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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.
121

Conservação refrigerada de abacate 'Hass' e 'Fuerte' submetidos à atmosferas modificadas ativas /

Russo, Viviane Citadini, 1983- January 2012 (has links)
Orientador: Rogério Lopes Vieites / Banca: Erica Regina Daiuto Bastos / Banca: Sergio Marques Costa / Resumo: O presente trabalho teve como objetivo avaliar a conservação refrigerada de frutos de abacates 'Hass' e 'Fuerte' submetidos à aplicação de atmosfera modificada ativa. Os frutos foram selecionados visando à homogeneização do lote quanto à ausência de injúrias e lavados com água e detergente no intuito de remover resíduos da colheita e microrganismos aderidos à superfície. A higienização dos abacates foi realizada com uma solução de hipoclorito de sódio a 1%, por aproximadamente 20 minutos antes da montagem do experimento. Os frutos das duas variedades foram acondicionados em embalagem de nylon+polietileno e submetidos a injeção de mistura de gases constituindo os tratamentos: I - mistura gasosa do ambiente (0,03% de CO2 e 21,0% de O2); II - 5,0% de CO2 e 4,0% de O2; III - 6,0% de CO2 e 4,0% de O2; IV - 7,0% de CO2 e 4,0% de O2 e V - 8,0% de CO2 e 4,0% de O2. Os frutos foram armazenados em câmara frigorífica a uma temperatura de 10ºC±1 e umidade relativa de 90±5% e avaliados durante 25 dias, sendo as análises realizadas a cada 5 dias. As análises realizadas foram perda de massa, atividade respiratória, potencial hidrogeniônico (pH), firmeza, acidez titulável (AT), sólidos solúveis (SS) e atividade das enzimas Pectinametilesterase (PME) e Poligalacturonase (PG). Os resultados foram submetidos à análise de variância e as médias foram comparadas pelo teste Scott-Knott ao nível de 1 ou 5% de probabilidade, conforme a característica avaliada. Nas condições em que os experimentos foram realizados, pode-se concluir que as concentrações de 5,0% e 8,0% de CO2 apresentaram os melhores resultados pós colheita dos abacates 'Hass' e 'Fuerte' frigorificado / Abstract: This study aimed to evaluate the cold storage of fruit avocado 'Hass' and 'Fuerte' submitted to the application of active modified atmosphere. The fruits were selected aiming at the homogenization lot about the lack of injuries and washed with water and detergent in order to remove crop residues and microorganisms adhered to the surface. The cleaning of the avocados was performed with a solution of sodium hypochlorite 1% for about 20 minutes before assembling the experiment. The two varieties of fruits were packed in polyethylene + nylon and injected with mixture of gases constituting the treatments: I - the environment gas mixture (0,03% de CO2 e 21,0% de O2); II - 5,0% CO2 and 4,0% O2; III - 6,0% CO2 and 4,0% O2; IV - 7,0% CO2 and 4,0% O2 and V - 8,0% CO2 and 4,0% O2. The fruits were stored in cold chamber at a temperature of 10±1°C and relative humidity of 90±5% and evaluated for 25 days, with analyses performed every 5 days. The analyses were weight loss, respiratory activity, hydrogen potential (pH), firmness, titratable acidity (TA), soluble solids (SS), and activity of Pectinmethylesterase (SMEs) and Polygalacturonase (PG). The results were subjected to analysis of variance and the means are compared by the Scott-Knott test at 1 or 5 % probability, according to the trait. Under conditions in which the experiments were performed, one can conclude that concentrations of 5,0% and 8,0% CO2 yielded better post-harvest avocados 'Hass' and 'Fuerte' refrigerated / Mestre
122

Avaliação da dieta enriquecida com Persea americana Mill. na inflamação intestinal induzida por TNBS em ratos

