Influência da microbiota natural e de fatores físico-químicos na adesão de Salmonella Enteritidis em alface de cultivo hidropônico e convencional
Ano de defesa: | 2008 |
---|---|
Autor(a) principal: | |
Orientador(a): | |
Banca de defesa: | , |
Tipo de documento: | Dissertação |
Tipo de acesso: | Acesso aberto |
Idioma: | por |
Instituição de defesa: |
Universidade Federal de Viçosa
|
Programa de Pós-Graduação: |
Mestrado em Ciência e Tecnologia de Alimentos
|
Departamento: |
Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos
|
País: |
BR
|
Palavras-chave em Português: | |
Palavras-chave em Inglês: | |
Área do conhecimento CNPq: | |
Link de acesso: | http://locus.ufv.br/handle/123456789/2841 |
Resumo: | Adhesion of Salmonella Enteritidis in lettuces leaves of hidroponic and convencional systems was evaluated in reason of the native microbiota, with or without sanitization with chlorinated organic compound and vegetal roughness, using Atomic Force Microscopy. Besides, surfaces hydrophobicities of the lettuce leaves and S. Enteritidis were determined, through water contact angle and free energy. Also, a thermodynamic study was accomplished based on the quantification of the total free energy of interaction of the surfaces to foresee the pathogen adhesion on the leaf surfaces. The presence of Salmonella sp. Was not observed in none of the lettuces samples. Except filamentous fungi and yeasts counts, the lettuce cultivars grown hydroponically presented smaller counts (P < 0,05) for aerobic mesophilic, lactic bacteria and coliforms at 35ºC. Sanitization with 200mg.L-1 of total residual chlorine, pH 6.8, during 15 min reduced (P < 0,05) the counts of all of the microbial groups, altering the native microbiota of the lettuces surface. The adhesion of S. Enteritidis was larger (P < 0,05) in the Hydroponic lettuce and in both types of lettuces after the sanitization procedure (P < 0,05). Images obtained by Scanning Electron Microscopy showed that the leaf surface presented different micro photographic characteristics and that the present stomats in surfaces served as entrance and shelter for the pathogen cells. The roughness values showed that the surface of lettuces cultivars qrown hydropomically was more wrinkled (P < 0,05), with average of 1211.2 nm. The lettuce of conventional cultivaiton presented a mediumroughness of 293.3 nm. The qualitative analysis of hydriohobicity revealed that the surface S. Enteritidis was hydrophilic and that the surfaces of the hydroponic and conventional lettuces can be classified as hydrophobic and slightly hydrophilic,respectively. Free energies values were positive (Δgsws > 0) for the surface of conventional cultivaion lettuce, and for S. Enteritidis surface, indicating hydrophilic surface, while for the lattuce cultivas grown hydroponically the value of the free energy was nagative (Δgsws < 0), in other words, hydrophonic. The main factors involved in the adhesion of the pathogen in this research were superfaces roughness and competitor microbiota. Adhesion of S. Enteritidis to the leave surface was thermodynamically unfarvirable, independent of the cultivation way (ΔgAdesão > 0). Thus, the termodynamic evaluation explains the low number of S. Enteritidis cells adhered to the leave surface. Results show the importance of the vegetables sanitization processe and of the sppropriate production practices and suggest that the recontamination is an important factor to be considered. In that sense, the biological preservation should be considered as an additional measure a not like a substitution of the hygienic-sanitarium processes. Besides, the study of factors that involve the bacterial adhesion in foods surfaces is of great importance for the control of this process and the obtaining of safe foods from the microbiological point of view. |
