Drying of agricultural products using solar energy is a method for preservation that has been used for centuries all over the world. This method has been effective especially in tropical and subtropical climates, due to the great availability to solar energy. The village Edumafa in Ghana has great cultivation of pineapples but has no post harvest process. A post harvest process as drying of pineapples can increase cultivation and introduce a new product to be sold at the market. This thesis is investigating the possibility of drying pineapples in coastal Ghanaian climate including both experimental method and simulation. A well functioning solar dryer is constructed based on literature study, which after the dryer is studied in simulated environment. Modifications on the model based on the actual dryer are simulated focusing on the temperature and air velocity distribution. The experimental study results in drying pineapple slices corresponding to eight pineapples in two days. Simulation of the solar collector shows that increased temperature at the end of the solar collector can be achieved when decreasing inclination and decreasing the size of the energy storage layer. Simulation of the drying chamber results in improved distribution of temperature and air velocity inside the drying chamber, providing improved drying conditions with increased inlet size and added flow disturbance. Further studies based on this thesis would be a study of adjustable thickness of the energy storage, and transient simulation. Adjustable thickness of the energy storage and air duct on a experimental dryer could improve the drying in undesirable weather conditions, why a study of defining the optimal adjustment thicknesses for different weather conditions could be of interest. Transient simulation of the drying process accounting for the weather change could improve the drying, since the geometry changes could be made and the drying process studied directly in the simulation tool before building the actual dryer. Transient study of the drying process could even study the effect of different thicknesses of the pineapple slices during drying.

For African farmers, proper drying is considered to be the biggest single factor in determining whether grain can be effectively stored without deterioration. The primary goal of the project is to develop and test the Pico solar crOp Dryer (POD). The overall goal is to improve the POD’s performance, making it acceptable to small holder farmers in Kenya and other developing countries, and positioning it for commercialization. In the POD tests shelled maize was placed in wooden or plastic trays and that were covered with plastic sheets. In the final design, seven small fans of the type used for cooling electronics moved air through the dryer. Power was supplied by a 12 volt, 30 Watt Solar Panel and a 12 volt 7 ampere hour lead acid battery. A charge controller allowed the fans to draw energy from both the solar panel and the battery. The POD was tested at Purdue from 2017 to 2019. The most recent Purdue test on freshly harvested maize was conducted in September 2018. The POD was able to dry 142 kg of 30.1% mc maize to 13.3% in 24.5 hours of drying over 3 calendar days giving an overall drying rate of 0.68 percentage points per hour. The POD dried the maize in 0.84 of the time required to dry maize on a tarp. In the summer of 2018, the components for assembling 5 POD’s were prepared and sent to Kenya for testing. The tests were conducted in Nakuru county in November 2018, and in Trans-Nzoia, Uasin Gishu, and Nandi counties in March 2019. Overall average drying rates for the tests varied, depending on weather conditions, from 0.58 to 0.97 percentage points per hour. A thin layer drying equation was adapted for use in investigating the effects of weather conditions and the airflow rate on the POD drying rate. Adoption of the POD by small holder farmers in Kenya and other developing countries should lead to a reduction in post-harvest losses caused by improper drying. Although testing has been primarily focused on drying maize, it could be adapted for drying other crops.

