254 resultados para Desidratação


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No presente estudo, sinais clínicos e alterações patológicas foram avaliados por 30 dias em frangos de corte, linhagem Cobb, machos, com dez dias de idade, infectados com Eimeria acervulina. Foram utilizados 192 animais distribuídos em 3 grupos: grupo A inoculado com 1x10(6) oocistos esporulados; grupo B inoculado com 1x10(5) oocistos esporulados; grupo C inoculado com água destilada. Os sinais clínicos observados foram anorexia, diarréia e apatia. As alterações patológicas macroscópicas observadas foram: enterite, hiperemia seguido de congestão intestinal, excesso de exsudato mucoso no lúmen do intestino delgado, palidez e desidratação muscular, alto acúmulo de bile na vesícula biliar e deposição de gordura hepática. A atrofia de vilosidades e alta presença de células inflamatórias foram as alterações microscópicas observadas no epitélio intestinal. Na análise histopatológica do fígado observaram-se infiltrados inflamatórios e deposição de gordura. Os resultados demonstraram que frangos de corte infectados experimentalmente com E. acervulina apresentam progressivas lesões intestinais de intensidade variável e que essas anormalidades são as principais causas de redução no desenvolvimento da ave.

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O objetivo deste trabalho foi avaliar a lixiviação de K da palha de aveia-preta (Avena strigosa) e de milheto (Pennisetum glaucum), utilizando-se chuva simulada em diferentes períodos após a dessecação química. As plantas foram cultivadas em vasos, e aos 50 dias da emergência foram manejadas com herbicida e submetidas à chuva simulada de 5 e 10 mm, aos 3, 6, 9, 12 e 15 dias após a dessecação (DAD). A quantidade de K lixiviado das palhas, considerando uma quantidade de palha equivalente a 8,0 t ha-1 de matéria seca, aumentou à medida que o estado de senescência das plantas evoluiu após a dessecação. Com a aplicação de 10 mm de chuva aos 15 DAD, a palha de aveia-preta disponibilizou, aproximadamente, 11,1 kg ha-1 de K. A água da chuva extrai maior quantidade de K da palha de aveia-preta em relação à palha de milheto, tanto com a lâmina de 5 mm como de 10 mm, e essas diferenças são maiores de acordo com o estado avançado de desidratação do material vegetal.

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With the objective to determine the influence of the dehydration and of the size and/or weight on germination percentage and the vigor of jussara palm seeds (Euterpe edulis Mart.), 10 individuals' ripe fruits, picked in the Experimental Station of Ubatuba (IAC) they were classified by size in 5 sieves of circular sieve: 26/64" (10,31mm), 28/64" (11,11mm), 30/64" (11,90mm), 32/64" (12,69mm) and 34/64" (13,49mm). It was determined, the medium weight of the classified seeds. The quality of the seeds was evaluated through the following parameters: water content of the seeds; germination and vigor (first germination counting). It was evaluated the drying speed of different seed sizes for 48 hours, in dry chamber. The sizes of 28/64", 30/64" and 32/64" represented 98,7% of the total weight of the harvested seeds and showed similar drying speed, percentage of germination and vigor. With the increase of the drying period, the smaller seeds (28/64") had their germination less affected them the intermediate (30/64") and bigger sized seeds (32/64").

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Chitin and chitosan are nontoxic, biodegradable and biocompatible polymers produced by renewable natural sources with applications in diverse areas such as: agriculture, textile, pharmaceutical, cosmetics and biomaterials, such as gels, films and other polymeric membranes. Both have attracted greater interest of scientists and researchers as functional polymeric materials. In this context, the objective of this study was to take advantage of the waste of shrimp (Litopenaeus vannamei and Aristeus antennatus) and crabs (Ucides cordatus) from fairs, beach huts and restaurant in Natal/RN for the extraction of chitin and chitosan for the production of membranes by electrospinning process. The extraction was made through demineralization, deproteinization, deodorization and deacetylation. Morphological analyzes (SEM and XRD), Thermal analysis (TG and DTG), Spectroscopy in the Region of the Infrared with Transformed of Fourier (FTIR) analysis Calorimetry Differential Scanning (DSC) and mechanical tests for traction were performed. In (XRD) the semicrystalline structure of chitosan can be verified while the chitin had higher crystallinity. In the thermal analysis showed a dehydration process followed by decomposition, with similar behavior of carbonized material. Chitosan showed temperature of maximum degradation lower than chitin. In the analysis by Differential Scanning Calorimetry (DSC) the curves were coherent to the thermal events of the chitosan membranes. The results obtained with (DD) for chitosan extracted from Litopenaeus vannamei and Aristeus antennatus shrimp were (80.36 and 71.00%) and Ucides cordatus crabs was 74.65%. It can be observed that, with 70:30 solutions (v/v) (TFA/DCM), 60 and 90% CH3COOH, occurred better facilitate the formation of membranes, while 100:00 (v/v) (TFA/DCM) had formation of agglomerates. In relation to the monofilaments diameters of the chitosan membranes, it was noted that the capillary-collector distance of 10 cm and tensions of 25 and 30 kV contributed to the reduction of the diameters of membranes. It was found that the Young s modulus decreases with increasing concentration of chitosan in the membranes. 90% CH3COOH contributed to the increase in the deformation resulting in more flexible material. The membranes with 5% chitosan 70:30 (v/v) (TFA/DCM) had higher tensile strength

