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Joachim Muller - One of the best experts on this subject based on the ideXlab platform.
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sorption behaviour of Papayas as affected by compositional and structural alterations from osmotic pretreatment and drying
Journal of Food Engineering, 2015Co-Authors: Patchimaporn Udomkun, Dimitrios Argyropoulos, Marcus Nagle, Busarakorn Mahayothee, Joachim MullerAbstract:Abstract Moisture sorption dynamics and isotherms of fresh, osmotically-pretreated and dried Papayas at temperatures of 30, 50 and 70 °C and water activity in the range of 0.113–0.907 were investigated. Chemical composition as well as volume, density, porosity and microstructure of the fruits were analysed. Results showed that the time required to reach equilibrium moisture content was mainly dependent on temperature, water activity level and processing method. The difference in moisture sorption characteristics between fresh, pretreated and dried Papayas was attributed to (i) changes in the contents of sugars after osmotic dehydration and (ii) structural modifications caused by drying, which were corroborated by examination of micrographs. The differences in sorption were also proven by the selected isotherm models. The modified Halsey equation described the sorption behaviour of the pretreated and dried Papayas, whereas the untreated, fresh samples were better predicted by the modified Oswin equation. Further indication that osmotic pretreatment and drying influenced the interaction between the sorption sites and water molecules was imparted by the values of isosteric heat of sorption ( Q st ) for fresh and dried Papayas at different temperatures.
Dennis Gonsalves - One of the best experts on this subject based on the ideXlab platform.
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Transgenic Papaya in Hawaii and Beyond
2020Co-Authors: Dennis GonsalvesAbstract:Papaya ringspot virus (PRSV) is often a limiting factor in the production of papaya worldwide. In 1992, PRSV was discovered in the district of Puna on Hawaii island, where 95% of Hawaii's papaya was grown. Within two years, PRSV was widespread and causing severe damage to the papaya in that area. Coincidentally, a field trial to test a PRSV-resistant transgenic papaya had started in 1992, and by 1995 the 'Rainbow' and 'SunUp' transgenic cultivars had been developed. These cultivars were commercialized in 1998. 'Rainbow' is now widely planted and has helped to save the papaya industry from devastation by PRSV. Transgenic papaya have also been developed for other countries, such as Thailand, Jamaica, Brazil, and Venezuela. Efforts to have these papaya deregulated in these countries are ongoing.
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Transgenic Papaya: A Case for Managing Risks of Papaya ringspot virus in Hawaii
Plant Health Progress, 2020Co-Authors: Dennis Gonsalves, Steve FerreiraAbstract:In May 1992, Papaya ringspot virus (PRSV) was detected in the Puna district of Hawaii Island, the main papaya growing region of the state of Hawaii. By 1994 Hawaii’s papaya industry was facing devastating damage from PRSV. Efforts to develop resistant transgenic papaya were started in the mid 1980s and a resistant line was identified in 1991. Two cultivars were developed from this line and were commercialized in 1998. Rainbow, an F1 hybrid from a cross of the transgenic SunUp, and nontransgenic Kapoho are now widely planted and have helped save the papaya industry. In addition, PRSV inocula in Puna were greatly reduced as abandoned infected fields were replanted with transgenic papaya. These conditions have allowed growers to continue the production of nontransgenic Kapoho in Puna to keep the Japanese market supplied, since transgenic papaya is not yet deregulated in that country.
