With an ever-increasing population, we meet a constantly growing need for resources, such as food. Globally, 1,6 million tonnes of food are wasted. This amount corresponds to everything that goes to waste throughout the whole food production from farm to table. One of the major sources of food waste comes from grocery stores. Grocery stores throw away large amounts of food, partly because of people’s high demands for quality. A brown spotted banana is no longer considered to be saleable and it is removed from the shelves and discarded. These bananas have often travelled around the world to end up in our garbage bins.   In order for the bananas long journey not to have been unnecessary they need to be taken care of, instead of being thrown away when they become brown spotted. Hot air-drying is one of the world’s most widely used method in food preservation. The main purpose of air-drying is to remove water from the food to a level in which microbiological spoilage and degradation are greatly minimized. Bananas dried to 20 % moisture content on dry base have a shelf life of six months, therefore, drying is an approach that allows the bananas to be reintroduced in the grocery stores as a new product. The purpose of this exam work was thereby to investigate hot air-drying as an alternative to reducing the food waste of bananas in grocery stores, and instead introduce a new product in the form of dried banana crisps to promote a circular bioeconomy as a step towards sustainable development.   A conventional table dryer for drying of fruit and vegetables has been studied, using energy and mass balances as well as drying experiments to obtain the connections that exists during the drying process. In order to investigate how temperature and air flow influence the drying kinetics in the existing dryer, drying curves has been established. Finally, a calculation model was made of the drying process in Excel in order to study how different loads of banana affects the energy consumption.   The results show that a small measurement error in the equipment causes large deviation, which means that the appearance of the drying curves does not correspond to the literature. This demonstrates that measurement accuracy is the deciding factor for evaluating how the drying parameters are affected during different conditions. The results also show that the method used is not appropriate and needs to be further developed.   Finally, results indicate that an upscale of the dryer would imply a total effect of 1,4 kW with an air flow of 0,027 kg/s, for a capacity of 20 kg of banana (with peel) applicable in ordinary stores and 5,9 kW respectively 0,13 kg/s for a drying capacity of 84 kg suitable for five stores’ food waste of banana. / Med en befolkningsmängd som ökar, möter vi ett konstant växande behov av resurser, så som mat. Globalt sett går 1,6 biljoner ton mat förlorad. Denna mängd motsvarar allt som går till spillo genom hela livsmedelsframställningen från jord till bord. En av de stora källorna till matsvinn är livsmedelsbutiker. Livsmedelsbutiker slänger stora mängder mat, bland annat på grund av konsumenters höga krav på kvalitet. En brunprickig banan anses inte längre vara säljbar utan tas bort från hyllorna och kasseras. Dessa bananer har ofta rest världen över för att hamna i just våra soptunnor.   För att inte bananernas långa resa ska ha varit i onödan behöver de tas till vara på, istället för att slängas när de blivit brunprickiga. Varmluftstorkning är en av världens mest använda metoder inom livsmedelskonservering. Det huvudsakliga syftet med torkningen är att driva bort fukten till en nivå där patogener och degradering minimeras. Bananer som torkas till 20 % fukthalt på torr bas har en hållbarhetstid på upp till sex månader, därför är torkning ett tillvägagångssätt som gör att bananerna kan återintroduceras i livsmedelsbutikerna som en ny produkt. Syftet med examensarbetet var därför att utreda varmluftstorkning som ett alternativ för att minska matsvinnet av bananer i butik och istället introducera en ny produkt i form av torkade bananchips för att främja en cirkulär bioekonomi som ett steg i hållbar utveckling.   En vanlig bordstork för varmluftstorkning av frukt och grönt har studerats med hjälp av energi- och massbalanser samt med egna torkförsök för att få fram de samband som verkar under torkningen. För att undersöka hur temperatur och luftflöde påverkar torkparametrarna i den befintliga torken, upprättades torkkurvor. Slutligen gjordes en beräkningsmodell över torkprocessen i Excel för att studera hur olika laster av banan påverkar energiåtgången.   Resultaten visar att små mätfel i mätinstrumenten ger stora avvikelser vilket gör att torkkurvornas utseende inte stämmer överens med litteraturen. Detta påvisar att mätnoggrannheten är den avgörande faktorn för att kunna utvärdera hur torkparametrarna påverkas under olika förutsättningar. Resultaten indikerar även i att metoden som använts inte är lämplig och måste utvecklas mer.   Slutligen visar resultaten att en uppskalning av torken skulle innebära en total effekt på 1,4 kW med tillhörande luftflöde på 0,027 kg/s, för en kapacitet av 20 kg banan (med skal) anpassad för matbutik och 5,9 kW respektive 0,13 kg/s för en torkkapacitet av 84 kg, anpassad för fem butikers banansvinn.

