Orientadores: Paulo Ademar Martins Leal, Sylvio Luís Honório / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-20T12:03:10Z (GMT). No. of bitstreams: 1 Oliveira_DenizeCristineRodriguesde_M.pdf: 1514216 bytes, checksum: 5b23bd3986cd65f29487a7dbef3936db (MD5) Previous issue date: 2012 / Resumo: Devido a uma tendência da população mundial em adquirir hábitos de vida mais saudáveis, cresce o consumo de hortaliças folhosas a cada ano, juntamente com a exigência da população pela qualidade total e segurança do alimento. Lactuca sativa L. (Asteraceae) é considerada a mais importante das hortaliças no grupo das folhosas, sendo também a mais produzida e mais consumida no Brasil. Um dos entraves é a alta perecibilidade do produto, ocorrendo perdas ao longo de toda cadeia produtiva. O objetivo principal deste trabalho foi estudar a influência de sistemas de colheita diferenciada em quatro tipos de alface (Repolhuda Americana 'Graciosa', Solta Crespa 'Vanda', Solta Lisa 'Marcela' e Solta Crespa 'Lavínia'), visando a melhor forma de manutenção da qualidade. Foram estudados os sistemas de colheita diferenciada com raiz e com corte que minimizem o dano por corte, denominados de corte 1 e 2, realizados na transição caule raiz, e entre o início da zona radicular e a primeira inserção de folha, comparado com o processo de colheita convencional. A qualidade do produto foi determinada por análises físico-químicas e sensoriais. A interpretação dos resultados foi realizada por análise de variância e teste de Tukey a 95% de confiabilidade, além de análise de componentes principais. Concluiu-se que para todas as características avaliadas houve degradação da qualidade ao longo do período de armazenamento. Para a alface 'Graciosa' o sistema de colheita realizado pelo tratamento corte 1 (transição caule raiz) não é recomendado, sendo os demais iguais para manutenção da qualidade. Já para a alface 'Vanda' recomenda-se os sistemas corte do produtor e corte 1, pois obtiveram uma degradação lenta dos parâmetros físico-químicos. Para a alface 'Marcela' recomenda-se o sistema de colheita representado pelos tratamentos com raiz e corte 2 (entre o início da zona radicular e a primeira inserção de folha). Para a alface 'Lavínia', recomenda-se o sistema de colheita representado pelos tratamentos com raiz e corte do produtor.Houve redução da qualidade das plantas de alface do 1° ao 5° dia de armazenamento, sendo que no 6° dia apenas a alface 'Lavínia' no tratamento com raiz e corte 2 foram consideradas aceitáveis No 9° dia de armazenamento todas as amostras foram consideradas impróprias para o consumo / Abstract: Leafy vegetables consumption increases every year due to a tendency of the world's population in acquiring a healthier lifestyle. Lactuca sativa L. (Asteraceae) is considered the most importantin the group of leafy vegetables. It is almost exclusively used, in natura, as a fresh vegetable. Lettuce (Lactuca sativa L.) is the leafy vegetable most widely produced and consumed in Brazil, main production areas are concentrated in green belts next to big consumercenters, to avoid losses caused to its perishability. In addition, is also increased every year the demand of the population for total quality and safety of the food. This project aims to integrate the stages of harvesting of four different types (Repolhuda Americana 'Graciosa', SoltaCrespa 'Vanda', Solta Lisa 'Marcela' e SoltaCrespa 'Lavínia'), suggesting that the procedures for collection, be carried out with minimum handling, least loss of mass and exuberance; keeping the quality and extending the shelf-life, respecting the legal standards of use. Differentiated harvest was studied, with root and cutting that minimize the damage and mass loss, when compared to traditional harvesting procedures. The product's quality were determined by physical-chemical and sensorial analyses. Interpretation of the results was performed by analysis of variance and Tukey test at 95% reliability, as well as principal component analysis, with the aid of programsAssistat version 7.6 beta (SILVA, 