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development of virus resistant transgenic Papayas expressing the coat protein gene from a brazilian isolate of papaya ringspot virus
Fitopatologia Brasileira, 2005Co-Authors: Manoel Teixeira Souza, Osmar Nickel, Dennis GonsalvesAbstract:Versoes traduziveis e nao traduziveis do gene da capa proteica (cp) de um isolado de Papaya ringspot virus (PRSV) coletado no Estado da Bahia, Brasil, foram produzidas para expressao nas variedades Sunrise e Sunset Solo de mamoeiro (Carica papaya). O sistema de biobalistica foi utilizado para transformar embrioes somaticos secundarios derivados de embrioes zigoticos imaturos. Cinquenta e quatro linhas transgenicas, sendo 26 contendo versoes traduziveis e 28 contendo versoes nao traduziveis do gene cp foram regeneradas, o que resultou em 2,7% de eficiencia de transformacao, quando considerado o numero de linhas transgenicas obtidas por embriao zigotico imaturo excisado. Desafios de plantas R0 com PRSV BR, PRSV HA ou PRSV TH, respectivamente isolado brasileiro, havaiano e tailandes, revelaram linhas com resistencia a um, dois e tres isolados de PRSV. Apos analises moleculares e avaliacao agronomica preliminar, 13 populacoes R1 e R2 de mamoeiros transgenicos foram incorporadas ao programa de melhoramento genetico da Embrapa Mandioca e Fruticultura, em Cruz das Almas, Bahia, Brasil.
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sequence similarity between the viral cp gene and the transgene in transgenic Papayas
Pesquisa Agropecuaria Brasileira, 2005Co-Authors: Manoel Teixeira Souza, Dennis GonsalvesAbstract:The Papaya ringspot virus (PRSV) coat protein transgene present in 'Rainbow' and 'SunUp' Papayas disclose high sequence similarity (>89%) to the cp gene from PRSV BR and TH. Despite this, both isolates are able to break down the resistance in 'Rainbow', while only the latter is able to do so in 'SunUp'. The objective of this work was to evaluate the degree of sequence similarity between the cp gene in the challenge isolate and the cp transgene in transgenic Papayas resistant to PRSV. The production of a hybrid virus containing the genome backbone of PRSV HA up to the Apa I site in the NIb gene, and downstream from there, the sequence of PRSV TH was undertaken. This hybrid virus, PRSV HA/TH, was obtained and used to challenge 'Rainbow', 'SunUp', and an R2 population derived from line 63-1, all resistant to PRSV HA. PRSV HA/TH broke down the resistance in both papaya varieties and in the 63-1 population, demonstrating that sequence similarity is a major factor in the mechanism of resistance used by transgenic Papayas expressing the cp gene. A comparative analysis of the cp gene present in line 55-1 and 63-1-derived transgenic plants and in PRSV HA, BR, and TH was also performed.
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comparative development and impact of transgenic Papayas in hawaii jamaica and venezuela
Methods of Molecular Biology, 2005Co-Authors: Gustavo Fermin, Paula Tennant, C Gonsalves, Dennis GonsalvesAbstract:We present data concerning the creation of transgenic Papayas resistant to Papaya ringspot virus (PRSV) and their adoption by three different countries: the United States (e.g., Hawaii), Jamaica, and Venezuela. Although the three sets of transgenic Papayas showed effective resistance to PRSV, the adoption rate in each country has varied from full utilization in Hawaii to aggressive testing but delay in deregulating of the product in Jamaica to rejection at an early stage in Venezuela. Factors that contributed to the rapid adoption in Hawaii include a timely development of the transgenic product, PRSV causing severe damage to the papaya industry, close collaboration between researchers and the industry, and the existence of procedures for deregulating a transgenic product. In Jamaica, the technology for developing the initial field-testing of the product progressed rather rapidly, but the process of deregulation has been slowed down owing to the lack of sustained governmental efforts to complete the regulatory procedures for transgenic crops. In Venezuela, the technology to develop and greenhouse test the transgenic papaya has moved abreast with the Jamaica project, but the field testing of the transgenic papaya within the country was stopped very early on by actions by people opposed to transgenic products. The three cases are discussed in an effort to provide information on factors, other than technology, that can influence the adoption of a transgenic product.
Eugênio Ferreira Coelho - One of the best experts on this subject based on the ideXlab platform.
