Estudo de um secador solar fabricado apartir de sucata de tambor de polietileno

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

Viabilidade de uso de um fogão solar para cocção de alimentos com parábola refletora fabricada em compósito que utiliza fibras de Carnaúba e resina Ortoftálica

Presents a composite formed by orthophthalic resin and fiber loading of carnauba straw. The fibers were first dried in direct sun exposure and subsequently ground into fodder for the reduction in size. Various formulations of the composite were preliminarily tested by choosing the one presenting the best processability in applying the mold. The composite produced is used for the manufacture of a parabolic surface subsequently coated with mirror segments, flexible plastic, for reflecting the solar rays incident on it. The reflective parable represents the main element of the solar cooker that works with the concentration of sunlight and has dimensions of 1.14 m in diameter and area of 1.0 m². Manufacturing processes and assembly of solar cooker concentration produced are presented. The results of tests for cooking and baking various foods, including rice, pasta, beans, cake, cassava, shrimp, beef, breaded demonstrating the competitiveness of solar cooker studied with other stoves already manufactured and tested in Brazil are presented and in the world. It was also demonstrated the feasibility of the proposed composite for Prototypes manufacture of solar and other structures that do not require great efforts resistance

Qualidade fisiológica de sementes de palmiteiro-vermelho em função da desidratação e do armazenamento

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Armazenamento a frio de ramos porta-borbulhas e métodos de enxertia de cultivares de marmeleiro

Visando a aumentar o aproveitamento do material propagativo, ampliar o período de oferta das mudas de marmeleiro e dinamizar o uso da mão-de-obra no viveiro, faz-se necessário o armazenamento dos ramos porta-borbulhas. Sendo assim, o presente trabalho teve por objetivos estudar a viabilidade da manutenção dos ramos porta-borbulhas de diferentes cultivares de marmeleiro, por meio do armazenamento a frio, e diagnosticar o método de enxertia para promover melhor desenvolvimento do enxerto. Ramos dos marmeleiros 'Japonês' (Chaenomeles sinensis), 'Smyrna', 'Portugal', 'Mendoza Inta-37' e 'Provence' (Cydonia oblonga) foram coletados em julho de 2008. Uma parte dos ramos foi utilizada para a realização da enxertia (métodos de borbulhia e garfagem) em mudas de seis meses de idade do porta-enxerto 'Japonês', e a outra parte foi armazenada sob baixa temperatura (estacas envoltas em papel umedecido, embrulhadas em sacos de polietileno colocadas em câmara fria a 4°C), por 30 e 60 dias. Passados 60 dias, foi mensurada a porcentagem de brotação dos enxertos e, ao final de 120 dias da realização das enxertias, foram mensurados o comprimento, o diâmetro e a massa seca média dos enxertos. Concluiu-se que, apesar de as cultivares apresentarem diferença, recomenda-se que os ramos sejam armazenados por até 30 dias, sendo utilizada a enxertia pelo método de garfagem.

Posição do racemo e do fruto na qualidade fisiológica de sementes de mamona durante o armazenamento

The present research had as objective to evaluate the influence of raceme and fruit position on physiological quality of castor bean seeds (Ricinus communis L.) during storage of cultivar AL Guarany 2002. The treatments were: position of the raceme in plants (primary, secondary and tertiary) and position of fruit in racemes (low, medium and high). After fruit extraction, seeds were stored under environmental conditions for twelve months. The experimental design used was the completely randomized in a split-plot arrangement. Main plots consisted of the interaction raceme x fruit position and subplots were the storage time. Physiological quality was evaluated quarterly through tests of moisture content, germination and vigor (first count, accelerated aging, seedling length and seedling dry matter). Neither the position of racemes in the plant nor fruit in racemes does not affect germination of castor bean seeds. Dormancy of castor bean seeds decreases during storage, but also increases percentage of abnormal seedlings, seedling dry matter and root, hypocotyl and seedling total length.

