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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.
1

Estudo da desidrata??o osm?tica de fatias de chuchu (Sechium edule, Sw.) / Study of osmotic dehydration of chayote

Ferreira, J?natas de Aguiar 30 August 2005 (has links)
Submitted by Leticia Schettini (leticia@ufrrj.br) on 2016-10-11T14:28:18Z No. of bitstreams: 1 2005 - Jonatas de Aguiar Ferreira.pdf: 582914 bytes, checksum: cf08766dd08ac2ba431524c048eecb30 (MD5) / Made available in DSpace on 2016-10-11T14:28:18Z (GMT). No. of bitstreams: 1 2005 - Jonatas de Aguiar Ferreira.pdf: 582914 bytes, checksum: cf08766dd08ac2ba431524c048eecb30 (MD5) Previous issue date: 2005-08-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior-CAPES / In this research, the drying kinetics and equilibrium conditions during osmotic dehydration of chayote (Sechium edule, Sw.) were studied using 20, 30 and 40 % (w/v) sucrose solutions. A thermostatic bath was built to allow the experimental evaluation of osmotic dehydration kinetics and equilibrium moisture content determination. The experiments were carried out at three different temperatures (30 ?C, 40 ?C and 50 ?C) in order to evaluate the influence of temperature and sucrose concentration. Chayote fruits were washed and submerged in sodium hypochloride solution for ten minutes, for sanitization. Afterwards, the fruits were dried and cut into slices of about 0.5 cm thickness. Then, the slices were put into hypertonic sucrose solutions during preestablished time intervals. After osmotic dehydration, the solution was discarded and the slices were softly dried with absorbent paper to remove surface moisture. The moisture content was determined gravimetrically. Long time experiments up to 96 h were performed to provide information about the equilibrium moisture content. An specific equilibrium isotherm was selected by statistical methods. The correlation that better described equilibrium moisture content behavior was the Smith sorption isotherm, adapted to osmotic environment. The Overhults model was used to describe osmotic dehydration kinetics and estimate the drying constants k and n. Based on the results obtained in this research, it could be demonstrated that the equilibrium moisture content is strongly influenced by sucrose concentration and that k is a parameter dependent on the temperature and sucrose concentration, whereas n may be considered constant for the given experimental setup. / Neste trabalho foi feito um estudo da desidrata??o osm?tica de fatias de chuchu em um sistema que possibilitou a determina??o da umidade de equil?brio e dos coeficientes do modelo de Overhults para descrever a cin?tica de desidrata??o osm?tica das fatias. O procedimento experimental consistiu em lavar e escovar os frutos, para a remo??o de impurezas da casca, fatiar o chuchu, em fatias de 5 mm de espessura, num fatiador dom?stico de alimentos, submeter o material ? desidrata??o osm?tica em solu??o hipert?nica de sacarose a 20,30 e 40%, por at? 96 horas, tomando amostras em per?odos determinados para levantar a curva de desidrata??o do material e tamb?m determinar a umidade de equil?brio das fatias de chuchu como uma fun??o da concentra??o inicial da solu??o hipert?nica e da temperatura. Com base nos resultados obtidos foi poss?vel determinar os par?metros do modelo de Overhults para as fatias de chuchu, bem como a uma correla??o para a umidade de equil?brio do material e constatar que h? forte influ?ncia da temperatura e da concentra??o sobre a cin?tica de desidrata??o osm?tica do chuchu, que cerca de 50 % da umidade das amostras ? removida nas primeiras duas horas de imers?o, que a umidade de equil?brio ? atingida em cerca de 48 horas de imers?o e que o modelo de Overhults descreve satisfatoriamente as curvas de desidrata??o osm?tica.
2

