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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

Pré-tratamento de uvas cv. Thompson Seedless cultivadas no Vale do São Francisco com altas concentrações de CO2

MELO NETO, Manoel Luiz de 31 January 2009 (has links)
Made available in DSpace on 2014-06-12T23:01:16Z (GMT). No. of bitstreams: 2 arquivo3862_1.pdf: 1193876 bytes, checksum: f9118d1c04aa6cd89bb1aa270bf3bd14 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Faculdade de Amparo à Ciência e Tecnologia do Estado de Pernambuco / Fungos que causam podridões pós-colheita acarretam prejuízos nas Regiões produtoras de uvas no mundo, inclusive no Vale do São Francisco, Nordeste do Brasil. Para contornar este problema as uvas destinadas ao mercado externo, são tratadas com saches de SO2 colocados dentro das embalagens, cujos efeitos na qualidade da uva são discutíveis. Uma das alternativas pesquisadas com relação a este método é a utilização de altas concentrações de CO2 em pré-tratamento que até o momento não foi aplicado à uva Thompson Seedless do Vale, justificando este estudo, que visa avaliar o emprego desta técnica na sua conservação. Assim, realizaram-se três experimentos: 1. Sintomas da podridão foram reproduzidos por meio de quatro procedimentos: disco de micélio; papel de filtro; gota; pulverização e o controle, testados em uvas Itália Melhorada e Crimson , com suspensões de Botrytis (105 e 106 conídios.mL-1) a 25 ± 1 °C/80-90% UR. 2. Uvas Thompson Seedless foram inoculadas com Aspergillus niger em quatro concentrações por gota e pulverização, em três condições ambientais (Temperatura ambiente, Ar condicionado e Frigocâmara). Os dados foram submetidos ao teste de Tukey a 5% de probabilidade. 3. Uvas Thompson Seedless foram submetidas aos tratamentos: controle sem inóculo (CSI); controle com inóculo (CCI); sache de metabissulfito; 10% CO2, 20% CO2 e 30% CO2, submetidos a 6 ± 1°C/85-95% UR por 39 dias. Os sólidos solúveis; acidez titulável; firmeza; perda de peso; compostos fenólicos totais, número de micélio por baga e análises sensoriais, foram comparados por Duncan. A atmosfera 10% CO2 conservou a qualidade das uvas
2

Effect of shading and ethephon on the anthocyanin composition of ‘Crimson seedless’ (Vitis vinifera L.)