O tomate constitui-se uma das hortaliças mais exploradas cientificamente, devido à sua importância comercial. O tomate pode, através de processamento adequado, dar origem a inúmeros produtos, alguns deles de elevado consumo no Brasil. Depois da boa aceitação do tomate cereja pelo consumidor, um novo segmento de mini-tomate, chamado Grape, começa a despontar nos mercados brasileiros. O destaque é o híbrido Sweet Grape, que está agradando ao gosto do consumidor e animando agricultores que aderiram às experiências com a nova cultivar. Seu teor de sólidos solúveis chega a 10 °Brix e tem menos acidez, comparado a outras variedades, as quais contem entre 4 e 5 °Brix. Nesse trabalho foi avaliado o processo produtivo do tomate seco, a partir de mini-tomates sweet grape, congelados desidratados em secador solar e convencional, visando obter um alimento seguro do ponto de vista microbiológico, físico-quimica, instrumental cor e aceitabilidade) Os tomates cereja tipo Sweet Grape, foram secos até teores de umidade entre 35% e 0%, e observadas suas mudanças em relação aos tomates in natura , e seu comportamento nos períodos de armazenamento após processados de 0, 30, 60 e 90 dias, verificando assim a sua estabilidade. Foi ainda caracterizado o fruto in natura e submetido a um précongelamento para uma previa perda de água facilitando a secagem. A avaliação da qualidade do produto foi realizada através das análises microbiológicas, físico-químicas, composição centesimal e sensorial. Houve diferença significativa entre os secadores, elétrico e solar, para todos os parâmetros analisados, porém não houve alteração significativa para o período de armazenamento. Em relação à avaliação sensorial, o tomate seco ao sol obteve melhor aceitação entre os provadores / The tomato is one of the vegetables are more scientifically investigated, due to its commercial importance. The tomato can, through appropriate processing, giving rise to numerous products, some of high consumption in Brazil. After the good acceptance by consumers of cherry tomatoes, a new segment of mini-tomato, called Grape, begins to emerge in the Brazilian markets. The highlight is the hybrid Sweet Grape, which is pleasing to the taste of consumers and encouraging farmers adhered to experiment with new cultivars. Your soluble solids content reaches 10 ° Brix and has less acidity compared to other varieties, which contain between 4 and 5 ° Brix. In this study we evaluated the production process of dried tomato, from mini-sweet grape tomatoes, frozen and dehydrated in conventional solar dryer was used to obtain a food safe from microbiological point of view,. physico-chemical, instrumental color and acceptability) Cherry Tomatoes Sweet Grape type, have been dried to moisture contents between 35% and 50%, and observed their changes for tomatoes in nature, and their behavior during periods of storage after processed 0, 30, 60 and 90 days, thus confirming its stability. It was further characterized the fresh fruit and undergo a pre-freeze to a predicted loss of water facilitating drying. Assessing the quality of the product was carried out by microbiological, physicochemical, chemical composition and sensory. There were significant differences between the dryers, electric and solar, for all parameters analyzed, but no significant change for the period of storage. Regarding the sensory evaluation, the sun-dried tomatoes the best won acceptance among judges

Drying of fruits has been done for many years and different techniques have been developed. For preservation of fruit, drying is a good method for producing sustainable food products that avoids waste. The interest in producing sustainable food products that are nutritious and safe from bacterial growth has increased. In developing countries large amounts of food are destroyed, while many people are undernourished. Every year large amounts of pineapples are produced in Ghana. The pineapples are either being sold fresh or distributed to juice producers. To minimize the wastes and improve the economy in rural areas, drying is an interesting method. The unreliable power supply system is a problem in Ghana. Power failure is frequent. During dry season, sun drying is a suitable method for Ghana, which has a tropical climate with dry and rain seasons. A solar dryer for pineapples has been developed, constructed, modified, tested