2011) and R version 2.14.1 (R, 2011). It was found that for all attributes, quality degradation has occurred during the storage period. For 'Graciosa' lettuce, the worst harvest system studied was the cutting 1. As for the 'Vanda' lettuce, the best cuts were the producer cut and cutting 1, since it had a slow degradation of the physical chemical parameters. For the 'Marcela' lettuce, the producer treatment showed the worst results. Finally for 'Lavínia' lettuce, the best harvesting system was represented by the treatments with root and producer cutting. Results of sensorial analysisindicated that from the sixth storage day lettuce plants were considered unacceptable in respect to its acquisition, except for the 'Lavínia' lettuce with root treatment and cut 2, which reach the same situationonly in the ninth day / Mestrado / Tecnologia Pós-Colheita / Mestre em Engenharia Agrícola

Philosophiae Doctor - PhD / We hypothesize that South African medicinal plants contain compounds that can act in synergism with synthetic antifungal compounds. Four fungicides - Sporekill™, Rovral™, Terminator™ and Teldor™ at doses 0.1, 0.2, 0.4 and 0.8 mL L-1 and plant species Galenia africana, Elytropappus rhinocerotis and Tulbaghia violacea were tested aloneand in different combinations for their potency (efficacy) on radial growth inhibition of Botrytis cinerea strains on potato dextrose plates. Four doses of plant extract for each of the respective plant species were used. A total of 48 combinations were tested for each strain. Mixtures of plant extracts were far more effective in controlling strains compared to the individual components alone, representing significant levels of in vitro synergistic interactions. Combinations of these components represent an attractive future prospect for the development of new management strategies for controlling B. cinerea. Since the in vitro tests of these mixtures showed inhibitory activity, the mixtures were tested for activity in assays on Granny Smith apples. In vitro tests can be used to screen mixtures to obtain information on their inhibitory activity on a pathogen, however, the environmental conditions of the fruit and the ability of the pathogen to grow into the fruit cannot be simulated in vivo. A series of two-fold doses of medicinal plant extracts were combined with fungicides to conduct decay inhibition studies. The incidence of gray mold was significantly reduced by mixtures of plant extracts and fungicides. Under conditions similar to those in commercial storage, a drench treatment with G. africana and Rovral™ significantly (p=0.05) inhibit gray mold on the apples and was more effective than the plant extract and fungicide alone. The treatments exerted synergistic effects and were markedly better than the components applied alone. The wound colonization assay was used for optimal decay control. In a drench, much higher volumes of the treatments are used to ensure that the components of the suspension are deposited evenly over the entire fruit surface. Drenching of fruit to apply other chemicals is an established practise in the pome (fleshy) fruit industry, and simplifies the commercial application of the mixtures, as no additional infrastructure at commercial packing houses will be required. This approach not only makes it possible to reduce fungicide concentrations while maintaining adequate decay control, but also ensures a reduction of the chemical residue on the fruit. / South Africa

