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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evaluación de las condiciones del proceso de secado en túneles de polietileno para frutos de ciruelo europeo (Prunus domestica) variedad D'Agen / Condition evaluation of the drying process in polyethylene tunnels for D'agen prunes (Prunus domestica)

Morales Ramírez, Raúl Horacio January 2011 (has links)
Memoria para optar al título profesional de: Ingeniero Agrónomo Mención: Agroindustria y enología / Se evaluó la evolución del proceso de secado de ciruelas mediante la utilización de túneles de secado de polietileno. Los objetivos del estudio fueron determinar la pérdida de peso de la fruta dentro del túnel; estudiar la temperatura y humedad dentro de éste; y evaluar la calidad de la fruta luego del proceso de secado. El primer objetivo se planteó para validar una cartilla de humedad conseguida en estudios anteriores, en la que se relaciona los sólidos solubles y el calibre de la fruta con el peso esperado de la fruta a 20 % de humedad, que es el porcentaje de humedad objetivo en el secado. Para el segundo objetivo se midió la temperatura y humedad dentro de los túneles, para analizar cómo se comportaba el túnel en su interior y así poder segmentar el túnel y ver en que posiciones a lo largo de éste el secado era más eficiente. Los resultados validaron la cartilla de humedad. La temperatura dentro del túnel es superior entre 8 y 15 °C a la del ambiente, mientras la humedad de la fruta se comporta de acuerdo a lo esperado, tendiendo a la disminución a medida que trascurren los días de secado. La utilización de túneles de secado de polietileno reduce el tiempo de secado en 1/3 con respecto al secado tradicional al sol, sin efecto en la calidad de la fruta. / The evolution of prune drying process in polyethylene tunnels was evaluated. The objectives were to determine daily fruit weight loss, temperature and humidity inside the tunnels and fruit quality obtained after drying. The first goal was established to validate a fruit moisture card obtained from previous studies which relates soluble solids and fruit size with the expected fruit weight when it has 20% moisture, which is the goal when drying fruit in the field. For the second goal we measured the temperature and humidity of the air inside the tunnel in order to analyze it´s behavior and with this information, to be able to see which part of the tunnel were the most efficient in the fruit drying. The results validated the fruit moisture card. Temperature inside the tunnel was 8 to 15 °C higher than the environment, fruit moisture behave as expected, tending to decrease as drying increased. The use of polythene tunnels reduces drying time in 1/3. The quality of the fruit was not affected by the use of polythene tunnels.
2