and implemented in the village Edumafa, in a rural area of Ghana. The only energy source that has been used to dry the pineapples is the sun. Before the trip to Ghana, drying tests were made in a laboratory in Sweden and a prototype of the dryer was built in the university workshop. This was done to facilitate the work in Ghana by gaining experience from drying and constructing. The prototyping also clarified which type of tools that would be needed so the tools could be transported from Sweden. The results from drying pineapple slices at 70°C in an oven in Sweden resulted in slices with hard shells and a soft, moist content (the moisture could not be removed since it became enclosed inside the slices).The conclusion was drawn that the pineapples cannot be dried in such a high temperature. Slices were in good quality when dried at 50°C. Since the citizens in the village Edumafa have never dried pineapples before, it is important for them to learn how to use the dryer and keep it in good working condition. During wet season it is important that the dryer is protected against rain. In the mid of a sunny day, when the temperature in the ambient air was 30°C, the temperature in the drying chamber could be around 50°C. Temperatures over 50°C were possible to achieve and there were no risk for getting to high temperature in the drying chamber. Therefore good drying temperatures can be achieved. To change the economy in considerable proportions for the citizens in Edumafa, a bigger dryer is necessary. The villagers need investment help to afford a bigger dryer of this type. The dryer can minimize losses of pineapples and create bigger incomes if the solar dryer is maintained in good condition and the villagers use it often to dry pineapples. / Att torka frukt har gjorts i många år och olika tekniker har utvecklats. Torkning av frukt är en bra metod för att förlänga hållbarheten och minimera spill. Att producera mat som både har en lång hållbarhet, är näringsrik och har låg mikrobiologisk tillväxt har idag blivit mer och mer aktuellt.  I utvecklingsländer förstörs stora mängder av mat samtidigt som det finns ett problem med undernärda människor. I Ghana skördas stora mängder ananas varje år och säljs antingen färska eller skickas iväg för juiceproduktion. För att minimera spill och förbättra ekonomin på landsbygden, torkning är en intressant metod. Ett problem i Ghana är det instabila elnätet. Strömavbrott är vanligt förekommande och därför är det bra om torkningen sker med metoder som inte kräver elektricitet. Klimatet är tropiskt med torr- och regnperioder, och soltorkning passar sig bara under torrperioden. En soltork för ananas har utvecklats, byggts upp, modifierats, testats och implementerats i byn Edumafa på den ghanesiska landsbygden. Den enda energikällan som används av torken är solen. Inför resan till Ghana har i Sverige torkförsök gjorts i ett laboratorium samt en prototyp av en soltork byggts upp i universitetets verkstad. Detta för att underlätta arbetet i Ghana genom att få erfarenheter från torkning och byggande. Byggandet har även klargjort vilken typ av verktyg som kan tänkas behövas så att de kan bli transporterade från Sverige. Resultatet av torkförsöken i Sverige visade att vid 70°C blir ananasen bränd på ytan (fukten kan inte transporteras ut eftersom den blir instängd inuti skivorna), vilket gör att ananasen inte går att torka vid en sådan hög temperatur. Ananasskivorna fick bra kvalité vid torkning i 50°C i laboratoriets ugn. Eftersom soltorkning av ananas är något som byborna i Edumafa aldrig har gjort tidigare, är det viktigt att de förstår hur torken fungerar samt att de kan torka ananas på egen hand.  Under regnperioden är det viktigt att torken skyddas från regn. Mitt under en solig dag då utetemperaturen är cirka 30°C kan temperaturen i torkkammaren bli cirka 50°C. Temperaturer över 50°C var möjliga att uppnå och det blev aldrig för varmt i torkkammaren. Vilket tyder på att bra torktemperaturer kan uppnås. För att kunna få till stånd en betydande förändring i ekonomin i Edumafa, är det nödvändigt att bygga en större tork. Invånarna behöver ekonomisk hjälp till investeringen för att ha råd med en större tork av denna typ. Torken kan minimera spill av ananas och generera större inkomster, om torken bevaras i ett gott skick och invånarna använder den ofta för att torka i.

