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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.
191

Produção de banana ´Nanicão` (Musa sp. AAA) em clima Cwa / Production of banana cv. Nanicão (Musa sp. AAA) in climate Cwa

Andréa Ribeiro Domingues 24 January 2012 (has links)
O clima classificado como Cwa é considerado marginal para a cultura da bananeira, pois apresenta inverno típico com baixas temperaturas e deficiência hídrica. O objetivo desse trabalho foi estudar o desenvolvimento da bananeira cv. Nanicão (Musa sp. AAA) em clima Cwa. Foram realizados dois experimentos, o primeiro para verificar a formação do cacho da bananeira desde a emissão da inflorescência até a colheita. No segundo experimento avaliou-se os quatro primeiros ciclos, com o objetivo de verificar a variação da duração do ciclo, produção e rendimento anual de cada ciclo. O experimento foi realizado em bananal com 5 anos de idade localizado no município Tiête SP. O bananal corresponde a uma área de 16,0 hectares com plantas oriundas de mudas micropropagadas, espaçamento de 2,4 m x 2,00m, irrigada por aspersão. Os dados meteorológicos foram retirados do Centro Integrado de Informações Agrometeorológicas. Para a condução do experimento 1 foram avaliadas 1104 famílias, no período de maio de 2010 a julho de 2011. Os fatores em estudo foram: época de emissão da inflorescência, duração do intervalo entre a emergência da inflorescência e colheita (I - C), quantidade de emissão de inflorescência nas diferentes épocas, época de colheita, massas dos cachos e produção. No segundo experimento avaliou-se 16,0 hectares de bananeira no período de setembro de 2005 a agosto de 2011. Avaliou - se a duração do ciclo de produção e o período da colheita de cada ciclo, bem como a produção e rendimento médio anual/ha. Foi observado no estudo que a produção de banana nesse tipo de clima é marcada por oscilações. As maiores taxas de emissões de inflorescências e menores durações de I-C ocorrem na época mais quente e chuvosa e taxas inferiores de emissões e durações de I-C foram maiores na época fria e seca do ano. As massas dos cachos e consequentemente as produções variam ao longo do ano, massas superiores são encontradas na época fria e seca e menores massas ocorrem na época quente do ano. Os quatro primeiros ciclos de produção apresentam variações na duração total do ciclo bem como no período de colheita, em consequência o rendimento médio anual de cada ciclo varia, de modo que, a partir do terceiro ciclo o rendimento médio decresce e estabiliza-se devido à extensão da duração do ciclo de produção. / The climate classificated by Cwa is not considerate totally appropriate for banana crop, because has the typical dry winter with low temperature, conditions that injure the plant development. The objective of this research was to verify the banana development cv. Nanicão (Musa sp. AAA) in Cwa climate. Two experiments were performed, the first one verified the development banana bunch formation, since the inflorescence emission until the harvest. The second experiments evaluated the first four cycles, aimed to verify the cycles variation, production and annual yield per cycle. The experiment was developed in field banana Nanicão with 5 years from planting, localized in Tiête São Paulo city. The total area is 16 ha with plants originated by micropropagated seedlings, spacing of 2,4m x 2,00m, irrigated by sprinkling. The meteorogical data was offered by Integrated Centre of Agrometeorogical Information. For the conduction the experiment 1 was evaluated 1104 families in period from May 2010 to July 2011. The factors studied were: epoch of inflorescence emission, time interval between the inflorescence emissions to harvest (I-H), amounts of inflorescences in different epochs of year, time of harvest, mass of bunch and production. In the second experiments aimed the production in total area of 16 ha, between September 2005 to August 2011. Evaluated the cycle time, the period of harvest, the production and medium annual yield per hectare. It was observed in this study the banana Nanicão production in this kind of climate is characterized for great oscillation in the yield during the production cycle. The higher rates of inflorescence emission and lower duration of I-H occurred in the hottest time of the year. The bunch mass and production vary throughout the year. The bunch mass biggest and production occurred in cooler time of the year. The first four production cycles vary a well as the time interval harvest in consequence the annual yield per cycle, so that from third cycle the medium annual yield decrease due to the extension of cycle duration.
192

Síntese da sacarose no amadurecimento da banana. Envolvimento da sacarose sintetase e sacarose fosfato sintetase / Sucrose synthesis during banana ripening: sucrose synthetase and sucrose phosphate synthetase involviment