Chez la banane dessert, les saveurs sucrée et acide, caractéristiques importantes pour les consommateurs, sont pilotées par les teneurs en acides citrique et malique. Ce travail a donc porté sur l’étude des processus physiologiques qui pilotent l’accumulation de ces acides dans la pulpe de banane (Musa sp. AA) en combinant analyse expérimentale et modélisation écophysiologique. Nous nous sommes notamment intéressés à l’effet du génotype et des conditions de croissance du fruit en adoptant une approche intégrative liant les phases pré et post récolte.Les effets de la charge en fruit, de la fertilisation potassique, et du stade de récolte sur l’accumulation du citrate et du malate dans la pulpe ont été étudiés expérimentalement. La variabilité génotypique a été prise en compte en choisissant trois génotypes présentant des acidités contrastées à maturité. Des différences d’évolution des teneurs en acides, dues à des modifications métaboliques, ont été observées entre les génotypes pendant les phases pré et post récolte. Le stade de récolte a eu un effet significatif sur les teneurs en acides des fruits pendant la maturation post récolte. La charge en fruit et la fertilisation potassique n’en ont eu aucun. Des modèles écophysiologiques ont été développés pour prédire différents critères d’acidité de la banane en pré et post récolte. Le pH et l’acidité titrable ont été prédits par un modèle d’équilibres acido-basiques, la teneur en malate par un modèle de stockage vacuolaire, et la teneur en citrate par un modèle du cycle de Krebs. Ces modèles ont permis d’identifier les processus physiologiques clés qui pilotent l’acidité de la banane. Des paramètres génotypiques ont été identifiés liés à l’activité de l’enzyme malique mitochondriale et à celle des transporteurs mitochondriaux du malate pour le modèle citrate, et à l’activité des pompes à protons vacuolaire ATPases pour le modèle malate. Ces modèles ont également permis de disséquer l’effet des conditions de croissance du fruit sur l’acidité de la banane. L’intégration des modèles développés dans un modèle d’élaboration de l’acidité et son utilisation potentielle pour l’amélioration variétale sont discutées. / Citric and malic acids determine the sourness and sweetness of banana pulp, which are the two main determinants of consumer preferences. The present work focused on the physiological processes controlling the accumulation of citric and malic acids in banana pulp (Musa sp. AA) using experimental analysis and ecophysiological modeling. We chose an integrative approach linking the pre and post-harvest stages, and focused on the effect of genotype and fruit growing conditions. Experiments were conducted to study the effect of fruit load, potassium fertilization and fruit age at harvest on the accumulation of citrate and malate in banana pulp. To account for genotypic variability, three genotypes with contrasting acidity at the eating stage were studied. Major differences in the pattern of citrate and malate accumulation were found in the three cultivars both during growth and post-harvest ripening and were shown to be the result of metabolic changes. The harvest stage had a significant effect on the concentrations of acids during post-harvest ripening. Fruit load and potassium fertilization had no effect.Ecophysiological models were developed to predict several banana acidity criteria during the pre and post harvest stages. pH and titratable acidity were predicted by a model of acid-base reactions; malate content by a model of vacuolar storage; and citrate content by a model of the TCA cycle. These models led to the identification of the key physiological processes that control banana acidity. Genotypic parameters were identified, which were related to the activity of the mitochondrial malic enzyme and of the malate mitochondrial carriers in the citrate model, as well as to the activity of the vacuolar proton pump, ATPase, in the malate model. The two models were also used to analyze the effects of fruit growth conditions on banana acidity.Combining the three models in a global model of banana acidity, and the possible use of this model for varietal improvement are discussed.