Estudo da desidrata??o de tomates em peda?os com pr?-tratamento osm?tico

Souza, Josilma Silva de 07 June 2002 (has links)
Made available in DSpace on 2014-12-17T15:01:20Z (GMT). No. of bitstreams: 1 JosilmaSS.pdf: 490115 bytes, checksum: b796ab795af867ca3ee2bfaee9a69f80 (MD5) Previous issue date: 2002-06-07 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / 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 60?C, 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 / A secagem de hortali?as ocupa uma posi??o muito representativa na ?rea de desidrata??o de alimentos, processo esse que teve in?cio com a secagem ao sol, tem a finalidade de preservar os excedentes das colheitas para serem consumidos nos per?odos de escassez. Dentre estas hortali?as se encontra o tomate, originado da Am?rica, que ap?s a colheita apresenta-se um fruto bastante perec?vel fazendo com que a sua desidrata??o seja um desafio, devido ao seu alto teor de ?gua (95% b.u.). Esse trabalho teve como principal objetivo encontrar formas alternativas de conserva??o do tomate, atrav?s da secagem de peda?os com e sem pele, na forma in natura ou pr?-desidratados osmoticamente. Inicialmente, foram definidas as melhores condi??es da pr?-desidrata??o osm?tica (temperatura, tempo de imers?o, concentra??o da solu??o osm?tica) baseados nos resultados de perda de umidade, ganho de s?lidos e redu??o de peso, dos tomates pr?-desidratados em diferentes condi??es de processamento. A solu??o osm?tica utilizada foi composta de NaCl (5 e 10%) e sacarose (25 e 35%) em diversas combina??es. Para uma condi??o fixa de desidrata??o osm?tica, realizou-se os ensaios de secagem dos tomates pr?-processados e in natura em estufa com circula??o de ar e em secador convectivo de bandejas, em dois n?veis de temperatura. Foi realizada a an?lise sensorial e o estudo de prateleira dos tomates desidratados sem pele e pr?-tratados osmoticamente. Os resultados obtidos mostraram que a secagem dos tomates ocorre sob condi??o de controle interno do transporte de umidade, n?o apresentando per?odo de taxa constante, e verificando-se dois per?odos distintos da fase decrescente. O pr?-tratamento osm?tico reduziu substancialmente a umidade inicial dos tomates, reduzindo o tempo necess?rio para o produto atingir n?veis de umidade intermedi?rios. Foi identificado o car?ter impermeabilizante da pele do tomate, e a influ?ncia desfavor?vel do pr?-tratamento nos tomates sem pele, cujo ganho de s?lidos provocou a diminui??o da atividade de ?gua com conseq?ente redu??o das taxas de secagem. Apesar das in?meras simplifica??es, o modelo difusional proposto ajustou-se de forma satisfat?ria aos dados experimentais, possibilitando a determina??o de coeficientes de difus?o efetivos, cujos resultados mostraram-se consistentes e compat?veis com os encontrados na literatura. Com rela??o as maiores taxas de evapora??o e ao menor tempo de processamento, os melhores resultados foram obtidos na secagem ? 60?C de tomates in natura sem pele e os tomates com pele pr?-desidratados, ambos processados no secador convectivo. Os resultados da an?lise sensorial do produto pr?-tratado e sem pele, n?o foram satisfat?rios. Com rela??o a vida de prateleira, durante um per?odo de 45 dias de armazenamento, n?o se verificou qualquer altera??o f?sico-qu?mica ou microbiol?gica do produto
3

