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Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-04-05T15:52:39Z No. of bitstreams: 1 Dissertação - Milleno Dantas Mota (2012).pdf: 1199233 bytes, checksum: a649e5b9bd0f55f2c7ed56b1596245ba (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-04-15T13:30:06Z (GMT) No. of bitstreams: 1 Dissertação - Milleno Dantas Mota (2012).pdf: 1199233 bytes, checksum: a649e5b9bd0f55f2c7ed56b1596245ba (MD5) / Made available in DSpace on 2013-04-15T13:30:06Z (GMT). No. of bitstreams: 1 Dissertação - Milleno Dantas Mota (2012).pdf: 1199233 bytes, checksum: a649e5b9bd0f55f2c7ed56b1596245ba (MD5) / CAPES / O presente trabalho objetiva apresentar um novo método testado para análise de trans-resveratrol em diferentes marcas e variedades de vinhos tintos por meio de calibração multivariada, no qual foram analisados os espectros das amostras, e das amostras aditivadas com o padrão de trans-resveratrol, obtidos por espectroscopia UV-VIS, através de tratamento quimiométrico de análise de componentes principais (PCA) e calibração multivariada. Na PCA obtida com os espectros de absorção, observou-se que com apenas 4 componentes principais foi possível agrupar amostras com base nas características de variedade e/ou região de produção. Através dos loadings ficou demonstrado que os comprimentos de onda de 230 e 260 nm foram os maiores responsáveis por esse agrupamento. A partir da construção de modelos de calibração por mínimos quadrados parciais (PLS) e por regressão linear múltipla (RLM) foi possível predizer a concentração de trans-resveratrol das amostras que apresentaram semelhanças entre os grupos observados na PCA e as amostras utilizadas na construção dos modelos. O teor de trans-resveratrol predito nessas amostras variou entre 0,29 e 23,3 mg/L. A comparação do método multivariado empregado com o univariado sugere uma maior capacidade de predição das concentrações pelo primeiro, uma uma vez que apresentou valores mais próximos daqueles descritos na literatura. / Salvador

Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-03-07T14:14:24Z No. of bitstreams: 1 PGCS14MA150.pdf: 1221454 bytes, checksum: 7cfff928e9529b8dfc1feb403423ca28 (MD5) / Made available in DSpace on 2018-03-07T14:14:24Z (GMT). No. of bitstreams: 1 PGCS14MA150.pdf: 1221454 bytes, checksum: 7cfff928e9529b8dfc1feb403423ca28 (MD5) Previous issue date: 2014-12-15 / Capes / To evaluate the effects of soil and weather conditions in the grape, the objective this study was evaluate the influence of three soil classes (Pachic Humudeps, Typic Dystrudepts and Nitosol) and climatic factors (precipitation, maximum and minimum temperatures) on the quantitative and qualitative characteristics of Cabernet Sauvignon whegrapes (Vitis vinifera L). The experiment was conducted in São Joaquim, Santa Catarina in 2011/12 and 2012/13 season. In each soil 20 points were marked, where soil samples were collected for physical and chemical analysis. At each point we collected bunches for physical and chemical analysis and physical phenolic components of the grape. Data were submitted to analysis of variance (ANOVA) and the means were compared using the "t" test. The Nitosol and the Typic Dystrudepts, due to the position in the landscape and better drainage produce grapes with the most suitable composition for the preparation of wines, while the Pahic Humudeps due to higher water availability in years with higher rainfall has the composition of the grape negatively affected. Weather the 2012/13 crop, resulted in better physical characteristics of the grape and higher productivity compared to 2011/12 / Para avaliar os efeitos do solo e das condições meteorológicas na uva, este trabalho teve como objetivo determinar a influência de três classes de solos (Cambissolo Húmico, Cambissolo Háplico e Nitossolo Bruno) e os fatores climáticos (precipitação-pluviométrica, temperaturas máximas e mínimas) sobre as características quantitativas e qualitativas da uva da variedade Cabernet Sauvignon (Vitis vinifera L). O experimento foi realizado no município de São Joaquim, Santa Catarina nas safras 2011/12 e 2012/13. Em cada classe de solo, foram demarcados 20 pontos, onde foram coletadas as amostras