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.

Šiuo metu populiariausias konservavimo būdas yra džiovinimas. Džiovinimas – tai technologinis procesas, kurio metu yra pašalinama iš produkto drėgmė, tokiu būdu prailginamas produkto tinkamumo laikas, tuo pačiu išlaikomos arba pagerinamos medžiagų savybės. Džiovinimo metu svarbiausia išlaikyti kokybę, kad džiovinamoje medžiagoje nepakistų pagrindinės medžiagų savybės. Ekstrudavimo procesas suintensyvina kombinuotųjų pašarų džiovinimo procesą. Magistrantūros darbo tikslas – ištirti ekstruduotų kombinuotų pašarų šunims džiovinimo procesą konvejerinėje džiovykloje. Atlikus informacijos šaltinių apžvalgą yra išanalizuotas džiovinimo procesas,džiovinimo būdai, džiovinimo proceso teoriniai pagrindai, šilumos rekuperatorių panaudojimo studija ir kombinuotų pašarų šunims procesas. Ekstruduotieji kombinuotieji pašarai konservuojami išgarinant perteklinę drėgmę konvejerinėje džiovykloje, sumažinant drėgnumą nuo 19,60 iki 8,51 %, kuris atitinka standarto reikalavimus. Džiovinant pašarus konvejerinėje džiovykloje buvo sunaudota 14000 kJ/kgvandens šilumos vienam kilogramui drėgmės išgarinti. Šilumos kiekis reikalingas džiovinimo procesui 654,48 kW. Nustatyta, kad rekuperatoriaus naudingumo koeficientai yra 72%. Šilumos kiekis reikalingas džiovinimo procesui 654,48 kW. Rekuperatorimi konpensuojamos grąžinamos šilumos kiekis yra 471,50 kW. / Currently drying is the most popular conservation method. Drying is a technological process, which removes moisture from the product, in this way the shelf life of the product is extended, at the same time the properties of materials are maintained or upgraded. It is important to maintain the quality in the process of drying in order to avoid unwanted changes of main characteristics of the drying material. The aim of master thesis is to explore drying process in conveyor dryer for the extruded combined feed for dogs. The analysis of the material data was performed specific attention paying to the process of drying, the methods of drying, theoretical background of drying, the study of the heat recuperator use and the process of combined feed for dogs. Extruded combined feed in conveyor dryer is preserved by evaporating excess moisture, the moisture is reduced from 19,60 to 8,51%, which complies with the requirements of the standard. For the feed drying the amount of heat to evaporate one kilogram of water in the conveyor dryer is 14000 kJ/kgH2O. The quantity of heat needed for the drying process is 654,48 kW. It was established that the efficiency units of recuperator are 72 %. The quantity of heat needed for the drying process is 654,48 kW. Compensated returned heat amount in recuperator is 471,50 kW.

In this study, new methods and processing equipments for sesame dehulling were investigated. First, water absorption of sesame seed was studied at 20, 30, and 40&deg / C. The data could be modeled using Peleg equation where it was found that the constant k1 was inversely related to temperature but the effect of temperature on k2 was negligible. In the second phase of the work a lab scale continuous screw conveyor as dehuller and two equipments, (1) fluidized bed dryer and (2) hull separator to function as agitator, dryer and separator, for hull separation were designed. Fluidized bed unit was unsuccessful as it caused rapid drying of seeds before hulls can be removed. Using designed dehuller and hull separator, seeds at 30.5, 50.4 and 70.7 % db moisture contents were processed at dehuller speeds of 420, 840, and 1150 rpm. It was found that the percentage of dehulled seeds was linearly dependent on moisture content, optimal speed of designed dehuller was 840 rpm, and results for the efficiency of dehulling the seeds were significantly the same at 420 and 1150 rpm. Repeated passes of seeds through dehuller not only increased the efficiency of dehulling but also the percentage of damaged seeds. A dehulling efficiency of about 92.5 % was attained after four passes. The possibility of soaking seeds in an enzyme solution before dehulling was also investigated. By this means, after soaking in 0.2 % (v/v) Peelzyme-I solution for 15 min, a dehulling efficiency of 95 % was achieved.