Submitted by Kilvya Braga (kilvyabraga@hotmail.com) on 2018-04-27T12:01:23Z No. of bitstreams: 1 CAIO TÁCITO MIRANDA CASTRO BEZERRA DE MELO - DISSERTAÇÃO (PPGEM) 2016.pdf: 5031190 bytes, checksum: 98397cbbbbe303c0c4d003b0a137dde7 (MD5) / Made available in DSpace on 2018-04-27T12:01:23Z (GMT). No. of bitstreams: 1 CAIO TÁCITO MIRANDA CASTRO BEZERRA DE MELO - DISSERTAÇÃO (PPGEM) 2016.pdf: 5031190 bytes, checksum: 98397cbbbbe303c0c4d003b0a137dde7 (MD5) Previous issue date: 2016-08-19 / Este trabalho apresenta o desenvolvimento e o estudo experimental de um secador solar com foco nas tecnologias apropriadas para a agricultura brasileira, disseminando a cultura das energias renováveis e contribuindo para promoção do desenvolvimento sustentável. Trata-se de um secador solar de exposição indireta, com coletor solar e câmara de secagem. Apresenta como inovações um capacitor térmico no interior do coletor solar e um sistema de movimentação do ar de secagem acionado por energia solar fotovoltaica, para obtenção de convecção forçada. Foi utilizada a relação entre volumes do coletor solar e da câmara de secagem de 5:1 e instalados sensores TH11, que medem a temperatura e umidade relativa do ar de secagem, conectados a uma placa de Arduino. O secador desenvolvido foi submetido a experimentos na secagem de banana prata (Musa Spp.). Foram coletados dados de variação de massa do produto, temperatura e umidade relativa do ar de secagem que permitiram avaliar as curvas de cinética de secagem da banana, a eficiência do processo de secagem e o rendimento térmico do secador solar. As inovações utilizadas permitiram obter temperaturas do ar no interior da câmara de secagem na média de 50ºC ± 5ºC, e umidade relativa do ar de secagem no interior da câmara de secagem na média de 30% ± 5%. O secador solar mostrou-se eficiente, pois, o tempo necessário para a banana atingir os valores de teor de umidade em base úmida em torno de 25%, foi de 840 minutos (14 h), compatível com os tempos relatados na literatura para equipamentos equivalentes. Constatou-se que o processo de secagem se comportou como nos secadores tradicionais com uma média na eficiência mássica do processo de secagem em torno de 83,95%. O Arduino, permitiu a medição de temperatura e umidade relativa do ar de secagem nas entradas e saídas do coletor solar e da câmara de secagem, o que possibilitou a realização do balanço de energia do secador solar, resultando no cálculo do rendimento termodinâmico do secador solar, o qual foi de 28,51% em média, e na obtenção das outras propriedades termodinâmicas do ar de secagem. As curvas de secagem ajustadas ao modelo matemático de Page, apresentaram em média um coeficiente de determinação de 99,06% podendo assim, ser utilizado para predizer o tempo de secagem da fruta até o ponto desejado. É possível concluir que o secador solar desenvolvido atende as demandas necessárias aos processos de secagem de banana, além de ser de baixo custo e de fácil operacionalidade, comparado com equipamentos semelhantes, o que justifica a sua viabilidade. / This paper presents the development and experimental study of a solar dryer with a focus on appropriate technologies for Brazilian agriculture, spreading the culture of renewable energy and contributing to promoting sustainable development. It is a solar dryer of indirect exposure to solar collector and coupled drying chamber, presenting innovations, among which the use of a thermal capacitor inside the solar collector and a drying air drive system powered by photovoltaic solar energy to obtain forced convection. Other innovations were the choice of the relationship between volumes of the solar collector and drying chamber of 5:1 and the installation TH11 sensors that measure temperature and relative humidity, connected to an Arduino board. The dryer developed was subjected to experiments in Silver banana drying (Musa spp.) Which were collected mass of product data, temperature and relative humidity for assessment of drying process efficiency, the drying kinetics curves and the thermal efficiency of the solar dryer and its components. The innovations have enabled used air temperature inside the drying chamber on average 50°C ± 5°C and relative humidity of the drying air in the average of 30% ± 5%. The solar dryer was efficient, because the time required for bananas reach the moisture content values on a wet basis of about 25% was 840 minutes (14 hours) compatible with the times reported in the literature for equipment equivalents. It was found that the drying process behaved as in traditional dryers with an average mass efficiency in the drying process of around 83.95%. The Arduino, guaranteed measuring temperature and relative humidity drying the entrances and exits of the solar collector and drying chamber, which enabled the realization of the energy of the solar drier balance, resulting in the calculation of the thermodynamic efficiency of the solar dryer which was 26.47%, and determination of other thermodynamic properties of the drying air. The drying curves adjusted to the mathematical model of Page, had an average coefficient of determination of 99.06% and can thus be used to predict the fruit drying time to the desired point. The conclusion of this work, the solar dryer developed meets the demands necessary for banana drying processes, in addition to being low cost and easy operation, with efficiency and reliability, compared to similar equipment, which justifies its viability.