Análisis de la competitividad de Chile en la exportación de ciruela deshidratada

Rodríguez Vergara, Natalia Patricia January 2011 (has links)
Memoria para optar al título profesional de Ingeniero Agrónomo Mención Economía agraria / El ciruelo europeo es una especie cultivada hace más de dos mil años cuyas variedades producen ciruelas aptas para el desecado o deshidratado. Por las propiedades beneficiosas para la salud de los consumidores, esta fruta deshidratada presenta un incremento positivo en la demanda los últimos años. Entre los mayores productores de ciruela deshidratada se encuentran EE.UU., Chile, Francia y Argentina. El 67 % de la producción mundial se exporta y representa un negocio de USD 467 millones equivalente a un volumen de 190 mil toneladas. Chile es el segundo productor y exportador de ciruelas deshidratadas, de manera que se necesita evaluar la competitividad que el país tiene en el negocio. Para tales efectos se identificó y dimensionó el mercado actual y potencial, además de determinar cuantitativamente la competitividad de este mercado. Dicho análisis se realizó para el período comprendido entre los años 2005 y 2009, utilizando indicadores de competitividad tales como la balanza comercial relativa, transabilidad, grado de apertura exportadora, grado de penetración de las importaciones e indicador de especialización. Conjuntamente se construyó un modelo que permitiera evaluar la competitividad de los principales exportadores a través de lo que se ha denominado “matriz de inserción al mercado internacional”, y por otra parte, la “matriz de la demanda internacional” con la cual se busca determinar dónde están localizadas las oportunidades de negocios. Asimismo se elaboró un ranking para establecer los países que son más competitivos en el rubro, información que se complementó con una matriz FODA y el modelo de las cinco fuerzas competitivas de Porter. Chile, resultó ser altamente competitivo en el negocio de exportación de ciruela deshidratada, su consumo es marginal, coincidiendo con su condición de exportador neto y abastecedor propio. Además, presenta ventajas de producción primaria y arancelaria que le permiten posicionarse como un actor importante a nivel mundial. Según los resultados del ranking de competitividad los principales países competidores para Chile en la exportación de ciruelas deshidratadas son Argentina, EE.UU., Tayikistán y Serbia. Los potenciales mercados compradores de ciruelas deshidratadas para las exportaciones de Chile son EE.UU., Francia, Rusia, Alemania, Japón, Italia, Reino Unido, Brasil y México. / The European plum is a species cultivated for more than two thousand years which produce varieties suitable for dried plums or dried. For the properties beneficial to health consumers, dried plums have a positive demand in recent years. Among the largest producers of prunes are EE.UU., Chile, France and Argentina. 67% of world production is exported dried plum and represents USD 467 million equal to 190 thousand tons. Chile is the second largest producer and exporter, so we need to assess the competitiveness that the country is in the business. For such effects are identified and dimensioned the current market and potential of chilean prunes, as well as quantitatively determine the competitiveness of this market. The analysis was conducted for the period between 2005 and 2009, indicators of competitiveness such as trade balance relative, transacion index, export openness, degree of import penetration indicator and specialization. Jointly built a model that allowed assess the competitiveness of the leading exporters through what has been called "matrix of international market integration." in addition, they built the "matrix of international demand" to determine where are located the business opportunities. Beside that a list was made to establish which countries are most competitive in the area, information was complemented by a SWOT matrix and the model of Porter's five competitive forces, allowing a comprehensive study of competitiveness. Chile, proved to be highly competitive in the export business prunes, its consumption is marginal, coinciding with its status as a net exporter and supplier of its own. It presents primary production and taxes advantages that allow position it as a major player worldwide. According to the results of the main competitiveness ranking for Chile competitor countries in the export of dried plums are Argentina, EE.UU., Tajikistan, and Serbia. Potential buyers of prunes markets for export from Chile are EE.UU., France, Russia, Germany, Japan, Italy, UK, Brazil and Mexico.
3

Eficácia de revestimentos de goma arábica incorporados com óleo essencial de Origanum vulgare L. e Rosmarinus officinalis L. no controle da podridão mole em ameixas

