Two lipid-based edible coatings, Apex B (AC Humko, Memphis, TN) and Durafresh (Pacrite, Ecoscience Produce Systems, Orlando, Fl) were evaluated for their ability to preserve post harvest quality changes in green bell peppers (Capsicum annum L. cv. King Arthur). Post harvest storage quality conditions tested included respiration rates, weight, color and texture changes, and stability of ascorbic acid (AA) and dehydroascorbic acid (DHA) content. Results indicated that no appreciable changes between days or treatment groups occurred in three of the parameters tested: weight, texture, and hue angle (p>0.05 for all parameters). Significant weekly changes were seen in respiration rates, dehydroascorbic acid content, and chromaticity values. Respiration rates and DHA were significantly higher during the last two weeks of the study (p=0.0001, p=0.0001 respectively). Chromaticity values were significantly lower, indicating a more faded color on the 14th day of the study alone (p=0.0097). Initial AA levels were much lower than expected (average initial content=78.72mg/100g). Significant differences between coated and uncoated pepper groups were seen in AA and DHA levels. AA content was found to be significantly lower in coated peppers (p=0.0279), while DHA levels were significantly higher in coated groups (p=0.0126). Overall, coated groups differed little from uncoated counterparts, except in the area of vitamin content in which the coated peppers showed an increase in vitamin breakdown. Despite the results, modifications of lipid coatings are needed, such as creating bilayer and composite coatings that contain either polysaccharide or protein constituents to enhance coating effectiveness. / Master of Science

Kangaroo paw inflorescences stored dry at 0 to 1 Degrees Celsius for 14 days have been found previously to have substantially reduced post-storage vase life. In this project, experiments were conducted to quantify the vase life of dry, stored Kangaroo paw flowers following storage at either 0, 7.5 or 13 Degrees Celsius for up to four weeks. the aim of these experiments was to determine a dry storage temperature suitable for commercial use. experiments were carried out using two cultivars of Kangaroo paw, 'Bush Dawn' and 'Big Red'. For each cultivar, vase life was assessed by (1) determining the time taken for each flower to lose 20% of its initial fresh weight and (2) determining the time taken for 10% of the inflorescence to become to discoloured. Vase life studies were carried out a 22 Degrees Celsius prior to and following removal from low temperature storage and flowers were weighed, inflorescence colour determined and chlorophyll fluorescence parameters Fo, minimal fluorescence emission, and Fm, maximum fluorescence emission were determined.

Orientador: Marcos David Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-19T15:37:33Z (GMT). No. of bitstreams: 1 Rodrigues_MicheleCarvalhodaSilva_M.pdf: 1787890 bytes, checksum: ad42d636315e1e015773f4c6f3929bd8 (MD5) Previous issue date: 2011 / Resumo: O beneficiamento da batata lavada no Estado de São Paulo, destinada ao mercado in natura ou ao processamento, consome volume excessivo de água, provocando danos ao meio ambiente principalmente no descarte da água residual da etapa de lavagem. Tendo em vista a exigência do mercado consumidor por batata lavada, e a necessidade da redução do consumo de água utilizado para este tipo de beneficiamento, a hipótese deste trabalho é a de que é possível reduzir o consumo de água na etapa de lavagem da batata modificando os parâmetros de funcionamento dos equipamentos utilizados atualmente (vazão e rotação), mantendo a eficiência de limpeza, sem afetar a qualidade do produto. Sendo assim, o objetivo deste trabalho foi avaliar a etapa de limpeza em linhas de beneficiamento de batata lavada produzida no Estado de São Paulo, e propor modificações para redução no volume de água com manutenção da qualidade do produto e da eficiência de limpeza. Para tanto, inicialmente foi realizada a avaliação de desempenho da etapa de limpeza em unidades de beneficiamento de batata lavada no Estado de São Paulo, identificando o método de lavagem, os tipos de roletes/escovas, velocidade média do produto, e volume de água consumido. A partir do estudo de desempenho, foram propostas alterações para melhoria na etapa de limpeza com relação ao volume de água consumido e a limpeza do produto. A eficiência de limpeza, o consumo de água, e a influência do beneficiamento na qualidade da batata lavada foram avaliados e comparados nos sistemas propostos, onde foram avaliadas três rotações para as escovas, e três vazões de água na lavagem de tubérculos de dois solos com diferentes teores de argila. A qualidade do produto beneficiado foi avaliada por meio dos parâmetros: perda de massa fresca, coloração, danos físicos e firmeza. Neste trabalho foi possível verificar que o consumo de água nas