Made available in DSpace on 2014-12-17T14:58:25Z (GMT). No. of bitstreams: 1 EleniseBBA.pdf: 2555564 bytes, checksum: 204e9e7884310336d7433cc3d80fd571 (MD5) Previous issue date: 2007-01-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / It?s been motivating motivated by the current rulers as an energy solution the use of the biodiesel as source of energy, that doesn't damage the environment and promotes the development of the areas where the base plant are grown. The process of production of the biodiesel, starting from the castor oil plant and its derivers, generates a known product as castor oil plant pie that has been used as fertilizer. Once disintoxicated, it can serve as animal ration, because it contains high content of proteins, presenting larger joined value. The disintoxication process, can be obtained through the process of drying the pie with the construction and use of models of dryers capable to elevate the temperature of the castor oil plant pie to approximately 60?C.In this temperature the product tends to eliminate the ricina, with the aid of an aqueous solution of hydroxide of calcium, or still reach higher temperatures to make the disintoxication without a chemical treatment. It was made a bibliographical research about known processes of disintoxication of the castor oil plant pie from the autoclave use to the drying direct exposure to the sun. Starting from the state of the art and identification of the object, it was chosen solar dryers to eliminate the ricina. It was applied two types of solar dryers: the one of solar direct exposure, and the one with concentrador. The castor oil plant pie was separated in samples, with measurement of its initial mass, codified and placed in the dryers. The results were presented in graphs and tables forms, with the values of temperatures noticed. It was noticed the variations of temperature and the relationships analyzed related with the ricina content eliminated from the pie. The analysis of the ricina content was accomplished by Embrapa - Campina Grande, by eletroforese method. The analysis of the result of considering the content of ricina of the samples. It was observed that, we obtained lower rate of ricina in samples that had larger drying time and average value temperature above 60?C. Comparing with the ones submitted to higher temperatures and in a shorter period of time. It was possible to evaluate the efficiency of the dryers in the desintoxication process of the samples, as well as the type of more appropriate dryer for the drying pie process. Finally, it was concluded that the solar dryer with concentrador presents higher values temperatures than the direct exposure one. So, it?s being more opportune applied in the castor oil plant pie drying process. However, more than one hour for drying time is needed / O uso do biodiesel como fonte de energia, que n?o danifica o meio ambiente e promove o desenvolvimento das regi?es que plantam as mat?rias primas para sua fabrica??o, ? uma alternativa energ?tica incentivada pelos atuais governantes. O processo de fabrica??o do biodiesel, a partir do ?leo de mamona e seus derivados, gera um subproduto conhecido como torta de mamona que vem sendo utilizada como adubo. Desintoxicada ela poder? servir como ra??o animal, tendo em vista o alto teor de prote?nas, apresentando, assim, maior valor agregado. A desintoxica??o pode ser obtida por meio do processo de secagem da torta com a constru??o e utiliza??o de modelos de secadores capazes de elevar a temperatura da torta de mamona a aproximadamente 60?C. Ao atingir essa temperatura, o produto tende a eliminar a ricina, com o aux?lio de uma solu??o aquosa de hidr?xido de c?lcio ou ainda atingir temperaturas maiores para realizar a desintoxica??o sem o tratamento qu?mico. Realizou-se um levantamento bibliogr?fico quanto aos processos conhecidos para a desintoxica??o da torta de mamona que v?o desde o uso de autoclave at? a secagem ao sol. A partir do estado da arte e identifica??o do objeto optou-se eliminar a ricina por meio de secadores solares, sendo utilizados dois tipos de secadores o solar de exposi??o direta e o solar com concentrador. A torta de mamona foi separada em amostras, com medi??o de sua massa inicial, codificada e colocada nos secadores. Os resultados apresentados sob a forma de gr?ficos e tabelas, com valores de temperaturas, permitiram que fossem analisadas suas varia??es e as