Estudo da desidrata??o osm?tica da cenoura (Daucus carota) em fatias

Ara?jo, Paulyanna Medeiros de 30 April 2010 (has links)
Made available in DSpace on 2014-12-17T15:01:24Z (GMT). No. of bitstreams: 1 PaulyannaMA_DISSERT.pdf: 1268166 bytes, checksum: cabfafbcdec9a837c1e9a990c1cdc369 (MD5) Previous issue date: 2010-04-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In the area of food dehydration, drying of vegetables has a very representative position, it has the objective to preserve the surplus of crops and began with sun drying. Among the vegetable is the carrot, which had its origin in Southeast Asia and in Brazil is a vegetable cultivated enough. The principal objective of this works is to find alternative ways for the conservation of carrot slices by osmotic dehydration with additional drying in heart. Were initially defined the best conditions of pre-osmotic dehydration (temperature, immersion time, type of osmotic solution) based on the results of humidity loss, solid gain, weight reduction and efficiency ratio of predehydrated carrots slices. The osmotic solutions used were composed by NaCl (10%) and sucrose (50 ? Brix) named DO1 and sucrose (50 ? Brix) called DO2. Was made experiment of pre-osmotic dehydration of carrot slices in two temperature levels, with complementary drying in heart with air circulation at 70 ? C. Sensory analysis was performed and the study of slices dehydration osmotically and the slices without osmotic treatment. The best results were obtained with the solution DO1 60?C with immersion time of 60 min. The drying of carrot slices presented period of constant rate and decreasing rate. The osmotic pre-treatment reduced the initial humidity of carrot slices, reducing the time to the product to reach the same humidity content. Fick's model, considering the shrinkage, and the Page s model, adapt satisfactorily to experimental datas, allowing the determination of effective diffusion coefficients, consistent with the references. The results of sensory analysis of dry product, showed greater acceptance of sliced carrots with osmotic treatment / Na ?rea de desidrata??o de alimentos, a secagem de hortali?as ocupa uma posi??o muito representativa, tem a finalidade de preservar os excedentes das colheitas e teve in?cio com a secagem ao sol. Dentre as hortali?as encontra-se a cenoura, que teve sua origem no Sudoeste Asi?tico e no Brasil ? uma hortali?a bastante cultivada. Esse trabalho teve como objetivo principal encontrar formas alternativas de conserva??o para fatias de cenoura, atrav?s da desidrata??o osm?tica com secagem complementar em estufa. Inicialmente foram definidas as melhores condi??es da pr?-desidrata??o osm?tica (temperatura, tempo de imers?o, tipo de solu??o osm?tica) baseadas nos resultados de perda de umidade, ganho de s?lidos, redu??o de peso e ?ndice de efici?ncia das fatias de cenoura pr?-desidratadas. As solu??es osm?ticas utilizadas foram compostas de NaCl (10%) e sacarose (50? Brix) denominada DO1, e sacarose (50? Brix) denominada DO2. Realizaram-se os ensaios de pr?-desidrata??o osm?tica das fatias de cenouras em dois n?veis de temperatura, com secagem complementar em estufa com circula??o de ar a 70?C. Foi realizada an?lise sensorial e o estudo da reidrata??o das fatias desidratadas osmoticamente e das fatias sem tratamento osm?tico. Os melhores resultados foram obtidas com as cenouras desidratadas com a solu??o DO1 a 60?C com tempo de imers?o de 60 min. A secagem das fatias de cenoura apresentou per?odo de taxa constante e de taxa decrescente. O pr?-tratamento osm?tico reduziu a umidade inicial das fatias de cenoura, reduzindo o tempo para o produto atingir o mesmo teor de umidade. O modelo de Fick, considerando o encolhimento, e o modelo de Page, se ajustaram de forma satisfat?ria aos dados experimentais, possibilitando a determina??o de coeficientes de difus?o efetivos, consistentes com a literatura. Os resultados de an?lise sensorial do produto seco indicaram maior aceita??o das fatias de cenouras com tratamento osm?tico
4

Desidrata??o osm?tica de banana utilizando solu??es de fruto-oligossacar?deos e xarope de milho em diferentes temperaturas / Study banana osmotic dehydration using solutions containing fructo-oligosaccharides and corn syrup at different temperatures