unidades de beneficiamento pode ser reduzido, mantendo a eficiência de limpeza do produto, apenas com ajustes de vazão e rotação do equipamento de lavagem. Com relação à qualidade, verificou-se o incremento na perda de massa e incidência de brotamento, e redução da e firmeza da batata lavada em comparação aos tubérculos não lavados / Abstract: The washing for potatoes in São Paulo, for the fresh market or industry, consumes excessive amounts of water, causing damage to the environment mainly due to waste water discharge from the washing step. Considering the requirement of the consumer market for washed potatoes, and the need to reduce water consumption, the hypothesis is that it is possible to reduce water consumption on the washing of potato just modifying the configuration of the equipment currently used (flow and rotation), and maintaining the cleaning efficiency without affecting quality. Therefore, the main goal was to evaluate the cleaning step in processing lines of washed potatoes produced in the state of Sao Paulo, and propose modifications to reduce the amount of water and with maintenance of product quality and cleaning efficiency. Therefore, early, characterization of the cleaning step was made in processing and classification units of washed potatoes in the state of Sao Paulo, identifying the method of washing used, types of rollers / brushes, average speed of the product, and water volume consumed on this step. From the characterization study, changes were proposed in the cleaning step that would improve the efficiency with respect to water consumption and cleaning product. The cleaning efficiency, water consumption, and influence of improvement in the quality of washed potatoes were evaluated and compared in the proposed systems. The quality of the processed product was evaluated by the following parameters: weight loss, color, physical damage and firmness. In this study, it was possible to verify that water consumption on processing units can be reduced maintaining cleaning efficiency, only adjusting water flow and rotation of the equipment. Related to tuber quality, it was also observed an increase of mass and firmness loss, and sprouting of washed potatoes compared with unwashed tubers / Mestrado / Tecnologia Pós-Colheita / Mestre em Engenharia Agrícola

Apples stored onshore in Australia and New Zealand, are maintained at optimal storage conditions with the aid of low temperatures; controlled atmospheres (CA) and new technologies that retard the production or effect of ethylene (AVG and 1-MCP respectively). These technologies allow distribution of the highest quality apples to local and export markets on a year round basis. However, during distribution, maintenance of optimal storage conditions may be lost due to refrigeration system breakdown, operational constraints or management decisions. This thesis quantifies the influence of commercially realistic breaks in optimal storage conditions (temperature and CA) on fruit physiology and quality, both at the time of the break and in subsequent optimal storage conditions. The ‘Cripps Pink’ (‘Pink Lady™’) apple cultivar was chosen for consideration in this thesis because it is a high value cultivar that is of considerable importance to the Australian apple industry. The knowledge of the behaviour of ‘Cripps Pink’ apples in coolstorage conditions (in air and CA) was confirmed through comparison of physiological and quality change behaviour of fruit from three harvests collected in this research and those reported recently by other authors. The investigation of the influence of breaks in temperature control during storage in air at 0°C, revealed that preclimacteric apples exposed to a break in temperature control, were advanced towards the establishment of the climacteric. Postclimacteric apple, responded by doubling ethylene production a short time after return to coolstorage. Harvest maturity, timing of break during coolstorage, length of break of temperature control and multiple breaks in temperature control, had little influence on the increase ethylene production response. Quality factors (firmness, background hue angle, and titratable acidity) were all reduced as a result of exposure to warmer temperatures, but on return to coolstorage temperatures rates of loss in these quality factors were not influenced by the increased ethylene production. Short-term (3-day) breaks in CA while fruit remained at refrigerated temperatures were shown to have no substantial effect on fruit physiology or quality, either during the period of the break in CA or in subsequent CA storage. Breaks in temperature control in combination with breaks in CA were observed to cause a doubling of ethylene production on CA stored apples regardless of being returned to 0°C in air or CA. Those apples that were exposed to a break in temperature control and returned to air storage at refrigerated temperature