Andrade, Sonalle Carolina Albuquerque de 03 March 2016 (has links)
Submitted by Maike Costa (maiksebas@gmail.com) on 2017-02-03T13:57:27Z No. of bitstreams: 1 arquivo total.pdf: 1734629 bytes, checksum: 2485fd4f3e9a230cdc84add290e3ede2 (MD5) / Made available in DSpace on 2017-02-03T13:57:27Z (GMT). No. of bitstreams: 1 arquivo total.pdf: 1734629 bytes, checksum: 2485fd4f3e9a230cdc84add290e3ede2 (MD5) Previous issue date: 2016-03-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this study, the efficacy of coatings comprising gum arabic (GA) and the essential oil from Origanum vulgare L. (OVEO) alone or in combination and Rosmarinus officinalis L. (ROEO) as a postharvest treatment to control Rhizopus soft rot on plums during storage at room temperature (25 °C for 8 days) and cold temperature (12 °C for 21 days) was evaluated. The effects of these coatings on some physicochemical and sensory characteristics of the fruit were also assessed. The minimum inhibitory concentrations (MIC) of OVEO and ROEO were 0.25 μL/mL and 1 μL/mL, respectively. The Fractional Inhibitory Concentration Index of the combined EOs (≤ 0.25) against Rhizopus stolonifer indicated a synergic interaction. The incorporation of a combination of GA and OVEO at 0.25 μL/mL or of GA and OVEO at 0.06 μL/mL plus ROEO at 0.25 μL/mL in the growth media strongly inhibited the mycelial growth, spore germination and sporulation of R. stolonifer. Both the combination of GA + OVEO and GA + OVEO + ROEO delayed the occurrence of soft rot in artificially contaminated plums and decreased the number of infected fruits at the end of storage at room and cold temperatures. GA-OVEO or GA-OVEO-ROEO coatings preserved the postharvest physicochemical quality aspects and enhanced the sensory parameters color and flavor of plums. However, the GA-OVEO coating negatively affected the aftertaste of fruit. Fruit coated with GA-OVEO and GA-OVEO-ROEO exhibited greater amounts of xylose, malic and ellagic acid and rutin at the assessed storage period. These results indicate the coatings comprising GA and OVEO alone or in combination with ROEO as promising postharvest treatments to prevent the Rhizopus soft-rot and preserve the postharvest quality in plums. / Este estudo avaliou a eficácia de revestimentos de goma arábica (GA) e óleo essencial de Origanum vulgare L. (OEOV) sozinho ou em combinação com o óleo essencial de Rosmarinus officinalis L. (OERO) como tratamento pós-colheita para controlar a podridão mole causada pelo fungo Rhizopus stolonifer em ameixas durante o armazenamento à temperatura ambiente (25 °C durante 8 dias) e temperatura refrigerada (12 °C durante 21 dias). Os efeitos dos revestimentos nas características físico-químicas e organolépticas dos frutos também foram avaliados. As concentrações inibitórias mínimas (CIM) do OEOV e do OERO foram 0,25 μL/mL e 1 μL/ mL, respectivamente. O Índice de Concentração Inibitória Fracionada dos óleos essenciais (EOs) combinados foi ≤ 0,25 contra Rhizopus stolonifer indicando interação sinérgica. A incorporação da combinação de GA (1 mg/mL) e OEOV (0,25 μL / mL) ou de GA (1 mg/mL) e OEOV (0,06 μL / mL) + OERO (0,25 μL / mL) inibiu fortemente o crescimento micelial, a germinação de esporos e a esporulação de R. stolonifer. As combinações de GA + OEOV (GA-OEOV) e GA + OEOV + OERO (GA-OEOV-OERO) retardaram a ocorrência de podridão mole em ameixas artificialmente contaminadas e reduziram o número de frutos infectados no final do armazenamento na temperatura ambiente e refrigerada. Os revestimentos GA-OEOV ou GA-OEOV-OERO preservaram os aspectos de qualidade físico-químicas pós-colheita e reforçaram os parâmetros sensoriais cor e aroma das ameixas. No entanto, o revestimento GA-OEOV afetou negativamente o atributo sabor residual. Frutos revestidos com GA-OEOV e GA-OEOV-OERO exibiram maiores quantidades de xilose, ácido málico, elágico e rutina nos períodos de armazenamento avaliados em comparação com aqueles não-revestidos. Esses resultados indicam que revestimentos de GA e OEOV sozinho ou em combinação com OERO são tratamentos promissores para a prevenção da podridão mole e manutenção da qualidade pós-colheita de ameixas.
4

Procédé novateur d'extraction de jus de fruits par micro-onde : viabilité de fabrication et qualité nutritionnelle des jus / Extraction of fruit juices by microwave hydrodiffusion : tests and nutritional juice quality

