 51 ? C and with 75% ethanol. For the assays obtained by EAU, the best total phenolic content was (92.2 ? 0.8 mgGAE / g) in the EAU 10 test (extraction time of 30 minutes at 42 ? C and 50% ethanol) And flavonoids (67.72 ? 1.0 mgEQ / g) in the UAE 12 assay (extraction time of 17.5 minutes at 60 ? C and 50% ethanol). The best values for percent inhibition (% SRL) were 87.3% (EAMF 8) and 31.3% (UAE 12). Mass spectrometry analysis showed the presence of phenolic compounds and terpenes. In relation to the antimicrobial activity of extracts obtained by EAMF, the MIC for S. aureus was 0.5 mg / ml for E. coli 0.25 mg / ml, whereas the extract of EAU presented MIC of 0.5 mg / Ml for the two microorganisms analyzed. In the phytochemical study, it was possible to isolate 7 substances: agasthiflavone, tetrahydrorobustaflavone, masticadienoic acid (Z), masticadienoic acid (E), schinol, gallic acid and squalene, as well as a mixture with unsaturated fatty acid profile and a mixture with trisaccharide characteristics. Their chemical structures being determined by spectrophotometric methods such as 1H and 13C NMR, UV and MS. Two of the 17 EAMF extracts were selected, which were incorporated into an active high-methoxylation pectin-based film called "Extract 2" and "Extract 8" in various concentrations (0, 1, 3 and 5%). The films had a mean thickness of 0.007 mm for all concentrations of the extracts tested. It was observed in relation to the mechanical properties that there was an interaction of the polyphenolic components of the extracts with the materials used in the production of the films. The films were more permeable to water vapor (6.18-7.80 g.mm/m2.h.kPa) than the control film (5.12 g.mm/m2.h.kPa). The films of both extracts showed good thermal stability independent of the concentration tested. The films produced in this study presented antioxidant activity, and the films added from extract 8 presented the best% SRL values (54.45 and 67.08, respectively). All films obtained inhibition halo against the microorganisms tested. In view of the results, it can be inferred that FTS have antioxidant potential, antimicrobial activity and high inhibition of acetylcholinesterase and can be used in cosmetics, nutraceuticals and food industry, as well as a promising alternative in the production of active films. / O presente estudo teve como objetivo principal obter extratos bioativos dos frutos de Schinus terebinthifolius Raddi (STF), com a??o antioxidante e antimicrobiana, para incorpora??o em uma embalagem bioativa para alimentos, al?m de inibi??o da acetilcolinesterase. O processo de extra??o foi realizado por micro-ondas focalizado (EAMF) e ultrassom (EAU). A compara??o entre os m?todos de extra??o foi monitorada pelas atividades biol?gicas desses extratos. Os resultados mostraram que para o rendimento n?o teve diferen?a significativa. Para os ensaios de EAMF o melhor valor de fen?lico (5950 ? 1,4 mgGAE/g) e flavonoides totais (1750 ? 3,2 mgEQ/g) foi no tempo de extra??o de 25 minutos, na temperatura de 51 ?C e com 75% de etanol. Para os ensaios obtidos por EAU o melhor teor de fen?licos totais foi (92,2 ? 0,8 mgGAE /g) no ensaio EAU 10 (tempo de extra??o de 30 minutos, na temperatura de 42 ?C e com 50% de etanol) e de flavonoides (67,72 ? 1,0 mgEQ /g) no ensaio EAU 12(tempo de extra??o de 17,5 minutos, na temperatura de 60 ?C e com 50% de etanol). Os melhores valores para a percentagem de inibi??o (%SRL) foi de 87,3% (EAMF 8) e 31,3% (EAU 12). A an?lise por espectrometria de massa mostrou a presen?a de compostos fen?licos e terpenos. Em rela??o ? atividade antimicrobiana dos extratos obtidos por EAMF, a CIM para S. aureus foi de 0,5 mg/ml, para E. coli 0,25 mg/ml, enquanto que o extrato de EAU apresentou CIM de 0,5 mg/ml para os dois microrganismos analisados. No estudo fitoqu?mico foi poss?vel isolar 7 subst?ncias: agasthiflavona, tetrahidrorobustaflavona, ?cido