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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.
11

Avaliação de morangos submetidos a resfriamento rapido e armazenamento em diferentes embalagens e temperaturas / Strawberries evaluation submitted to fast cooling and followed by storage in different packings and temperatures

Castillo Pizarro, Cintya Alejandra 02 March 2009 (has links)
Orientador: Paulo Ademar Martins Leal / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-13T09:54:07Z (GMT). No. of bitstreams: 1 CastilloPizarro_CintyaAlejandra_D.pdf: 538268 bytes, checksum: a0775d761ca852aadb1dc74aa8998449 (MD5) Previous issue date: 2009 / Resumo: O morango é produzido e apreciado nas mais variadas regiões do mundo, sendo a espécie de maior expressão econômica entre as pequenas frutas. O Estado de São Paulo é um dos seus maiores produtores no Brasil. De todo o ciclo produtivo do morango, a comercialização tem se mostrado a fase mais complexa e problemática, podendo afetar mais o lucro do que todas as outras etapas de produção. Isso ocorre devido às características do produto, como fragilidade, manuseio inadequado, alta perecibilidade e falta de embalagens e de refrigeração adequados. Por possuir elevado valor comercial, principalmente no mercado in natura, a tecnologia do frio para sua melhor conservação pós-colheita, pode ser utilizado para manter as boas características de qualidade do fruto. Este trabalho teve por objetivo geral definir qual a melhor condição pós-colheita para conservação de morangos quanto a embalagem cumbucas de tereftalato de polietileno (PET) ou em meia cumbuca de tereftalato de polietileno, envoltas por filme de policloreto de vinila (PVC), resfriamento rápido e armazenamento refrigerado, visando seu consumo in natura. Realizaram-se dois experimentos, sendo um para monitoramento da taxa respiratória dos pseudofrutos a 0°C, 5°C, 10°C e 15°C em dois sistemas (sistema de fluxo contínuo e sistema estático). Outro experimento foi feito para avaliar a resposta da fruta expressa pelos parâmetros respiração, sólidos solúveis, pH e acidez titulável, quando estes foram submetidos a processos de resfriamento rápido e armazenagem. As variedades avaliadas foram Camarosa, Sweet Charlie, Dover e Oso Grande. Neste experimento utilizou-se câmaras de armazenamento com regulagem de 0 e 10°C, e os frutos foram embalados em cumbucas PET e PVC. As frutas foram analisadas a cada dois dias, até ficarem impróprias para o consumo. Verificou-se que o melhor método para avaliação da taxa respiratória é o método do sistema de fluxo contínuo, por possuir um fluxo constante durante todo o experimento, assim como melhor reprodutibilidade dos tempos de retenção e da quantificação do CO2 dentro dos frascos. A temperatura 0°C, foi a que possibilitou a maior vida de prateleira dos frutos. Não se observou diferença entre as embalagens PET e PVC no armazenamento a 0°C e a 10°C. Das variedades avaliadas a Sweet Charlie é a que se mostrou mais indicada para consumo in natura, devido suas características fisico-químicas. Enquanto a variedade Camarosa a mais indicada para indústria. / Abstract: The strawberry is cultivated and appreciated in several regions around the world, being the specie with the most economical value among the small fruits. The São Paulo state is one of the biggest producers in Brazil. From all productive cycle of strawberry the commercialization has shown the most complex and problematic phase, and it can affect more the profit than all the others. This happens due to the product characteristics, such as fragility, improper handling, high perishable, inadequate packaging, and use of cold chain. Since strawberry has high commercial value, mainly on in natura maket, the cold chain technology may be used to keep the good characteristics of fruit quality. The objectives were to define which are the best conditions postharvest for the strawberry fruits in terms of packing PET or PVC, precooling and refrigerated storage aiming the consumption in natura. Two experiments were realized, being one to monitoring and evaluating the respiratory rate of the fruits at the temperatures of 0, 5, 10 and 15°C in two different systems: continuous flow system, and static flow system, in BOD's. The other experiment was to evaluate the answer of biochemical parameters (respiration rate, soluble solids, pH and titratable acidity) submitted to the precooling and refrigerated processes using the Camarosa, Sweet Charlie, Dover, and Oso Grande varieties. For this experiment was used chambers at 0 and 10oC, and the fruits had been packed in packs of tereftalate of polyethylene (PET) clam shell type, and packs of tereftalate of polyethylene (PET) wrap with PVC film. Physical-chemical analyses were carried every two days until the fruits got improper for consumption. The experiment show that the optimum method for evaluation respiratory rate is the one using the continuous flow system since presented a constant flow during all the experiments, and allows better accuracy for the retention time and CO2 quantification inside of the bottles. The temperature of 0°C was the one that shows longest fruits shelf life time. There were not differences between packs of tereftalate of polyethylene (PET) clam shell type and packs of tereftalate of polyethylene (PET) wrap with PVC film storaged at 0 and 10°C. Among the varieties, the Sweet Charlie was the most indicated for in natura consumption, due to its physical-chemical characteristics. Meanwhile the variety Camarosa was the most appropriate for industry use. / Doutorado / Tecnologia Pós-Colheita / Doutor em Engenharia Agrícola
12

Detection and molecular identification of Mucorales isolated from spoilt agricultural commodities collected in fresh produce markets in Gauteng province, South Africa

Kwinda, Grace Thiambi 12 1900 (has links)
Fruit and vegetables are often spoilt during storage, handling and transportation due to microorganisms. The common spoilage causes are fungi within the order Mucorales, the largest order of the class Zygomycetes. Such spoilage can result in reduced food supplies, poor quality and severe losses to producers and traders. The study was to investigate the type of Mucorales prevalent in various commodities and in a particular market than others. Fifty infected papaya, peaches and strawberries were collected at five occasions from large, medium and small markets. Isolation was done aseptically in a biosafety cabinet. Mucorales were identified morphologically, through culture based tests and molecular techniques. Mucorales isolated are Rhizopus stolonifer, Mucor circinelloides and Mucor racemosus. Mucorales were isolated at a higher rate in samples collected from the small market than other two markets. Spoilage in all three markets is assumed to be influenced by lack of modified temperatures in the storage room. / Life and Consumer Sciences / M. Sc. (Life Sciences)
13

Detection and molecular identification of Mucorales isolated from spoilt agricultural commodities collected in fresh produce markets in Gauteng province, South Africa

Kwinda, Grace Thiambi 12 1900 (has links)
Fruit and vegetables are often spoilt during storage, handling and transportation due to microorganisms. The common spoilage causes are fungi within the order Mucorales, the largest order of the class Zygomycetes. Such spoilage can result in reduced food supplies, poor quality and severe losses to producers and traders. The study was to investigate the type of Mucorales prevalent in various commodities and in a particular market than others. Fifty infected papaya, peaches and strawberries were collected at five occasions from large, medium and small markets. Isolation was done aseptically in a biosafety cabinet. Mucorales were identified morphologically, through culture based tests and molecular techniques. Mucorales isolated are Rhizopus stolonifer, Mucor circinelloides and Mucor racemosus. Mucorales were isolated at a higher rate in samples collected from the small market than other two markets. Spoilage in all three markets is assumed to be influenced by lack of modified temperatures in the storage room. / Life and Consumer Sciences / M. Sc. (Life Sciences)

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