LANDIM, Ana Paula Miguel 02 June 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-09T17:18:58Z No. of bitstreams: 1 2016 - Ana Paula Miguel Landim.pdf: 1756748 bytes, checksum: edb655700eacaf99a7fa2c3d482f3283 (MD5) / Made available in DSpace on 2017-05-09T17:18:58Z (GMT). No. of bitstreams: 1 2016 - Ana Paula Miguel Landim.pdf: 1756748 bytes, checksum: edb655700eacaf99a7fa2c3d482f3283 (MD5) Previous issue date: 2016-06-02 / CAPES / Banana is a perishable fruit, as it ripens fast and cannot be adequately preserved by the cold, resulting in large post-harvest losses. The application of preservation techniques, such as osmotic dehydration, reduces losses of the commodity in post-harvest stage, extend its shelf-life, while not severely affecting its nutritional values, and functional and sensorial properties, which makes it at processing alternative for the fruit. The aim of this study is to evaluate the kinetics of osmotic dehydration, as well as the quality of the osmotically dehydrated samples in terms of color, texture, and antioxidant capacity, using fructo-oligosaccharide, corn syrup and the mixture of both, under different temperatures. To determine the kinetics, the fruit, cut in cubes, was dehydrated in different solutions, under temperatures of 40, 50 and 60 ? C. The kinetics of water loss (WL) and solid gain (SG) were evalueted at 30, 60, 90, 120, 180, 240, 360, 720 to 1440 minutes. The analysis of variance was used to verify the effect of each solution and temperature on kinetics. The kinetic parameters were modeled based on the equations of Peleg, Page modified and Barbosa Junior et al. using non-linear regression. The time to reduce the dehydration rate or penetration to one third of its initial values (t(1/3)) and the process average time (t(average)) were obtained on the Barbosa Junior et al. model The quality of the samples was accessed at these two times, in different solutions under different temperatures. For such, the variation of the instrumental parameters of color, antioxidant capacity (FRAP, DPPH and total phenolic content), and texture (axial compression tests) of samples, in nature as well as processed, were verified. The WL was not affected significantly by the type of solute used, however, the temperature presented significant influence over these parameters (p < 0.05). The experimental data for the WL was adequately adjusted to the Peleg and Page modified models with coefficients of determination (R?) superior than 0.98, mean relative error (E) inferior than 6.5% in all treatments. The water loss content values varied from 15.75 to 28.79% at time t(1/3), while for the time t(averege) 15.75 to 30.27% between treatments. The process of osmotic dehydration had affect on the quality of the final product, showing significant differences between the fruits in natura and processed state, in terms of color, antioxidant capacity and texture of the samples. / A banana ? um fruto perec?vel, pois sofre r?pido amadurecimento, n?o pode ser devidamente conservado pelo frio, sendo acometido por grandes perdas p?s-colheita. A utiliza??o de t?cnicas de conserva??o, como a desidrata??o osm?tica, reduz as perdas p?s-colheita, estende a validade comercial, n?o acarreta em severas altera??es nas caracter?sticas nutricionais, funcionais e sensoriais e mostra-se como uma alternativa de processamento para este fruto. O objetivo desde trabalho foi avaliar a cin?tica da desidrata??o osm?tica, bem como, a qualidade das amostras desidratadas osmoticamente em termos de cor, textura e capacidade antioxidante, utilizando fruto-oligossacar?deo, xarope de milho e a mistura de ambos, em diferentes temperaturas. Para determina??o da cin?tica, a banana, cortada em cubos foi desidratada nas diferentes solu??es, sob as temperaturas de 40, 50 e 60 ?C. As Cin?ticas de Perda de ?gua (PA) e ganho de s?lidos (GS) foram avaliadas nos tempos 30, 60, 90, 120, 180, 240, 360, 720 e 1440 minutos. A an?lise de vari?ncia foi usada, a fim de verificar o efeito do tipo de soluto e da temperatura na cin?tica. Os par?metros cin?ticos foram modelados de acordo com a equa??o Peleg, Page modificado e Barbosa J?nior et al. utilizando regress?o n?o-linear. A partir do modelo de Barbosa J?nior et al., obteve-se o tempo para reduzir a taxa de desidrata??o ou impregan??o a um ter?o de seus valores iniciais (t(1/3)) e o tempo m?dio de processo (t(m?dio)). A qualidade das amostras foi avaliada nestes dois tempos, nos diferentes solutos e temperaturas. Para tal, foram verificadas a varia??o dos par?metros instrumentais de cor, a capacidade antioxidante (FRAP, DPPH e teor de fen?licos totais) e a textura (ensaios de compress?o axial) das amostras in natura e processadas. A PA n?o foi afetada significamente pelo tipo de soluto empregado, no entanto, a temperatura apresentou influ?ncia significativa neste par?metro (p < 0,05). Os dados experimentais para a PA se ajustaram adequadamente ao modelo de Peleg e Page modificado e obtiveram-se coeficientes de determina??o (R?) maiores do que 0,98, desvio relativos m?dios (E) inferiores a 6,5% em todos os tratamentos. O modelo do tempo de n-redu??o da taxa de desidrata??o se mostrou uma boa alternativa na defini??o do tempo de processamento das amostras submetidas ? desidrata??o osm?tica. Os valores de perda de ?gua variaram de 15,70 a 28,79% no tempo t(1/3), enquanto que para o tempo de t(m?dio) de 15,75 a 30,27% entre os tratamentos. O processo de desidrata??o osm?tica influenciou na qualidade final dos produtos, apresentando diferen?as significativas entre a fruta in natura e a processada para varia??o dos par?metros de cor, a capacidade antioxidante e a textura das amostras in natura e processadas.
5