masticadienoico (Z), ?cido masticadienoico (E), schinol, ?cido g?lico e o esqualeno, al?m de uma mistura com perfil de ?cidos graxos insaturados e uma mistura com caracter?stica de trissacar?deos. Sendo suas estruturas qu?micas determinadas por m?todos espectrom?tricos tais como RMN 1H e 13C, UV e EM. Selecionou-se 2 dos 17 extratos EAMF, os mesmos foram incorporados em um filme ativo, ? base de pectina de alta metoxila??o, denominados ?Extrato 2? e ?Extrato 8? em concentra??es diversas (0, 1, 3 e 5%). Os filmes apresentaram espessura m?dias de 0,007 mm para todas as concentra??es dos extratos testados. Observou-se em rela??o as propriedades mec?nicas que houve uma intera??o dos componentes polifen?licos dos extratos com os materiais utilizados na produ??o dos filmes. Os filmes foram mais perme?veis ao vapor d??gua (6,18?7,80 g.mm/m2.h.kPa) do que o filme controle (5,12 g.mm/m2.h.kPa). Os filmes de ambos extratos mostraram uma boa estabilidade t?rmica independente da concentra??o testada. Os filmes produzidos neste estudo apresentaram atividade antioxidante, sendo que os filmes adicionados do extrato 8 apresentaram os melhores valores de %SRL (54,45 e 67,08, respectivamente). Todos os filmes obtiveram halo de inibi??o contra os micro-organismo testados. Diante dos resultados encontrados pode-se inferir que os STF t?m potencial antioxidante, atividade antimicrobiana e alta inibi??o de acetilcolinesterase podendo ser utilizados em cosm?ticos, produtos nutrac?uticos e na ind?stria alimentar, al?m de uma alternativa promissora na produ??o de filmes ativos.
2

Elabora??o e caracteriza??o f?sico-qu?mica de filmes de amido adicionados de a?a? (Euterpe oleracea mart.) liofilizado / Preparation and physicochemical characterization of starch films added a?a? (Euterpe oleracea Mart.) lyophilized

PESSANHA, K?nia Let?cia Ferreira 02 March 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-07-11T18:42:28Z No. of bitstreams: 1 2016 - K?nia Let?cia Ferreira Pessanha.pdf: 2366902 bytes, checksum: 926a4615f4a193d9328fe681ce73019f (MD5) / Made available in DSpace on 2017-07-11T18:42:28Z (GMT). No. of bitstreams: 1 2016 - K?nia Let?cia Ferreira Pessanha.pdf: 2366902 bytes, checksum: 926a4615f4a193d9328fe681ce73019f (MD5) Previous issue date: 2016-03-02 / CNPq / The use of synthetic materials derived from non-renewable sources has generated a high environmental impact, which required from the industry, the development of polymeric materials based on biodegradable polymers. Polysaccharides such as starch, are capable of forming low cost homogeneous edible films, resulting in aggregate value to the food due to the film increased biodegradability and increased shelf life of packaged food by the possibility of adding antioxidants, nutrients and natural pigments, which raise the nutritional and organoleptic characteristics of the product. This work was aimed at developing and evaluating, chemically and physically, films from filmogenic solutions (SF) developed with cassava starch, freez-dried acai and glycerol, through spreading technique casting. After preparation under controlled conditions, SF were dried at 30 ? 5 ? C for 24 hours in an oven with forced air circulation. The resulting films were unmolded and stowed in relative humidity controlled at 52.9% for six days for further characterization. The developed films were characterized as the quantification of anthocyanins by High-Performance Liquid Chromatography (HPLC), Antioxidant Capacity by ABTS? + and ORAC, thickness, water solubility, permeability to water vapor (PVA), water activity (Aw) , contact angle, optical properties and mechanical properties. At the same time a control film was elaborated (without the addition of acai) that underwent the same physical tests. The results indicated that the addition of acai pulp enabled the development of an edible plastic rich