para as análises físicas e químicas. Em cada ponto foram coletados os cachos para determinações físicas e físico-químicas da uva. Os dados foram submetidos análise de variância (ANOVA) e as médias foram comparadas pelo teste “t”. O Nitossolo Bruno e o Cambissolo Háplico, devido à posição na paisagem e melhor drenagem produzem uvas com composição mais adequada à elaboração de vinhos, enquanto que o Cambissolo Húmico, devido ao maior armazenamento e disponibilidade de água em anos com maior volume pluviométrico tem a composição da uva afetada negativamente. As condições meteorológicas da safra 2012/13 resultaram em melhores características físicas da uva e maior produtividade em relação à safra 2011/12

Vinhos espumantes, assim como os vinhos brancos, são muito susceptíveis a oxidação nas etapas de elaboração e durante o armazenamento e envelhecimento. A glutationa (GSH), antioxidante naturalmente presente nas uvas e derivados, contribui positivamente na preservação de aromas, prevenção do escurecimento e outros defeitos decorrentes do armazenamento prolongado em vinhos brancos. A molécula de GSH é muito reativa, devido a seu grupo sulfidrila. Neste sentido, uma alternativa para preservá-la e manter suas propriedades antioxidantes por um maior período durante o armazenamento dos espumantes seria a microencapsulação em um sistema polimérico. A microencapsulação também poderia evitar um aspecto negativo da utilização de GSH em vinhos, que é indução da formação de H2S (off-flavour), visto que, se a GSH for liberada lentamente poderia evitar o efeito redutor de oxigênio no vinho. Neste contexto, este trabalho teve como objetivo avaliar o efeito da adição de GSH livre em espumantes e preparar microcápsulas contendo glutationa para adição em vinhos e/ou espumantes. A GSH livre (10, 20 e 30 mg L-1) foi adicionada em diferentes etapas da elaboração (mosto, vinho base e espumante) de espumantes pelo método tradicional. Foram avaliados os efeitos da adição de GSH sobre compostos aromáticos, os compostos fenólicos relacionados ao escurecimento de vinhos brancos e as concentrações de SO2 livre. As análises dos compostos fenólicos e da glutationa total e reduzida foram realizadas por cromatografia líquida de alta eficiência e espectrofotometria UV e, as análises dos compostos aromáticos foram realizadas por cromatografia gasosa. As micropartículas contendo GSH como composto ativo foram preparadas por spray-dryer com quitosana ou β-ciclodextrina (β-CD), como polímeros e sua caracterização foi realizada por microscopia eletrônica de varredura (MEV), análise termogravimétrica (TGA), calorimetria exploratória diferencial (DSC), espectroscopia na região do infravermelho com transformada de Fourrier (FT-IR), difratometria de raios-X (DRX). Além disso, foram realizados testes para verificar a recuperação da GSH, a eficiência de encapsulação e a cinética de liberação da GSH em vinho modelo. A adição de GSH ao mosto influenciou mais na composição do espumante do que a adição ao vinho base. Entretanto, a adição de GSH ao vinho base manteve níveis elevados de SO2 na forma livre. A adição de 10 mg L-1 de GSH no mosto é suficiente para assegurar menores concentrações de ácidos cafeico, cumárico e ferrúlico nos espumantes. A adição de 20 mg L-1 de GSH no espumante junto com o liquor de expedição resultou em menor índice de cor, maiores quantidades de SO2 na forma livre, menores concentrações de acetaldeído e mesma quantidade de compostos fenólicos até 12 meses de armazenamento em garrafas. A quantidade de GSH adicionada no espumante pronto decaiu em um mês de armazenamento e estabilizou nos primeiros seis meses, porém a quantidade de glutationa total permaneceu maior no espumante com adição de 30 mg L-1, até 12 meses de armazenamento. Apesar de somente a GSH ter propriedade antioxidante, a quantidade de glutationa total teve maior correlação com os resultados obtidos e, por isso, o nível de glutationa total pode ser um melhor indicador da condição antioxidante do vinho. Foi possível encapsular glutationa tanto utilizando β-CD, quanto utilizando quitosana. A caracterização das microcápsulas comprovaram um microrrevestimento do composto ativo e uma interação entre a GSH e os polímeros