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

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

Efeitos do ambiente de armazenamento na qualidade de sementes de sorgo-sudão

O trabalho objetivou avaliar efeitos do ambiente de armazenamento na qualidade de sementes de sorgo-sudão (Sorghum sudanense (Piper) Stapf) de diferentes procedências. Cinco lotes de diferentes origens foram armazenados por nove meses, acondicionados em sacos de papel unifoliado, em quatro condições ambientais: ambiente natural de laboratório (sem controle de umidade relativa e temperatura); 30 a 40% de umidade relativa e sem controle de temperatura (simulada através de câmara seca); 10 a 15% de umidade relativa e 5 a 7ºC de temperatura (simulada através de um refrigerador Frost Free); 40 a 50% de umidade relativa e -20ºC de temperatura (simulada através de freezer). As avaliações laboratoriais, realizadas em intervalos trimestrais, foram: teor de água, massa de mil sementes, germinação, crescimento de plântulas, massa seca de plântulas, envelhecimento acelerado, condutividade elétrica, emergência em campo e índice de velocidade de emergência. O delineamento utilizado foi o inteiramente casualizado, com quatro repetições, num esquema fatorial 4 x 5, e comparação de médias pelo teste de Tukey a 5% de probabilidade. A origem das sementes, relacionada à qualidade das mesmas, mostrou-se como o principal fator a influenciar a conservação. Os ambientes refrigerador e freezer, seguidos da câmara seca, mostraram-se adequadas à conservação de sementes de sorgo-sudão. A capacidade de conservação de sementes dessa espécie relaciona-se com a sua qualidade inicial dependente da sua origem.

Jambolão (Syzygium cumini) desidratado por liofilização e secagem em leito de jorro: avaliação do impacto do processo de secagem e caracterização do potencial funcional do produto final

Tropical fruits have been extensively studied due to their functional potential attributed to the presence of natural bioactive compounds. The exotic fruit jambolan (Syzygium cumini) has been reported for its appreciable amount of phenolic compounds, especially anthocyanins and antioxidant capacity. Nevertheless, there are hardly any derived jambolan products in the Brazilian market. In addition to that, considerable volumes of fruit are lost due to their high perishability. Dried fruits have become an important fruit market segment due to its weight and volume reduction and decreased transportation and storage costs. Thus, this study evaluated the jambolan pulp submitted to spouted bed drying (JLJ) and lyophilization (JLI), besides assessing the drying impact on the final product. In order to achieve this, the process performance was calculated and compared, as well the physicochemical and bioactive characteristics (moisture, water activity (aw), solubility, hygroscopicity, density, color, structure through images obtained by scanning electron microscopy (SEM), concentration of bioactive (total phenolic compounds (TPC), anthocyanins, proanthocyanidins and ascorbic acid) and antioxidant activity. The results showed drying efficiency higher than 60% for both products and that JLJ group showed higher moisture and water activity when compared to the JLI group (p<0.05). The two types of drying were able to produce stable final product in the microbiological point of view, given that both showed aw < 0.6. The final products exhibited high solubility (73.7 to 81.6%) and low hygroscopicity (9.8 to 11.6%), desirable characteristics for dehydrated foods. Despite the losses caused by drying, the dried jambolan pulp by both methods showed high TPC (468.6 to 534.0 mg GAE/100g dm), anthocyanins (from 491.9 to 673.4 mg. eq. cyanidin-3-glicoside/100g dm), proanthocyanidins (66.9 to 76.6 mg QTE/g dm) and ascorbic acid (156.4 to 186.8 mg/100 g dm). Taken together, the results of this study reveal spouted dried and freeze dried jambolan pulp as bioactive-rich natural products with suitable physicochemical and functional characteristics to be used as food ingredients. The data also demonstrate the drying techniques as rational strategies for the exploitation of the exotic fruit jambolan

Influencia de la deshidratación osmótica y de la adición de cloruro de calcio en la conservación de kivis minimamente procesados

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.

Influencia de la deshidratación osmótica y de la adición de cloruro de calcio en la conservación de kivis minimamente procesados

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.

Vida-de-prateleira de goiabas, cv. Sassaoka, minimamente processadas e armazenadas em diferentes embalagens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Caracterização geológico-geofísica do meio aqüífero fissural : uma contribuição aos modelos de fluxo e armazenamento de água subterrânea