This research investigates possible monitoring methods to non-invasively detect blockages in the cyclone of milk powder spray driers to avoid costly production shutdowns. Two possible solutions have been identified. These are guided wave and vibration analysis. This research focuses on vibration analysis method, based on variation in the natural frequencies and/or damping ratios caused by blockages. Experimental simulation studies the performance to assess the viability of the vibration analysis method in identifying blockage in the cyclone. To test this method, a 1.87m long vertical cylindrical steel tube with both ends simply supported was setup as a prototype and flour was used as the powder conveyed by the tube. Analytical, numerical and experimental methods were implemented on the prototype using vibration analysis techniques. Experimental resonant frequencies of the empty shell from the impact hammer excitation were compared with analytical and numerical solutions to analyse the modal shapes. The first bending mode was determined as 79 Hz, which decreased with the amount of added mass and location closer to the middle point. This was validated by the simulated mass experiment, which also matched with the beam-mass theory. Flour induced experiment further validated the variation of the first bending mode. Experimental 270Hz, 380Hz and 398Hz resonant frequencies increased with the amount of added mass, which was validated by the simulated mass and flour induced experiment. Besides the variation of the natural frequencies, the damping ratio was also studied and quantified using the Hilbert transform envelope curve method. Onsite monitoring of the vibration of the cyclone in a spray dryer was done at Fonterra Te Rapa and clear resonant frequencies were obtained. The research results from the prototype demonstrate that vibration analysis as a non-destructive method to detect the milk powder deposition or blockage in the cyclone is possible and promising. However, more work is required before industry application.

Este trabalho tem como principal objetivo o estudo da redução dos níveis de pressão sonora em secadores de cabelo, proposto através de uma mudança conceitual em seus projetos de fabricação. A proposta é extensiva aos aparelhos manuais e aos de base fixa, avaliando os níveis de pressão sonoros a que seus usuários estão expostos. A redução das emissões sonoras faz-se importante, não somente visando o atendimento da legislação quanto à manutenção da saúde do operador e os do seu entorno, como principalmente proporcionar e valorizar seu conforto no ambiente. Um modelo de secador de cabelo conceitual, e como tal ainda há que se adequar forma, tamanho e peso, portanto passivo de evoluções, foi elaborado para viabilizar os trabalhos práticos das avaliações das emissões sonoras em laboratório e em campo aberto. A partir de um secador de cabelo tradicional e um ventilador centrífugo foram realizados ensaios comparativos de medição de fluxo de massa entre ambos para garantir sua equivalência. Uma vez encontrados os parâmetros mássicos, os termos diferenciais entre os dois aparelhos passam a ser seus níveis de pressão sonora (NPS) e potências sonoras irradiadas (W) que, também, foram levantados e comparados. Para tomar ciência e identificar as faixas de frequência de trabalho de cada aparelho, foi procedida uma coleta de dados a campo aberto, identificando e comparandoos, através de um programa de computador (Agilent VEE por BECKER, 2006) onde tornam conhecidas as diferentes e predominantes faixas de freqüência de trabalho de ambos os aparelhos Os resultados demonstram uma redução de 7,0 dB a campo aberto e de até 10,5 dB em ambiente restrito, entre o secador de cabelo Parlux 2600 e o Secador de Cabelo Conceito quando deles em operação em velocidade máxima. Os ensaios pertinentes foram realizados nos laboratórios e dependências da Universidade Federal do Rio Grande do Sul, seguindo entre outras a norma ISO 3744 para os ensaios de campo livre, na Fundação Zoobotânica de Porto Alegre. / This work has as main objective the study of the reduction of sound pressure levels in hair dryers, proposed using a conceptual change in their manufacturing projects. The proposal is akin to the manual instruments and fixed-base, assessing the levels of sound pressure to which users are exposed. The reduction of noise it is important not only to the fulfillment of the law regarding the preservation of health of the operator and his surroundings, especially as provide comfort and enhance your environment. A model of conceptual hair dryer, still in need to adapt form, size and weight, therefore passive of evolutions, was elaborated to make possible the practical works of the evaluations of the resonant emissions in laboratory and in open field. Starting from a traditional hair dryer and a centrifugal fan, it was made comparative rehearsals of measurement of mass flow between both to guarantee its equivalence. As soon as it was found the mass parameters the differential terms between the two devices start to be their sound pressure level (SPL) and irradiated sound potencies (W) that, also were presented and compared. To understand and identify the zones of work frequency of each device, a collection of data were produced in open field identifying and comparing them through a computer program (Agilent VEE by BECKER, 2006) where it was known the different and predominant zones of work frequency of both devices. The results show a reduction of 7,0 dB in open field and until 10,5dB at restrict work room, between the hair dryer Parlux 2600 and the Conceptual hair dryer operating in maximum speed. The pertinent rehearsals were accomplished in the laboratories and dependences of the Federal University of Rio Grande do Sul, following among others, the norm "ISO 3744, of open field, and in the Zoobotanical Foundation of Porto Alegre.