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Rio Grande do Sul (RS), the most important state of grape production in Brazil, harvests, approximately, 780 thousand tons annually. One of the biggest constraint factors to the obtainment of higher production numbers is the incidence of late season diseases in vineyards, being botrytis bunch rot, caused by Botrytis cinerea, one of the major contributors for field and post-harvest losses. Red grapes can show more resistance against this fungus, due to higher levels of phenolic compounds. The use of biological control agents (BCAs) emerges as a promising alternative to control botrytis disease. For this reason, the objectives of this study were to test isolates from this fungal pathogen, originated from the two main grape production regions in the state of RS, trough in vitro direct confront test against BCAs fungal isolates (Trichoderma spp. and Gliocladium sp.) and to test the same pathogen isolates on semi in vivo biological control, against the BCAs isolates which obtained the highest biological activity during the in vitro test, on the post-harvest storage of table grapes, on a red and a white cultivar. The B. cinerea isolates used were UFSM SG01, UFSM SG02, from serra (mountain range) region, UFSM CM01, and UFSM CM02, from campanha meridional (meridional pampas) region. The BCAs isolates used in this study were Tricoderma spp., UFSM T20, UFSM T17, UFSM T15.1 (obtained from soil), UFSM TSG, UFSM TCM (obtained from the same grape bunches where B. cinerea was isolated, representing each region), and Gliocladium sp., UFSM G4DB (obtained from soil). UFSM TSG, UFSM TCM and UFSM T15.1 showed the highest biocontrol activity (B. A.) in vitro, in general over 50% against all B. cinerea isolates. The same BCAs were selected to be used at the semi in vivo test with detached berries for three inoculation periods: B+T, pathogen and BCA inoculated at the same time; B+24hT, pathogen inoculated first and BCA 24 h later, T+24hB, BCA inoculated first and pathogen 24 h later. A higher control, considered as the lower damage level, on T+24hB period, showed the importance of preventive treatment. Cracks on berries played a more important role than the color of the skin for botrytis infection. / O Rio Grande do Sul, o estado produtor de uvas mais importante no Brasil, colhe em média 780 mil toneladas por ano. Um dos maiores entraves para a obtenção de maiores médias de produção é a incidência de doenças de final de ciclo (DFC), sendo Botrytis cinerea, agente causador da podridão-cinzenta, um dos maiores responsáveis por perdas de produção no campo e na pós-colheita. Uvas tintas podem apresentar maior resistência à podridão-cinzenta, devido à maior concentração de compostos fenólicos. O uso de agentes de controle biológico (BCAs) é uma alternativa promissora no controle da podridão de botrytis. Dessa maneira, os objetivos deste estudo foram testar isolados do patógeno coletados das duas principais regiões vitivinícolas do RS em confronto direto in vitro com isolados de agentes antagonistas (Trichoderma spp e Gliocladium sp.) e testar os mesmos isolados do patógeno em controle biológico semi in vivo com os isolados antagonistas que obtiveram as maiores médias de atividade de biocontrole no teste in vitro, na pós-colheita de uvas de mesa, em cultivares branca e tinta. Os isolados de B. cinerea empregados foram UFSM SG01, UFSM SG02, UFSM SG 03, oriundos da serra, e UFSM CM01 e UFSM CM02, oriundos da campanha meridional. Os isolados antagonistas empregados no teste in vitro foram UFSM T20, UFSM T17, UFSM T15.1 (oriundos de solo), UFSM TSG, UFSM TCM (oriundos de cachos de uva coletados nas mesmas regiões de coleta do patógeno), de Trichoderma spp., e UFSM G4DB, de Gliocladium sp.. Os isolados UFSM TSG, UFSM TCM e UFSM T15.1 foram os três que obtiveram as maiores médias de atividade de biocontrole, em geral acima de 50%, para todos os isolados de B. cinerea, testados em confronto direto in vitro. Esses isolados BCAs foram selecionados para o teste de controle biológico semi in vivo em bagas destacadas, em três períodos de inoculação: B+T, antagonista e patógeno aplicados ao mesmo tempo; B+24hT, patógeno inoculado primeiro e antagonista 24h após, T+24hB, antagonista aplicado primeiro e patógeno 24h após. O maior controle, assumido a partir do menor grau de dano, no período T+24hB, evidenciou a importância do tratamento preventivo. Rachaduras em bagas tiveram maior influência do que a coloração da casca na ocorrência da podridãocinzenta.