utilizados. A β-CD foi mais eficiente para encapsular a GSH, permitindo a liberação gradativa da molécula em solução de vinho modelo e maior proteção da molécula, conferindo melhor estabilidade térmica para GSH. / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2017-04-20T19:33:06Z No. of bitstreams: 1 Tese Vanessa Webber.pdf: 8465675 bytes, checksum: 87ce873e4aae66fb29eeaed34242e2c4 (MD5) / Made available in DSpace on 2017-04-20T19:33:06Z (GMT). No. of bitstreams: 1 Tese Vanessa Webber.pdf: 8465675 bytes, checksum: 87ce873e4aae66fb29eeaed34242e2c4 (MD5) Previous issue date: 2017-04-20 / Sparkling wine, white wines as well, are very susceptible to oxidation in the processing stages and during storage and aging. Glutathione (GSH), present naturally in grapes and derivatives, is an antioxidant which positively contributes to the preservation of aromas, prevention of browning and other defects resulting from prolonged storage of white wines. The GSH molecule is very reactive due to its sulfhydryl group. In this sense, an alternative to preserve it and maintain its antioxidant properties for a longer period during the storage of sparkling wine would be the microencapsulation of GSH into a polymeric system. Microencapsulation of GSH could also prevent a negative aspect of the use of GSH in wine, which is inducing the formation of H2S (off-flavor), once the GSH is released slowly avoid oxygen reduced conditions in wine. In this context, this study aimed to evaluate the effect of adding free GSH in sparkling wine and prepare microcapsules containing glutathione to addition to the wine and/or sparkling wine. The free GSH (10, 20 and 30 mg L-1) was added at different stages (must, base wine and sparkling wine) of sparkling wine elaboration by the traditional method. The effects of the addition of GSH on aromatics compounds, phenolic compounds related to browning of white wines and on the free SO2 concentrations were evaluated. The analysis of phenolic compounds and the total and reduced glutathione were performed by high-performance liquid chromatography and UV spectrophotometry and; the analyzes of the aromatic compounds were made by gas chromatography. The microparticles containing GSH as active compound were prepared by spray-dryer with chitosan or β-cyclodextrin as polymers and their characterization was performed by scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), spectroscopy in the infrared with Fourier transform (FT-IR), X-ray diffraction (XRD). Furthermore, tests were performed to verify the recovery of GSH, the encapsulation efficiency and release kinetics of GSH in a model wine. The addition of GSH to the must influenced more in the sparkling wine composition than the addition to the base wine. However, the addition of GSH to the base wine appears to maintain higher levels of SO2 in its free form. The addition of 10 mg L-1 of GSH in the mus is sufficient for lower concentrations of caffeic acid, coumaric acid and ferulic in sparkling wine. The addition of 20 mg L-1 of GSH in the sparkling wine toghether with the expedition liqour resulted in lower color index, larger amounts of SO2 in free form, lower acetaldehyde concentration and same amount of phenolic compounds up to 12 months storage in bottle. The amount of GSH added to the ready sparkling wine declined in one month storage and stabilized within the first six months, but the amount of total glutathione remained higher in sparkling wine with addition of 30 mg L-1 until 12 months of storage. Although only GSH have antioxidant property, the total amount of glutathione had a higher correlation with the results obtained and therefore, the overall glutathione levels are a better indicator of wine antioxidant condition than GSH itself. It was possible to encapsulate glutathione using both, β-CD or chitosan. The characterization of microcapsules proved the micro surfacing of the active compound and an interaction between GSH and the polymers as well as improvement of the thermal stability of the molecule. The β-CD was more efficient for encapsulating GSH, allowing a gradual release of the molecule into model wine solution and added protection of the molecule, giving improved thermal stability for GSH.