This thesis deals with the constructional design of the industry dryer meant for the production of the current and voltage transformers of the KPB Intra s.r.o. company. The basic theory of the drying and the heat balance of the dryer are processed in this thesis, and also the brief overview of the constructional solutions of the industry dryers and their usage. In detail it focuses on the constructional possibilities of the chosen dryer for the given application. Essential parts of the thesis are the constructional calculations for the power determination of the ventilator, heating units, condensational units, the exchanger, engine with transmission and the calculations for the mechanism dimensioning of the shelf adjusting, clamping case and the springs for the chain stretching. Last but not least it consists of the technical-economical evaluation of the suggested solution and its risk analysis. Drawing documentation, 3D model and the animation of its moving components form also the part of this thesis.

Spray drying is a process, which produces powders from the fluid state. This type of process is mostly used in the industrial sector. In this process, a liquid slurry is atomized, forming droplets, which are dried with hot air. During spray drying these droplets will interact and upon impact can show different types of interactions; droplet-droplet collisions as well as interactions with partially or completely dried particles, leading to agglomeration. The result of collision gives properties of the dried powder. The focus of the thesis is to investigate the droplet-droplet collision outcomes of WPC 80 (Whey Protein Concentrate 80) and Lactose. Then the effects of the absolute droplet diameter and the droplet diameter ratios are to be determined. Existing experimental setup and Image Processing Tool of MATLAB is used to study the collision outcome. The outcomes are shown in a regime map. The present results are compared with different products result and literature study. It is observed that there is an effect on collision outcome for different droplet size ratios and no effect for absolute droplet diameter.

Submitted by Maykon Nascimento (maykon.albani@hotmail.com) on 2015-05-04T17:55:57Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese Ramon Ramos de Paula.pdf: 1203744 bytes, checksum: a274158b9e8be92298dc963783bfa3a8 (MD5) / Approved for entry into archive by Elizabete Silva (elizabete.silva@ufes.br) on 2015-05-04T19:20:34Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese Ramon Ramos de Paula.pdf: 1203744 bytes, checksum: a274158b9e8be92298dc963783bfa3a8 (MD5) / Made available in DSpace on 2015-05-04T19:20:34Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese Ramon Ramos de Paula.pdf: 1203744 bytes, checksum: a274158b9e8be92298dc963783bfa3a8 (MD5) Previous issue date: 2015-05-04 / O soro de leite é um subproduto da fabricação do queijo, seja por acidificação ou por processo enzimático. Em condições ideais, a caseína do leite se agrega formando um gel, que posteriormente cortado, induz a separação e liberação do soro. É utilizado de diversas formas em toda a indústria alimentícia, possui rica composição em lactose, sais minerais e proteínas. A desidratação é um dos principais processos utilizados para beneficiamento e transformação do soro. Diante disto, o objetivo deste trabalho foi avaliar a influência dos métodos de secagem: liofilização, leito de espuma (nas temperaturas de 40, 50, 60, 70 e 80ºC) e spray-dryer (nas temperaturas de 55, 60, 65, 70 e 75ºC), sobre as características de umidade, proteína, cor e solubilidade do soro, bem como estudar o seu processo de secagem. O soro foi obtido e desidratado após concentração por osmose reversa, testando 11 tratamentos, em 3 repetições, utilizando um delineamento inteiramente casualizado. Os resultados demonstraram que o modelo matemático que melhor se ajustou foi o modelo de Page, apresentado um coeficiente de determinação ajustado acima de 0,98 e erro padrão da regressão em todas as temperaturas abaixo de 0,04 para o método por leito de espuma. Para o método de liofilização os respectivos valores foram 0,9975 e 0,01612. A partir disso, pode-se elaborar um modelo matemático generalizado, apresentando um coeficiente de determinação igual a 0,9888. No caso do leito de espuma, observou-se que à medida que se aumenta a temperatura do ar de secagem, o tempo de secagem diminui e os valores do coeficiente de difusão efetiva aumentam. Porém, a redução no tempo de secagem entre os intervalos de temperatura, diminui com o aumento da mesma. A energia de ativação para a difusão no processo de secagem do soro foi de 26,650 kJ/mol e para todas as avaliações físico-químicas e tecnológicas, a análise de variância apresentou um valor de F significativo (p<0,05), indicando que há pelo menos um contraste entre as médias dos tratamentos que é significativo. / Whey is a product of cheese manufacturing, either by acidification or by enzymatic process. Ideally, the milk casein is aggregate to form a gel, later cut when the separation thereof occurs. It is used of various forms within the food industry, has a high levels of lactose, minerals and proteins in the composition and dehydration is one of the major processing procedures and