Philosophiae Doctor - PhD / We hypothesize that South African medicinal plants contain compounds that can act in synergism with synthetic antifungal compounds. Four fungicides - Sporekill™, Rovral™, Terminator™ and Teldor™ at doses 0.1, 0.2, 0.4 and 0.8 mL L-1 and plant species Galenia africana, Elytropappus rhinocerotis and Tulbaghia violacea were tested alone and in different combinations for their potency (efficacy) on radial growth inhibition of Botrytis cinerea strains on potato dextrose plates. Four doses of plant extract for each of the respective plant species were used. A total of 48 combinations were tested for each strain. Mixtures of plant extracts were far more effective in controlling strains compared to the individual components alone, representing significant levels of in vitro synergistic interactions. Combinations of these components represent an attractive future prospect for the development of new management strategies for controlling B. cinerea. Since the in vitro tests of these mixtures showed inhibitory activity, the mixtures were tested for activity in assays on Granny Smith apples. In vitro tests can be used to screen mixtures to obtain information on their inhibitory activity on a pathogen, however, the environmental conditions of the fruit and the ability of the pathogen to grow into the fruit cannot be simulated in vivo. A series of two-fold doses of medicinal plant extracts were combined with fungicides to conduct decay inhibition studies. The incidence of gray mold was significantly reduced by mixtures of plant extracts and fungicides. Under conditions similar to those in commercial storage, a drench treatment with G. Africana and Rovral™ significantly (p=0.05) inhibit gray mold on the apples and was more effective than the plant extract and fungicide alone. The treatments exerted synergistic effects and were markedly better than the components applied alone. The wound colonization assay was used for optimal decay control. In a drench, much higher volumes of the treatments are used to ensure that the components of the suspension are deposited evenly over the entire fruit surface

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-04-15T11:58:47Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) merged (1).pdf: 10208935 bytes, checksum: 35aefcc6b201ff097898a09141c31612 (MD5) / Made available in DSpace on 2016-04-15T11:58:47Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) merged (1).pdf: 10208935 bytes, checksum: 35aefcc6b201ff097898a09141c31612 (MD5) Previous issue date: 2015-02-25 / O tomate (Lycopersicon esculentum) é uma das frutas mais populares do mundo, porém, 21% de sua produção é perdida devido a doenças pós-colheita, especialmente causadas por fungos patogênicos, como a podridão causada por Rhizopus stolonifer. Para controle de doenças póscolheita, antimicrobianos naturais, como a quitosana (QUI) e óleos essenciais (OE), vêm sendo utilizados. Tais compostos apresentam comprovada ação antimicrobiana, além de baixa toxicidade. Este estudo avaliou a eficácia da aplicação combinada de quitosana (QUI) e óleo essencial de Cymbopogon citratus Dc. Ex Nees (OECC) para controle de Rhizopus stolonifer (R. stolonifer) URM 3728 em meio laboratorial e em tomates frescos (Lycopersicon esculentum Mill.) em temperatura ambiente ao longo de 12 dias. A concentração inibitória mínima (CIM) da quitosana e do óleo, foi realizada pela técnica de diluição seriada em caldo. A partir da CIM, diferentes concentrações subinibitórias foram utilizadas nos experimentos ‘in vitro’ para determinação da influência sobre a germinação dos esporos fúngicos (18 horas de incubação), efeito na integridade de membrana dos esporos fúngicos, crescimento micelial radial (3 dias de incubação) e efeito na morfologia de hifas fúngicas. Para a aplicação dos compostos nos frutos, foram determinados o