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Mamão ‘Tainung 1’ produzido sob secamento parcial do sistema radicular: qualidade do fruto desidratado / Papaya 'Tainung 1' produced under partial rootzone drying: the quality of the dehydrated fruit
2017Co-Authors: Maristella Martineli, Jenilson Ferreira Da Silva, Mateus Pinheiro Fonseca, Ariane Castricini, Polyanna Mara De Oliveira, Camila Maida De Albuquerque Maranhão, Luciana Albuquerque Caldeira Rocha, Eugênio Ferreira CoelhoAbstract:A regiao Norte de Minas Gerais e a 10o maior produtora de mamao no pais. Para tal, faz-se necessario o uso de irrigacao de forma otimizada, contribuindo, assim na reducao do dispendio de agua pela agricultura irrigada. Desta forma, o presente estudo objetivou avaliar a influencia tecnica de secamento parcial do sistema radicular (SPR) sobre os parâmetros de qualidade envolvidos na producao de mamao desidratado. Os mamoes da variedade Tainung n.1 foram produzidos em Mocambinho - MG e cultivados com reducao da lâmina calculada em 50%, com frequencia de alternância de 7 dias (irrigacao 1) e com reducao da lâmina calculada em 50%, fixando-se apenas um lado irrigado (irrigacao 2). Para o processamento, os frutos foram desidratados em secador de cabine com circulacao de ar forcada de ar a 65oC por 8, 9 e 10 horas. Os mamoes desidratados foram avaliados quanto aos aspectos fisicos: grau de umidade e cor instrumental (luminosidade, croma e ohue), e quimicos: solidos soluveis e acidez titulavel. Nao houve interacao entre os fatores tempo de secagem e irrigacao para nenhuma caracteristica estudada, porem o tempo de secagem influenciou o grau de umidade, luminosidade e a tonalidade da cor dos mamoes desidratados. O croma do produto final proveniente da irrigacao com reducao da lâmina calculada em 50%, fixando-se apenas um lado irrigado foi superior, indicando cor mais intensa. O conteudo de solidos soluveis e acidez titulavel nao sofreu alteracao apos a desidratacao. Abstract: The Northern region of Minas Gerais is the 10th largest producer of papaya in the country. Therefore, it is necessary the use of irrigation in an optimized way, thus contributing in reducing the amount of water for irrigated agriculture. Thus, the present study aimed to evaluate the effect of partial rootzone drying (PRD) on the quality parameters involved in the production of dehydrated papaya. The Papayas of the variety Tainung No.1 were produced in Mocambinho - MG and cultivated with reduction of irrigation water depths calculated in 50%, with a frequency of alternation of 7 days (irrigation 1) and with a reduction of irrigation water in 50%, being fixed only one side irrigated (irrigation 2). For the processing, the fruits were dehydrated in a booth dryie with forced air forced circulation at 65oC for 8, 9 and 10 hours. The dehydrated Papayas were evaluated in relation to the physical aspects: degree of moisture and instrumental color (lightness, chroma and ohue), and chemicals: soluble solids and titratable acidity. There was no interaction between the factors drying time and irrigation for any characteristic studied, but the drying time influenced the degree of humidity, brightness and color tone of dehydrated Papayas. The chroma of the final product originated from irrigation with reduction of irrigation water depths calculated in 50%, being fixed only one irrigated side was higher, indicating more intense color. The content of soluble solids and titratable acidity did not change after the dehydration.