lost quality (firmness and background hue angle) more rapidly than apples not exposed to breaks in temperature control and transferred to air storage. This result strengthened the knowledge of the influence of ethylene on changes in apple quality, as found for many other apple cultivars. The influence of the decision to transport fruit in CA or air atmosphere shipping containers was initially investigated with a laboratory simulation. Physiology (respiration rate and ethylene production) of air shipped fruit was found not only to be more rapid, but more variable between fruit, than for apples shipped in CA. This more rapid and larger variation of possible fruit physiologies, suggests that in addition to losing quality at a faster rate, the variation in the quality of fruit shipped in air will also enlarge during shipment. This hypothesis was confirmed with data pooled from treatments subjected to 0°C and 3°C, simulating the likely temperature variability within a shipping container. Validation of the influence of shipping atmosphere on delivered fruit quality, was conducted in the commercial environment. This trial found that the length of time to ship fruit from Australia and New Zealand to European markets was not sufficient to induce commercially significant differences between ‘Cripps Pink’ apples shipped in the two atmospheres. Finally, as ethylene production was influenced by fluctuations in temperature control and subsequently affected quality of apples previously stored in CA, an investigative attempt to model ethylene production in temperature variable scenarios was conducted. Published models of ethylene production in apples were adapted to the variable temperature storage scenario and a new model was proposed. Unfortunately, none of the models investigated were able to predict all of the consistent behaviours of ethylene production observed during the experimental work, indicating that more knowledge of the ethylene production pathway is required, before modelling of ethylene production and subsequently apple quality can be conducted successfully.

Tomatoes are widely produced and consumed due to their nutritional content and versatility. However, the tomato is a soft fruit liable to damage and flavour deterioration. Hence, the main challenge for the tomato producing industry is to prevent the high loss incurred during harvest, handling and transportation of the crops. The objective of this study was to investigate the overall nutritional implication of controlled storage of tomatoes using ozone on the ripening process and the basic nutritional components of tomatoes. This investigation was also designed to focus on the effect of different ozone doses on the basic components and properties (carotenoids, ascorbic acid, total antioxidant activity and soluble sugars content) of the quality and dynamic maturity of tomatoes. Green tomatoes (Rio Grande) were treated in glass chambers with ozone enriched air [(air + 2, 7 and 21 mg O3/g tomato) and control (air only)] under humidity and temperature of 90-95% and 14-17 oC respectively. Tomatoes were sampled after 14 days of ozone treatment in the storage chamber and analyzed for different quality parameters (appearance, weight loss, Total Soluble Solids (TSS), titratable acidity, total ascorbic acid and carotene) of the ripening. The variety Elegance tomatoes were selected and the fruits were graded by colour and subjected to treatment with ozone (in doses 0 (clean air), 0.25, 0.50, and1.00 mg O3/g tomatoes) during storage for 6 days under the same humidity and temperature conditions. The fruits were analysed for carotenoids, ascorbic acid content, total antioxidant activity and soluble sugars. Analysis of the fruits clearly showed that ozone significantly delayed the development of colour on the surface, particularly in the low doses, and caused black spots on the surface of the tomatoes, particularly in higher ozone doses. Ozone did not affect the ascorbic acid and titratable acidity content. However ozone did reduce the Total Soluble Solids (TSS) by about 10% at the lowest ozone dose. A high inhibition of accumulation of carotenoids, particularly at low dose, of the tomatoes (Rio Grande) was also observed. Tomatoes (Elegance) under ozone treatments contained higher ß-carotene than those under the control treatment and lycopene content increased during storage in the red stage of tomato fruits. Ascorbic acid (AsA), dehydroascorbic acid (DHA) and the total of AsA and DHA concentrations, and ratios of redox (ASA/ (ASA + DHA) and DHA/AsA in pericarp and pulp of tomatoes tissue, did not show clear differences between the different treatments. The concentrations of the glucose and fructose increased in the tomatoes which were subjected to ozone treatments. Results from this study show that controlled atmosphere storage of tomatoes using ozone is a viable technique which warrants further study.