crescimento fúngico superficial e em frutos artificialmente feridos. Além disso, durante o período de armazenamento avaliou-se também os efeitos dos tratamentos (QUI e OECC) sobre a microbiota autóctone, bem como sobre algumas características físico-químicas dos frutos determinantes da qualidade do fruto, tais como perda de peso, sólidos solúveis, acidez titulável, pH e ácido ascórbico. A concentração inibitória mínima (CIM) da QUI e OECC contra R. stolonifer foi de 8 mg / mL e 5 μL/mL, respectivamente. Concentrações subinibitórias de QUI e OECC (QUI: 4 mg / mL; OECC: 1,25 uL / mL) inibiram a germinação de esporos de fungos em até 97,7% e o crescimento micelial foi completamente inibido. O revestimento composto pelas combinações de QUI e OECC foram eficazes na prevenção da colonização (infecção) por R. stolonifer em tomates, entretanto, apresentou baixo efeito curativo da infecção por R. stolonifer nos frutos. O revestimento também foi eficaz no na inibição da microbiota fúngica autóctone durante o armazenamento. Em geral, a aplicação de QUI e OECC como revestimento, preserva a qualidade dos frutos do tomateiro, conforme medido por alguns atributos físico-químicos. A partir destes resultados, os revestimentos compostos de QUI e OECC podem ser utilizados como o tratamento pós-colheita promissor para prevenir a infecção por R. stolonifer em tomates. / Tomato (Lycopersicon esculentum) is one of the most popular fruits in the world. However, 21% of the annual production of tomato fruits is lost due to postharvest diseases, especially caused by pathogenic fungi as the rot caused by Rhizopus stolonifer. To control of postharvest diseases, natural antimicrobials have been used, such as chitosan (CHI) and essential oils (EO). These compounds have proven antimicrobial activity, and low toxicity. This study evaluated the efficacy of the combined application of chitosan (CHI) and Cymbopogon citratus Dc. Ex Nees (lemongrass) essential oil (CCEO) to control Rhizopus stolonifer URM 3728 (R. stolonifer) in synthetic media and when inoculated in fresh tomatoes fruits at room temperature along 12 days. The minimum inhibitory concentration (MIC) of the chitosan and the essential oil, was performed by the serial dilution technique. From the MIC, subinibitory different concentrations were used in “in vitro” experiments to determine the influence on the germination of fungal spores (18 hours incubation), effect on membrane integrity of fungal spores, radial mycelial growth (90 hours of incubation) and effect on the morphology of fungal hyphae. On the application in the fruits they were determined superficial fungal growth and artificially wounded fruits. Furthermore, during the storage period was also evaluated the effects of treatments (CHI and CCOE) on autochthonous microflora as well as some physicochemical characteristics of fruits determining the quality of the fruit, such as weight loss, soluble solids, titratable acidity, pH and ascorbic acid. The Minimum Inhibitory Concentration (MIC) of CHI and CCEO against R. stolonifer was 8 mg/mL and 5μL/mL, respectively. Sub-inhibitory concentrations of CHI and CCEO (CHI: 4 mg/mL; CCEO: 1.25 μL/mL) inhibited fungi spore germination up to 97.7% and completely inhibited mycelial growth. The coating composed of the combinations of CHI and CCEO were effective to prevent colonization (infection) of R. stolonifer on tomatoes, otherwise, presented weak curative effect of the R. stolonifer infection in fruits. The coating also controlled the autochthonous mycoflora in fruits during storage. In general, the application of CHI and CCEO as a coating preserved the quality of tomato fruits as measured by some physicochemical attributes. From these results, the coatings composed of CHI and CCEO could be a promising post-harvest treatment to prevent R. stolonifer infection in tomatoes fruits.