Estudo da reidrata??o do feij?o verde (Vigna unguiculata L. Walp) desidratado por micro-ondas com e sem pr?-tratamento osm?tico

Queiroga, Priscila Vanini Dantas de Medeiros 19 March 2012 (has links)
Made available in DSpace on 2014-12-17T15:01:54Z (GMT). No. of bitstreams: 1 PriscilaVDMQ_TESE.pdf: 3706825 bytes, checksum: a3b44c4a57772c9356ce81d22bdb9174 (MD5) Previous issue date: 2012-03-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The green bean has organoleptic and nutritional characteristics that make it an important food source in tropical regions such as the Northeast of Brazil. It is a cheap source of protein and important for nutrition of rural population contributing significantly in subsistence farming of the families from Brazil s northeast. It is consumed in entire region and together with the dry meat and other products composes the menu of typical restaurants, being characterized as an important product for economy of Northeast. The green bean is consumed freshly harvested and has short cycle, being characterized as a very perishable food, which hampers your market. The drying method is an alternative to increase the lifetime and provide a reduction volume of this product making easier your transportation and storage. However is necessary to search ways of drying which keep the product quality not only from the nutritional standpoint but also organoleptic. Some characteristics may change with the drying process such as the coloring, the rehydration capacity and the grains cooking time. The decrease of drying time or of exposure of the grains to high temperature minimizes the effects related with the product quality loss. Among the techniques used to reduce the drying time and improve some characteristics of the product, stands out the osmotic dehydration, widely used in combined processes such as the pretreatment in drying food. Currently the use of the microwaves has been considered an alternative for drying food. The microwave energy generates heat inside of materials processed and the heating is practically instantaneous, resulting in shorter processing times and product quality higher to that obtained by conventional methods. Considering the importance of the green beans for the Northeast region, the wastefulness of production due to seasonality of the crop and your high perishability, the proposal of this thesis is the study of drying grain by microwaves with and without osmotic pretreatment, focusing on the search of conditions of processes which favor the rehydration of the product preserving your organoleptic characteristics. Based on the analysis of the results of osmotic dehydration and dielectric properties was defined the operating condition to be used in pretreatment of the green bean, with osmotic concentration in saline solution containing 12,5% of sodium chloride, at 40?C for 20 minutes. The drying of green bean by microwave was performed with and without osmotic pretreatment on the optimized condition. The osmotic predehydration favored the additional drying, reducing the process time. The rehydration of dehydrated green bean with and without osmotic pretreatment was accomplished in different temperature conditions and immersion time according to a factorial design 22, with 3 repetitions at the central point. According to results the better condition was obtained with the osmotically pretreated bean and rehydrated at a temperature of 60?C for 90 minutes. Sensory analysis was performed comparing the sample of the green bean in natura and rehydrated in optimized conditions, with and without osmotic pretreatment. All samples showed a good acceptance rate regarding the analyzed attributes (appearance, texture, color, odor and taste), with all values above 70%. Is possible conclude that the drying of green bean by microwave with osmotic pretreatment is feasible both in respect to