processing whey. Hence, the objective of this study was to evaluate the influence of the drying methods: freeze drying, foam-mat drying (in temperatures of 40, 50, 60, 70 and 80ºC) and spray-dryer (in temperatures of 55, 60, 65, 70 and 75°C) on the moisture characteristics, protein, color and solubility of the whey as well as studying your drying process. The whey was obtained and dehydrated after concentration by reverse osmosis, testing 11 treatments and 3 replications, using a completely randomized design. The results showed that the mathematical model best fit was the Page's model, with a coefficient of determination adjusted above 0.98 and standard error of the regression at all temperatures below 0.04 for the foam-mat drying. In the lyophilization method, the respective values were 0.9975 and 0.01612. From this a generalized mathematical model could be achieved, with a coefficient of determination same to 0.9888. In the case of the foam-mat drying was observed that as one increases the temperature of the drying air, the drying time decreases and values of the effective diffusion coefficient increases. However, the reduction in drying time between the intervals of temperature decreases with the increase of the same. The activation energy for diffusion of whey at drying process was 26.650 kJ/mol and in all physico-chemical and technological assessments, analysis of variance showed a significant F value (p <0.05), indicating that there are at least a contrast between the treatments that is significant.

Submitted by THAÍS PAES RODRIGUES DOS SANTOS null (thaispaes.btu@ig.com.br) on 2016-04-27T14:43:11Z No. of bitstreams: 1 TESE_THAIS P R DOS SANTOS.pdf: 2813733 bytes, checksum: 65a5985853cbb6a257d3371ffa95a48a (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-04-29T17:37:38Z (GMT) No. of bitstreams: 1 santos_tpr_dr_bot.pdf: 2813733 bytes, checksum: 65a5985853cbb6a257d3371ffa95a48a (MD5) / Made available in DSpace on 2016-04-29T17:37:39Z (GMT). No. of bitstreams: 1 santos_tpr_dr_bot.pdf: 2813733 bytes, checksum: 65a5985853cbb6a257d3371ffa95a48a (MD5) Previous issue date: 2016-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Amidos pré-gelatinizados podem ser usados em aplicações de produtos de conveniência pela indústria de alimentos, pois apresentam maior solubilidade em água fria e menor temperatura de gelatinização. As modificações físicas por spray drying e por extrusão são métodos que podem resultar em alterações na região cristalina, com mudanças nas propriedades térmicas e de pasta dos amidos. Objetivou-se neste trabalho verificar as alterações estruturais e funcionais provocadas, pelos métodos de modificações físicas citados, nos amidos de mandioca, mandioquinha-salsa e batata-doce. A modificação por spray drying foi realizada com aquecimento da suspensão à 57 °C e concentração de 8 % de amido, com temperatura de saída e vazão no spray dryer, respectivamente, de 105 °C e 0,5 L h-1. A modificação por extrusão foi realizada no amido a 20 % de umidade, temperaturas de 25, 50 e 75 ºC, respectivamente, na 1a zona, 2ª zona e 3ª zona do extrusor e rotação de 245 rpm. Após a finalização deste experimento, os resultados evidenciaram que a modificação por spray drying provocou alterações menos severas nas características dos amidos estudados. Sendo assim, foi realizado um segundo experimento com os amidos de mandioca e batata-doce a fim de determinar as melhores condições de processo da modificação por spray drying, seguindo planejamento experimental central composto rotacional nos dois ensaios experimentais. Os amidos modificados no primeiro experimento foram analisados em relação as características estruturais e propriedades de pasta e térmica. A modificação por spray drying não provocou alterações no teor de amilose, massa molecular e raio médio de giro, assim como na distribuição dos comprimentos das cadeias ramificadas de amilopectina, mostrando que não houve degradação das ligações glicosídicas. Houve redução dos picos do padrão de difração de Raios X dos amidos, refletindo na diminuição na cristalinidade relativa. A morfologia dos grânulos apresentou aglomerados para os amidos de mandioca e mandioquinha-salsa, indicando gelatinização parcial dos grânulos. O amido de mandioquinha-salsa modificado por spray drying apresentou aumento na viscosidade a frio e diminuição da viscosidade de pico e final. Para todos os amidos, houve aumento no setback (tendência a retrogradação). As temperaturas de gelatinização não sofreram alterações significativas, porém a variação da temperatura diminuiu, assim como a variação da entalpia. Os amidos modificados por extrusão não apresentaram alteração no teor de amilose e na distribuição dos comprimentos das cadeias ramificadas da amilopectina, no entanto, houve alteração na massa molecular e no raio médio de giro, indicando provável rompimento das ligações glicosídicas. Os amidos modificados por extrusão apresentaram redução total dos picos do padrão de difração dos amidos, indicando total gelatinização. Nas imagens de microscopia eletrônica de varredura não foram observados grânulos para todos os tratamentos, confirmando a gelatinização total do amido com perda da estrutura granular durante o processo de extrusão, o que também foi observado