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In this work a solar drying system for food dehydration was developed. It is a direct exposition drying apparatus that uses solar energy to heat the circulating air. First, the construction and assembly of this apparatus was described, in which was used scrap wraps of used tires for thermal insulation, allowing the reuse of solid waste, being an ecologically correct recycling option. After, the results obtained in experiments for cashew drying showed the thermal and economical feasibility of the proposed solar drying system, focusing on the process of flour production and in its chemical characterization. It was also demonstrated the social importance of this production for socially excluded people, since the value added to this fruit, in relation to its in nature form, may represent an option for job and income generation. The main features of the proposed dryer are its low cost and its easy fabrication and assembly process. After cashew drying, the obtained product was processed into flour by using a knife mill and it was added crushed rapadura to reduce the rancid taste caused by tannin

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Given the growing environmental crisis caused by degradation, mainly due to the use of polluting energy sources, increasing the growing use of renewable energies worldwide, with emphasis on solar energy, an abundant supply and available to everyone, which can be harnessed in several ways: electricity generation; dehydration of food; heating, disinfection and distillation and cooking. The latter has as its primary feature the viability of clean, renewable energy for society, combating ecological damage caused by large-scale use of firewood for cooking foods, use in tropical countries with high solar radiation, and has funding NGOs throughout the world with the goal of achieving low-income population. The proposed project consists of a solar cooker for concentration, working from the reflection of sunlight by a hub that they converge to a focal point at the bottom of the pot, getting lots of heat. The solar cooker under study consists of two elliptical reflecting parabolas made from the recycling of scrap TV antenna, having 0.29 m² of surface area for each antenna, which were covered by multiple mirrors of 2 mm thick and mounted on a metal structure, with correction for the mobility of the apparent movement of the sun. This structure was built with the recycling of scrap metal, possessing a relatively low cost compared with other solar cookers, around US$ 50.00. This cost becomes negligible, since that will involve a great benefit to not have fuel costs for each meal, unlike the use of gas or firewood for cooking food. The tests show that the cooker has reached the maximum temperature of 740 ° C, for boiling water in an average time of 28 minutes, cooking various types of foods such as potatoes, rice and pasta in an average time of 45 minutes and still going as a solar oven, making pizza baking and meat. These cooking times do not differ much from the cooking times on a gas stove, it becomes the solar cooker as a good consumer acceptance, and furthermore not to deliver the same gases that can poison the food as with the wood stove. Proves the viability of using the stove to cook or bake in two daily meals for a family, still presenting a position to improve his performance with the addition of new materials, equipment and techniques

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The scarcity of farmland, reducing the supply of irrigation water and lack of technologies for conservation, makes the globalized world facing serious difficulties in the production of food for its population. The most viable outlet for this dilemma is the dissemination of technologies, economically viable and available to the whole population, for dehydration of perishable foods produced. This paper presents a solar dryer of direct exposure to the production of dried fruit, made from recycled polyethylene drum of 200 liters, used for storing water or trash. The drum was sectioned in half in its longitudinal axis and has its halves together forming a trough-like structure. It describes the processes of construction and assembly of solar dryer proposed, whose main characteristic its low cost, and was designed for use by people with low income, for processing fruits widely available in our region (mango, banana, guava, cashew, pineapple, tomato and others) in dried fruit and flour, contributing significantly to increase the life of these foods. The nuts and flours can be used for own consumption and for marketing jobs and income generation. Tests were conducted to diagnose the feasibility of using solar dryer for the various types of tropical fruits. Were also compared parameters such as drying times and thermal efficiency obtained with the prototype found in the specialized literature in food dehydration. The drying times in the dryer were obtained competitive with those obtained in other models of dryers LMHES developed