Beatriz Rosana Cordenunsi 20 April 1989 (has links)
A sacarose sintetase pode ser extraída de bananas pré-climatéricas cisteína (0,02M), em tampão tris-HCl pH 8,0 (0,05M), contendo EDTA (O,OlM), PVP (1%) e bissulfito de sódio (0,02M) na proporção de 1:4 (massa de banana/volume desolução f extratora). O seu isolamento pode ser efetuado por precipitação com sulfato de amônio, cromatografia por peneira molecular seguida de troca iônica ou, alternativ~ente, por cromatografia apenas em troca iônica. Obtém-se assim preparações com atividade específica entre 0,42 e 6,11 e grau de purificação de 5 a 18 vezes. A enzima purificada tem elevada afinidade por UDPG (Km = 0,67), UDP (Km = O, 17) , frutose (Km = 0,31) e reduzida afinidade para a sacarose (Km = 22,7). A enzima está presente durante a fase de desenvolvimento do fruto até o período préclimatérico, quando sua atividade sintética e hidrolítica tende a desaparecer a medida que aumenta o tempo decorrido após a colheita. Contrariamente, a sacarose fosfato sintetase não é detectada nas fases iniciais de desenvolvimento do fruto, mas tem sua atividade aumentada durante o amadurecimento, concomitantemente ao desaparecimento do amido. A sacarose fosfato sintetase e não a sacarose sintetase pode estar envolvida na transformação amido-sacarose durante o amadurecimento. / Banana sucrose synthetase can be purified almost to homogeneity by extraction with tris-HCl pH 8.0 (0.05M) buffer containing cystein (0.02M), EDTA (O.OlM), PVP (1%) and NaHS03 (O.O2M), ammonium sulfate precipitation, followed by cromatography on DEAE-cellulose (or alteratively on Sepharose-6B followed by DEAE-cellulose). The purified enzyme activities has high affinity for UDPG (Km = 0.67), UDP (Km = 0.17), fructose (Km = 0.31) and low affinity for sucrose (Km = 22.7). The sucrose synthetase is present during all stages of fruit development until the climateric when its activity tends to disappear, as the time after harvesting decurs contrarily the activity of sucrose phosphate synthetase is not detected in the initial stages of development but its activity increases during ripening following starch desappearance. Sucrose phosphate synthetase instead of sucrose synthetase may be involved in starch-sucrose conversion in post-harvest bananas.
193

Produção de nanofibras de celulose por hidrólise enzimática / Cellulose nanofibers produced by enzymatic hydrolysis

Tibolla, Heloisa, 1989- 25 August 2018 (has links)
Orientadores: Florencia Cecilia Menegalli, Franciele Maria Pelissari Molina / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-25T00:00:43Z (GMT). No. of bitstreams: 1 Tibolla_Heloisa_M.pdf: 30429584 bytes, checksum: 643238deef75b3825c3b74575e11f722 (MD5) Previous issue date: 2014 / Resumo: A presente dissertação objetivou estudar o potencial da técnica de hidrólise enzimática na produção de nanofibras de celulose (NFCs) a partir da casca de bananas verdes da variedade "Terra" (Musa paradisiaca). Na primeira etapa do trabalho, o farelo da casca da banana foi caracterizado com base em suas propriedades físico-químicas, funcional e estrutural. Na segunda etapa, testou-se combinações de tratamentos (químico, hidrólise enzimática e tratamento mecânico) para isolar nanofibras de celulose. Na terceira etapa do trabalho avaliou-se a influência das condições de processo (pH, temperatura, concentração de enzima e concentração de substrato) na hidrólise enzimática com xilanase. Os experimentos foram realizados empregando-se um planejamento fatorial fracionado 24-1 com três pontos centrais. As NFCs foram caracterizadas quanto ao diâmetro, distribuição do comprimento, potencial zeta, grupos funcionais por FTIR, cristalinidade por difração de raios-X (DRX), concentração de NFCs produzidas e característica morfológica por microscopia eletrônica de transmissão (MET). A quarta e última etapa, foi realizada com o intuito de estudar a adição de mais uma hidrólise enzimática, usando o complexo celulolítico, na produção de NFCs. O farelo apresentou uma estrutura irregular, com teor de celulose de 7,5% e índice de cristalinidade de 15%. A presença de componentes amorfos (hemicelulose e lignina) foi constatada no farelo através da análise de grupos funcionais. Como resultados da segunda etapa, foram obtidas partículas de celulose em dimensões micro e nanométricas, evidenciando que o tratamento com potencial para produzir NFCs foi o branqueamento do farelo com KOH 5%, hidrólise enzimática com xilanase e celulase e após, desintegração das fibrilas com homogeneização mecânica, obtendo-se partículas com diâmetro médio de 14,9 nm. Na terceira etapa da pesquisa, as imagens da microscopia confirmaram que o tratamento com a enzima xilanase foi eficaz no isolamento de fibras de celulose na escala nanométrica. O diâmetro médio apresentado pelas mesmas foi de 8,8 nm. Em água neutra, as suspensões de nanofibras apresentaram potencial zeta alto e negativo, na faixa de -22,8 e -29,5, o que minimiza as interações que levam à formação de agregados de nanofibras, colaborando para a formação de uma suspensão coloidal mais estável. O índice de cristalinidade do farelo foi de 15,0% e das nanofibras variou entre 48,5 e 61,0%, demonstrando que o tratamento utilizado promoveu a remoção das frações amorfas. Os resultados obtidos a partir do planejamento fatorial mostrou que a enzima xilanase opera sobre o isolamento do NFCS em uma ampla faixa de condições do processo, dentro do intervalo de estudo. Os resultados encontrados na quarta etapa demonstraram que as cadeias de celulose das nanofibras foram reduzidas à monômeros de açúcares, principalmente glicose, visto que o complexo celulolítico atua de forma sinérgica na degradação total da celulose. O farelo da casca de banana é um resíduo agroindustrial com potencial uso para produção de nanopartículas. A hidrólise enzimática com xilanase mostrou-se ser uma técnica promissora na produção de nanofibras de celulose com alto desempenho como material de reforço em compósitos, sendo desnecessária a realização de um tratamento com a enzima celulase / Abstract: This dissertation aimed to study the potential use of the technique of enzymatic hydrolysis in the production of cellulose nanofibers (CNFs) from peel unripe bananas of the variety "Terra" (Musa paradisiaca). In the first stage of the work, the bran of the peel banana was characterized on the basis of their physicochemical, structural and functional properties. In the second stage, to isolate cellulose nanofibers, we tested combination of treatments (chemical, enzymatic hydrolysis and mechanical treatment). In the third stage of the study was evaluate the influence of process conditions (pH, temperature, enzyme concentration and substrate concentration) on enzymatic hydrolysis with xylanase. The experiments were performed employing a fractional factorial design 24-1 with three center points. The NFCS were characterized by diameter, length distribution, zeta potential, functional groups by FTIR, crystallinity by X-rays diffraction (XRD) and morphology features by transmission electron microscopy (TEM). The fourth and final stage was performed in order to study the efficiency of further enzymatic hydrolysis using cellulolytic complex to produce NFCS. The bran presented an irregular structure, with amount of cellulose of 7.5% and the crystallinity index of 15%. The presence of amorphous components (hemicellulose and lignin) was noted in the bran by functional groups analysis. As a result of the second stage, cellulose particles in micro and nanometric dimensions were obtained, indicating that the treatment with the potential to produce NFCS was bleaching bran with KOH 5%, enzymatic hydrolysis with cellulase and xylanase and after mechanical homogenization for disintegration of the fibrils, yielding particles with an average diameter of 14.9 nm. In the third step of research, the images of the microscope confirmed that the treatment with enzyme xylanase was effective in the isolation of cellulose fibers in the nanoscale. The average diameter presented by the same was 8.8 nm. In neutral water, suspensions of nanofibers showed high and negative zeta potential in the range of -22.8 and -29.5, which minimizes the interactions that lead to the formation of aggregates of nanofibers, contributing to the formation of a colloidal suspension more stable. The crystallinity index of the bran was 15.0% and the nanofibers was between 48.5 and 61.0%, demonstrating that the treatment promoted the removal of the amorphous fractions. Results obtained from the factorial design showed that xylanase enzyme operates on the isolation of the NFCS in a wide range of process conditions, within the evaluated range. The results found in the fourth step showed that the cellulose chains of the nanofibers were reduced to monomers sugars, especially glucose, since the cellulolytic complex acts synergistically in overall degradation of cellulose. The bran banana peel is an agricultural waste with potential use for production of nanoparticles. The enzymatic hydrolysis with xylanase was shown to be a promising technique for producing cellulose nanofibers with high performance as reinforcing material in composites, due to its ability to make it unnecessarily performing a treatment with cellulase enzyme, which was detrimental to the formation of NFCS / Mestrado / Engenharia de Alimentos / Mestra em Engenharia de Alimentos
194