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mamao tainung 1 produzido sob secamento parcial do sistema radicular qualidade do fruto desidratado papaya tainung 1 produced under partial rootzone drying the quality of the dehydrated fruit
Caderno de Ciências Agrárias, 2017Co-Authors: Maristella Martineli, Jenilson Ferreira Da Silva, Mateus Pinheiro Fonseca, Ariane Castricini, Polyanna Mara De Oliveira, Camila Maida De Albuquerque Maranhão, Luciana Albuquerque Caldeira Rocha, Eugênio Ferreira CoelhoAbstract:A regiao Norte de Minas Gerais e a 10o maior produtora de mamao no pais. Para tal, faz-se necessario o uso de irrigacao de forma otimizada, contribuindo, assim na reducao do dispendio de agua pela agricultura irrigada. Desta forma, o presente estudo objetivou avaliar a influencia tecnica de secamento parcial do sistema radicular (SPR) sobre os parâmetros de qualidade envolvidos na producao de mamao desidratado. Os mamoes da variedade Tainung n.1 foram produzidos em Mocambinho - MG e cultivados com reducao da lâmina calculada em 50%, com frequencia de alternância de 7 dias (irrigacao 1) e com reducao da lâmina calculada em 50%, fixando-se apenas um lado irrigado (irrigacao 2). Para o processamento, os frutos foram desidratados em secador de cabine com circulacao de ar forcada de ar a 65oC por 8, 9 e 10 horas. Os mamoes desidratados foram avaliados quanto aos aspectos fisicos: grau de umidade e cor instrumental (luminosidade, croma e ohue), e quimicos: solidos soluveis e acidez titulavel. Nao houve interacao entre os fatores tempo de secagem e irrigacao para nenhuma caracteristica estudada, porem o tempo de secagem influenciou o grau de umidade, luminosidade e a tonalidade da cor dos mamoes desidratados. O croma do produto final proveniente da irrigacao com reducao da lâmina calculada em 50%, fixando-se apenas um lado irrigado foi superior, indicando cor mais intensa. O conteudo de solidos soluveis e acidez titulavel nao sofreu alteracao apos a desidratacao. Abstract: The Northern region of Minas Gerais is the 10th largest producer of papaya in the country. Therefore, it is necessary the use of irrigation in an optimized way, thus contributing in reducing the amount of water for irrigated agriculture. Thus, the present study aimed to evaluate the effect of partial rootzone drying (PRD) on the quality parameters involved in the production of dehydrated papaya. The Papayas of the variety Tainung No.1 were produced in Mocambinho - MG and cultivated with reduction of irrigation water depths calculated in 50%, with a frequency of alternation of 7 days (irrigation 1) and with a reduction of irrigation water in 50%, being fixed only one side irrigated (irrigation 2). For the processing, the fruits were dehydrated in a booth dryie with forced air forced circulation at 65oC for 8, 9 and 10 hours. The dehydrated Papayas were evaluated in relation to the physical aspects: degree of moisture and instrumental color (lightness, chroma and ohue), and chemicals: soluble solids and titratable acidity. There was no interaction between the factors drying time and irrigation for any characteristic studied, but the drying time influenced the degree of humidity, brightness and color tone of dehydrated Papayas. The chroma of the final product originated from irrigation with reduction of irrigation water depths calculated in 50%, being fixed only one irrigated side was higher, indicating more intense color. The content of soluble solids and titratable acidity did not change after the dehydration.
Joao Paulo Fabi - One of the best experts on this subject based on the ideXlab platform.
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pectin interaction with immune receptors is modulated by ripening process in Papayas
Scientific Reports, 2020Co-Authors: Samira Bernardino Ramos Do Prado, Martin Beukema, Eva Jermendi, Henk A Schols, Joao Paulo FabiAbstract:Dietary fibers have been shown to exert immune effects via interaction with pattern recognition receptors (PRR) such as toll-like receptors (TLR) and nucleotide-binding oligomerization domain (NOD)-like receptors. Pectin is a dietary fiber that interacts with PRR depending on its chemical structure. Papaya pectin retains different chemical structures at different ripening stages. How this influence PRR signaling is unknown. The aim of this work was to determine how ripening influences pectin structures and their ability to interact with TLR2, 3, 4, 5 and 9, and NOD1 and 2. It was evaluated the interaction of the water-soluble fractions rich in pectin extracted from unripe to ripe Papayas. The pectin extracted from ripe Papayas activated all the TLR and, to a lesser extent, the NOD receptors. The pectin extracted from unripe Papayas also activated TLR2, 4 and 5 but inhibited the activation of TLR3 and 9. The differences in pectin structures are the higher methyl esterification and smaller galacturonan chains of pectin from ripe Papayas. Our finding might lead to selection of ripening stages for tailored modulation of PRR to support or attenuate immunity.