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Para avaliar procedimentos para a manutenção da umidade do substrato durante o teste de germinação de Brachiaria brizantha. Estudou-se o efeito da posição das caixas plásticas na câmara de germinação sobre a perda de água semanal, testando-se nove posições verticais (bandejas) e três posições horizontais (porta, meio e fundo do germinador). Foi também avaliado o efeito de procedimentos para manter a umidade do substrato, sobre a germinação, a perda de água semanal e o tempo despendido para a instalação do teste. Os procedimentos testados foram: (a) vedação da caixa plástica com vaselina, (b) vedação com saco plástico dobrado em quatro e colocado entre a tampa e a caixa, (c) colocação da caixa tampada dentro de saco plástico, (d) espuma sob o papel de germinação e (e) testemunha, caixa apenas tampada. Concluiu-se que a câmara de germinação promove a desidratação desigual do substrato conforme a posição das caixas; aquelas localizadas na primeira bandeja superior são as mais prejudicadas. Entre os procedimentos, a vedação com vaselina, a colocação da caixa dentro de saco plástico e a vedação com saco plástico dobrado em quatro entre a tampa e a caixa são eficientes na manutenção da umidade do substrato em taxas que não alteram os resultados do teste de germinação de B. brizantha; os dois últimos procedimentos são os mais rápidos e práticos, adaptando-se à rotina de um laboratório de análise de sementes.

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The waste in the industries of escargot processing is very big. This is composed basically of escargot meat out of the commercialization patterns and the visceras. In this context, there is a need to take advantage to the use of these sub-products. A possibility should be drying them and transforming them in a certain form to be reused. Than, the present work has the objective of studying the reutilization of the sub-products of the escargot industrialization for by means of drying process. The samples were transformed in pastes, through a domestic processor for approximately 1 minute and compacted in trays of aluminum without perforations with three different heights (5 mm, 10 mm and 15 mm). The drying was accomplished in a tray dryer with air circulation and transverse flow at a speed of 0,2 m/s and three temperature levels (70°C, 80°C and 90ºC). A drying kinetics study was accomplished for the obtained curves and for the heat and mass transfer coefficients using experimental procedures based in an experimental planning of 22 factorial type. Microbiological and physiochemical analysis were also accomplished for the in nature and the dehydrated sub-products. In the drying process, it was observed the great importance of the external resistances to the mass transfer and heat in the period of constant tax influenced by the temperature. The evaporation taxes indicated a mixed control of the mass transfer for the case of the thickest layers. As already expected, the drying constant behavior was influenced by the temperature and thickness of the medium, increasing and decreasing. The statistical analysis of the results, in agreement with the factorial planning 22, showed that the fissures, the shrinking of the transfer area and the formation of a crust on the surface might have contributed to the differences between the practical results and the linear model proposed. The temperature and the thickness influenced significantly in the answers of the studied variables: evaporation tax and drying constant. They were obtained significant statistical models and predictive ones for evaporation tax for the meat as well as for the visceras

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The food industry is interested in natural products. Anthocyanins are phenolic antioxidants of great importance with health-relevant applications. Several studies have linked the intake of fruits and vegetables with reduced risk of chronic degenerative diseases because of its antioxidant properties. This study aimed to compare different strategies for obtaining natural pigments from red jambo (Syzygium malaccence) and analyze its functional potential. Two different strategies were studied: (1) solid-liquid extraction (SLE) in reactor with controlled parameters, (2) powder obtention. The investigation of the functional potential was conducted taking into account the total phenolic content (TPC), the antioxidant activity (AA), the total anthocyanins concentration (TA) and α-amylase and α-glucosidase inhibition. The best extracts obtained by SLE showed TPC of 174.15 mg GAE/100g, AA of 3.56 μmol Trolox eq/g and TA of 133.59 mg cyd-3-glu/100 g. The best results for the second strategy were TPC of 1024.22 mg GAE/100 g, AA of 29.03 μmol Trolox eq/g and TA of 1193.41 mg cyd-3- glu/100 g. It was observed moderate amylase inhibition (26.30%) and high glucosidase inhibitory activity (97.47%). Skin extracts showed, in general, superior results when compared to whole red jambo, with superior values for dehydrated products. Based on our result, red jambo can be considered as a rich source of phenolic antioxidants, as well on amylase and glucosidase inhibitors