The European Union banana market: demand estimation and evaluation of the new import regime

Chacón Cascante, Adriana January 1900 (has links)
Doctor of Philosophy / Department of Agricultural Economics / John M. Crespi / The EU is one of the world’s biggest importers of bananas and, as such, import policies enforced by this trade union are likely to have a great impact on major producers of bananas. Aiming to protect communitarian producers and exporters from selected ex-colonies of Africa, the Caribbean and Pacific and to honor previous agreements, the EU unified its import policy for bananas in 1993. This policy, known as the Common Market Organization for Bananas, generated one of the most controversial trade disputes in history. After several modifications of the original regime, in January 2006, the EU changed its import regime to satisfy a World Trade Organization mandate and to honor an agreement signed with the United States in 2000. This dissertation reviews the history of the trade disputes in the EU banana market and analyzes the effects that the new import regime will have on major suppliers. To do this, a theoretically-consistent demand system is estimated and then the calculated parameters are used to model the effects of the tariff-only import system in the EU banana market. Based on the results, producers surplus are estimated and Monte Carlo simulations are performed to do a sensitivity analysis of the results. In the demand estimation component, the EU market is modeled as a system containing four major suppliers using the Almost Ideal Demand System (AIDS). This estimation fills an important gap in literature regarding the lack of well-estimated demand elasticities of bananas in the EU. The EU banana market is then modeled based on a equilibrium displacement model framework. Results of this analysis are then used to calculate point estimates of producer surplus changes as a measure of the impact of the new import policy on banana suppliers. Monte Carlo simulations are based on parameter estimates obtained from the AIDS model. These simulations allowed not only sensitivity analysis but also probabilistic inferences about the statistical significance of the estimates obtained in the previous components. Results indicate that the hypothesis that the new import regime will not affect the major suppliers of the EU banana market cannot be rejected. This might indicate that the policy enforced by the Common Market Organization for Bananas and the current tariff-only import regime are statistically equivalent. In other words, the EU expertly enacted a tariff level that will leave much as status quo.
195

Management of Fusarium wilt of banana by means of biological and chemical control and induced resistance