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metabolome and proteome of ethylene treated Papayas reveal different pathways to volatile compounds biosynthesis
Food Research International, 2020Co-Authors: Roberta Ghedini Der Agopian, Joao Paulo Fabi, Beatriz Rosana CordenunsilysenkoAbstract:Abstract Papayas undergo fast postharvest changes triggered by the plant hormone ethylene. Some important pathways have been analyzed in limited studies (transcriptomics and targeted metabolomics); however, broad use of proteomics or untargeted metabolomics have not yet been used in Papayas. In this study, two groups of green Papayas (150 days after anthesis—physiological maturity for Papayas) were treated with ethylene at different times (6 and 12 h) and their metabolic changes in fruit pulp were evaluated with untargeted metabolomics (general metabolites and volatile compounds) and proteomics. Polar metabolites exhibited distinct patterns, especially with regard to some amino and fatty acids during stimulated ripening. In particular, glutamate increased through a possible gamma aminobutyric acid (GABA) shunt and/or proteases activity. Moreover, the stimulated ripening altered the volatile compounds and the protein profiles. The results suggest that changes in membrane breakdown and the resulting oxidative processes could be responsible for volatile compound production, altering some sensorial qualities of Papayas, such as pulp softening and the specific papaya linalool volatile compound increment. Thus, GABA levels could also be a strong biological marker for papaya development and ripening stages. This study applied two “omic” techniques that provided insight into how the plant hormone ethylene could influence papaya postharvest quality.
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changes in cell wall composition associated to the softening of ripening papaya evidence of extensive solubilization of large molecular mass galactouronides
Journal of Agricultural and Food Chemistry, 2009Co-Authors: Tania Misuzu Shiga, Joao Paulo Fabi, Joao Roberto Oliveira Do Nascimento, Lucia Cristina Vriesmann, Franco Maria Lajolo, Carmen Lúcia De Oliveira Petkowicz, Beatriz Rosana CordenunsiAbstract:Papaya (Carica papaya) is a climacteric fruit that undergoes dramatic pulp softening. Fruits sampled at three different conditions (natural ripening or after exposition to ethylene or 1-methylcyclopropene) were used for the isolation of cell wall polymers to find changes in their degradation pattern. Polymers were separated according to their solubility in water, CDTA, and 4 M alkali, and their monosaccharide compositions were determined. Water-soluble polymers were further characterized, and their increased yields in control and ethylene-treated fruit, in contrast to those that were treated with 1-MCP, indicated a strong association between fruit softening and changes in the cell wall water-soluble polysaccharide fraction. The results indicate that the extensive softening in the pulp of ripening Papayas is a consequence of solubilization of large molecular mass galacturonans from the pectin fraction of the cell wall. This process seems to be dependent on the levels of ethylene, and it is likely that the ...
Baojian Li - One of the best experts on this subject based on the ideXlab platform.
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cloning of the papaya ringspot virus prsv replicase gene and generation of prsv resistant Papayas through the introduction of the prsv replicase gene
Plant Cell Reports, 2001Co-Authors: Guanghao Chen, C M Ye, J C Huang, M Yu, Baojian LiAbstract:Papaya ringspot virus (PRSV) can cause a destructive disease in papaya (Carica papaya L.). Based on observations that viral replicase (RP) gene confers resistance to virus in other plants, we designed a pair of primers and cloned the RP gene from PRSV by RT-PCR. The 3′-truncated and 5′-extended RP gene fragment was then oriented under the control of the CaMV35 S promoter and nos termination sequence in the mini Ti plasmid vector pRok to construct a plant expression vector, designated pRPTW. Papaya (C. papaya L.) cv. Tai-nong-2 embryogenic calli were transformed by Agrobacterium tumefaciens LBA4404 harboring the pRPTW vector. After selection on 100 mg/ml kanamycin, 20 putative transgenic Papayas were regenerated and confirmed by PCR-Southern blot and Southern blot analyses. PRSV inoculation tests showed that the RP gene conferred resistance to PRSV in transgenic Papayas and those offspring carrying the RP gene. The consistency of the presence of the RP gene and PRSV resistance indicates that replicase-mediated resistance against PRSV was attained in papaya. Possible mechanisms include RNA-mediated resistance and protein-mediated resistance, as well as others, although further studies are required.