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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

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Este trabalho teve como objetivo estudar o efeito combinado da desidratação osmótica e a influência do cloreto de cálcio em rodelas de kiwi submetidas ao processamento mínimo. Amostras com e sem desidratação osmótica foram armazenadas a 5 °C em embalagem PET. A adição do cloreto de cálcio foi realizada durante a desidratação osmótica. Foram avaliados a perda de peso, acidez, sólidos solúveis, pH, umidade, coliformes, fungos e leveduras nas amostras até 15 dias de armazenamento. A avaliação microbiológica e sensorial definiu a vida de prateleira do produto. Os resultados mostraram que o pré-tratamento osmótico com adição de cloreto de cálcio aumentou a vida útil em até 15 dias, enquanto as rodelas tratadas por osmodesidratação, sem a adição do sal apresentaram vida útil de 12 dias. Sensorialmente, os consumidores preferiram as rodelas de kiwi processadas com pré-tratamento osmótico e adição de cloreto de cálcio.

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O tomate é um fruto muito perecível por causa do seu conteúdo de umidade. A secagem é uma das práticas industriais mais utilizadas em alimentos para manter a qualidade do produto final. A pesquisa foi desenvolvida para estudo dos parâmetros de secagem de tomate (Lycopersicon esculentum Mill), cv Carmen, com relação ao tipo de corte (meio e um quarto) e à temperatura de processo (60 e 70 ºC), bem como à escolha do tempo de secagem para a obtenção de um produto com umidade de 45% (base úmida). As cinéticas de secagem foram determinadas experimentalmente por convecção forçada e ajustadas ao modelo de Page. Os resultados obtidos mostraram que a geometria de corte influenciou na taxa de secagem e no tempo de desidratação. Os tomates cortados em quatro partes e desidratados a 70 ºC alcançaram umidade de 45% em menor tempo (10 horas), quando comparados aos tomates com o corte em metades. O modelo de Page forneceu bom ajuste nas cinéticas de secagem

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A pimenta vermelha é rica em vitamina C e outros fitoquímicos e pode ser consumida como produto desidratado. A avaliação das melhores condições de secagem pode garantir melhor qualidade do produto. Assim, o objetivo deste trabalho foi estudar o efeito da temperatura do ar de secagem (55, 65, 75 ºC) sobre a cinética de secagem, conteúdos de vitamina C e fenólicos totais e cor do produto desidratado, comparando-os à pimenta in natura. A desidratação foi feita por convecção forçada em estufa. A cinética de secagem foi determinada por pesagens periódicas até peso constante. A umidade da pimenta in natura foi de aproximadamente 86%. As curvas de secagem foram ajustadas por três modelos diferentes, avaliados na literatura. O modelo de Page apresentou o melhor ajuste para este processo. A análise de variância mostrou que a temperatura de secagem influenciou significativamente (p < 0,05) os parâmetros de qualidade (conteúdo de vitamina C, conteúdo de fenólicos totais, cor) da pimenta desidratada quando comparados aos da pimenta in natura. Após a secagem, a retenção de vitamina C aumentou com a redução da temperatura de secagem. de maneira geral, a qualidade do produto foi favorecida na secagem com menor temperatura, devido à redução nas perdas de compostos bioativos.

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Este trabajo tubo como objetivo estudiar el efecto combinado de la deshidratación osmótica y la influencia del cloruro de calcio en rodajas de kivi sometidos al proceso mínimo. Muestras con y sin deshidratación osmótica fueron almacenadas a 5 °C en embalajes PET. La adición de cloruro de calcio fue realizada durante la deshidratación osmótica. Se evaluaron la pérdida de peso, acidez, sólidos solubles, pH, humedad, coliformes, hongos y levaduras en las muestras hasta 15 días de almacenamiento. La deshidratación osmótica consistió en la inmersión de las rodajas de kivi en solución de sacarosa a 60% y en solución de sacarosa (60%) con adición de cloruro de calcio (0,1 M), ambos tratamientos se realizaron a temperatura ambiente (25 °C) por 24 horas y relación fruta:solución de 1:5. Los resultados mostraron que el pré-tratamiento osmótico con adición de cloruro de calcio aumentó la vida útil hasta 15 días, en cuanto las rodajas tratadas por osmodeshidratación sin adición de sal presentaron vida útil de 12 días. Sensorialmente, los consumidores prefirieron las rodajas de kivi procesadas con pré-tratamiento osmótico y adición de cloruro de calcio.