Nel, Barbara 18 August 2008 (has links)
Management of Fusarium wilt of banana, one of the most important diseases of agricultural crops, is complicated and involves the consideration of factors such as the biology, epidemiology and population structure of the pathogen, and genetic resources and production practices of the crop. The development of an integrated disease management programme, therefore, is of great importance in countries where the Fusarium wilt pathogen, Fusarium oxysporum f.sp. cubense Foc, has been introduced into banaria fields, and where resistant cultivars are not acceptable to local markets. To achieve this, it is important to investigate new management strategies and to review methods that have been less successful in the past. These management practices need to be practical and affordable. Since certain cultural practices have proven to be effective, management practices that could compliment them should be considered. This thesis has attempted to investigate such practices in order to develop an integrated disease management programme for Fusarium wilt of banana. One of the most important findings of this study, was that the surface sterilant previously used to prevent the introduction of the Fusarium wilt into uninfected areas in South Africa, are not effective. The sterilants Sporekill and Prazin proved to be highly effective, and are now recommended to replace the sterilants previously used. Several fungicides reduced mycelial growth of Foc in vitro, with the OMI fungicides and Benomyl found to be the most effective. The same fungicides reduced the disease severity of Fusarium wilt in the greenhouse significantly, especially when they were applied as root dip treatments. None of the fungicides found effective against Foc have been evaluated in the field against Foc before. The next step, therefore, would be to evaluate root dip treatments combined with drench treatment in the field. Although it is expected that these fungicides might have a negative effect on the microbial populations in the soil, this has yet to be investigated. Fungicides may even weaken or stress the pathogen, making it more vulnerable for the action of an effective biocontrol agent or agents. Chemical activators are probably one of the most attractive strategies to combat Fusarium wilt of banana, since it stimulate the plants' own defence system. Banana plantlets were found to be quite sensitive to the amount and method whereby chemical activators were applied. The activator benzo-(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester induced resistance against Foc on the susceptible Williams cultivar in the greenhouse, but not in the field. In field studies, environmental conditions were much more variable than in the greenhouse, which made it difficult to evaluate the effectiveness of chemical activators. Sodium nitroprusside and a product containing the harpin protein showed promising results on the Williams and DRSI cultivars, respectively. These activators need to be considered as part of an integrated disease management programme. Since they are not directly applied to the soil, they will not have a negative effect on the microbial populations in the soil. Several Fusarium isolates had been collected from banana fields with disease suppressive soils in Kiepersol, South Africa. Most of these isolates were F. oxysporum, and with the exception of one isolate, proved to be non-pathogenic to banana plants. A PCR-based restriction fragment length polymorphism (RFLP) analysis of the intergenic spacer region of the ribosomal RNA operon grouped the non-pathogenic F. oxysporum isolates into 12 distinct genotypes. A great diversity could be seen among the non-pathogenic isolates compared to the pathogenic Foc isolates. The known-biological control agent F047 grouped with three of the South African isolates, while the one pathogenic isolate grouped with the pathogenic Foc from diseased Cavendish bananas in South Africa By using PCR-RFLPs, we were able to rapidly characterize the structure of non-pathogenic isolates of F. oxysporum in disease suppressive soils in Kiepersol. This could assist us in our search for potential biological control agents for Fusarium wilt of banana. Representative isolates from the 12 genotype groups were selected for evaluation of Fusarium wilt suppressive properties in banana. These non-pathogenic F. oxysporum isolates appeared to be good biological control candidates and was compared to known biological control agents and commercial biological control products. Fourteen of the non-pathogenic isolates, the combination of two Trichoderma strains form suppressive soils in South Africa, and two Pseudomonas fluorescens isolates were found to significantly reduce Fusarium wilt development in the greenhouse. The commercial products Patostop, B-rus and a mixture of arbuscular mycorrhizae were also found to suppress the disease severity of Foc significantly. The well-know biological control agent F047 proved to be not effective. Results concluded that two of the non-pathogenic F. oxysporum isolates and the two P. fluorescens isolates, one of which was the well-known WCS 417, were the most effective of all the agents evaluated. Since combinations of biocontrol agents may provide even more consistent and effective control than a single agent, future research will include the combination of biocontrol agents found effective in this study. It would also be of great value to determine the mode of action of these isolates, so that isolates with different modes of action could be combined to enhance the