Human, Michael Adriaan 12 1900 (has links)
Thesis (MScAgric (Viticulture and Oenology)--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: ‘Crimson Seedless’ is currently one of the most important and popular table grape cultivars produced in South Africa, and as such it is of great economic value for table grape producers. Major concerns with ‘Crimson Seedless’ is that it is prone to inadequate colouring, and with increased yields the berry size decreases. An additional difficulty is that methods used to increase berry size, further impede berry colouring. A plant growth regulator (PGR) commonly used in table grape production, to enhance colour formation, is ethephon (2-chloro-ethyl-phosphonic acid, 2-CEPA). In recent years significant research has been done on the effect of sunlight on anthocyanin production in grapes, although this has primarily been on wine grape cultivars. Currently, there is limited knowledge on the effect of sunlight on table grapes, and how this might influence their anthocyanin composition and content. The effect of ethephon on colour of grapes and other fruit have been extensively researched and well documented. However, the effect of ethephon on the anthocyanin composition of ‘Crimson Seedless’ is not well known. The current study aimed to explore the effect of sunlight (by matter of exclusion) and management practices, namely defoliation and ethephon application, on the anthocyanin profile and content of ‘Crimson Seedless’. Four different treatments were applied to two ‘Crimson Seedless’ vineyards, the first site located in Paarl, and the second in De Doorns. The treatments were: 1. Naturally exposed bunches, 2. Exposed bunches treated with ethephon, 3. Bunches kept in shade boxes, 4. Shaded bunches treated with ethephon. At the De Doorns site an additional defoliation treatment was superimposed over the above treatments. An HPLC technique was modified for the separation and detailed profiling of ‘Crimson Seedless’ anthocyanins and was used to analyse the effect of the reported treatments on the anthocyanin profile of berry skins. The predominant anthocyanin in ‘Crimson Seedless’ is peonidin-3-glucoside (Pn-gluc), and this was found to be significantly increased only by ethephon application, and was not altered by sunlight or leaf removal. The responses of the other anthocyanin types varied according to the respective treatments applied. However, a general observation was that ethephon application more consistently increased the concentration of anthocyanins in berry skins than did sunlight. Leaf removal had the least significant effect on anthocyanin concentration. / AFRIKAANSE OPSOMMIMG: ‘Crimson Seedless’ is tans een van die belangrikste en gewildste tafeldruif cultivars wat in Suid-Afrika verbou word en daarom is dit van groot ekonomiese waarde vir tafeldruifprodusente. ‘Crimson Seedless’ is egter daarvoor bekend dat dit te swak kleur (volgens uitvoer spesifikasies) en tweedens is die cultivar geneig om kleiner korrels te ontwikkel wanneer die oeslading vermeerder word. ‘n Addisionele probleem is dat die praktyke wat in die industrie gebruik word om korrels te vergroot ‘n verdere negatiewe impak op ‘Crimson Seedless’ se kleur ontwikkeling kan veroorsaak. Die plant-groei-reguleerder wat algemeen in tafeldruif verbouing gebruik word, ten einde beter gekleurde druiwe te produseer, is ethephon (2-chloro-ethyl-phosphonic acid, 2-CEPA). In die laaste paar jaar was daar baie navorsing gedoen oor die effek wat sonlig het op die antosianien produksie van druiwe, maar navorsing was gefokus op wyndruif cultivars. Huidiglik is daar beperkte tegniese kennis oor die effek wat sonlig op tafeldruiwe het, en hoe dit moontlik die antosianien samestelling en inhoud kan beïnvloed. Daar is ook reeds verskeie studies gedoen en data gepubliseer oor die invloed wat ethephon op die kleur het van druiwe en ander vrugte, maar die invloed wat ethephon op die antosianien samestelling van ‘Crimson Seedless’ het, is nie wel bekend nie. Die doel van hierdie studie was om die effek van sonlig (deur uitsluiting) en bestuurspraktyke (blaarverwydering en ethephon toediening) te bestudeer en hoe dit die antosianien samestelling van ‘Crimson Seedless’ beïnvloed. Vier verskillende behandelings is toegedien in twee ‘Crimson Seedless’ wingerde, die eerste proefperseel in die Paarl en die tweede proefperseel in De Doorns. Die behandelings was: 1. Natuurlik blootgestelde trosse, 2. blootgestelde trosse met ethephon, 3. Trosse met skadubokse omhul, 4. Skaduboks trosse met ethephon. By De Doorns is ‘n addisionele blaarverwydering proef bygebring. ‘n HPLC tegniek was aangepas om die antosianien samestelling en inhoud van ‘Crimson Seedless’ te bepaal, en om die effek van die behandelings te ondersoek. Die HPLC data het getoon dat peonodien-3-glukosied (Pn-gluc) die primêre antosianien in ‘Crimson Seedless’ is met die hoogste inhoud van al die antosianiene. Pn-gluc was betekenisvol beïnvloed deur ethephon toediening, terwyl die ander behandelings geen betekenisvolle effekte daarop gehad het nie. Die effekte wat die ander antosianiene gehad het, het gevarieer volgens die behandelings wat toegedien was. ‘n Algemene observasie was dat ethephon toediening die antosianien konsentrasie in ‘Crimson Seedless’ druiwe skille meer konsekwent vermeerder het as die sonlig blootstelling. Die blaarverwydering het die minste betekenisvolle effek op die antosianien inhoud van ‘Crimson Seedless’ gehad.
3

Otimização da desidratação osmótica de uva Crimson Seedless (Vitis vinifera L.)

