Direct sun drying is one of the oldest methods of food preservation. A drying method that utilizes solar energy while minimizing negative aspects of sun drying is a solar dryer. However, research about the quality characteristics of fruits and vegetables dried using a solar dryer compared to a traditional dryer is lacking. To measure this, apple, tomato and carrot slices, and grape halves and whole peas were prepared and dried using either a solar or FA dehydrator (FA), Consumer liking was measured using two sensory panels that asked panelists 9-point hedonic questions between like products. Quality differences were analyzed using a TA.XT2 texture analyzer. Color was measured using a Hunterlab colorimeter. There were no significant differences in consumer liking (p<0.05) between drying methods for any fruits and vegetables with regards to overall acceptability. Grapes, tomatoes and carrots all had significant differences in consumer liking with regards to appearance, which correlates well with observed differences in a* values. Consumers liked the aroma of solar-dried peas significantly more. The texture of FA grapes was liked significantly more than their solar counterparts, which likely contributed to consumers significantly ranking the FA grapes higher than their solar counterparts when asked to rank which one they prefer.

Made available in DSpace on 2014-12-17T14:58:22Z (GMT). No. of bitstreams: 1 TiagoSS_DISSERT.pdf: 3176219 bytes, checksum: 52cc9f63816eb64b9870125bb84fe2a5 (MD5) Previous issue date: 2013-07-26 / 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 / A escassez de ?reas de cultivo, redu??o da oferta de ?gua para irriga??o e falta de tecnologias para conserva??o, faz o mundo globalizado enfrentar graves dificuldades na produ??o de alimentos para sua popula??o. A sa?da mais vi?vel para tal dilema ? a dissemina??o de tecnologias, economicamente vi?veis e dispon?veis a toda popula??o, para desidrata??o dos alimentos perec?veis produzidos. Este trabalho apresenta um secador solar de exposi??o direta para a produ??o de frutas secas, fabricado a partir de um tambor de polietileno reciclado, de 200 litros, usado para armazenamento de ?gua ou lixo. O tambor foi seccionado ao meio, em seu eixo longitudinal, e teve suas metades unidas formando uma estrutura tipo calha. Ser?o descritos os processos da constru??o e montagem do secador solar proposto, que tem como principal caracter?stica seu baixo custo, e foi idealizado para uso de pessoas com baixa renda, para o processamento de frutas amplamente dispon?veis em nossa regi?o (manga, banana, goiaba, caju, abacaxi, tomate e outros) em frutas secas e farinhas, contribuindo significativamente para aumentar a vida ?til desses alimentos. As nozes e farinhas podem ser utilizadas para consumo pr?prio e para trabalhos de marketing e gera??o de renda. Foram realizados testes para diagnosticar a viabilidade do uso de secador solar para os diversos tipos de frutas tropicais. Foram tamb?m comparados par?metros como tempos de secagem e efici?ncia t?rmica, obtidos no prot?tipo com os encontrados na literatura especializada em desidrata??o de alimentos. Os tempos de secagem obtidos no secador foram competitivos com os obtidos em outros modelos de secadores desenvolvidos no LMHES