Oliveira, Ellen Cristina Souza January 2016 (has links)
Orientador: Aline Witaicenis Fantinati / Resumo: A Doença Inflamatória Intestinal (DII) engloba duas principais doenças: a Doença de Crohn e a Retocolite Ulcerativa. Esta doença é multifatorial com etiologia complexa e não totalmente elucidada. Considerando-se que não existe cura e que os fármacos utilizados podem apresentar sérios efeitos colaterais, além de muitos pacientes não responderem aos tratamentos disponíveis; estudos voltados para o desenvolvimento de novas estratégias de tratamento são importantes. Estudos têm evidenciado que a associação entre fármacos e alimentos funcionais, pode resultar em uma relação de muito sucesso no tratamento de pacientes com doenças crônicas, sobretudo nas doenças que afetam o trato gastrointestinal. Assim, o uso de alimentos funcionais, especialmente, os ricos em fibras, compostos antioxidantes e lipídeos bioativos podem ser potenciais na prevenção ou tratamento da DII. Com base nisto, a espécie Persea americana Mill., conhecida popularmente como abacate ou avocado, foi selecionada para o presente estudo, pois além de possuir estes compostos, apresenta descrita atividade antioxidante, anti-cancerígena, anti-bacteriana, anti-inflamatória e cicatrizantes. Diante disso, o presente estudo teve como objetivo avaliar a atividade da dieta enriquecida com a polpa de Persea americana Mill. var. Hass no modelo experimental de inflamação intestinal induzida por TNBS em ratos. Para tanto, a polpa da espécie foi incorporada na dieta de ratos Wistar machos, nas concentrações de 5%, 10% ou 20%, por... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Inflammatory Bowel Disease (IBD) comprises two major diseases: Crohn Disease and Ulcerative Colitis. This disease is multifactorial with complex and not fully elucidated etiology. Considering that there is no cure and the drugs may cause serious side effects, and many patients do not respond to the available treatments; therefore researches focused on the development of new treatment strategies are important. Studies have evidenced that the association between drugs and functional foods can result in a very successful relationship forward treating patients with chronic diseases, mainly diseases that affect the gastrointestinal tract. Thus, the use of functional foods, especially ones rich in fibers, antioxidants and bioactive lipids could be potential candidates to the prevention or treatment of IBD. Based on this, Persea americana Mill., popularly known as avocado, was selected for this study, due to the presence of mentioned compounds and also for the antioxidant, anti-cancer, anti-bacterial, anti-inflammatory and cicatrizing activities. Therefore the present study aimed to evaluate the activity of enriched diet with Persea americana Mill. var. Hass pulp in the experimental model of intestinal inflammation induced by TNBS in rats. For this, the fruit pulp was incorporated in the diet of male Wistar rats, in concentrations of 5%, 10% or 20% for 21 days before and 7 days after of induction of intestinal inflammation by TNBS and the animals were killed on the 29º day. Addition... (Complete abstract click electronic access below) / Mestre
123

Efecto de la atmosfera controlada y manejo de temperatura en la calidad de palta Hass