PORTO, Maria Anunciada Leal 29 August 2011 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2016-07-27T11:28:24Z No. of bitstreams: 1 Maria Anunciada Leal Porto.pdf: 1114756 bytes, checksum: 0011c80ff1bdc5f6d7a48254d4913f7a (MD5) / Made available in DSpace on 2016-07-27T11:28:24Z (GMT). No. of bitstreams: 1 Maria Anunciada Leal Porto.pdf: 1114756 bytes, checksum: 0011c80ff1bdc5f6d7a48254d4913f7a (MD5) Previous issue date: 2011-08-29 / Crimson Seedless Grapes (Vitis vinifera L.) is one of the most important seedless variety, due to its attractive bunch medium, and large dark pink berries. It features excellent sensory characteristics due to its firm texture and crisp flavor that varies from sweet to neutral and uniform color. Stands out as the second most important seedless variety of the São Francisco. Osmotic dehydration is presented as a good alternative to reduce the water activity of this grape, allowing its storage for long periods and improving its stability and quality. This study aimed to relate the influences of different parameters for efficient osmotic dehydration of fruit, in order to reduce post-harvest losses as well as offer new alternatives for the producer. To optimize the osmotic dehydration preliminary test was conducted with independent variables: temperature (T) (20ºC to 40ºC), immersion time (t) (0.5 to 4.0 hours, with breaks every 30 minutes) and concentration of osmotic solution (C) (35ºBrix, 50ºBrix and 60ºBrix) was the dependent variable moisture loss (ML). Then 26-2 fractional design was used, having as independent variables: T (30ºC and 50ºC), t (1.0 and 4.0 hours), NaOH (0% and 2%), bleach (0 and 1 minute), perforated in the fruit (0 and 16 holes/cm2) and C (30ºBrix and 60ºBrix) and the dependent variables and solids ML and incorporation of solid (IS). Proceeding was conducted a factorial design 23, with independent variables: T (30ºC to 50ºC), t (1 to 4 hours) and C (40ºBrix to 50ºBrix), being constant bleaching (30 seconds) and perforated (8 holes/cm2); the dependent variables were ML, IS and DEI (Dehydration Efficiency Index). The best conditions for osmotic dehydration using DEI as a parameter was the application of bleach for 30 seconds, 8 holes/cm2, osmotic solution at 42ºBrix, immersion time of 1.6 hours and temperature of 46 ° C. The response surface models obtained were predictive of ML and IS, except for DEI. The product selected best set Page's equation (R2 = 0.995). / A uva Crimson Seedless (Vitis vinifera L.) é uma das mais importantes variedades sem sementes, devido ao seu atraente cacho médio, e grande bagas rosadas escuras. Apresenta característica sensorial excelente devido a sua textura firme e crocante, sabor que varia do doce ao neutro, e coloração uniforme. Destaca-se como a segunda variedade sem semente mais importante do Vale do São Francisco. À desidratação osmótica apresenta-se como boa alternativa para reduzir a atividade de água desta uva, permitindo o seu armazenamento por períodos longos e melhorando a sua estabilidade e qualidade. Esta pesquisa teve como objetivo relacionar as influências de diferentes parâmetros para um eficiente processo de desidratação osmótica deste fruto, com a finalidade de reduzir as perdas pós-colheita como também oferecer novas alternativas para o produtor. Para otimizar a desidratação osmótica foi realizado ensaio preliminar com as variáveis independentes: temperatura (T) (20ºC a 40ºC), tempo de imersão (t) (0,5 a 4,0 horas, com intervalos a cada 30 minutos) e concentração da solução osmótica (C) (35ºBrix, 50ºBrix e 60ºBrix); sendo a variável dependente perda de umidade (PU). Em seguida foi aplicado planejamento fracionado 26-2, tendo como variáveis independentes: T (30ºC e 50ºC), t (1,0 e 4,0 horas), NaOH (0% e 2%), branqueamento (0 e 1 minuto), perfurações no fruto (0 e 16 perfurações/cm2) e C (30ºBrix e 60ºBrix); e as variáveis dependentes PU e incorporação de sólidos (IS). Prosseguindo foi realizado um planejamento fatorial 23, com variáveis independentes: T (30ºC a 50ºC), t (1 a 4 horas) e C (40ºBrix a 50ºBrix), sendo constante o branqueamento (30 segundos) e perfurações (8 perfurações/cm2); as variáveis dependentes foram PU, IS e IED (Índice de Eficiência de Desidratação). As melhores condições para a desidratação osmótica utilizando o IED como parâmetro foi a aplicação de branqueamento por 30 segundos, 8 perfurações/cm2, solução osmótica com 42ºBrix, tempo de imersão de 1,6 horas e temperatura de 46ºC. Os modelos de superfície de resposta obtidos foram preditivos para PU e IS, exceto para o IED. O produto selecionado ajustou melhor a equação de Page (R2 = 0,995).
4