Vinhos espumantes, assim como os vinhos brancos, são muito susceptíveis a oxidação nas etapas de elaboração e durante o armazenamento e envelhecimento. A glutationa (GSH), antioxidante naturalmente presente nas uvas e derivados, contribui positivamente na preservação de aromas, prevenção do escurecimento e outros defeitos decorrentes do armazenamento prolongado em vinhos brancos. A molécula de GSH é muito reativa, devido a seu grupo sulfidrila. Neste sentido, uma alternativa para preservá-la e manter suas propriedades antioxidantes por um maior período durante o armazenamento dos espumantes seria a microencapsulação em um sistema polimérico. A microencapsulação também poderia evitar um aspecto negativo da utilização de GSH em vinhos, que é indução da formação de H2S (off-flavour), visto que, se a GSH for liberada lentamente poderia evitar o efeito redutor de oxigênio no vinho. Neste contexto, este trabalho teve como objetivo avaliar o efeito da adição de GSH livre em espumantes e preparar microcápsulas contendo glutationa para adição em vinhos e/ou espumantes. A GSH livre (10, 20 e 30 mg L-1) foi adicionada em diferentes etapas da elaboração (mosto, vinho base e espumante) de espumantes pelo método tradicional. Foram avaliados os efeitos da adição de GSH sobre compostos aromáticos, os compostos fenólicos relacionados ao escurecimento de vinhos brancos e as concentrações de SO2 livre. As análises dos compostos fenólicos e da glutationa total e reduzida foram realizadas por cromatografia líquida de alta eficiência e espectrofotometria UV e, as análises dos compostos aromáticos foram realizadas por cromatografia gasosa. As micropartículas contendo GSH como composto ativo foram preparadas por spray-dryer com quitosana ou β-ciclodextrina (β-CD), como polímeros e sua caracterização foi realizada por microscopia eletrônica de varredura (MEV), análise termogravimétrica (TGA), calorimetria exploratória diferencial (DSC), espectroscopia na região do infravermelho com transformada de Fourrier (FT-IR), difratometria de raios-X (DRX). Além disso, foram realizados testes para verificar a recuperação da GSH, a eficiência de encapsulação e a cinética de liberação da GSH em vinho modelo. A adição de GSH ao mosto influenciou mais na composição do espumante do que a adição ao vinho base. Entretanto, a adição de GSH ao vinho base manteve níveis elevados de SO2 na forma livre. A adição de 10 mg L-1 de GSH no mosto é suficiente para assegurar menores concentrações de ácidos cafeico, cumárico e ferrúlico nos espumantes. A adição de 20 mg L-1 de GSH no espumante junto com o liquor de expedição resultou em menor índice de cor, maiores quantidades de SO2 na forma livre, menores concentrações de acetaldeído e mesma quantidade de compostos fenólicos até 12 meses de armazenamento em garrafas. A quantidade de GSH adicionada no espumante pronto decaiu em um mês de armazenamento e estabilizou nos primeiros seis meses, porém a quantidade de glutationa total permaneceu maior no espumante com adição de 30 mg L-1, até 12 meses de armazenamento. Apesar de somente a GSH ter propriedade antioxidante, a quantidade de glutationa total teve maior correlação com os resultados obtidos e, por isso, o nível de glutationa total pode ser um melhor indicador da condição antioxidante do vinho. Foi possível encapsular glutationa tanto utilizando β-CD, quanto utilizando quitosana. A caracterização das microcápsulas comprovaram um microrrevestimento do composto ativo e uma interação entre a GSH e os polímeros utilizados. A β-CD foi mais eficiente para encapsular a GSH, permitindo a liberação gradativa da molécula em solução de vinho modelo e maior proteção da molécula, conferindo melhor estabilidade térmica para GSH. / Sparkling wine, white wines as well, are very susceptible to oxidation in the processing stages and during storage and aging. Glutathione (GSH), present naturally in grapes and derivatives, is an antioxidant which positively contributes to the preservation of aromas, prevention of browning and other defects resulting from prolonged storage of white wines. The GSH molecule is very reactive due to its sulfhydryl group. In this sense, an alternative to preserve it and maintain its antioxidant properties for a longer period during the storage of sparkling wine would be the microencapsulation of GSH into a polymeric system. Microencapsulation of GSH could also prevent a negative aspect of the use of GSH in wine, which is inducing the formation of H2S (off-flavor), once the GSH is released slowly avoid oxygen reduced conditions in wine. In this context, this study aimed to evaluate the effect of adding free GSH in sparkling wine and prepare microcapsules containing glutathione to addition to the wine and/or sparkling wine. The free GSH (10, 20 and 30 mg L-1) was added at different stages (must, base wine and sparkling wine) of sparkling wine elaboration by the traditional method. The effects of the addition of GSH on aromatics compounds, phenolic compounds related to browning of white wines and on the free SO2 concentrations were evaluated. The analysis of phenolic compounds and the total and reduced glutathione were performed by high-performance liquid chromatography and UV spectrophotometry and; the analyzes of the aromatic compounds were made by gas chromatography. The microparticles containing GSH as active compound were prepared by spray-dryer with chitosan or β-cyclodextrin as polymers and their characterization was performed by scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), spectroscopy in the infrared with Fourier transform (FT-IR), X-ray diffraction (XRD). Furthermore, tests were performed to verify the recovery of GSH, the encapsulation efficiency and release kinetics of GSH in a model wine. The addition of GSH to the must influenced more in the sparkling wine composition than the addition to the base wine. However, the addition of GSH to the base wine appears to maintain higher levels of SO2 in its free form. The addition of 10 mg L-1 of GSH in the mus is sufficient for lower concentrations of caffeic acid, coumaric acid and ferulic in sparkling wine. The addition of 20 mg L-1 of GSH in the sparkling wine toghether with the expedition liqour resulted in lower color index, larger amounts of SO2 in free form, lower acetaldehyde concentration and same amount of phenolic compounds up to 12 months storage in bottle. The amount of GSH added to the ready sparkling wine declined in one month storage and stabilized within the first six months, but the amount of total glutathione remained higher in sparkling wine with addition of 30 mg L-1 until 12 months of storage. Although only GSH have antioxidant property, the total amount of glutathione had a higher correlation with the results obtained and therefore, the overall glutathione levels are a better indicator of wine antioxidant condition than GSH itself. It was possible to encapsulate glutathione using both, β-CD or chitosan. The characterization of microcapsules proved the micro surfacing of the active compound and an interaction between GSH and the polymers as well as improvement of the thermal stability of the molecule. The β-CD was more efficient for encapsulating GSH, allowing a gradual release of the molecule into model wine solution and added protection of the molecule, giving improved thermal stability for GSH.