rela??es com o teor de ricina eliminado da torta. A an?lise do teor de ricina foi realizada pela Embrapa -Campina Grande, pelo m?todo de eletroforese. No resultado da an?lise do teor de ricina das amostras, observou-se que aquelas que tiveram maior tempo de secagem e valor de temperatura em m?dia acima de 60?C apresentavam uma menor taxa de ricina em compara??o com as submetidas a maiores temperaturas por um curto per?odo de tempo, assim foi poss?vel avaliar a efici?ncia dos secadores na desintoxica??o das amostras, bem como o tipo de secador mais apropriado para o processo de secagem da torta. Conclui-se, finalmente, que o secador solar com concentrador apresenta valores de temperaturas mais elevados quando comparado com o de exposi??o direta, sendo ent?o mais oportuno na secagem da torta de mamona, por?m ? necess?rio um tempo superior a 1 hora de secagem

The manufacturing process of biodiesel from castor oil produces a byproduct known as pie or meal, which has anti-nutritional characteristics that only allow its use as fertilizer. If there is a chance to detoxify the pie, it can be used as animal feed with high protein content, increasing its value. There are detoxification processes physical, chemical, biological and combined processes. The possibility of physical treatment by the solar dryer becomes attractive because the process tends to raise the temperature of the bran to about 60 ° C, temperature that eliminates the ricin, a lethal toxin that represents approximately 1.5% of the bran. In the present work was made a review of the literature about the known processes for the detoxification of castor bean meal, ranging from the use of autoclave until the sun drying. After the review, was defined as an object to eliminate the toxin ricin, the solar dryer of indirect exposure. Initially, the castor bean meal were separated into samples and measuring their mass. The initial moisture content and water activity of the samples were identified and these were placed in electric and solar dryers. The results of drying experiments are presented in the form of graphs and tables, with values of temperature, percentage of dry matter, acidity, total moisture, and protein content of ricin eliminated. The results of drying experiments are presented in the form of graphs and tables, with the values of temperatures, percentage of dry matter, acidity, total moisture, and protein content of ricin eliminated. These data allowed us to observe the optimum conditions of treatment depending on the quality of ricin, concluding that the solar dryer of indirect exposure eliminates part of ricin, but not entirely, because it takes approximately 95 ° C and 6.5 hours of drying to complete elimination of toxin. / O processo de fabricação do biodiesel, a partir do óleo de mamona, gera um subproduto conhecido como torta ou farelo, que possui características antinutricionais que só possibilitam sua utilização como adubo. Se houver a possibilidade de destoxicar o farelo, ele poderá servir como ração animal, com alto teor de proteínas, aumentando o seu valor agregado. Existem processos de destoxicação físicos, químicos, biológicos e processos combinados. A possibilidade de fazer o tratamento físico com o secador solar se torna atraente, pois o processo tende a elevar a temperatura do farelo a aproximadamente 60°C, temperatura que elimina a ricina, uma toxina letal que representa aproximadamente 1,5% do farelo. No presente trabalho realizou-se um levantamento bibliográfico quanto aos processos conhecidos para a destoxicação do farelo de mamona, que vão desde o uso de autoclave até a secagem ao sol. Após a revisão, foi definido como objeto eliminar a toxina ricina por meio de secador solar de exposição indireta. Inicialmente, os farelos de mamona foram separados em amostras, com medição de sua massa, umidade e atividade de água iniciais identificadas e colocadas nos secadores elétrico e solar. Os resultados dos ensaios de secagem estão apresentados sob a forma de gráficos e tabelas, com valores de temperaturas, percentual de massa seca, acidez, umidade total, proteínas e teor de ricina eliminado. Esses dados permitiram observar as condições ótimas de tratamento em função do teor de ricina, concluindo que o secador solar de exposição indireta elimina a ricina, mas não totalmente, pois são necessários aproximadamente 95°C e 6,5 horas de secagem para eliminação completa da toxina.

