Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico

Detalhes bibliográficos
Autor(a) principal: Souza, Josilma Silva de
Data de Publicação: 2002
Tipo de documento: Dissertação
Idioma: por
Título da fonte: Repositório Institucional da UFRN
Texto Completo: https://repositorio.ufrn.br/jspui/handle/123456789/15777
Resumo: Vegetables drying plays an important role in the field of food dehydration, being a very old practice that was originated from sun drying items of food in order to preserve them to be consumed during the periods of scarcity. One of these vegetables is the tomato, that was originally grown in South America. Tomatoes are easily perishable after being picked up from the tree and this makes the process of tomato dehydration a challenge due to the high amount of water (95%) contained in them. The present research work was mainly intended to develop alternative processes for tomato conservation, by drying slices of skinned and unskinned tomatoes in the in natura form or in the osmotically pre-dehydrated form. Firstly, the best conditions of the osmotic pre-dehydration process were defined including temperature, immersion time and concentration of the osmotic solution, based on the results of water loss, solids gain and weigh reduction of the pre-dehydration tomatoes at different processing conditions. The osmotic solution used was made up of NaCl (5 and 10%) and sucrose (25 and 35%) at different combinations. For a fixed conditions of osmotic pre-dehydration, the drying tests of the pre-processed and in natura tomatoes were carried out in a stove with air circulation and a convective dryer with trays, at two levels of temperature. The sensorial analysis of the osmotically pre-treated and unskinned dehydrated tomatoes was carried out as well as a study on the their shelf-live. The results obtained showed that the drying of the tomatoes took place as a result of the internal control of the water transport, and did not show a constant rate, while two distinct periods of the decreasing phase were observed. The osmotic pre treatment substancially reduced the initial amount of humidity in the tomatoes, thus reducing the necessary time for the product to attain levels of intermediate humidity. The impermeability of the tomato skin was identified as well as the unfavorable influence of the pre-treatment on the unskinned tomatoes, whose solid gain brought about a decrease in the water activity with subsequent reduction of the drying rate. Despite the various simplifications carried out during the development of this study, the proposed diffusive model adjusted to the experimental data satisfactorily, thus making it possible to determine the effective coefficients of diffusion, whose results were consistent and compatible with those found in the current literature. Concerning the higher rates of evaporation and the lowest processing time, the best results were obtained in the drying of the unskinned, in natura tomatoes and of the skinned, pre-dehydrated tomatoes, at 60ºC, both processed in the convective drier. The results of the sensorial analysis of the unskinned and pre-treated product did not prove to be satisfactory. Regarding the shelf-live of the tomatoes, for a period of 45 days, no physicochemical or microbiological alteration of the product was noted
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spelling Souza, Josilma Silva dehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4797174H9Medeiros, Maria de Fátima Dantas dehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788622A0Alsina, Odelsia Leonor Sanchez dehttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783955Z6Costa, José Maria Correia dahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4799COSTA,Silva, Gabriel Francisco dahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4782708P2Magalhães, Margarida Maria dos Anjos2014-12-17T15:01:20Z2014-12-092014-12-17T15:01:20Z2002-06-07SOUZA, Josilma Silva de. Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico. 2002. 