A uvaia (Eugenia pyriformis Cambess) é uma espécie nativa do Brasil, pertencente à família das mirtáceas, que se destaca por possuir um fruto de sabor e aroma agradável. No entanto, ainda faltam informações básicas, principalmente em relação a variabilidade existente em populações e sobre a fisiologia pós-colheita. Nesse contexto, este estudo objetivou caracterizar 31 acessos de uvaia originados de semente, quanto aos aspectos físicos, químicos e compostos bioativos e avaliar a influência do estádio de maturação na qualidade pós-colheita. O estudo foi dividido em duas etapas. Na primeira, caracterizou-se a variabilidade dos acessos baseado nos atributos físicos e químicos. Foram realizadas análises de massa fresca, massa de sementes, diâmetro, formato, cor da casca, rendimento de polpa, sólidos solúveis, acidez total titulável, ácido ascórbico, compostos fenólicos, carotenoides, flavonoides e capacidade antioxidante. Na segunda, avaliou-se a qualidade pós-colheita de uvaias colhidas em três estádios de amadurecimento quanto a cor da casca, sólidos solúveis, acidez titulável, ácido ascórbico, flavonoides, carotenoides, compostos fenólicos, capacidade antioxidante e compostos voláteis, respiração (CO2) e produção de etileno (C2H4). Entre os acessos foi verificada ampla diversidade na coloração dos acessos, variando de amarelo claro a alaranjado, com frutos classificados majoritariamente como achatados. Os atributos que apresentaram maior variação entre os acessos foram os sólidos solúveis, ácido ascórbico, compostos fenólicos e a capacidade antioxidante. Os resultados do armazenamento, mostraram que os frutos verdes alcançaram a mesma cor da casca, teor de acidez titulável, ácido ascórbico, flavonoides, carotenoides, compostos fenólicos e atividade antioxidante dos frutos maduros. Por outro lado, frutos colhidos verdes apresentaram baixo teor de sólidos solúveis e menor variedade de compostos voláteis. Não foi identificada relação entre o estádio de amadurecimento e a respiração. A produção de etileno foi diretamente proporcional ao estádio de amadurecimento. Estas informações sobre a qualidade da fruta colhida em diferentes estádios podem auxiliar a escolha daquele que melhor atender as exigências de uso para o consumo in natura e para a elaboração de produtos. / The uvaia (Eugenia pyriformis Cambess) is a native species of Brazil, belonging to the family Myrtaceae, which stands out for having a fruit of pleasant taste and aroma. However, basic information is still lacking, especially in relation to the variability in populations and their postharvest physiology. In this context, this study aimed to characterized 31 accessions of uvaia (propagated by seeds), as to physical, chemical and bioactive compounds and to evaluate the maturity stage influence on postharvest quality. The study was divided in two parts. First, was characterized the variability of the accessions based on physical and chemical attributes, were analyzed: fresh mass, seed mass, diameter, shape, skin color, yield of pulp, soluble solids, total titratable acidity, ascorbic acid, phenolic compounds, carotenoids, flavonoids and antioxidant capacity. Second, was evaluated the postharvest quality of uvaia at three stages of maturation as to skin color, soluble solids, titratable acidity, ascorbic acid, flavonoids, carotenoids, phenolic compounds, antioxidant capacity and volatile compounds, respiration (CO2) and production of ethylene (C2H4). There was a wide diversity in the color of the accessions, varied from light yellow to orange, with fruits classified mainly as flattened. The highest variation among the accessions was observed in the attributes of soluble solids, ascorbic acid, phenolic compounds and antioxidant capacity. During storage, the fruits picked green achieved the same color of the skin, titratable acidity, ascorbic acid, flavonoids, carotenoids phenolic compounds and antioxidant activity of mature fruits. On the other hand, fruits harvested green exhibited low content of soluble solids and less variety of volatile compounds. There was no relationship between respiratory rate and ripening. Ethylene production was proportional to the ripening stage. This information on the quality of the fruit harvested in different stages can help to choose the one that best meets the requirements of use for fresh consumption and for the elaboration of products.