A banana é um fruto consumido no mundo todo, sendo que o Brasil é o quarto maior produtor. A degradação do amido e a síntese de sacarose são responsáveis pelo adoçamento do fruto e, portanto, pela qualidade do mesmo. Os produtores de banana do Vale do Ribeira enfrentam dificuldade de produzir frutos de qualidade, principalmente devido a Sigatoka Negra e a Sigatoka Amarela que são as duas principais doenças da cultura bananeira. Estas duas doenças causam necroses nas folhas diminuindo a área fotossinteticamente ativa da planta podendo diminuir o peso dos cachos, das pencas e até dos frutos. Além disso, as Sigatokas também causam alterações no metabolismo pós-colheita do fruto acelerando seu amadurecimento. No intuito de aprofundar os conhecimentos sobre as alterações causadas pelas Sigatokas nos frutos, estudos foram realizados visando o metabolismo amido-açúcares por se tratar de um processo metabólico importante para a qualidade dos frutos. Para isso, foi conduzido, em 2008, um experimento no Vale do Ribeira aonde três áreas foram marcadas: uma com a presença exclusiva da S. Amarela, outra com predominância da S. Negra e outra área com controle eficiente das doenças. Nestas áreas foi acompanhado o nível de infestação das plantas através do índice de severidade que é uma estimativa visual da doença. Também foram marcadas plantas no momento da antese para que sua idade fisiológica pudesse ser estimada. Pencas foram colhidas em duas idades fisiológicas diferentes: 700 Graus Dia (GD) e 960 GD. Os frutos dessas pencas tiveram suas respiração e produção de etileno medidas diariamente até a senescência. Também foram congeladas amostras ao longo do amadurecimento que, posteriormente foram analisadas quanto aos teores de amido, açúcares solúveis, oligossacarídeos e atividade das enzimas α-amilase e β-amilase utilizando os reagentes Ceralpha e Betamyl (Megazyme) e amido-fosforilases visualizadas em P.A.G.E-nativo. As Sigatokas causaram desordens fisiológicas diferentes na pós-colheita da banana, mas ambas as doenças causaram mudanças nos padrões de respiração e produção de etileno, vida-verde, e no acúmulo e degradação do amido. Exceto pela vida-verde, que foi igualmente afetada por ambas as doenças, os outros fatores foram mais severamente afetados pela Sigatoka Negra, enquanto os frutos oriundos de plantas infectadas pela Sigatoka Amarela foram muito semelhantes aos frutos-controle. Tanto o acúmulo quanto a degradação do amido e enzimas, principalmente a β-amilase e a isoforma plastidial das amido-fosforilases, envolvidas no processo de degradação foram afetados pela Sigatoka Negra. / Banana is one of the most consumed fruits in the world and Brazil is the fourth largest producer of bananas in the world. The degradation of starch and sucrose synthesis are responsible for the sweetening and the quality of fruits. Banana producers in the Vale do Ribeira, southeastern state of Sao Paulo, have difficulty to achieve fruits with high quality, mainly due to Black Leaf Streak Disease and Sigatoka Disease, which are the two main disease problems of banana production. These two diseases cause necrosis in the leaves, reducing the photosynthetic active area of the plant and can also decrease the weight of bunches and fruits. Moreover, both diseases also cause alterations in post-harvest ripening of fruits. In order to better understand the changes caused by these diseases in the fruit ripening, studies were conducted on the starch-to-sugar metabolism, because of its importance for fruit quality. The experiment was conducted in 2008, in the Vale do Ribeira, where we selected three plots: one with the exclusive presence of S. Disease, another one with predominance of Black Leaf Streak disease and another area with an effective disease control. Disease infestation rate were determined by monitoring Severity Index, which is a visual estimate of the disease. To determine the physiological age of fruit, banana plants were marked at the flowering time and the mean temperature were measured daily. The fruits were harvested in two different physiological ages: 700 degree-days (GD) and 960 GD. The samples were also frozen during ripening. In these samples were analyzed the contents of starch, soluble sugars and oligosaccharides; and measured the activities of α-amylase, β-amylase and starch-phosphorylases. Leaf spot diseases caused different physiological disorders in post-harvest banana, but both diseases caused changes in patterns of respiration, ethylene production, green-life, accumulation and degradation of starch. Except for the green-life, which was similarly affected by both diseases, other factors were more severely affected by the Black Leaf Streak disease while the fruits of plants infected by the Sigatoka disease were very similar to control fruit. Both the accumulation and degradation of starch and enzymes, particularly of isoform β-amylase and the plastidial starch phosphorylase, involved in the degradation process were affected by Black Leaf Streak disease.