105 f. Dissertação (Mestrado em Pesquisa e Desenvolvimento de Tecnologias Regionais) - Universidade Federal do Rio Grande do Norte, Natal, 2002.https://repositorio.ufrn.br/jspui/handle/123456789/15777Vegetables drying plays an important role in the field of food dehydration, being a very old practice that was originated from sun drying items of food in order to preserve them to be consumed during the periods of scarcity. One of these vegetables is the tomato, that was originally grown in South America. Tomatoes are easily perishable after being picked up from the tree and this makes the process of tomato dehydration a challenge due to the high amount of water (95%) contained in them. The present research work was mainly intended to develop alternative processes for tomato conservation, by drying slices of skinned and unskinned tomatoes in the in natura form or in the osmotically pre-dehydrated form. Firstly, the best conditions of the osmotic pre-dehydration process were defined including temperature, immersion time and concentration of the osmotic solution, based on the results of water loss, solids gain and weigh reduction of the pre-dehydration tomatoes at different processing conditions. The osmotic solution used was made up of NaCl (5 and 10%) and sucrose (25 and 35%) at different combinations. For a fixed conditions of osmotic pre-dehydration, the drying tests of the pre-processed and in natura tomatoes were carried out in a stove with air circulation and a convective dryer with trays, at two levels of temperature. The sensorial analysis of the osmotically pre-treated and unskinned dehydrated tomatoes was carried out as well as a study on the their shelf-live. The results obtained showed that the drying of the tomatoes took place as a result of the internal control of the water transport, and did not show a constant rate, while two distinct periods of the decreasing phase were observed. The osmotic pre treatment substancially reduced the initial amount of humidity in the tomatoes, thus reducing the necessary time for the product to attain levels of intermediate humidity. The impermeability of the tomato skin was identified as well as the unfavorable influence of the pre-treatment on the unskinned tomatoes, whose solid gain brought about a decrease in the water activity with subsequent reduction of the drying rate. Despite the various simplifications carried out during the development of this study, the proposed diffusive model adjusted to the experimental data satisfactorily, thus making it possible to determine the effective coefficients of diffusion, whose results were consistent and compatible with those found in the current literature. Concerning the higher rates of evaporation and the lowest processing time, the best results were obtained in the drying of the unskinned, in natura tomatoes and of the skinned, pre-dehydrated tomatoes, at 60ºC, both processed in the convective drier. The results of the sensorial analysis of the unskinned and pre-treated product did not prove to be satisfactory. Regarding the shelf-live of the tomatoes, for a period of 45 days, no physicochemical or microbiological alteration of the product was notedA secagem de hortaliças ocupa uma posição muito representativa na área de desidratação de alimentos, processo esse que teve início com a secagem ao sol, tem a finalidade de preservar os excedentes das colheitas para serem consumidos nos períodos de escassez. Dentre estas hortaliças se encontra o tomate, originado da América, que após a colheita apresenta-se um fruto bastante perecível fazendo com que a sua desidratação seja um desafio, devido ao seu alto teor de água (95% b.u.). Esse trabalho teve como principal objetivo encontrar formas alternativas de conservação do tomate, através da secagem de pedaços com e sem pele, na forma in natura ou pré-desidratados osmoticamente. Inicialmente, foram definidas as melhores condições da pré-desidratação osmótica (temperatura, tempo de imersão, concentração da solução osmótica) baseados nos resultados de perda de umidade, ganho de sólidos e redução de peso, dos tomates pré-desidratados em diferentes condições de processamento. A solução osmótica utilizada foi composta de NaCl (5 e 10%) e sacarose (25 e 35%) em diversas combinações. Para uma condição fixa de desidratação osmótica, realizou-se os ensaios de secagem dos tomates pré-processados e in natura em estufa com circulação de ar e em secador convectivo de bandejas, em dois níveis de temperatura. Foi realizada a análise sensorial e o estudo de prateleira dos tomates desidratados sem pele e pré-tratados osmoticamente. Os resultados obtidos mostraram que a secagem dos tomates ocorre sob condição de controle interno do transporte de umidade, não apresentando período de taxa constante, e verificando-se dois períodos distintos da fase decrescente. O pré-tratamento osmótico reduziu substancialmente a umidade inicial dos tomates, reduzindo o tempo necessário para o produto atingir níveis de umidade intermediários. Foi identificado o caráter impermeabilizante da pele do tomate, e a influência desfavorável