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.

Carotenoides são pigmentos encontrados em grande abundancia em frutos do tomateiro. A capacidade de sequestro de radicais destes pigmentos faz do tomate uma excelente opção para inclusão de compostos nutricionais pela dieta. Embora a síntese de carotenoides seja reconhecida como uma das respostas da cascata de eventos que levam ao amadurecimento, pouco se sabe a respeito de sua influência neste processo. Deste modo, o objetivo deste trabalho foi determinar se o conteúdo e a composição de carotenóide nos frutos acarretam alterações na conservação e na suscetibilidade dos frutos ao fungo B. cinerea. Foram utilizadas linhagens quase isogênicas (NILs) ao Micro Tom (MT) carregando as mutações, Beta carotene (B), tangerine (t), yellow flesh (r) e Delta carotene (Del). A caracterização dessas variações alélicas revelou, não apenas alterações no conteúdo de carotenoides, mas também outros efeitos pleiotrópicos relacionados ao amadurecimento, parâmetros de qualidade, espessura da cutícula e propriedades nutricionais dos frutos. Em face disso, subsequentemente investigamos se o diferencial conteúdo e composição de carotenóides nas referidas NILs altera a suscetibilidade dos frutos ao fungo Botrytis cinerea. A caracterização do amadurecimento demonstrou que o pico climatérico dos frutos do mutante r foi antecipado, assim como a transição para o estádio breaker. De modo contrário, a alteração na coloração da epiderme do mutante t foi atrasada, reafirmando suspeitas de outros autores que sugeriram que a enzima carotenoide-isomerase é necessária para a síntese de carotenoides no escuro. O conteúdo de ácido ascórbico também foi contrastante entre estes genótipos, sendo que no mutante r a sua concentração foi elevada, enquanto em t sua concentração foi reduzida. A perda de massa dos frutos foi menor no mutante Del, no entanto, esta característica não esteve relacionada a espessura da cutícula, que foi maior em B. A inoculação com B. cinerea por meio de ferimentos na pele dos frutos revelou menor suscetibilidade do mutante t, e em menor amplitude, do mutante Del. Ainda, o mutante t também se mostrou menos suscetível à inoculação do patógeno sobre frutos intactos. A maior espessura da cutícula de B não reduziu sua suscetibilidade ao fungo, que infectou os tecidos preferencialmente através da cicatriz do pedúnculo. A interação com B. cinerea desencadeou a produção de etileno e de espécies reativas de oxigênio (EROs), assim, é provável que a capacidade de sequestro de radicais livres tenha contribuído para a redução da suscetibilidade em t e Del, que mostraram menor produção de superóxido. Juntos, estes resultados sugerem que a modulação na atividade de enzimas da carotenogênese pode servir como ferramenta para obtenção de frutos com diferente vida útil durante o armazenamento pós-colheita de tomate. / Carotenoids are pigments found in great abundance in tomato fruits. The radical sequestration capacity of these pigments makes tomato an excellent option for inclusion of nutritional compounds in diet. Although the synthesis of carotenoids is recognized as one of the cascade responses that trigger ripening, little is known about its influence in this process. Thus, the aim of this study was to determine if the content and composition of carotenoids in the fruits alters the conservation and the susceptibility of the fruits to the B. cinerea fungus. Micro Tom (MT) near-isogenic lines (NILs) harboring the mutations Beta carotene (B), tangerine (t), yellow flesh (r) and Delta carotene (Del) has been used. The characterization of these allelic variations revealed not only changes in the carotenoid content but also other pleiotropic effects related to maturation, quality parameters, cuticle thickness and nutritional properties of fruit. In this way, we subsequently investigated