Northeastern Brazil is mainly formed by crystalline terrains (around 60% in area). Moreover, this region presents a semi-arid climate so that it is periodically subject to drought seasons. Furthermore, ground water quality extracted fromwells usually presents poor quality because of their high salinity contents. Nevertheless, ground water is still a very important source of water for human and animal consumption in this region. Well sitting in hard rocks terrains in Northeastern Brazil offers a mean success index of aboul 60%, given that a successful siting is defined by a well producing at least 0.5 m³/h. This low index reveals lack of knowledga about the true conditions of storage and percolation of ground water in crystalline rocks. Two models for structures storing and producing ground water in crystalline rocks in Northeastem Brazil have been proposed in the literature. The first model,tradnionally used for well sitting since the sixties are controlled by faults or fractures zones. This model is commonly referred, in Brazilian hydrogeological literature, as the "creek-crack" model (riacho-fenda in Portuguese). Sites appearing to present dense drainage network are preferred for water well siting - particularly at points where the drainages cross-cul each other. Field follow up work is usually based only on geological criteria. The second model is the "eluvio-alluvial through" (calha eluvio-aluvionar in Portuguese); it is also described in the literature but it is not yet incorporated in well sitting practice. This model is based on the hypothesis that reclilinear drainages can also be controlled by the folietion of the rock. Eventually, depending upon the degree of weathering, a through-shaped structure filled with sediments (alluvium and regolith) can be developed which can store and water can be produced from. Using severalfield case studies, this Thesis presents a thorough analysis ofthe two above cited models and proposes a new model. The analysis is based on an integrated methodological approach using geophysics and structural geology. Both land (Resitiviy and Ground Penetrating Radar- GPR) and aerogeophysical (magnetics and frequency domain eletromagnetics) surveys were used. Slructural analysis emphasized neolectonic aspects; in general, itwas found that fractures in the E-W direction are relatively open, as compared to fracturas inthe N-S direction, probably because E-W fractures were opened by the neotectonic stress regime in Northeastern Brazil, which is controlled by E-W compression and N-S extension. The riacho-fenda model is valid where drainages are controlled by fractures. The degree of fracturing and associated weathering dictale the hydrogeological potential of the structure. Field work in structural analogues reveals that subvertical fractures show consistent directions both in outcrop and aerophotograph scales. Geophysical surveys reveal subvertical conductive anomalies associated to the fracture network controlling the drainage; one of the borders of the conductive anomaly usually coincide wih the drainage. An aspect of particular importance to the validation of fracture control are the possible presence of relalively deep conductive anomalies wihoul continuation or propagalion to the surface. The conductive nature of lhe anomaly is due to the presence of wealhered rock and sedirnenls (alluvium and/or regolilh) storing ground waler which occur associated to the fracture network. Magnetic surveys are not very sensisnive to these structures.lf soil or covering sedirnents are resislive (> 100 Ohm.m), GPR can ba used to image precisely lhe fracture network. A major limialion of riacho-fenda model, revealed by GPR images, is associated to the fact thal subhorizontal fractures do play a very important role in connecting the fracture network, besides connect shallow recharge zones to relalively deep subvertical frecture zones. Iffractures play just a secondary control on the drainage, however, r/acho-fenda model may have a very limiled validny; in these cases, large portions oflhe drainage do nol coincide wilh frectures and mosl oflhewells localed in lhe drainage surrounding would resull dry. Usually, a secondary conlrol on lhe drainage by Ihefraclure networkcan be revealed only wilh detailed geophysical survey. The calha elClv1o-aluvlonarmodel is valid where drainages are conlrolled by folialion. The degree 01 wealhering 01 lhe lolialion planes dictales lhe hydrogeological polenlial 01 lhe slruclure. Outcrop analysis reveals Ihal lolialion and drainage direclions are parallel and Ihal no Iraclures, orfraclures wilh diflerent directions 01 lhe drainage direclion occur. Geophysical surveys reveal conduclive anomalies in a slab lorm associaled 10 lhe Ihrough 01 lhe wealhered rock and sedimenls (alluvium and/or regolith). Magnelic surveys can ofler a very good conlrol on lolialion direclion. An importanl aspect 10 validale lolialion conlrol are lhe presence 01 conductive anomalies showing shallow and deep portions area which are linked. Illhere is an exlensive soil cover, r/acho-fenda and calha eIClv1o-aluv/onar conlrols can be easily misinlerpreled in lhe absence 01 geophysical conlrol. Certainly, Ihis lacl could explain at leasl a part of lhe failure index in well sitting. The model wealhering sack (bolsllo de Intempertsmo in Portuguese) is proposed to explain cases where a very inlensive wealhering occur over lhe crystalline rock so Ihal a secondary inlerslilial porosity is crealed. The waler is Ihen stored in lhe porous of lhe regolilh in a similar mannerlo sedimentary rocks. A possible example ofthis model was delecled by using land geophysical survey where a relalivelyvery deep isolaled conduclive anomaly, in a slab form, was delected. Iflhis structure does store ground waler, certainly Ihere must be a link 01 lhe deep slructure wilh lhe surface in orderlo provide walerfeeding. This model mighl explain anomalous waler yields as greal as 50 m³/h Ihalsomelimescan occur in crystalline rocks in Northeaslern Brazil