Quezada T., Diana January 2005 (has links)
No description available.
124

Screening of avocado rootstock material for tolerance to Phytophthora cinnamomi

Bijzet, Zelda 07 October 2005 (has links)
During the initiation and execution of a rootstock breeding programme to overcome the financially crippling disease, Phytophthora root rot of avocado, various constraints have been identified for both the breeding as well as the screening aspect of the programme. A review of the literature revealed a complex host-pathogen interaction that should be taken into account in the recombination and screening of genetic material. With the detection of beneficial genotypes being the crux of a breeding programme, this dissertation was focused on the screening of rootstock material for tolerance to Phytophthora cinnamomi. Screening should be scientific but at the same time also be time and cost effective. Specific attention was given to (i) the correct medium for screening mass numbers of seedlings, (ii) fast and effective cloning of single selections, and (iii) evaluation of clonal material for tolerance to P. cinnamomi. Soil as a screening medium was compared with three inert hydroponic media as well as one aeroponic system. Only soil was found to be ineffective due to its properties. The other media tested, namely, sand, vermiculite, water and the aeroponic system were equal in performance. The medium to be used will depend on the preference of the breeder as each medium has its own pro's and con's. It was, however, found that the evaluation criterion to be applied depends on the medium that is used. With regard to cloning of single selections, a definite difference with regard to the cloning ability of the different selections was found. An inability to be etiolated was displayed by some of the selections and these could thus not be vegetatively propagated and were not further tested. One of the tolerance mechanisms in the standard cultivar Duke 7, is root regeneration. It was thus expected that this characteristic cloning would give an indication of the rootstock's ability to tolerate P. cinnamomi. This could not be confirmed, but most of the selections did, however, perform better than Duke 7. Comparison of feeder root percentage in non-inoculated and inoculated treatments was not sufficient for facilitating the final selection of candidate rootstocks from a large number of potential clonal selections. Four selections were made, based on the hypothesis that a larger root system will be a better forager and thus enhance the horticultural aspects of the rootstock-scion combination. Valuable information was obtained with regard to various mediums and criteria to be used during mass screening and final screening of clonal selections. This knowledge must be taken into account in the planning of future breeding projects. During this project a total of 38 984 seedlings were screened and four selections were made. For both the nursery and the producer, knowledge of the clonal ability of a potential new rootstock is important from a financial point of view. / Dissertation (MSc (Horticultural Science))--University of Pretoria, 2006. / Plant Production and Soil Science / unrestricted
125

Is Avocado Toast the Reason I'm Still Living with My Parents?

MacDonald, Brendan 01 January 2018 (has links)
Is avocado toast the reason that I am still living with my parents? In other words, does the consumption of avocado toast, or more specifically eating out in general, have any impact on one’s ability to be a homeowner. In May of 2017, an Australian real estate developer by the name of Tim Gurner was asked to provide advice to young people who could not afford to purchase a home. He responded by saying, “when I was trying to buy my first home, I wasn’t buying smashed avocado for $19 and four coffees at $4 each,” (Victor, 2017). While the claim may appear to be laughable at first glance, this is not the first time that statements such as this have been made. The United States Census Bureau tells us that annual homeownership rates for individuals under the age of 35 has been on the steady decline. Additionally, per Goldman Sachs, it is known that the percentage of adults age 18-31 that were married and living in their own homes has decreased from 56% in 1968 to 23% in 2012. This paper assesses and compares the spending habits of different generations, working to discern if there are notable differences particularly between Millennials and other generations. Data sets from the Consumer Expenditure Survey (CEX) and Zillow between the years 2000-2013 were examined. Although there is not data on avocado toast specifically, it is possible to broaden the hypothesis to examine the expenditures on the consumption of meals prepared away from home. For the purpose of this study, I take Tim Gurner’s statement and apply it more broadly to the idea of spending money on the experience of eating out. The results show that the consumption of avocado toast, defined as money spent on meals prepared away from home, does not have an impact on whether an individual owns a home, nor is it an indicator as to whether they will be renters or living with their parents. Rather, the results indicate that owning a home leads to consuming more avocado toast. This means that although it is commonly perceived that Millennials are consumers as opposed to savers, their inability to afford home ownership does not have any direct connection to their spending habits on avocado toast, and more broadly, eating out in general.
126

Estudio prefactibilidad para la instalación de una planta de procesamiento de aceite de palta extra virgen para consumo nacional

Cabrera-Gonzales, David-Alejandro, Lombardi-Benavides, José-Ignacio January 2017 (has links)
El aceite de palta extra virgen es un producto atractivo para el mercado ya que posee un sabor exótico y especial, además de sus particulares características que lo hacen muy beneficioso para la salud. El objetivo general propuesto es realizar el análisis del potencial mercado, así como determinar la viabilidad económica y técnica para la producción y venta de aceite de palta extra virgen para el consumo nacional, como una forma de añadir valor agregado a la palta, ofreciendo una alternativa para pequeños y medianos productores de palta en el país. La propuesta como producto, comprende: extraer, procesar y ofrecer un aceite con fines culinarios el cual esté orientado a segmentos de consumidores que buscan estilos de vida saludables. En la construcción del posicionamiento se busca resaltar los múltiples beneficios funcionales del producto y una atractiva presentación. Se añade, además, su contribución social al ofrecer a los pequeños y medianos agricultores una alternativa que ofrezca mejores condiciones y oportunidades para sus productos, mejora de los estándares e incremento de su producción. / Trabajo de investigación
127