suppression effect. Biological control can be a very useful component of an integrated disease management programme, since the effective agent or agents can easily be established on tissue culture banana plantlets before they are planted in the field. AFRIKAANS : Een van seker die mees belangrikste grondgedraagte siektes in lanbou, is Fusarium verwelksiekt van piesangs. In Suid-Afrika, is die siekte verantwoordelik vir emstige verliese in die piesang produksie. Aangesien daar geen weerstandbiedende kultivars beskikbaar is wat deur die mark aanvaar word nie, is dit van kardinale belang dat 'n geintegreerde siekte beheer program vir Suid-Afrika ontwikkel word. Voordat so 'n program saamgestel kan word, is dit belangrik dat verskeie faktore aangaande die patogeen en piesang poduksiepraktyke in ag geneem moet word. Beheermaatreëls moet prakties en bekostigbaar wees, en moet die reeds bestaande praktyke kan bevoordeel. Studies wat in hierdie tesis aangebied word, oorweeg beheermaatreëls wat gekombineer kan word met die huidige praktyke, nadat vorige praktyke ook in ag geneem is. Daar word gesoek na nuwe meer doeltreffende en ekonomiese metodes om siektes te beheer. Metodes wat doeltreffend aangewend kan word om die voorkoms van die siekte te vermirider. In vitro en in vivo studies het getoon dat die DMI swamdoders en Benomil die groei van die patogeen en die ontwikkeling van Fusarium verwelksiekte die meeste onderdruk. Die beste resultate is in die glashuis gevind nadat die wortels van plante in die middels geweek is. Positiewe resultate is ook verkry met die grondtoediening van Benomil 'n week nadat plante geplant is in Foc geïnfekteerde grond. Die chemiese beheer van Fusarium verwelsiekte kan verder ondersoek word deur die effek van die grondtoedienings en wortelbehandelings in die veld te ondersoek. Daar word egter verwag dat die swamdoders moontlik 'n negatiewe uitwerking op die mikrobiese aktiwiteit in die grond kan veroorsaak. Die gebruik van effektiewe ontsmettingmiddels is uiters belangrik vir die voorkomende beheer van Fusarium verwelkdiekte op piesangs. Die ontsmettingmiddel, koper oxichloried, wat tot onlangs in Suid Afrika gebruik was, is ondoeltreffend gevind vir ontsmettingsdoeleindes. Prazin en Sporekill, twee omgewingsvriendelike middels, is baie effektief gevind en word dus aanbeveel vir die ontsetting van voertuie, skoene en veld toerusing. Chemiese plant aktiveerders stimuleer plante om hulleself te beskerm deur middel van weerstandsmeganisms. Piesang plante het sensitiwiteit getoon toonoor die konsentrasie en die toedieningsmetode van hierdie chemiese aktiveerders. In die glashuisproewe het die aktiveerder benzo-(1,2,3)thiadiazole-7-carbothioic suur S-metiel ester weerstand gestimuleer in die Williams kultivar. As gevolg van veranderende toestande in die veld was dit moeiliker om die chemiese aktiveerders se werking te evalueer. Nogtans het die middels natrium nitroprussied en 'n produk wat die protein harpin bevat die voorkoms van siekte op die Williams en DRS 1 plante verlaag. Chemiese aktiveerders behoort sterk oorweeg te word as deel van 'n geintegreerde beheer program, aangesien chemiese aktiveerders nie direk tot die grond aangewend word nie, en geen negatiewe uitwerking op die natuurlike mikrobiese populasies in die grond uitoefen nie. Verskeie Fusarium isolate is geisoleer vanuit siekte onderdukkende gronde in die Kiepersol area van Suid-Afrika. Die meeste van die isolate is geidentifiseer as F. oxsysporum. 'n PKR-gebaseerde restriksie fragment lengte polimorfisme (RFLP) ontleding van die "intergenic spacer region" van die ribosomale DNS operon het die niepatogeniese F. oxysporum isolate in 12 verskillende genotypes opgedeel. 'n Groot diversiteit was sigbaar onder die nie-patogeniese isolate in vergelyking met die patogeniese foc isolate. Die bekende beheer agent, Fo47 het gegroepeer saam met drie van die Suid Afrikaanse nie-patogene. Hierdie tegniek het ons in staat gestel om die nie-patogeniese populasie van onderdrukkende gronde in Kiepersol vinnig te karakteriseer en potentiele biologiese agente te identifiseer. Verteenwoordigende isolate van die 12 genotipiese groepe wat geidnetifiseer is, is geselekteer vir verdere evaluasie. Dit is gevind dat die isolate goeie kandidate vir moontlike bio-beheer agente maak. Die onderdrukkingsvermoe van die nie-patogene is vergelyk met die van bekende bio-beheer agente en komersiele produkte wat beskikbaar is. Veertien van die nie-patogene, die kombinasie van twee Trichoderma spp., en twee Pseudomonas fluorescens isolate het die siekte ontwikkeling van Fusarium verwelking merkwaardig onderdruk in die glashuis. Die komersiele produkte Patostop®, B-rus en die kombinasie van twee mycorrhizae isolate is ook gevind om die voorkoms van siekte te verlaag. Die wel-bekende biobeheer agent Fo47 is oneffektief gevind teen Fusarium verwelksiekte van piesangs. Resultate van die studie het bewys dat twee van die nie-patogeniese F.Oxysporum isolate en twee P. Fluorescens isolate, waarvan een die welbekende WCS 417 is, uiters effektiewe beheer agente teen Foc is. Toekomstige studies sal fokus op die kombinasie van die bio-beheer agente wat die meeste potensiaal getoon het in die studie, asook hulle meganismes van werking. Biologiese beheer is van groot waarde vir 'n geïntegreerde beheer program. Dit kan maklik met bestaande beheer maatreëls gekombineer word en potensiële biologiese beheer agente kan vooraf op weefselkultuur plante in die kwekery gevestig word. / Dissertation (MSc)--University of Pretoria, 2011. / Microbiology and Plant Pathology / unrestricted
196