pela ausência de curva de gelatinização na análise de propriedade térmica. Tais alterações levaram a um aumento na viscosidade a frio. As modificações por spray drying e extrusão resultam em amidos com diferentes propriedades, sendo que o amido modificado por spray drying seria indicado para produtos que necessitem de consistência mais firme, enquanto o amido modificado por extrusão seria indicado para produtos com viscosidade a frio e com consistência mais fluída. Em relação aos amidos estudados, o amido de mandioquinha-salsa apresentou maior sensibilidade ao processo, devido sua temperatura de gelatinização ser próxima às temperaturas utilizadas, e também, pelo defeito na área cristalina. Os resultados obtidos no segundo experimento evidenciaram que as melhores condições de modificação dos amidos de mandioca e de batata-doce por spray drying são: alta temperatura (60 °C) e baixa concentração (5 %). Nas condições citadas, podem ser obtidos amidos modificados por spray drying com boas características de pasta e térmica, como leve viscosidade a frio, consistência no produto final e temperatura de gelatinização uniforme, refletindo em melhor utilização de energia no processo. / Pregelatinized starches can be used in applications of convenience products by the food industry, since they have greater solubility in cold water and low gelatinization temperature. The physical modification by spray drying and extrusion are methods which can result in changes in the crystalline region, with changes in the thermal and pasting properties of starch. The aim of this work was to verify the structural and functional changes caused by physical modification methods mentioned in starches from cassava, Peruvian carrot and sweet potato. The modification by spray drying was performed using temperature of 57 °C and concentration of 8 %, with outlet temperature and feed rate in spray dryer of 105 °c and 0.5 L h-1, respectively. The modification by extrusion was carried out with 20 % of starch moisture, with temperatures of 25 °C, 50 °C and 75 °C in the 1st zone, 2nd zone and 3rd zone respectively, and rotation 245 rpm. After completion of this experiment, the results show that the modification by spray drying caused less severe changes in the characteristics of the studied starches. Thus, it was conducted a second experiment with starches from cassava and sweet potato, in order to determine the best process conditions of modification by spray drying, following experimental design central composite rotational in both experimental tests. The modified starches of the first experiment were analyzed for structural characteristics and thermal and pasting properties. The modification by spray drying caused no changes in the amylose content, molecular weight and the average gyration radius, and distribution branch chains-length of amylopectin showing that there was no degradation of glycosides bonds. There was reduction of the peaks of the diffraction pattern of starches, reflecting in decrease of relative crystallinity. The morphology of the granules showed agglomerates for the starches of cassava and Peruvian carrot, indicating partial gelatinization of the granules. Modified starch of Peruvian carrot by spray drying showed increase in cold viscosity and decrease in peak and final viscosity. For all starches, there was increase in setback. The temperatures of gelatinization no showed significant changes, although the temperature range decrease, as well as the enthalpy change. Modified starches by extrusion no show change in the amylose content and the distribution of branch chains-length of amylopectin, however, changes were observed in the molecular weight and the average gyration radius, indicating likely breaking of glycosidic bonds. Modified starches by extrusion showed total reduction in peaks of the diffraction pattern of the starches, indicating complete gelatinization of starches. In scanning electron microscopy observed no granules, confirming complete gelatinization of the starch, with loss of granular structure during the extrusion process, which also were observed by absence of gelatinization curve in thermal analysis. These changes leaded to increase of cold viscosity. The modifications by spray drying and extrusion resulted in starches with different properties, being the modified starch by spray drying can be indicated to apply in products that need of firmness consistency, and the modified starch by extrusion may be indicated to apply in products with cold viscosity and less consistency. Among of studied starches, Peruvian carrot starch showed be more susceptible for both process, due to its gelatinization temperature to be near the temperatures used in these experiments, and due to its defect in crystalline area. The results obtained in the second experiment show that the best conditions for modification of starches of cassava and sweet potato by spray drying are: high temperature (60 °C) and low concentration (5%). In these conditions can be obtained modified starches by spray drying with good pasting and thermal properties, as the cold viscosity, consistency in final product and gelatinization temperature uniform between the granules, reflecting in better utilization of energy by process.