Die invloed van kalsiumtoedienings op polifenoloksidase, peroksidase, sekere fenoliese verbindings en aspekte van die ultrastruktuur van avokadovrugte

Van Der Merwe, Pierre Johan 11 February 2014 (has links)
M.Sc. / Please refer to full text to view abstract
128

O óleo de abacate (Persea americana Mill) como matéria-prima para a indústria alimentícia / The avocado oil (Persea americana Mill) as raw material for food industry

Flávia Danieli 01 September 2006 (has links)
Hábitos de vida saudáveis e uma dieta balanceada aliados ao alto consumo de frutas e vegetais, estão associados a redução do risco de doenças e à manutenção da saúde. O óleo de abacate possui em sua composição substâncias bioativas capazes de prevenir e controlar as dislipidemias. Como existem poucas pesquisas científicas avaliando o potencial deste óleo para consumo humano, o presente trabalho estudou os processos de extração e refino do óleo de abacate, bem como suas propriedades funcionais. Os resultados mostraram que os processos de extração e refino do óleo a partir da variedade Margarida são tecnicamente viáveis, o que o torna excelente matéria-prima para a indústria alimentícia. Além disso, possui um perfil de ácidos graxos muito semelhantes ao azeite de oliva, predominando em ambos o ácido oléico, que em conjunto com os esteróis vegetais e a vitamina E presentes, é capaz de influenciar positivamente o controle metabólico do colesterol, prevenindo ou retardando as doenças cardiovasculares. / Healthy life habits and an equilibrate diet, associated with a high fruit and vegetable intake, are joined with the prevention of diseases and health maintenance. The avocado oil has in these composition bioactives substances that can help in the prevention and control of hyperlipidemia. As there are a few scientific researches evaluating the oil potential for human consumption, the present proposal studied the extraction and refining process of avocado oil and its functional properties. The results have been showed that extraction and refining process of Margarida's variety are technically possible, became it an excellent raw material for food industry. Besides, the fatty acid composition of avocado oil are similar to olive oil, predominating in both, the oleic acid, that together of sterols and vitamin E presents, can to influence to metabolic control of cholesterol, preventing or delaying the cardiovascular disease.
129

Antimicrobial, anticancer and catalytic activities of green synthesized Avocado seed extract-gold nanoparticles