whether the differential content and composition of carotenoids in NILs alters fruit susceptibility to the fungus Botrytis cinerea. The ripening characterization showed that the climacteric peak of the fruits of the r mutant was anticipated, as well as the transition to the breaker stage. Conversely, the change in epidermal coloration of mutant t was delayed, reaffirming suspicions of other authors who suggested that the carotenoid-isomerase enzyme is required for the synthesis of carotenoids in the dark. The ascorbic acid content was also contrasting among these genotypes, and in the r mutant its concentration was high, while at t its concentration was reduced. The fruit mass loss was lower in Del mutant, however, this characteristic was not related to cuticle thickness, which was higher in B. Wound-inoculation with B. cinerea revealed less susceptibility of the mutant t, and in a lesser extent, the mutant Del. Further, mutant t was also less susceptible to pathogen inoculation on intact fruits. The greater thickness of the cuticle of B did not reduce its susceptibility to the fungus, which infected the tissues preferentially through the scar of the peduncle. The interaction with B. cinerea triggered the production of ethylene and reactive oxygen species (ROS), so the free radical scavenging capacity probably contributed to the reduction of t and Del susceptibility, which showed lower production of superoxide. Together, these results suggest that modulation in carotenogenesis enzyme activity may serve as a tool to obtain fruit with different shelf-life during post-harvest tomato storage.

Cassava (Manihot esculenta Crantz Family Euphorbiaceae) is an important tropical food crop. However, harvested cassava roots have a shelf-life of only days due to post-harvest physiological deterioration (PPD). Within 1-3 days of harvesting, the roots show blue-black vascular streaking and are unpalatable. PPD includes altered gene expression and the accumulation of hydroxycoumarin secondary metabolites, e.g. scopoletin and esculetin, and their respective glucosides scopolin and esculin. In this research several important aspects of the biosynthesis of these phytochemically important hydroxycoumarins were resolved. Stable isotopically labelled intermediates on the postulated biosynthetic pathways of scopoletin were fed to cassava cubes and PPD was allowed to occur. Ethanolic extracts of these deteriorated roots were separated (HPLC) and analysed (HRESI-MS). Incorporation (in both scopoletin and scopolin) of only 3 deuterons from E-cinnamic-2,3,2',3',4',5',6'-d7 and E-cinnamic-3,2',3',4',5',6'-d6 is strong support that the E-Zisomerisation step is enzymatic and not photochemical. There are three hypothetical pathways for the biosynthesis of scopoletin via: 2',4'-dihydroxycinnamate, caffeate, or ferulate. High incorporation of label from p-coumaric-2-13C, caffeic-2-13C and ferulic-2-13C acids was observed into labelled scopoletin and scopolin while there was only a small incorporation from 18O-umbelliferone and 18O-esculetin. We conclude that the major biosynthetic pathway to scopoletin and scopolin is via ferulic acid. C18O2-enrichment of E-cinnamic and ferulic acids and feeding gave scopoletin containing only one 18O-labelled oxygen atom. Therefore the lactonisation step is through o-hydroxylation and not via a postulated spirolactone-dienone intermediate. These results were confirmed by feeding experiments in an atmosphere of 18O2-air which showed that the major isotopic peak was 18O3-enriched scopoletin. Three glucosyltransferases were isolated and identified from a cassava PPDrelated cDNA library. These genes are expressed in the cassava storage root during PPD and they are also expressed in the fresh root. While one of these glucosyltransferases was novel, two had previously been isolated from cassava cotyledons.