Cendres, Aurélie 29 September 2010 (has links)
Le procédé innovant d’hydrodiffusion par micro-onde a été testé et validé pour la fabrication de jus de fruit sur des raisins, abricots et prunes. Ce procédé présente des avantages au niveau technique : rapidité d’extraction, pas de préparation de l’échantillon, aucun auxiliaire de fabrication. Il permet l’obtention de jus à partir de fruits difficiles à presser, avec une pasteurisation « in line » et des produits se différenciant nettement des jus commerciaux par leur couleur et texture.Le jus est expulsé du fruit sous l’effet de la vapeur produite in situ. A partir du fruit congelé, la déstructuration liée à la croissance des cristaux de glace facilite l’extraction. Les rendements le plus élevés sont obtenus à partir de fruits congelés, et à basse puissance. Une partie de l’eau des fruits est convertie en vapeur, mais peut être récupérée en utilisant un réfrigérant, ce qui permet d’atteindre des rendements proches des rendements de jus obtenus avec un prétraitement enzymatique et pressurage. Globalement, le jus a une composition proche de celle du jus présent dans le fruit ou obtenus par pressurage. La composition du jus expulsé des fruits change au cours de l’extraction. La concentration des composés présents dans la chair et hydrosolubles (sucres, acides, acides phénoliques) baisse nettement en fin d’extraction, tandis que les anthocyanes, présentes dans l’épiderme des raisins ou des prunes, montrent un pic de concentration lors de la phase d’expulsion rapide des jus. La teneur en procyanidines est nettement plus élevée que pour des jus obtenus par pressurage / The hydrodiffusion process was tested and validated for production of juices from grapes, apricots and plums. Its major advantages are speed, no sample preparation, no processing aid. It allows production of juices from hard-to-press fruits with an in line pasteurisation. The juices present original characteristics notable bright colours, texture, and a fresh fruit aroma.The juice is expulsed from the fruit by the pressure due to in situ vapour generation. The destructuration occuring in frozen fruits due to growth of ice crystals facilitate the juice expulsion. The highest yields are obtained from frozen fruits and at low power densities. Part of the water from the fruits is vaporised, and can be collected by use of a cooler, allowing to reach yields comparable to those obtained by pressing after an enzymatic pre-treatment. Juice composition is close to that of juice extracted by pressing, though with slightly lower concentrations of most soluble solids. The composition of juice changes along the extraction. The highly soluble compounds present in the fruit flesh mostly show a clear exhaustion at the end ofextraction. Anthocyans, present exclusively in the peel of the test fruits, present a maximum during the fast juice extraction phase. Procyanidin concentrations is much higher in juices obtained by hydrodiffusion than in conventional juices
5

Procédé novateur d'extraction de jus de fruits par micro-onde : viabilité de fabrication et qualité nutritionnelle des jus

Cendres, Aurélie 29 September 2010 (has links) (PDF)
Le procédé innovant d'hydrodiffusion par micro-onde a été testé et validé pour la fabrication de jus de fruit sur des raisins, abricots et prunes. Ce procédé présente des avantages au niveau technique : rapidité d'extraction, pas de préparation de l'échantillon, aucun auxiliaire de fabrication. Il permet l'obtention de jus à partir de fruits difficiles à presser, avec une pasteurisation " in line " et des produits se différenciant nettement des jus commerciaux par leur couleur et texture.Le jus est expulsé du fruit sous l'effet de la vapeur produite in situ. A partir du fruit congelé, la déstructuration liée à la croissance des cristaux de glace facilite l'extraction. Les rendements le plus élevés sont obtenus à partir de fruits congelés, et à basse puissance. Une partie de l'eau des fruits est convertie en vapeur, mais peut être récupérée en utilisant un réfrigérant, ce qui permet d'atteindre des rendements proches des rendements de jus obtenus avec un prétraitement enzymatique et pressurage. Globalement, le jus a une composition proche de celle du jus présent dans le fruit ou obtenus par pressurage. La composition du jus expulsé des fruits change au cours de l'extraction. La concentration des composés présents dans la chair et hydrosolubles (sucres, acides, acides phénoliques) baisse nettement en fin d'extraction, tandis que les anthocyanes, présentes dans l'épiderme des raisins ou des prunes, montrent un pic de concentration lors de la phase d'expulsion rapide des jus. La teneur en procyanidines est nettement plus élevée que pour des jus obtenus par pressurage

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