As bananas devem ser colhidas em seu estado verde (pré-climatérico) para disponibilizar tempo suficiente para transporte e comercialização. Este tempo é conhecido como vida-verde, determinado pelo número de dias existentes entre a colheita e o início do amadurecimento natural do fruto. As Sigatokas, em especial a Sigatoka Negra, são atualmente os problemas mais sérios do cultivo da bananeira. Embora estas doenças ataquem as folhas, os principais danos causados podem ser atribuídos à perda de qualidade e, consequentemente, de valor comercial dos frutos. Este trabalhou investigou os efeitos causados por estas doenças sobre a vida-verde e outros parâmetros de qualidade; tais como, coloração da polpa, sensibilidade ao apodrecimento pós-colheita, tamanho e peso, perfil respiratório e produção diária de etileno. Além disso, foi avaliada, em caráter preliminar, a evolução diária de alguns desses e outros parâmetros durante o processo de amadurecimento induzido do fruto, simulando a qualidade do fruto durante a comercialização no mercado varejista. Os resultados indicam que a vida verde é fortemente reduzida por ambas doenças (cerca de 50%) e não apresenta nível crítico de infestação. A intensidade respiratória e a produção de etileno foram aumentados e desordenados para os frutos oriundos de bananais infestados pelas doenças, especialmente S. Negra. O peso é reduzido em 40% pela infestação de S. Negra. A S. Amarela parece não influenciar a sensibilidade dos frutos ao apodrecimento pós-colheita. A Sigatoka Amarela provoca alteração na coloração da polpa, semelhante a perda de intensidade de cor. / Banana fruits are harvested at a green mature stage (pre-climacteric) in order to allow sufficient time for transport and marketing. This period is known as greenlife, and it is determined by the number of days between harvest and the initiation of the natural ripening process. Sigatoka Disease and, specially, Black Leaf Streak Disease are the main seriously problems in banana production, and it is also called by Yellow Sigatoka and Black Sigatoka, respectively. Although it is foliar diseases, the main damage is related to reduced quality and loss of market value. This study has investigated the effects of these diseases on the greenlife and other quality parameters; such as, pulp color, sensitivity to post-harvest rot, size and weight, respiration profile and ethylene daily production. Besides, it was preliminary evaluated the daily evolution of some of those and other parameters during the induced ripening process, as simulating fruit quality over retail market. Results indicate that greenllife is strongly reduced (about 50%) and it had no critical level of disease infestation. Respiratory intensity and ethylene production were increased and disorderly, for fruits from infested plots, specially by Black Sigatoka. Weight is 40 % reduced by Black Sigatoka. Yellow Sigatoka appear to have no influence on the sensitivity os post-harvest rot. However, Yellow Sigatoka caused an altered pulp color, similar to less intensity.

In recent years there has been a considerable amount of work done on developing chemicals that would inhibit mold growth when applied to fresh fruit, and at the same time, be acceptable to man when taken orally. This would save many thousands of tons of fresh produce that are lost each year by spoilage before it ever reaches the consumer. Along with the development of new chemicals to inhibit mold growth there is a substantial amount of research being done on developing a packaging film that will prevent recontamination of the produce, at the same time allowing the passage of gasses into and out of the package to allow respiration of the fruit. During the present century much emphasis has been placed on growing certain varieties of fruit for our specific needs. It has been found that particular varieties are better for canning and that other varieties are better for freezing. With the release of atomic energy for peaceful use in 1933 by the United States Congress, a new era of food preservation was introduced. Men in the scientific fields believe it is possible to extend the shelf-life of fresh fruits without altering their physical condition to great extent. Many institutions have been awarded grants and contracts to work on various phases of food preservation with atomic energy. Utah State University was awarded a contract by the United States Army Quartermaster Corp to study the use of gamma radiation for extending the shelf-life of fresh produce. It was with this idea in mind that work for this thesis was conducted to study the effects of gamma radiation, fungicides, and packaging film on the microbial growth on certain varieties of strawberries and cherries. In addition, experiments were conducted using fungicides and packaging films in order to lower the dose of radiation necessary to prevent mold growth. In order for this method of preserving fresh fruit to become successful, new and more economical methods and techniques in handling the materials will have to be developed.

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