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Lima, Priscilla Macedohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4710767A9Ferreira, Sukarno Olavohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4786429E5Minim, Luis Antoniohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4789633Y8Andrade, Nélio José dehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788281Y5Silva, Cleuber Antonio de Sáhttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4705268H7Silva, Washington Azevedo dahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4765007Y52015-03-26T13:13:11Z2009-05-122015-03-26T13:13:11Z2008-10-11LIMA, Priscilla Macedo. Influence of the native microbiota and of physical- chemical factors in adhesion of Salmonella Enteritidis in lettuces of hydroponic and conventional sistems. 2008. 71 f. Dissertação (Mestrado em Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos) - Universidade Federal de Viçosa, Viçosa, 2008.http://locus.ufv.br/handle/123456789/2841Adhesion of Salmonella Enteritidis in lettuces leaves of hidroponic and convencional systems was evaluated in reason of the native microbiota, with or without sanitization with chlorinated organic compound and vegetal roughness, using Atomic Force Microscopy. Besides, surfaces hydrophobicities of the lettuce leaves and S. Enteritidis were determined, through water contact angle and free energy. Also, a thermodynamic study was accomplished based on the quantification of the total free energy of interaction of the surfaces to foresee the pathogen adhesion on the leaf surfaces. The presence of Salmonella sp. Was not observed in none of the lettuces samples. Except filamentous fungi and yeasts counts, the lettuce cultivars grown hydroponically presented smaller counts (P < 0,05) for aerobic mesophilic, lactic bacteria and coliforms at 35ºC. Sanitization with 200mg.L-1 of total residual chlorine, pH 6.8, during 15 min reduced (P < 0,05) the counts of all of the microbial groups, altering the native microbiota of the lettuces surface. The adhesion of S. Enteritidis was larger (P < 0,05) in the Hydroponic lettuce and in both types of lettuces after the sanitization procedure (P < 0,05). Images obtained by Scanning Electron Microscopy showed that the leaf surface presented different micro photographic characteristics and that the present stomats in surfaces served as entrance and shelter for the pathogen cells. The roughness values showed that the surface of lettuces cultivars qrown hydropomically was more wrinkled (P < 0,05), with average of 1211.2 nm. The lettuce of conventional cultivaiton presented a mediumroughness of 293.3 nm. The qualitative analysis of hydriohobicity revealed that the surface S. Enteritidis was hydrophilic and that the surfaces of the hydroponic and conventional lettuces can be classified as hydrophobic and slightly hydrophilic,respectively. Free energies values were positive (Δgsws > 0) for the surface of conventional cultivaion lettuce, and for S. Enteritidis surface, indicating hydrophilic surface, while for the lattuce cultivas grown hydroponically the value of the free energy was nagative (Δgsws < 0), in other words, hydrophonic. The main factors involved in the adhesion of the pathogen in this research were superfaces roughness and competitor microbiota. Adhesion of S. Enteritidis to the leave surface was thermodynamically unfarvirable, independent of the cultivation way (ΔgAdesão > 0). Thus, the termodynamic evaluation explains the low number of S. Enteritidis cells adhered to the leave surface. Results show the importance of the vegetables sanitization processe and of the sppropriate production practices and suggest that the recontamination is an important factor to be considered. In that sense, the biological preservation should be considered as an additional measure a not like a substitution of the hygienic-sanitarium processes. Besides, the study of factors that involve the bacterial adhesion in foods surfaces is of great importance for the control of this process and the obtaining of safe foods from the microbiological point of view.A adesão de Salmonella Enteritidis em folhas de alfaces provenientes de cultivo hidropônico e convencional foi avaliada em razão da microbiota nativa, com ou sem sanitização com composto clorado orgânico e da rugosidade do vegetal, avaliada pela Microscopia de Força Atômica. Além disso, foram determinadas as hidrofobicidades das