do pré-tratamento nos tomates sem pele, cujo ganho de sólidos provocou a diminuição da atividade de água com conseqüente redução das taxas de secagem. Apesar das inúmeras simplificações, o modelo difusional proposto ajustou-se de forma satisfatória aos dados experimentais, possibilitando a determinação de coeficientes de difusão efetivos, cujos resultados mostraram-se consistentes e compatíveis com os encontrados na literatura. Com relação as maiores taxas de evaporação e ao menor tempo de processamento, os melhores resultados foram obtidos na secagem à 60ºC de tomates in natura sem pele e os tomates com pele pré-desidratados, ambos processados no secador convectivo. Os resultados da análise sensorial do produto pré-tratado e sem pele, não foram satisfatórios. Com relação a vida de prateleira, durante um período de 45 dias de armazenamento, não se verificou qualquer alteração físico-química ou microbiológica do produtoCoordenação de Aperfeiçoamento de Pessoal de Nível Superiorapplication/pdfporUniversidade Federal do Rio Grande do NortePrograma de Pós-Graduação em Engenharia QuímicaUFRNBRPesquisa e Desenvolvimento de Tecnologias RegionaisTomatesConservaçãoDesidratação osmóticaSecagemDifusãoTomatoesConservationOsmotic dehydrationDryingDiffusion.CNPQ::ENGENHARIAS::ENGENHARIA QUIMICAEstudo da desidratação de tomates em pedaços com pré-tratamento osmóticoinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRNinstname:Universidade Federal do Rio Grande do Norte (UFRN)instacron:UFRNORIGINALJosilmaSS.pdfapplication/pdf490115https://repositorio.ufrn.br/bitstream/123456789/15777/1/JosilmaSS.pdfb796ab795af867ca3ee2bfaee9a69f80MD51TEXTJosilmaSS.pdf.txtJosilmaSS.pdf.txtExtracted texttext/plain152885https://repositorio.ufrn.br/bitstream/123456789/15777/6/JosilmaSS.pdf.txta6822336aea62c51c23c0d959419187fMD56THUMBNAILJosilmaSS.pdf.jpgJosilmaSS.pdf.jpgIM Thumbnailimage/jpeg3717https://repositorio.ufrn.br/bitstream/123456789/15777/7/JosilmaSS.pdf.jpg156b1b72e5b420abca773dab95b075a2MD57123456789/157772017-11-02 03:13:24.198oai:https://repositorio.ufrn.br:123456789/15777Repositório de PublicaçõesPUBhttp://repositorio.ufrn.br/oai/opendoar:2017-11-02T06:13:24Repositório Institucional da UFRN - Universidade Federal do Rio Grande do Norte (UFRN)false
dc.title.por.fl_str_mv Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico
title Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico
spellingShingle Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico
Souza, Josilma Silva de
Tomates
Conservação
Desidratação osmótica
Secagem
Difusão
Tomatoes
Conservation
Osmotic dehydration
Drying
Diffusion.
CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA
title_short Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico
title_full Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico
title_fullStr Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico
title_full_unstemmed Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico
title_sort Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico
author Souza, Josilma Silva de
author_facet Souza, Josilma Silva de
author_role author
dc.contributor.authorID.por.fl_str_mv
dc.contributor.advisorID.por.fl_str_mv
dc.contributor.advisorLattes.por.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4797174H9
dc.contributor.advisor-co1ID.por.fl_str_mv
dc.contributor.referees1.pt_BR.fl_str_mv Alsina, Odelsia Leonor Sanchez de
dc.contributor.referees1ID.por.fl_str_mv
dc.contributor.referees1Lattes.por.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783955Z6
dc.contributor.referees2.pt_BR.fl_str_mv Costa, José Maria Correia da
dc.contributor.referees2ID.por.fl_str_mv
dc.contributor.referees2Lattes.por.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4799COSTA,
dc.contributor.referees3.pt_BR.fl_str_mv Silva, Gabriel Francisco da
dc.contributor.referees3ID.por.fl_str_mv
dc.contributor.referees3Lattes.por.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4782708P2
dc.contributor.author.fl_str_mv Souza, Josilma Silva de
dc.contributor.advisor-co1.fl_str_mv Medeiros, Maria de Fátima Dantas de
dc.contributor.advisor-co1Lattes.fl_str_mv http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788622A0
dc.contributor.advisor1.fl_str_mv Magalhães, Margarida Maria dos Anjos
contributor_str_mv Medeiros, Maria de Fátima Dantas de
Magalhães, Margarida Maria dos Anjos
dc.subject.por.fl_str_mv Tomates
Conservação
Desidratação osmótica
Secagem
Difusão
topic Tomates
Conservação
Desidratação osmótica
Secagem
Difusão
Tomatoes
Conservation
Osmotic dehydration
Drying
Diffusion.
CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA
dc.subject.eng.fl_str_mv Tomatoes
Conservation
Osmotic dehydration
Drying
Diffusion.
dc.subject.cnpq.fl_str_mv CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA
description Vegetables drying plays an important role in the field of food dehydration, being a very old practice that was originated from sun drying items of food in order to preserve them to be consumed during the periods of scarcity. One of these vegetables is the tomato, that was originally grown in South America. Tomatoes are easily perishable after being picked up from the tree and this makes the process of tomato dehydration a challenge due to the high amount of water (95%) contained in them. The present research work was mainly intended to develop alternative processes for tomato conservation, by drying slices of skinned and unskinned tomatoes in the in natura form or in the osmotically pre-dehydrated form. Firstly, the best conditions of the osmotic pre-dehydration process were defined including temperature, immersion time and concentration of the osmotic solution, based on the results of water loss, solids gain and weigh reduction of the pre-dehydration tomatoes at different processing conditions. The osmotic solution used was made up of NaCl (5 and 10%) and sucrose (25 and 35%) at different combinations. For a fixed conditions of osmotic pre-dehydration, the drying tests of the pre-processed and in natura tomatoes were carried out in a stove with air circulation and a convective dryer with trays, at two levels of temperature. The sensorial analysis of the osmotically pre-treated and unskinned dehydrated tomatoes was carried out as well as a study on the their shelf-live. The results obtained showed that the drying of the tomatoes took place as a result of the internal control of the water transport, and did not show a constant rate, while two distinct periods of the decreasing phase were observed. The osmotic pre treatment substancially reduced the initial amount of humidity in the tomatoes, thus reducing the necessary time for the product to attain levels of intermediate humidity. The impermeability of the tomato skin was identified as well as the unfavorable influence of the pre-treatment on the unskinned tomatoes, whose solid gain brought about a decrease in the water activity with subsequent reduction of the drying rate. Despite the various simplifications carried out during the development of this study, the proposed diffusive model adjusted to the experimental data satisfactorily, thus making it possible to determine the effective coefficients of diffusion, whose results were consistent and compatible with those found in the current literature. Concerning the higher rates of evaporation and the lowest processing time, the best results were obtained in the drying of the unskinned, in natura tomatoes and of the skinned, pre-dehydrated tomatoes, at 60ºC, both processed in the convective drier. The results of the sensorial analysis of the unskinned and pre-treated product did not prove to be satisfactory. Regarding the shelf-live of the tomatoes, for a period of 45 days, no physicochemical or microbiological alteration of the product was noted
publishDate 2002
dc.date.issued.fl_str_mv 2002-06-07
dc.date.accessioned.fl_str_mv 2014-12-17T15:01:20Z
dc.date.available.fl_str_mv 2014-12-09
2014-12-17T15:01:20Z
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dc.identifier.citation.fl_str_mv SOUZA, Josilma Silva de. Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico. 2002. 105 f. Dissertação (Mestrado em Pesquisa e Desenvolvimento de Tecnologias Regionais) - Universidade Federal do Rio Grande do Norte, Natal, 2002.
dc.identifier.uri.fl_str_mv https://repositorio.ufrn.br/jspui/handle/123456789/15777
identifier_str_mv SOUZA, Josilma Silva de. Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico. 2002. 105 f. Dissertação (Mestrado em Pesquisa e Desenvolvimento de Tecnologias Regionais) - Universidade Federal do Rio Grande do Norte, Natal, 2002.
url https://repositorio.ufrn.br/jspui/handle/123456789/15777
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publisher.none.fl_str_mv Universidade Federal do Rio Grande do Norte
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