technical aspects and rehydration rates and sensory quality of the product / O feij?o verde apresenta caracter?sticas organol?pticas e nutricionais que fazem dele uma importante fonte aliment?cia em regi?es de clima tropical como o Nordeste do Brasil. ? uma fonte de prote?na barata e importante para a nutri??o da popula??o rural contribuindo significativamente na agricultura de subsist?ncia das fam?lias nordestinas. ? consumido em toda a regi?o e comp?e junto com a carne de sol e outros produtos o card?pio dos restaurantes t?picos, caracterizando-se assim como um produto importante para a economia da Nordeste. O feij?o verde ? consumido rec?m-colhido e apresenta ciclo curto, sendo caracterizado como um alimento de alta perecibilidade, o que dificulta a sua comercializa??o. A secagem desse produto se caracteriza como uma alternativa para o aumento da vida ?til deste alimento, al?m de proporcionar uma redu??o de volume facilitando seu manuseio no transporte e armazenagem. Todavia necess?rio se faz buscar formas de secagem que preservem a qualidade do produto n?o s? sobre o ponto de vista nutricional como organol?ptico. Dentre as caracter?sticas que se alteram com o processo de secagem, destacam-se a colora??o, a capacidade de reidrata??o e o tempo de cozimento dos gr?os. A diminui??o do tempo de secagem, ou de exposi??o dos gr?os a elevadas temperaturas minimizam os efeitos relacionados com a perda de qualidade do produto. .Dentre as t?cnicas empregadas para minimizar o tempo de secagem e melhorar algumas caracter?sticas do produto, destaca-se a desidrata??o osm?tica, muito utilizada em processos combinados como pr?-tratamento na secagem dos alimentos. Atualmente a utiliza??o do micro-ondas tem sido apontada como uma alternativa para a secagem de alimentos. A energia de micro-ondas gera calor no interior dos materiais processados e o aquecimento ? praticamente instant?neo, o que resulta em tempos de processamento mais curtos e qualidade do produto superior ? obtida pelos m?todos convencionais. Considerando a import?ncia do feij?o verde para a regi?o Nordeste, o desperd?cio da produ??o devido a sazonalidade da safra e sua alta perecibilidade, foi proposto nesta tese o estudo da secagem dos gr?os em micro-ondas com e sem pr?-tratamento osm?tico, tendo como foco principal a busca das condi??es de processo que favore?am a reidrata??o do produto, com preserva??o de suas caracter?sticas organol?pticas. A partir da an?lise dos resultados da desidrata??o osm?tica e propriedades diel?tricas foi definida a condi??o operacional a ser utilizada no pr?-tratamento do feij?o verde, com concentra??o osm?tica em solu??o salina contendo 12,5% de cloreto de s?dio, a 400C por 20 minutos. A secagem do feij?o verde por micro-ondas foi realizada sem e com pr?-tratamento osm?tico na condi??o otimizada. A pr?-desidrata??o osm?tica favoreceu a secagem complementar, reduzindo o tempo de processo. A reidrata??o do feij?o verde desidratado com e sem pr?-tratamento osm?tico foi realizada em diferentes condi??es de temperatura e tempo de imers?o de acordo com um planejamento fatorial 22, com 3 repeti??es no ponto central . De acordo com os resultados a melhor condi??o, foi obtida com o feij?o pr?-tratado osmoticamente e reidratado a uma temperatura de 600C por 90 minutos. Realizou-se a an?lise sensorial comparando-se as amostra de feij?o verde in natura e reidratado nas condi??es otimizadas, com e sem pr?-tratamento osm?tico. Todas as amostras apresentaram um bom ?ndice de aceita??o referente aos atributos analisados (apar?ncia, textura, cor, odor e sabor), estando todos os valores acima de 70%. Conclui-se que a secagem do feij?o verde por micro-ondas com pr?-tratamento osm?tico ? vi?vel, tanto em rela??o aos aspectos t?cnicos como aos ?ndices de reidrata??o e a qualidade sensorial do produto

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