Este trabalho tem como principal objetivo o estudo da redução dos níveis de pressão sonora em secadores de cabelo, proposto através de uma mudança conceitual em seus projetos de fabricação. A proposta é extensiva aos aparelhos manuais e aos de base fixa, avaliando os níveis de pressão sonoros a que seus usuários estão expostos. A redução das emissões sonoras faz-se importante, não somente visando o atendimento da legislação quanto à manutenção da saúde do operador e os do seu entorno, como principalmente proporcionar e valorizar seu conforto no ambiente. Um modelo de secador de cabelo conceitual, e como tal ainda há que se adequar forma, tamanho e peso, portanto passivo de evoluções, foi elaborado para viabilizar os trabalhos práticos das avaliações das emissões sonoras em laboratório e em campo aberto. A partir de um secador de cabelo tradicional e um ventilador centrífugo foram realizados ensaios comparativos de medição de fluxo de massa entre ambos para garantir sua equivalência. Uma vez encontrados os parâmetros mássicos, os termos diferenciais entre os dois aparelhos passam a ser seus níveis de pressão sonora (NPS) e potências sonoras irradiadas (W) que, também, foram levantados e comparados. Para tomar ciência e identificar as faixas de frequência de trabalho de cada aparelho, foi procedida uma coleta de dados a campo aberto, identificando e comparandoos, através de um programa de computador (Agilent VEE por BECKER, 2006) onde tornam conhecidas as diferentes e predominantes faixas de freqüência de trabalho de ambos os aparelhos Os resultados demonstram uma redução de 7,0 dB a campo aberto e de até 10,5 dB em ambiente restrito, entre o secador de cabelo Parlux 2600 e o Secador de Cabelo Conceito quando deles em operação em velocidade máxima. Os ensaios pertinentes foram realizados nos laboratórios e dependências da Universidade Federal do Rio Grande do Sul, seguindo entre outras a norma ISO 3744 para os ensaios de campo livre, na Fundação Zoobotânica de Porto Alegre. / This work has as main objective the study of the reduction of sound pressure levels in hair dryers, proposed using a conceptual change in their manufacturing projects. The proposal is akin to the manual instruments and fixed-base, assessing the levels of sound pressure to which users are exposed. The reduction of noise it is important not only to the fulfillment of the law regarding the preservation of health of the operator and his surroundings, especially as provide comfort and enhance your environment. A model of conceptual hair dryer, still in need to adapt form, size and weight, therefore passive of evolutions, was elaborated to make possible the practical works of the evaluations of the resonant emissions in laboratory and in open field. Starting from a traditional hair dryer and a centrifugal fan, it was made comparative rehearsals of measurement of mass flow between both to guarantee its equivalence. As soon as it was found the mass parameters the differential terms between the two devices start to be their sound pressure level (SPL) and irradiated sound potencies (W) that, also were presented and compared. To understand and identify the zones of work frequency of each device, a collection of data were produced in open field identifying and comparing them through a computer program (Agilent VEE by BECKER, 2006) where it was known the different and predominant zones of work frequency of both devices. The results show a reduction of 7,0 dB in open field and until 10,5dB at restrict work room, between the hair dryer Parlux 2600 and the Conceptual hair dryer operating in maximum speed. The pertinent rehearsals were accomplished in the laboratories and dependences of the Federal University of Rio Grande do Sul, following among others, the norm "ISO 3744, of open field, and in the Zoobotanical Foundation of Porto Alegre.