O tomate constitui-se uma das hortaliças mais exploradas cientificamente, devido à sua importância comercial. O tomate pode, através de processamento adequado, dar origem a inúmeros produtos, alguns deles de elevado consumo no Brasil. Depois da boa aceitação do tomate cereja pelo consumidor, um novo segmento de mini-tomate, chamado Grape, começa a despontar nos mercados brasileiros. O destaque é o híbrido Sweet Grape, que está agradando ao gosto do consumidor e animando agricultores que aderiram às experiências com a nova cultivar. Seu teor de sólidos solúveis chega a 10 °Brix e tem menos acidez, comparado a outras variedades, as quais contem entre 4 e 5 °Brix. Nesse trabalho foi avaliado o processo produtivo do tomate seco, a partir de mini-tomates sweet grape, congelados desidratados em secador solar e convencional, visando obter um alimento seguro do ponto de vista microbiológico, físico-quimica, instrumental cor e aceitabilidade) Os tomates cereja tipo Sweet Grape, foram secos até teores de umidade entre 35% e 0%, e observadas suas mudanças em relação aos tomates in natura , e seu comportamento nos períodos de armazenamento após processados de 0, 30, 60 e 90 dias, verificando assim a sua estabilidade. Foi ainda caracterizado o fruto in natura e submetido a um précongelamento para uma previa perda de água facilitando a secagem. A avaliação da qualidade do produto foi realizada através das análises microbiológicas, físico-químicas, composição centesimal e sensorial. Houve diferença significativa entre os secadores, elétrico e solar, para todos os parâmetros analisados, porém não houve alteração significativa para o período de armazenamento. Em relação à avaliação sensorial, o tomate seco ao sol obteve melhor aceitação entre os provadores / The tomato is one of the vegetables are more scientifically investigated, due to its commercial importance. The tomato can, through appropriate processing, giving rise to numerous products, some of high consumption in Brazil. After the good acceptance by consumers of cherry tomatoes, a new segment of mini-tomato, called Grape, begins to emerge in the Brazilian markets. The highlight is the hybrid Sweet Grape, which is pleasing to the taste of consumers and encouraging farmers adhered to experiment with new cultivars. Your soluble solids content reaches 10 ° Brix and has less acidity compared to other varieties, which contain between 4 and 5 ° Brix. In this study we evaluated the production process of dried tomato, from mini-sweet grape tomatoes, frozen and dehydrated in conventional solar dryer was used to obtain a food safe from microbiological point of view,. physico-chemical, instrumental color and acceptability) Cherry Tomatoes Sweet Grape type, have been dried to moisture contents between 35% and 50%, and observed their changes for tomatoes in nature, and their behavior during periods of storage after processed 0, 30, 60 and 90 days, thus confirming its stability. It was further characterized the fresh fruit and undergo a pre-freeze to a predicted loss of water facilitating drying. Assessing the quality of the product was carried out by microbiological, physicochemical, chemical composition and sensory. There were significant differences between the dryers, electric and solar, for all parameters analyzed, but no significant change for the period of storage. Regarding the sensory evaluation, the sun-dried tomatoes the best won acceptance among judges

The master’s thesis is focused on the issue of solar drying of sewage sludge. The sludge management of wastewater treatment plants is described in the first part of this thesis. This theoretical part also deals with description of drying and dryers used for sludge treatment. The second part of the thesis is focused on the experimental solar drying of sewage sludge and the evaluation of the results.

This study details the construction and performance testing of a mixed mode solar dryer using a combination of direct and indirect solar energy to dry food. One major benefit of this dryer design is its construction. It was simple to construct and was made with low cost materials, to make it feasible for use in developing countries. Previous research has identified several design factors that affect performance and efficiency: product loading density, number of trays, position of the absorber, and chimney type. Performance testing showed that chimney air speeds were not affected greatly by modifying the design aspects of the dryer, with only a small increase occurring when using a box-type chimney. Overall the temperatures were mostly dependent on irradiance, but using a collector-type chimney generally resulted in higher temperatures throughout the dryer. The RH change across the dehydrator was most affected by the number of trays, but the chimney type did have an effect on the RH right at the chimney exit. Efficiency testing showed that product loading density on the trays was tested at 40% and 60% capacity; there was no statistical difference observed for efficiency between the two levels. Our results show that the dryer was more efficient when using the maximum number of trays. The lowest position of the absorber (5 cm from the ground) was found to be most efficient. A box-type chimney was significantly more efficient than the collector-type chimney in this full factorial study.