Caracterização da maturidade, compostos bioativos e qualidade sensorial de uvas apirênicas no vale do submédio São Francisco / Characterization of maturity, bioactive compounds, and sensorial quality of seedless grapes in the Sub-Middle São Francisco River Valley.

Mascarenhas, Robson de Jesus 06 November 2009 (has links)
Made available in DSpace on 2015-04-17T14:49:32Z (GMT). No. of bitstreams: 1 parte1.pdf: 3805618 bytes, checksum: c5283752b1a8775c6dd8cef062f7c370 (MD5) Previous issue date: 2009-11-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The objective of this research was to evaluate the physical, physical-chemical, bioactive, and sensorial attributes of the first Brazilian seedless grapes (Vitis vinifera L.) varieties 'BRS Clara', 'BRS Linda', 'BRS Morena', and Advanced Selection 8, compared with the North American 'Crimson Seedless'. Three experiments had been carried out. For the first one, taking into account the Normative Brazilian/2002 and the requirements for exportations, it was determined that Advanced Selection 8 develops large cluster, inserted in class 2, with dark reddish berry, caliber 20, and ellipsoid format; 'BRS Morena' presents cluster of medium size, in class 2, with berry colored of black nuance, caliber 20, and format between ellipsoid and globoid; 'BRS Linda' with large cluster, in class 2, light-green color, and 'Crimson Seedless' with pink colored and small cluster inserted in class 1, offer berries in caliber 18 with ellipsoid formats; 'BRS Clara' develops medium size cluster in class 2, berry with caliber, green yellowish green color and a format elongated ellipsoid. All of these grapes meet the standards for national market that demands a minimum of 12 millimeters of diameter. On the other hand, 'BRS Clara' does not meet the minimum diameter demanded for exportations. The red grapes ' BRS Morena' e 'Crimson Seedless' develop the firmest berries. The hydrogenionic potential, titratable acidity and soluble solids content meet the official standard values. The largest clusters are significantly less acid and present higher soluble solid/titratable acidity ratio, inferring to be the sweetest when mature. For the second experiment, it was determined and correlated the content of acid Lascorbic, total phenolic composites, trans-resveratrol, and the total antioxidative capacity of the studied grapes. All grape samples presented low acid L-ascorbic contents. The white 'BRS Clara' presents marked content of total phenolic compounds, followed by the white 'BRS Linda', in third position are the red ones: Advanced Selection 8, 'BRS Morena', and 'Crimson Seedless'. 5 Grapes presented distinct contents of trans-resveratrol in this following order of superiority: 'BRS Morena', 'Crimson', Advanced Selection 8, 'BRS Linda', and 'BRS Clara'. Trans-resveratrol seems to provide varietal identity. Red grapes presented higher contents of trans-resveratrol. 'BRS Clara', ' Crimson Seedless', and 'BRS Linda', similarly, presented the highest antioxidative capacity and the color of the grape did not influence on that. The contents of total extractable phenolic compounds influenced positively on the antioxidative capacity. Grapes presenting larger contents of total extractable phenolic compounds presented lower content of transresveratrol. For the third experiment it was used the Quantitative Descriptive Sensorial Analysis, by means of selected and trained judges. On the global quality, 'BRS Morena' was superior than others grapes evaluated, while Advanced Selection 8 was in second position, and 'BRS Linda' and 'Crimson Seedless' occupied the third position, while 'BRS Clara' showed the most inferior sensorial quality. The general characteristics flavor, with large superiority, followed, in this order, by the strongest tonality, the red color, the most spherical format, the highest firmness, succulence, crispness, and sweetness contributed positively with the global quality. The bitter taste and the sensorial acidity, in this sequence of intensity, were the attributes of larger negative