Ngungeni, Yonela January 2019 (has links)
>Magister Scientiae - MSc / Nature through billions of years of trial and error has produced an immeasurable amount of natural systems like plants, birds and animals. The intelligence of nature is hidden in these natural systems and researchers are turning towards “Nature’s intelligence” to find inspiration and advance novelty in the development of nanomaterials. Gold nanoparticles (AuNPs) have unique optical, electronic and physicochemical features which has gained them popularity and widespread exploitation in various applications. The conventional methods used for AuNPs synthesis employs toxic chemicals which makes these NPs unsafe for biomedical applications. Hence, there is a search for new, ‘green’ and more cost effective methods for AuNPs synthesis. Plant extracts are regarded as a highly desirable system for nanoparticle synthesis due to their tremendous capability to produce a wide range of phytochemicals that can act as reducing agents. The main goal of this study was to synthesize AuNPs in a cost effective manner without the use of toxic chemicals in the synthesis process. Avocado seeds which are an agricultural waste by-product were used for the biosynthesis of AuNPs. The study reports on the synthesis optimization, characterization and activities of the biogenic AuNPs. The avocado seed extract mediated - AuNPs (AvoSE-AuNPs) were optimized by varying reaction parameters and characterized by UV-visible, Dynamic Light Scattering (DLS) and High Resolution Transmission Electron Microscopy (HRTEM), Zetasizer and Fourier Transform Infrared Spectroscopy (FTIR). The formation of AvoSE-AuNPs had an absorption maximum at 534 nm. HRTEM and DLS confirmed that the NPs were polydispersed and present in different shapes. The presence of phytochemical constituents on the AvoSE-AuNPs were confirmed by FTIR. Their potential antibacterial activity was tested on bacterial strains known to exhibit resistance to a number of current antibiotics. The catalytic activity of AvoSE-AuNPs was also assessed as a means to contribute to the development of new methods aimed at alleviating organic pollutants such as nitrophenols in the environment. The AvoSE-AuNPs demonstrated excellent catalytic activity in the reduction of 4-NP by NaBH4 as shown by the rapid decrease in the nitrophenolate absorption band at 400 nm and the appearance of new absorption band at 298 nm, revealing the formation of the 4-aminophenol. Furthermore, the rate constants calculated demonstrated that the reaction occurs faster in the presence AvoSEAuNPs. The AvoSE-AuNPs showed low significant cytotoxicity. Cell cycle analysis was conducted to further investigate the apparent exhibited toxicity of the AvoSE-AuNPs. The results showed that in both cell lines treated with AvoSE-AuNPs and AvoSE there was a ii | P a g e disruption in the regulation of cell cycle. Cell cycle analysis helped improve understanding of the low cytotoxicity observed by the MTT assay results. The results presented in this study clearly demonstrate the feasibility of using AvoSE for the synthesis of AuNPs. This study demonstrated that AvoSE mediated AuNPs synthesis is a greener alternative as it abides by the green chemistry principles. Furthermore, the study outcomes contributed to minimizing environmental pollution by finding use for agricultural waste and thus ultimately adding value to the field.
130

Desarrollo de un sistema automático de selección de paltas Hass por sus índices de calidad para la empresa Agroindustrias Verdeflor S.A.C. / Development of an automatic sorter system for Hass avocados based on its quality indexes for the company Agroindustrias Verdeflor S.A.C.

Bermeo Vargas, Elias Israel, Zorrilla Pascual, Dario Antonio 26 November 2019 (has links)
El presente proyecto de investigación propone el desarrollo e implementación de un sistema automático de selección para paltas tipo Hass, mediante sus diferentes índices de calidad (rozamiento, quemaduras y manchas negras). El sistema integra hardware y software para mejorar la calidad de exportación y la productividad en la industria agrícola. Este proyecto es la propuesta de solución a la problemática actual de las empresas exportadoras de paltas en la etapa de selección. La palta, también conocido como aguacate o avocado, en su variedad Hass, es la más conocida y se cultiva exclusivamente para la exportación, por tal motivo es necesario un control de calidad óptimo; sin embargo, actualmente este proceso es ineficiente al ser artesanal. Con el fin de mejorar este proceso, se propone su automatización, el cual consiste en diversas etapas mecánicas, diseñadas para realizar el movimiento de las paltas y un algoritmo de procesamiento de imágenes, encargado de detectar los desórdenes en los frutos. Finalmente, se muestran las pruebas de validación y los resultados del análisis empleado en la evaluación de la solución propuesta. / The following research project proposes the development and implementation of an automatic sorter system for Hass avocados, through its different quality indexes (burns, frictions and black spots). The system integrates hardware and software to improve export quality and productivity in the agricultural industry. This project is the proposed solution to the current problem avocado exporting companies are facing in the selection stage. The avocado, also known as aguacate or palta, in its Hass variety, is grown exclusively for export, which is why optimal quality control is necessary. However, this process is currently inefficient because it is a manual process. In order to improve it, an automatic method is proposed, which consists of various mechanical phases, designed to perform the movement of avocados and an image processing algorithm, responsible for detecting disorders in the fruits. Finally, the validation tests and results of the analysis used in the evaluation of the proposed solution are shown. / Tesis

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