superfícies das folhas de alface e da S. Enteritidis, pelo ângulo de contato com a água e pela energia livre. Também, foi realizado estudo termodinâmico baseado na quantificação da energia livre total de interação para prever a adesão desse patógeno nas superfícies foliares. A presença de Salmonella sp. não foi observada em nenhuma das amostras de alfaces. A exceção da contagem de fungos filamentosos e leveduras, a alface de cultivo hidropônico apresentou menores contagens (P<0,05) para mesófilos aeróbios, bactérias láticas e coliformes a 35 °C. A sanitização com 200 mg.L-1 de cloro residual total, pH 6,8. durante 15 min reduziu (P<0,05) as contagens de todos os grupos microbianos, alterando assim a microbiota nativa da superfície das alfaces. A adesão de S. Enteritidis foi maior (P<0,05) na alface hidropônica e em ambos os tipos de alfaces após o procedimento de sanitização (P<0,05). As imagens obtidas por Microscopia Eletrônica de Varredura mostraram que as superfícies foliares apresentaram características microfotográficas distintas e que os estômatos presentes nas superfícies serviram de entrada e abrigo para as células do patógeno. Os valores de rugosidade mostraram que a superfície da alface de cultivo hidropônico foi mais rugosa (P<0,05), com média de 1211,2 nm. A alface de cultivo convencional apresentou uma rugosidade média de 293,3 nm. A análise qualitativa de hidrofobicidade revelou que a superfície S. Enteritidis foi hidrofílica e que as superfícies de alfaces hidropônicos e convencional, podem ser classificadas como hidrofóbica e levemente hidrofílica. respectivamente. Os valores das energias livres foram positivos (ΔGsws > O) para a superfície de alface de cultivo convencional, e para a superfície de S. Enteritidis. indicando superfícies hidrofílicas, enquanto para a alface oriunda do sistema hidropônico o valor da energia livre foi negativo (ΔGsws < O), ou seja hidrofóbica. Nessa pesquisa os principais fatores envolvidos na adesão do patógeno foram a rugosidade das superfícies e microbiota competidora. A adesão de S. Enteritidis foi termodinamicamente desfavorável independente da forma de cultivo (ΔG adesão > O). Desse modo. a avaliação termodinâmica explica o baixo percentual de células de S. Enteritidis aderidas as superfícies foliares. Os resultados mostram a importância do processo de sanitização de vegetais e das práticas adequadas de produção e sugerem que a recontaminação é um importante fator a ser considerado. Nesse sentido. a preservação biológica deve ser considerada como uma medida adicional e não como uma substituição dos processos higiênico-sanitários. Além disso, o estudo dos fatores que envolvem a adesão bacteriana em superfícies de alimentos é de grande importância para o controle desse processo e obtenção de alimentos mais seguros do ponto de vista microbiológico.Coordenação de Aperfeiçoamento de Pessoal de Nível Superiorapplication/pdfporUniversidade Federal de ViçosaMestrado em Ciência e Tecnologia de AlimentosUFVBRCiência de Alimentos; Tecnologia de Alimentos; Engenharia de AlimentosAdesãoHidrofobicidadeSalmonella enteritidisAdhesionHydrophobicitySalmonella enteritidisCNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOSInfluência da microbiota natural e de fatores físico-químicos na adesão de Salmonella Enteritidis em alface de cultivo hidropônico e convencionalInfluence of the native microbiota and of physical- chemical factors in adhesion of Salmonella Enteritidis in lettuces of hydroponic and conventional sistemsinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:LOCUS Repositório Institucional da UFVinstname:Universidade Federal de Viçosa (UFV)instacron:UFVORIGINALtexto completo.pdfapplication/pdf4311014https://locus.ufv.br//bitstream/123456789/2841/1/texto%20completo.pdf9566a160012f96d6e6f19ca28e161c87MD51TEXTtexto completo.pdf.txttexto completo.pdf.txtExtracted texttext/plain71https://locus.ufv.br//bitstream/123456789/2841/2/texto%20completo.pdf.txtdbd087b0a9c1b88d633ce8d30f2c9baeMD52THUMBNAILtexto completo.pdf.jpgtexto completo.pdf.jpgIM Thumbnailimage/jpeg3600https://locus.ufv.br//bitstream/123456789/2841/3/texto%20completo.pdf.jpgf2eb6699d9bcb4efcbd4599f9e0a2364MD53123456789/28412016-04-08 23:14:11.069oai:locus.ufv.br:123456789/2841Repositório InstitucionalPUBhttps://www.locus.ufv.br/oai/requestfabiojreis@ufv.bropendoar:21452016-04-09T02:14:11LOCUS Repositório Institucional da UFV - Universidade Federal de Viçosa (UFV)false |