in anthocyanins and higher antioxidant capacity (150,70 ?mol Trolox) than fruist like strawberry and raspberry. The anthocyanins had a higher interaction with the starch molecules, probably through the hydroxyl of both which established hydrogen bonds allowing immobilization of anthocyanins in the film, which was advantageous given the high instability of anthocyanins. The polymeric matrix added with freeze-dried acai had its thickness increased which caused an increase of the PVA, reduction of water solubility and water activity, the latter two being advantageous parameters for a food package. Regarding the mechanical properties, it was observed that the rupture power in drilling and deformation were reduced. In the pull test there was a reduction of stress at break and modulus of elasticity. The deformation in traction showed higher results, indicating that the addition of the freeze-dried acai increased film flexibility. As for color, the film presented a darker color compatible with the fruit, with a potential use for packaging of dark foods. / O uso de materiais sint?ticos oriundos de fontes n?o renov?veis tem gerado um alto impacto a n?vel ambiental, o que demanda da ind?stria o desenvolvimento de materiais a base de pol?meros biodegrad?veis. Polissacar?deos como o amido, t?m a capacidade de formar filmes comest?veis, homog?neos e de baixo custo, gerando valor agregado aos alimentos devido ? maior biodegradabilidade dos filmes e aumento da validade comercial do alimento embalado pela possibilidade da adi??o de compostos antioxidantes, nutrientes e pigmentos naturais ao filme, o que pode elevar as caracter?sticas nutricionais e organol?pticas do alimento. Este trabalho teve como objetivo desenvolver e avaliar, qu?mica e fisicamente, filmes a partir de solu??es filmog?nicas (SF) elaboradas com amido de mandioca, a?a? liofilizado e glicerol, atrav?s da t?cnica de espalhamento casting. Ap?s o preparo sob condi??es controladas, as SF foram desidratadas a 30?C ? 5 ?C por 24h em estufa com circula??o de ar for?ada. Os filmes resultantes foram desenformados e acondicionados em umidade relativa do ar controlada a 52,9% por seis dias para posterior caracteriza??o. Os filmes foram caracterizados quanto a quantifica??o de antocianinas por Cromatografia L?quida de Alta Efici?ncia (CLAE), capacidade antioxidante por ABTS?+ e ORAC, espessura, solubilidade em ?gua, permeabilidade ao vapor de ?gua (PVA), atividade de ?gua (Aw), ?ngulo de contato, propriedades ?pticas e propriedades mec?nicas. Concomitantemente foi elaborado um filme controle (sem adi??o de a?a?) que foi submetido aos mesmos testes f?sicos. Os resultados indicaram que a adi??o do a?a? liofilizado permitiu o desenvolvimento de um filme pl?stico rico em antocianinas e com alta capacidade antioxidante (150,70 ?mol Trolox) superior a frutas como o morango e framboesa. As antocianinas tiveram uma alta intera??o com as mol?culas de amido, provavelmente atrav?s das hidroxilas de ambos que estabeleceram liga??es de hidrog?nio permitindo a imobiliza??o das antocianinas no filme, o que foi vantajoso visto a instabilidade das antocianinas. A matriz polim?rica adicionada de a?a? liofilizado teve sua espessura aumentada o que provocou aumento da PVA, redu??o da solubilidade em ?gua e da atividade de ?gua, sendo estes dois ?ltimos par?metros vantajosos para uma embalagem de alimentos. Quanto ?s propriedades mec?nicas, observou-se que a for?a de ruptura e a deforma??o na perfura??o foram reduzidas. No teste de tra??o houve redu??o da tens?o na ruptura e no m?dulo de elasticidade. A deforma??o na tra??o apresentou maior resultado, indicando que a adi??o do a?a? liofilizado aumentou a flexibilidade do filme. Quanto a cor, o filme apresentou colora??o escura compat?vel com o fruto, com potencial uso para embalagem de alimentos escuros.

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