Made available in DSpace on 2014-12-17T14:58:23Z (GMT). No. of bitstreams: 1 JoseMS_DISSERT.pdf: 2889418 bytes, checksum: 74b39d03124042e8cd8a6061bbd92425 (MD5) Previous issue date: 2012-05-23 / Licuri is a palm tree from the semiarid regions of Bahia State, Brazil. It is an important source of food and feed in that region, since their nuts are commonly eaten by humans and used as maize substitute for poultry feeding. The aim of this dissertation is to study the feasibility for use of natural convection solar dryers and forced being compared with the traditional drying outdoors for drying coconut licuri Syagrus coronate. The study led to the construction of two prototype solar dryer for carrying out experiments proving: model Solar Drying System Direct Exposure to Natural Convection built with wood, has a drying chamber with direct cover transparent glass laminates 4 mm, using techniques for proper isolation of the drying chamber. The two prototypes were comparatively analyzed for performance and drying efficiency with traditional extractive use by the community. Were evaluated the variables: time and drying rates and quality of the final samples of coconut licuri. The fruits were harvested and brought the town of Ouricuri, in the city of Caldeir?o Grande, BA for the experiments comparing the three methods of drying was used a standard load of 4.0 kg The quantitative analysis for the result of the drying rate was found in 74% yield and 44% for natural and forced convection respectively compared with the traditional drying. These drying rates represent variation 3-5 times lower. Drying using forced convection licuri showed better quality, was found in a reddish pulp, representing the quantities that were kept of the nutrient beta carotene, and not notice the flavor change from the previous system, the final cost of construction of this system were higher . The prototypes built competitive advantage and had testified fully to resolve the technical difficulties previously encountered in the production of products made of coconut licuri. Allowing add value and increase their potential use for the fruit extractive communities of semi-arid region of Bahia / O licuri (Syagrus coronata (Martius) Beccari) ? uma palmeira nativa do Brasil, largamente disseminada por todo o semi-?rido do pa?s. O fruto do licuri, conhecido pela mesma denomina??o da palmeira, ? totalmente comest?vel. Apesar do grande potencial nutritivo e oleaginoso do licuri, pouca aten??o tem sido dada para o estudo detalhado do valor nutritivo deste fruto. Nesta disserta??o ser? estudado a viabilidade para utiliza??o dos secadores solar de convec??o natural e for?ada (SSSEICF) sendo comparados com a secagem tradicional ao ar livre, para a secagem do coco licuri. O estudo levou a constru??o de dois prot?tipos de secador solar para a realiza??o de experimentos comprovativos: o Sistema de Secagem Solar de Exposi??o Direta e Convec??o Natural constru?do com madeira, possui uma c?mara de secagem direta com cobertura de lamina de vidro transparente de 4 mm, com utiliza??o de t?cnicas para o correto isolamento da c?mara de secagem e o Sistema de Secagem Solar de Exposi??o Indireta e Convec??o For?ada, fabricado com chapas de a?o galvanizado, tem a c?mara de secagem indireta com cobertura de l?mina de vidro transparente de 6 mm, tendo a utiliza??o de t?cnicas para correto isolamento da c?mara de secagem e a inser??o do equipamento de exaustor e?lico de ar respons?vel direto pela convec??o for?ada de ar da c?mara de secagem indireta. Os dois prot?tipos foram analisados comparativamente quanto ao desempenho e efici?ncia com a secagem tradicional em uso pela comunidade extrativista. Foram avaliados quanto as vari?veis: tempo e taxas de secagem e qualidade final das amostras de coco licuri. Os frutos foram colhidos e trazidos do povoado de Ouricuri, na cidade de Caldeir?o Grande BA, para a realiza??o dos experimentos comparativos entre os tr?s m?todos de secagem foi utilizada uma carga padr?o com 4,0 Kg. A an?lise quantitativa para o resultado da taxa de secagem, foi encontrado rendimento de 74% e 44% para o convec??o natural e convec??o for?ada respectivamente, em compara??o com a secagem tradicional. Essas taxas de secagem representam varia??o de 3 a 5 vezes menor. A an?lise qualitativa das amostras de fruto e das am?ndoas mostrou: que, a secagem utilizando a convec??o natural apresentou boa qualidade para o licuri, por?m foi constatada uma altera??o sensorial no sabor, conhecida como coco velado . A secagem utilizando a convec??o for?ada apresentou melhor qualidade do licuri, foi encontrada uma colora??o avermelhada na polpa, representando que foram mantidas as quantidades do nutriente beta caroteno e n?o se percebeu a mudan?a de sabor do sistema anterior, os custos finais de constru??o desse sistema foram maiores. Os prot?tipos constru?dos obtiveram vantagem competitiva e atestou perfeitamente para solucionar a dificuldade tecnol?gica encontrada anteriormente na produ??o de produtos a base do coco licur?. Permitindo agregar valor e elevar as possibilidades de aproveitamento do fruto pelas comunidades extrativistas da regi?o semi-?rida da Bahia

Solar energy is of huge interest due to the current situation with global warming. A number of solar technologies have been developed, such as photovoltaic, concentrated solar power, and solar water heating systems, to name a few. However, the technologies are being slowly implemented, and Botswana, with generous amounts of sun, is particularly suitable for solar energy. The opportunities were investigated due to the overwhelming and horrifying warnings echoed by many of the world's scientists regarding global warming. First, a handful of solar technologies were thoroughly investigated. A field study at Gakgatla village was then conducted, where the locals were interviewed. The interviews were analyzed, and solutions were suggested based on the identified needs of the locals. The biggest challenges identified were the lack of electricity in many of the households, parental figures not being supportive of the children's education, and theft. Additionally, many locals cooked with firewood. The most helpful solution but difficult to implement is photovoltaic panels. Solar water heating systems would also be helpful to the locals who predominantly had cold water. Additionally, solar cookers could help minimize exposure to hazardous smoke. Lastly, solar lamps could help students study during nighttime. Some locals also showed huge enthusiasm for what the future partnership with Botho University will bring. It is encouraged to develop a prototype of a solar cooker, particularly the parabolic solar cooker, in order to install solar cookers in Gakgatla village. Solar dryers would also greatly benefit the locals and are also suggested developments. Both of the mentioned solutions would help minimize the locals' exposure to the hazards of cooking with firewood. The solar dryers will also help eliminate bacteria by drying the food in a protected space inside a container.