dc.title.por.fl_str_mv |
Influência da microbiota natural e de fatores físico-químicos na adesão de Salmonella Enteritidis em alface de cultivo hidropônico e convencional |
dc.title.alternative.eng.fl_str_mv |
Influence of the native microbiota and of physical- chemical factors in adhesion of Salmonella Enteritidis in lettuces of hydroponic and conventional sistems |
title |
Influência da microbiota natural e de fatores físico-químicos na adesão de Salmonella Enteritidis em alface de cultivo hidropônico e convencional |
spellingShingle |
Influência da microbiota natural e de fatores físico-químicos na adesão de Salmonella Enteritidis em alface de cultivo hidropônico e convencional Lima, Priscilla Macedo Adesão Hidrofobicidade Salmonella enteritidis Adhesion Hydrophobicity Salmonella enteritidis CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS |
title_short |
Influência da microbiota natural e de fatores físico-químicos na adesão de Salmonella Enteritidis em alface de cultivo hidropônico e convencional |
title_full |
Influência da microbiota natural e de fatores físico-químicos na adesão de Salmonella Enteritidis em alface de cultivo hidropônico e convencional |
title_fullStr |
Influência da microbiota natural e de fatores físico-químicos na adesão de Salmonella Enteritidis em alface de cultivo hidropônico e convencional |
title_full_unstemmed |
Influência da microbiota natural e de fatores físico-químicos na adesão de Salmonella Enteritidis em alface de cultivo hidropônico e convencional |
title_sort |
Influência da microbiota natural e de fatores físico-químicos na adesão de Salmonella Enteritidis em alface de cultivo hidropônico e convencional |
author |
Lima, Priscilla Macedo |
author_facet |
Lima, Priscilla Macedo |
author_role |
author |
dc.contributor.authorLattes.por.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4710767A9 |
dc.contributor.author.fl_str_mv |
Lima, Priscilla Macedo |
dc.contributor.advisor-co1.fl_str_mv |
Ferreira, Sukarno Olavo |
dc.contributor.advisor-co1Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4786429E5 |
dc.contributor.advisor-co2.fl_str_mv |
Minim, Luis Antonio |
dc.contributor.advisor-co2Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4789633Y8 |
dc.contributor.advisor1.fl_str_mv |
Andrade, Nélio José de |
dc.contributor.advisor1Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788281Y5 |
dc.contributor.referee1.fl_str_mv |
Silva, Cleuber Antonio de Sá |
dc.contributor.referee1Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4705268H7 |
dc.contributor.referee2.fl_str_mv |
Silva, Washington Azevedo da |
dc.contributor.referee2Lattes.fl_str_mv |
http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4765007Y5 |
contributor_str_mv |
Ferreira, Sukarno Olavo Minim, Luis Antonio Andrade, Nélio José de Silva, Cleuber Antonio de Sá Silva, Washington Azevedo da |
dc.subject.por.fl_str_mv |
Adesão Hidrofobicidade Salmonella enteritidis |
topic |
Adesão Hidrofobicidade Salmonella enteritidis Adhesion Hydrophobicity Salmonella enteritidis CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS |
dc.subject.eng.fl_str_mv |
Adhesion Hydrophobicity Salmonella enteritidis |
dc.subject.cnpq.fl_str_mv |
CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS |
description |