Pós-colheita de pêssegos (Prunus pérsica L. Bastsch) revestidos com filmes a base de amido como alternativa à cera comercial

O presente trabalho objetivou prolongar a conservação póscolheita de pêssegos, armazenando-os à temperatura ambiente. Inicialmente selecionou-se uma microemulsão à base de fécula de mandioca e cera de abelha. Posteriormente ela foi testada, aplicando-a na superfície dos frutos em comparação com Fruit wax (cera comercial), com o intuito de se verificar o efeito dos diferentes tratamentos na composição química, física e físico-química dos mesmos. Utilizaram-se pêssegos 'Biuti' colhidos manualmente em 14/01/1999, ao atingirem o ponto de maturação fisiológica. do lote colhido foram selecionados 120 frutos sendo os mesmos analisados quanto a perda de massa fresca, taxa respiratória, textura, sólidos solúveis totais, acidez total titulável e pH, a cada 3 dias. Os frutos receberam os tratamentos: Testemunha, Fruit Wax, Fécula e Microemulsão. Os tratamentos Fruit Wax e Microemulsão proporcionaram melhor eficiência em relação à perda de massa fresca que os frutos dos tratamentos Testemunha e Fécula. Quanto à taxa de respiração, verificou-se picos da ordem de 40mg de CO2.kg-1.h-1 . Quanto aos açúcares, verificou-se que a sacarose foi o açúcar encontrado em maior quantidade, com apenas traços de glicose e frutose em algumas amostras. Quanto aos teores de sólidos solúveis totais, os frutos tratados com Fruit Wax apresentaram valores inferiores aos do tratamento Testemunha. O efeito da Microemulsão mostrou-se similar ao da cera Fruit Wax em todos os atributos e, superior ao dos tratamentos Testemunha e Fécula na redução da perda de massa fresca.

Valor nutritivo dos alimentos utilizados na formulação de rações para peixes tropicais

A seleção de ingredientes para a formulação de dietas para peixes requer o conhecimento prévio dos coeficientes de digestibilidade aparente da energia e nutrientes. O valor nutritivo de vários alimentos tem sido investigado no Brasil e o uso de fontes alternativas não deve resultar em efeitos negativos sobre o desempenho, saúde dos peixes e qualidade da água. Diversos fatores podem afetar a digestibilidade, sendo que os coeficientes de digestibilidade aparente dos ingredientes devem ser utilizados para a formulação de rações mais precisas e econômicas.

Efeitos da suplementação de fitase sobre a disponibilidade aparente de Mg, Ca, Zn, Cu, Mn e Fe em alimentos vegetais para a tilápia-do-nilo

Cem juvenis de tilápia-do-nilo (Oreochromis niloticus; PV = 100.0 ± 5.0 g) foram distribuídos em 10 tanques-rede com o objetivo de avaliar o efeito da suplementação da enzima fitase (0, 1.000 e 2.000 UFA/kg) sobre a disponibilidade de minerais em alguns alimentos energéticos (milho, milho extrusado, farelo de trigo, farelo de arroz e farelo de sorgo) e protéicos (farelo de soja extrusado, farelo de soja, farelo de girassol, farelo de algodão e glúten de milho) utilizados na alimentação de tilápia-do-nilo (Oreochromis niloticus). Para determinação dos coeficientes de disponibilidade aparente (CDA) do cálcio (Ca), magnésio (Mg), zinco (Zn), cobre (Cu), ferro (Fe) e manganês (Mn), foram confeccionadas 31 rações, marcadas com 0,10% de óxido de crômio III uma referência (ração purificada) e 30 contendo os dez alimentos e os diferentes níveis de suplementação da enzima fitase. O CDA dos nutrientes foi calculado com base no teor de crômio da ração e das fezes. A fitase aumenta, nos vegetais, a disponibilidade do Mg, Cu, Zn e Mn, os quais apresentam tendência diferenciada, em razão do seu valor biológico e do nível de suplementação de enzima.