Estudo dos parâmetros de extração de compostos fenólicos e avaliação da atividade antioxidante in vitro da banana (Musa sp.) / Study of extraction parameters of phenolic compounds and evaluation of in vitro antioxidant activity of banana (Musa sp.)

Pereira, Gustavo Araujo, 1991- 27 August 2018 (has links)
Orientador: Gláucia Maria Pastore / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-27T07:08:08Z (GMT). No. of bitstreams: 1 Pereira_GustavoAraujo_M.pdf: 1768265 bytes, checksum: 651e1ab8aaa3bc75e27daed3b11df00e (MD5) Previous issue date: 2015 / Resumo: O objetivo do presente trabalho foi estudar a influência dos parâmetros de extração sólido-liquido e de enzimas fenoloxidases (peroxidase) na recuperação de compostos fenólicos a partir do pó da casca de banana liofilizada (CBL), bem como quantificar o conteúdo de compostos fenólicos totais (FT), flavonoides totais (CF) e a atividade antioxidante da CBL e do pó da polpa de banana liofilizada (PBL). A banana utilizada foi da variedade Prata no estágio 6 de maturação (casca totalmente amarela). Primeiramente, o estudo foi iniciado com a seleção dos parâmetros de extração (temperatura, agitação, solvente e relação sólido-líquido) por meio de um Delineamento Fracionado 24-1 e, em seguida, o método de Superfície de Resposta foi empregado para otimizar os principais fatores do processo de extração (relação sólido-líquido e solvente). A casca da banana apresentou elevada atividade da enzima peroxidase (POD), o que provocou a oxidação dos compostos fenólicos e a redução da capacidade antioxidante do extrato. As melhores condições para a extração de compostos fenólicos a partir da casca de banana foram: relação sólido-solvente de 2,5 g/100 mL (1:40), solvente etanol 54% (v/v etanol:água) e homogeneização com auxílio de Ultra Turrax por 30s a 11.000 rpm. O conteúdo de FT obtido com esse sistema de extração foi de 2,44 g EAG/100 g CBL. A casca de banana apresentou conteúdo de FT (2,44 g EAG/100 g CBL), CF (2,32 g EC/100 g CBL) e atividade antioxidante mensurada pelos métodos de DPPH (380,84 ?mol EQT/g CBL; IC50 = 71,74 ?g/mL), TEAC (325,84 ?mol EQT/g CBL) e ORACFL (ORAC Total = 994,33 ?mol EQT/g CBL) maiores do que a polpa de banana (FT = 0,25 g EAG/100 g PBL; CF = 0,21 g EC/100g PBL; DPPHIC50 = 690,97 ?g/mL; TEAC = 11,05 ?mol EQT/g PBL; ORAC Total = 80,16 ?mol EQT/g PBL). A banana é uma das frutas mais produzidas no mundo, e devido ao seu elevado consumo e abundância pode ser considerada uma importante fonte de compostos antioxidantes. Finalmente, por meio deste estudo foi possível verificar que a polpa e a casca de banana apresentam compostos fenólicos antioxidantes. Mais estudos devem ser realizados para verificar a influência do consumo desse / Abstract: The objective of the present work was to study the influence of solid-liquid extraction parameters and phenoloxidases enzymes in the recovery of phenolic compounds from freeze-dried banana peel powder (BPP), as well as to quantify the total phenolic content (TPC), flavonoid content (FC) and antioxidant activity of BPP and freeze-dried banana pulp powder (BPU). The banana Prata variety was utilized in 6th stage of ripening (fully yellow peel). First of all, the study started with the selection of the extraction parameters (temperature, agitation, solvent and solid-liquid ration) through factionary design (24-1). Subsequently, the Response Surface Methodology (RSM) was employed to optimize the main parameters of the extraction process (solid-liquid ration and solvent). The banana peel showed high peroxidase activity (POD), which led the oxidation of phenolic compounds and the decrease of antioxidant activity of the extract. The best conditions for the extraction of phenolic compound from BPP were solid-liquid ration of 2.5 g/100 mL (1:40), solvent ethanol 54% (v/v ethanol:water) and homogenization using Politron at 11.000 rpm for 30 s. The total phenolic content obtained whit this extraction system was 2.44 g GAE/100 g BPP. The banana peel showed TPC (2.44 g GAE/100 g BPP), FC (2.32 g CE/100 g BPP), and antioxidant activity measured by DPPH (380.84 ?mol TE/g BPP; IC50 = 71.74 ?g/mL), TEAC (325.84 ?mol TE/g BPP) and ORACFL (ORAC Total = 994.33 ?mol TE/g BPP) methods higher than banana pulp (TPC = 0.25 g GAE/100 g BPU; FC = 0.21 g CE/100 g BPU; DPPHIC50 = 690.97 ?g/mL; TEAC = 11.05 ?mol TE/g BPU; ORAC Total = 80.16 ?mol TE/g BPU). The banana is one of the most produced and consumed fruit in the entire world and can be considered as an important source of natural antioxidants. In this sense, this study was to possible found that banana pulp and peel have phenolic compounds with antioxidants properties. More studies should be performed to verify the relationship between banana consumption and human health. Furthermore, research addressing the use of the banana peel by food and pharmaceutical and medical industries. fruto tropical na saúde do corpo humano e também pesquisas abordando o uso da casca na indústria de alimentos e no desenvolvimento de novos produtos / Mestrado / Ciência de Alimentos / Mestre em Ciência de Alimentos
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Identificação de genes com variação de expressão durante o amadurecimento da banana pela aplicação de técnicas de análise diferencial / Identification of genes with variation of expression during ripening of the banana by the application of differential analysis techniques