Made available in DSpace on 2015-03-26T13:36:39Z (GMT). No. of bitstreams: 1 texto conpleto.pdf: 495016 bytes, checksum: bf073371b94ee848f9aa951351ee78b1 (MD5) Previous issue date: 2009-07-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The aim of this work was to adjust the flowchart of fresh-cut bananas stored in sucrose solution with passion fruit pulp, as well as to know about the physical changes, chemical, biochemical, and physiological and to determine the shelf life of minimally processed banana kept in the solution. The cooling of the raw material in a cold chamber at 12° C for 4 hours was the minimum necessary time to reduce its temperature. After thermal treatment of sucrose solution, it was necessary to cool it down to 5º C for at least 6 hours. The banana slices stored in sucrose solution with passion fruit pulp showed metabolically active for 8 days of storage at 5º C. The banana slices had signs of browning 2 hours after cutting, so it is recommended to add the solution, as soon as the bananas are cut. It was found that the composed system of 60 grams of sliced bananas and 115 ml of sucrose (15%) with passion fruit pulp, minimized change content of soluble solids, firmness, electrical conductivity and reduced the electrolyte leakage from banana slices during storage. The presence of the passion fruit pulp in the solution was important to minimize enzymatic browning. Furthermore, this system has reduced the enzymatic browning, increased respiratory rate and virtually did not affect the ethylene production of banana slices during storage. Reduction of dissolved oxygen concentration of the solutions/ suspension was observed, after 2 hours of storage in these solutions/ suspension. The activity of dehydrogenase alcohol in banana slices kept in sucrose solution with passion fruit pulp increased, indicating that the tissue was in the process of fermentation. The system under study resulted in maintaining the quality of minimally processed banana and presented shelf life of 8 days at 5° C. / O presente trabalho objetivou ajustar o fluxograma do processamento mínimo da banana conservada em solução de sacarose com polpa de maracujá, assim como conhecer as alterações físicas, químicas, bioquímicas e fisiológicas e determinar o período de conservação da banana minimamente processada conservada na solução. O resfriamento da matéria-prima em câmara fria a 12 ºC, durante 4 horas, foi o tempo mínimo necessário para reduzir a temperatura da matéria-prima. Após o tratamento térmico da solução de sacarose, foi necessário resfriá-la a 5 ºC, por no mínimo 6 horas. As rodelas da banana conservadas em solução de sacarose com polpa de maracujá se apresentaram metabolicamente ativas durante 8 dias de conservação a 5 ºC. As rodelas de banana tiveram sinais de escurecimento 2 horas após o corte, logo, recomenda-se adicionar a solução após seu corte. Verificou-se que o sistema composto de 60 gramas de rodelas de banana e 115 mL de solução de sacarose (a 15 %) com polpa de maracujá minimizou alteração do teor de sólidos solúveis totais, da firmeza, da condutividade elétrica e reduziu o extravasamento de eletrólitos das rodelas da banana durante sua conservação. A presença da polpa de maracujá na solução foi importante para minimizar o escurecimento enzimático. Além disso, esse sistema reduziu o escurecimento enzimático, aumentou a taxa respiratória e praticamente não afetou a produção de etileno das rodelas da banana durante a conservação. Observou-se redução da concentração de oxigênio dissolvido das soluções/suspensão após 2 horas de conservação nessas soluções/suspensão. A atividade da álcool desidrogenase em rodelas de banana imersas em solução de sacarose com polpa de maracujá aumentou, evidenciando que o tecido estava em processo de fermentação. O sistema em estudo resultou em manutenção da qualidade de banana minimamente processada e apresentou vida útil de 8 dias a 5 ºC.

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