Adhesion of Salmonella Enteritidis in lettuces leaves of hidroponic and convencional systems was evaluated in reason of the native microbiota, with or without sanitization with chlorinated organic compound and vegetal roughness, using Atomic Force Microscopy. Besides, surfaces hydrophobicities of the lettuce leaves and S. Enteritidis were determined, through water contact angle and free energy. Also, a thermodynamic study was accomplished based on the quantification of the total free energy of interaction of the surfaces to foresee the pathogen adhesion on the leaf surfaces. The presence of Salmonella sp. Was not observed in none of the lettuces samples. Except filamentous fungi and yeasts counts, the lettuce cultivars grown hydroponically presented smaller counts (P < 0,05) for aerobic mesophilic, lactic bacteria and coliforms at 35ºC. Sanitization with 200mg.L-1 of total residual chlorine, pH 6.8, during 15 min reduced (P < 0,05) the counts of all of the microbial groups, altering the native microbiota of the lettuces surface. The adhesion of S. Enteritidis was larger (P < 0,05) in the Hydroponic lettuce and in both types of lettuces after the sanitization procedure (P < 0,05). Images obtained by Scanning Electron Microscopy showed that the leaf surface presented different micro photographic characteristics and that the present stomats in surfaces served as entrance and shelter for the pathogen cells. The roughness values showed that the surface of lettuces cultivars qrown hydropomically was more wrinkled (P < 0,05), with average of 1211.2 nm. The lettuce of conventional cultivaiton presented a mediumroughness of 293.3 nm. The qualitative analysis of hydriohobicity revealed that the surface S. Enteritidis was hydrophilic and that the surfaces of the hydroponic and conventional lettuces can be classified as hydrophobic and slightly hydrophilic,respectively. Free energies values were positive (Δgsws > 0) for the surface of conventional cultivaion lettuce, and for S. Enteritidis surface, indicating hydrophilic surface, while for the lattuce cultivas grown hydroponically the value of the free energy was nagative (Δgsws < 0), in other words, hydrophonic. The main factors involved in the adhesion of the pathogen in this research were superfaces roughness and competitor microbiota. Adhesion of S. Enteritidis to the leave surface was thermodynamically unfarvirable, independent of the cultivation way (ΔgAdesão > 0). Thus, the termodynamic evaluation explains the low number of S. Enteritidis cells adhered to the leave surface. Results show the importance of the vegetables sanitization processe and of the sppropriate production practices and suggest that the recontamination is an important factor to be considered. In that sense, the biological preservation should be considered as an additional measure a not like a substitution of the hygienic-sanitarium processes. Besides, the study of factors that involve the bacterial adhesion in foods surfaces is of great importance for the control of this process and the obtaining of safe foods from the microbiological point of view. |
publishDate |
2008 |
dc.date.issued.fl_str_mv |
2008-10-11 |
dc.date.available.fl_str_mv |
2009-05-12 2015-03-26T13:13:11Z |
dc.date.accessioned.fl_str_mv |
2015-03-26T13:13:11Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
LIMA, Priscilla Macedo. Influence of the native microbiota and of physical- chemical factors in adhesion of Salmonella Enteritidis in lettuces of hydroponic and conventional sistems. 2008. 71 f. Dissertação (Mestrado em Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos) - Universidade Federal de Viçosa, Viçosa, 2008. |
dc.identifier.uri.fl_str_mv |
http://locus.ufv.br/handle/123456789/2841 |
identifier_str_mv |
LIMA, Priscilla Macedo. Influence of the native microbiota and of physical- chemical factors in adhesion of Salmonella Enteritidis in lettuces of hydroponic and conventional sistems. 2008. 71 f. Dissertação (Mestrado em Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos) - Universidade Federal de Viçosa, Viçosa, 2008. |
url |
http://locus.ufv.br/handle/123456789/2841 |
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Universidade Federal de Viçosa |
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Mestrado em Ciência e Tecnologia de Alimentos |
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UFV |
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BR |
dc.publisher.department.fl_str_mv |
Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos |
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Universidade Federal de Viçosa |
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