Adriana de Godoy 26 July 2006 (has links)
No amadurecimento ocorrem alterações bioquímicas que têm impacto nas características organolépticas dos frutos, tais como cor, sabor, odor, maciez, etc e também na composição química com reflexos no valor nutricional. Nesse processo altamente coordenado, em que enzimas são sintetizadas de novo, a expressão gênica desempenha um papel importante em seu controle. Porém no que tange a frutos tropicais, em especial a banana (fruto de estudo), as informações relativas ao controle de expressão gênica, se restringem a algumas enzimas-chave. Assim sendo, uma abordagem ampla, e não restrita somente a alguns genes, pode contribuir para o entendimento da regulação de algumas etapas metabólicas do amadurecimento. Deste modo, o objetivo desse trabalho foi identificar genes com variação de expressão durante o amadurecimento da banana. O trabalho experimental foi feito com dois tipos de amostras, uma referente ao período pré-climatérico e a outra ao climatérico. Para tanto, foram utilizadas duas técnicas com princípios diferentes: \"differential display\" RT-PCR e a biblioteca de subtração de cDNA, de modo a otimizar e ampliar a possibilidade de se obterem genes diferentes, e que, por ventura, fossem obtidos por uma técnica, mas não por outra. Ambas metodologias tiveram como ponto de partida a extração de RNA de amostras de banana referentes aos dois períodos em estudo. Ao utilizar a técnica \"differential display\" RT-PCR foram obtidos nove genes com variação de expressão, quatro com aumento de expressão em bananas pré-climatéricas, similares à imunofilina, translocador de adenina nucleotídeo, proteína de cloroplasto e proteína bacteriana e cinco com aumento de expressão no período climatérico, similares à aquaporina, legumina, desoxiguanosina quinase, NADH dehidrogenase e proteína bacteriana. Com a biblioteca de subtração de cDNA foram obtidos cinco genes com aumento de expressão em bananas climatéricas, os quais foram similares à expansina, omega-3-desaturase, taumatina, NADH mitocôndrial e metalotioneína. / During ripening many biochemistry modifications have impact in organoleptical characteristics of fruits, like colour, flavor, softness, etc and also in chemical composition (nutritional value). In this process highly coordinated, which enzymes are de novo synthesize, genic expression has an important role in this control. However, in tropical fruits, especially banana (fruit choosen), some information relative to gene expression control, are restrict to some key enzymes. An approach, not only restrict to some genes, can contribute to understand some ripening metabolic steps. So, the objective ot this work was obtain and identify genes with altered expression in banana ripening, defining two analysis fases, about respiratory period and ethylene pick. The experimental work used two kinds of sample, one of them before climateric period and the other after climateric period. They were applied two tecniques with different principle: differential display RT-PCR and cDNA subtraction library, to optimize and increase the possibility to obtain different genes, and which can be obtain by one technique but not in other. Both metodologies had the same first step, the RNA extraction. Following, genes with altered expression were obtained, identified and confirmed. In differential display RT-PCR were obtained nine genes, four of them had an increase of expression before climateric bananas and they were similar to immunophilin, adenine nucleotide translocator, chloroplast protein and bacterial protein and five with an increase of expression after climateric which were similar to aquaporin, legumin, desoxiguanosine quinase, NADH dehydrogenase and bacterial protein. Using cDNA subtraction Iibrary were obtained five genes with an increase of expression in post-climateric bananas and these sequences were similar to expansin, omega-3-desaturase, thaumatin, NADH mithocondrial and methalotionein.
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Atividade e expressão gênica da α-1,4 glicosidase durante o amadurecimento da banana (Musa acuminata AAA cv. Nanicão) / Activity and gene expression of α-1,4-glycosidase during maturation of banana (Musa acuminata AAA cv. Nanicão)

Denise Perez Vieira 07 February 2006 (has links)
Dependendo da cultivar, a banana acumula entre 15 e 22% de amido de reserva, durante o desenvolvimento. Este amido é degradado durante o amadurecimento, com a síntese e acúmulo concomitantes de 12 a 20% de açúcares solúveis. Dentre as várias mudanças que a banana sofre durante o amadurecimento, esta é uma das mais complexas e ainda muito pouco conhecida. Dentre as várias enzimas possivelmente relacionadas à degradação do amido, foi detectada a atividade da α-(1,4) glicosidase em extratos de polpa de banana em amadurecimento. Neste trabalho, estudou-se a atividade da α-(1,4) glicosidase, a clonagem do seu gene e a transcrição do respectivo mRNA da α-(1,4) durante o amadurecimento da banana tratada ou não com 100 ppm de etileno. Ambas as isoformas, neutra e ácida, tiveram perfis de atividade paralela à degradação do amido, compatível com uma possível atuação sobre compostos derivados da degradação do amido. Já que nenhuma das isoformas atua sobre a maltose, parece não tratar-se de uma maltase típica. Além disso, o seqüenciamento de parte do gene da isoforma neutra mostrou alta homologia com glicosidases de outros vegetais, confirmando a sua identidade. Em amostras de banana não tratadas foi observada um aumento no nível de transcrito de α-glicosidase neutra, contudo, com alterações no perfil de atividade. Quando as amostras de banana foram tratadas com 100 ppm de etileno, foi observado um aumento nos níveis de transcrito de α-glicosidase constante durante todo o amadurecimento. / Banana fruit accumulates between 15 and 22% of reserve starch, during development, depending on the cultivar. The starch is degraded during banana ripening, in concomitance with soluble sugars accumulation (12-20%). Among the changes that banana fruit suffers during ripening, this is one of most complex and still very little known. Alpha-(1,4) glucosidase activity was already detected before in banana pulp extracts. Here we report the study of the α-(1,4) glucosidase activity, the clone of its gene and the transcription of respective mRNA of α-(1,4) during the banana (treated or not with 100 ppm of ethylene) ripening. Both isoformas, neutral and acid, had an increase in activity concomitant with starch degradation. Since both forms do not act on maltose, it is possible that they utilize oligossacharides derived from starch degradation as substrate. Moreover, a partial cDNA sequence of neutral isoform, showed high similarity with glucosidases of other vegetables. Bananas samples treated with 100 ppm of ethylene, showed an increase in the constant transcript levels of α-(1,4) glucosidase during all the ripening.
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Perfil metabólico da banana durante o amadurecimento / Metabolic profile of banana during ripening