influence. The results for physical and physical-chemical evaluations, together, reflect significantly the sensorial perceptions. Therefore, once inserted in the official standards of identity and quality, beside the varietal characteristic flavor, producers must prefer to produce grapes of stronger tone, larger sizes, and more spherical or globular formats. / O objetivo desta pesquisa foi avaliar os atributos físicos, físico-químicos, bioativos e sensoriais das primeiras variedades de uvas (Vitis vinifera L.) sem sementes brasileiras, 'BRS Clara', 'BRS Linda' e 'BRS Morena', mais a Seleção Avançada 8, comparadas com a norte-americana 'Crimson Seedless'. Foram conduzidos três experimentos. Assim, com o primeiro considerando as Normativas brasileiras/2002 e as exigências para exportações, determinou-se que a Seleção Avançada 8 possui cacho grande na classe 2 com baga avermelhada escura, calibre 20 e formato elipsóide; A 'BRS Morena' apresenta cacho médio na classe 2, com baga colorida de nuança preta, calibre 20 e de formato elipsóide a quase globoso; a 'BRS Linda' com cacho grande, classe 2, de cor verde clara e a 'Crimson' com cacho róseo, pequeno na classe 1 oferecem bagas de calibre 18 e com formatos elipsóides; a 'BRS Clara' possui cacho médio e de classe 2, com baga de calibre 14, tom verde amarelado e de formato elipsóide alongado. Todas atendem o mercado nacional quanto aos diâmetros mínimos de 12 milímetros. A 'BRS Clara' não atende os diâmetros exigidos para exportações. As uvas tintas 'BRS Morena' e 'Crimson Seedless' dispõem das bagas mais firmes. O potencial hidrogeniônico, a acidez titulável e os teores de açúcares solúveis atendem aos padrões oficiais. Os cachos maiores são os menos ácidos e apresentam a melhor relação de sólidos solúveis/acidez titulável, inferindo serem os mais doces, quando maduros. O segundo experimento determinou e correlacionou os teores de ácido L-ascórbico, compostos fenólicos totais extraíveis, trans-resveratrol e a capacidade antioxidante total das uvas estudadas. Todas as amostras apresentaram baixos conteúdos de ácido L-ascórbico. A branca 'BRS Clara' apresenta destacado teor de compostos fenólicos totais extraíveis, seguida pela branca 'BRS Linda', em terceiro lugar encontram-se as tintas Seleção 8, 'BRS Morena' e 3 'Crimson'. As uvas apresentaram conteúdos distintos do trans-resveratrol e nessa ordem de superioridade: 'BRS Morena', 'Crimson', Seleção Avançada 8, 'BRS Linda' e 'BRS Clara'. O trans-resveratrol parece conferir identidade varietal. As tintas apresentaram maiores conteúdos de trans-resveratrol. A 'BRS Clara', 'Crimson' e 'BRS Linda', igualmente, apresentaram a maior capacidade antioxidante. A cor não interferiu na capacidade antioxidante. Os compostos fenólicos totais influenciaram positivamente na capacidade antioxidante. Uvas com maiores quantidades de compostos fenólicos totais extraíveis, apresentam menores teores de transresveratrol. No terceiro experimento utilizou-se a Análise Sensorial Descritiva Quantitativa, mediante julgadores selecionados e treinados. Quanto à qualidade global, a 'BRS Morena' apresentou-se superior, a Seleção Avançada 8 destacou-se em segundo lugar, enquanto, a 'BRS Linda' e 'Crimson Seedless' ocuparam o terceiro lugar e a BRS Clara' foi de qualidade inferior, sensorialmente. O sabor geral característico, com ampla superioridade, seguido na ordem, pela tonalidade mais forte, a cor tinta, o formato mais esférico, a maior firmeza, suculência, crocância e doçura contribuíram positivamente com a qualidade global. O amargor e a acidez sensorial, nesta seqüência de intensidade, foram os atributos de maior influência negativa. Os resultados das avaliações físicas e físico-químicas, em conjunto, refletem com significância as percepções sensoriais. Uma vez, dentro dos padrões de identidade e qualidade oficiais, além do sabor varietal característico, os produtores devem preferir produzir uvas de tons mais fortes, tamanhos maiores e de formatos mais esféricos ou globosos.

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