Andreia Ricci Hernandes 11 October 2005 (has links)
A análise do perfil metabólico de frutos em amadurecimento pode prover informações a respeito de quais as vias metabólicas são ativadas e inativadas durante o processo. Tais informações podem auxiliar na identificação de genes expressos nessa fase do ciclo de vida do fruto, ampliando o conhecimento sobre os mecanismos envolvidos no amadurecimento. Usando esta abordagem, este trabalho tem por objetivo identificar mudanças significativas nos níveis de metabólitos da banana durante o amadurecimento induzido pelo etileno. Para tal utilizou-se a cromatografia em fase gasosa acoplada a espectrometria de massas para a análise em função do poder de resolução da técnica. Utilizando a biblioteca de espectros de massa NIST 98 foi possível identificar 70 substâncias na fração polar e 40 substâncias na fração apoiar incluindo aminoácidos, açúcares, ácidos orgânicos, lipídeos entre outros. A análise de perfil metabólico revelou importantes variações nos níveis metabólicos de açúcares e ácidos orgânicos, provavelmente devido ao aumento na taxa respiratória do fruto. A maltose e o mio-inositol foram os metabólitos escolhidos para uma análise mais detalhada, que evidenciou a influência de outros metabólitos independentes do etileno na regulação dos eventos da degradação do amido. / The analysis of the metabolic profile of fruits can provide information regarding which metabolic ways are activated and inactivated during the ripening. Such information may help the identification of expressed genes in this process extending the knowledge on the involved mechanisms of ripening. Using this approach, the aim of this work was identify significant changes in the levels of metabolites of the banana during the ripening induced by ethylene. In this way it was used gas chromatography connected the mass spectrometry for these analysis, due to the high resolution of this technique. Using the NIST 98 library of mass spectra it was possible to identify about 70 substances in the polar fraction and 40 substances in the apolar fraction, including amino acids, sugars, organic acid, lipids, and others. The analysis of metabolic profile revealed important variations in the metabolic levels of organic acid sugars and, probably due to an increase in the respiratory rate of the fruit. A detailed analysis was conducted with maltose and myo-inosytol and revealed the influence of other metabolites which independed of ethylene, in the regulation of starch degradation.
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O efeito da proximidade do fragmento florestal de Mata Atlântica sobre a área de cultivo no amadurecimento de bananas (Musa acuminata AAA cv. Nanicão) e nos compostos fenólicos das folhas de bananeiras / The effect of the proximity of the Atlantic Rainforest fragment over the crop area in the ripening of bananas (Musa acuminata AAA cv. Nanicão) and the phenolic compounds of banana leaves.

Victor Costa Castro-Alves 17 January 2014 (has links)
Considerando (1) a importância da bananicultura no Vale do Ribeira, (2) o destaque da Mata Atlântica no contexto da conservação da fauna e flora mundial, (3) a necessidade da adoção de práticas agrícolas alternativas mais eficientes do ponto de vista ambiental e econômico, (4) o papel dos hormônios etileno, acido indol-3-acético (AIA) e ácido abscísico (ABA) no contexto das respostas dos vegetais a diferentes condições ambientais e nos atributos de qualidade da banana, (5) a falta de metodologias otimizadas para a extração de compostos fenólicos solúveis totais (CFST) em bananeiras e (6) a importância do estudo da relação entre os CFST e fatores de estresse, o presente trabalho teve como objetivo avaliar a influência da proximidade do fragmento florestal de Mata Atlântica com a área de cultivo da banana (Musa acuminata AAA cv. Nanicão) sobre o amadurecimento da fruta e os CFST em folhas de bananeiras, além de otimizar uma técnica para a extração destes últimos. Foi observado que bananas colhidas próxima ao fragmento florestal apresentam vida-verde (período compreendido entre a colheita do fruto e o início do seu amadurecimento) maior quando comparados a frutos com a mesma idade fisiológica, porém colhidos em áreas sem a influência da floresta nativa. Este fato pode ser explicado, pelo menos em parte, pela diferença nos perfis de etileno, ABA e AIA ao longo do amadurecimento das bananas provenientes das diferentes áreas, que também influenciam no metabolismo amido-sacarose. Quanto aos CFST nas folhas, foi observado que a utilização de acetona 80% em água (v/v) e posterior emprego de hexano para a remoção do excesso de clorofilas é capaz de obter um bom rendimento de extração de CFST, sem extrair compostos que interferem significativamente no método de Folin-Ciocalteu. Além disso, a utilização da metodologia otimizada mostrou que bananeiras podem apresentar diferenças na sua composição de fenólicos quando influenciadas ou não pela presença de biodiversidade. Assim, a avaliação dos CFST em folhas pode fornecer informações importantes sobre as condições ambientais da planta. / Considering (1) the importance of banana production in Ribeira Valley, (2) the Atlantic Rainforest in the context of fauna and flora conservation, (3) the need for the adoption of more sustainable agricultural practices, (4) the ethylene, indole 3-acetic acid and abscisic acid responses in acclimation mechanisms of plants and in the quality attributes of the banana, (5) the lack of methodologies optimized for the extraction of total soluble phenolics compounds (TSPC) in banana leaves and (6) the importance of the relationship between the TSPC content and stress factors, the present work aimed to evaluate the influence of the Atlantic Forest fragments proximity in the banana (Musa acuminata AAA cv. Nanicão) crop area on fruit ripening and leaves TSPC levels, using a optimized methodology. It was observed that bananas harvested near to the forest fragment presented a longest greenlife (period between the harvest and the climacteric) when compared with the fruits with the same phisiologycal age, but without the influence of the native forest. This fact can be explained, at least partly, by the difference on ethylene, ABA and IAA profiles in the ripening of bananas from the different areas, which also influence the starch-sucrose metabolism. Moreover, it was observed that the extraction with acetone (80% v/v in water) and posterior hexane cycle to remove chlorophylls excess was able to obtain a good TSPC extraction yield in leaves, without extracting compounds that interfere significantly with Folin-Ciocalteu method. In additional, the use of optimized methodology showed that bananas leaves can present different TSPC amount when influenced by the presence of native forest. Thus, the evaluation of leaves TSPC profile can provide important information about the environmental conditions of the plant.

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