The purpose of this study has been to write a biography on the life of the versatile William Wines Phelps in conjunction with his contributions to and influence on the issues and problems of Mormon Pioneer History from Kirtland, Ohio, to the Great Basin.Prior to the year 1831, W.W. Phelps was active in the State of New York as an Anti-Masonic newspaper editor. The Anti-Masonic movement had grown out of the political enviornment that existed throughout the nation and especially in the State of New York during that period of time.During the year of 1831, W.W. Phelps completely abandoned the cause of Anti-Masonry to accept "Mormonism." As a result, when Joseph Smith, W.W. Phelps and others arrived in Missouri, Phelps was called to be the first Mormon editor-publisher, bringing with him the same enthusiasm and skill to the cause of Mormonism.

A indicação geográfica de vinhos possibilita a segmentação de mercados a partir da valorização das características do seu local de origem, o que lhes atribui uma identidade própria, além de distingui-los em relação aos seus similares disponíveis no mercado. Nesse sentido, o objetivo geral desta tese foi avaliar fatores relacionados à percepção de qualidade de consumidores de vinhos com indicação geográfica (IG) e seus estilos de tomada de decisão de compra. Para isso, são apresentados quatro estudos: o primeiro visou à compreensão das variáveis que interferem na decisão de compra dos consumidores de vinhos com indicação geográfica ou com atributos regionais. O segundo estudo foi voltado à identificação dos aspectos que são relacionados à percepção de qualidade e quais características estão associadas aos vinhos com indicação geográfica por consumidores. O terceiro estudo avaliou a escala CSI (Consumer Style Inventory) adaptada para alimentos por Cankurt et al. (2013), investigando os estilos de tomada de decisão de consumidores de vinhos com IG no Brasil. O quarto estudo buscou a identificação de grupos específicos de consumidores formados a partir de sete estilos selecionados no modelo de Cankurt et al. (2013), bem como verificar sua relação com algumas características associadas à percepção de qualidade de consumidores de vinhos com indicação geográfica. A abordagem metodológica apresenta, inicialmente, uma revisão sistemática da literatura voltada ao tema em periódicos internacionais nos portais ISI Web of Science, Scopus e Science Direct, além de um levantamento aprofundado em teses, dissertações, periódicos nacionais e internacionais. Foi realizada, a seguir, uma Survey com os 2.621 participantes do Circuito Nacional de degustação do Instituto Brasileiro do Vinho no ano de 2014. Para a análise dos dados, foram utilizadas análises de estatísticas descritivas (médias e frequências), testes de análise de variância - ANOVA, teste de comparações múltiplas DMS, Dunnet T3 ao nível de significância de 5% e teste de comparação Mann-Whitney, assim como análise fatorial exploratória e confirmatória, análise de clusters, análise discriminante e análise de variância - ANOVA dos clusters. Os resultados demonstram que os consumidores de vinhos com indicação geográfica ou com atributos regionais vêm valorizando a qualidade sensorial, tipicidade e prestígio dos vinhos, proporcionando maior credibilidade aos produtos. Os consumidores que, habitualmente, adquirem vinhos com indicação geográfica, associam-na à qualidade do produto, reconhecendo os fatores intrínsecos como a qualidade da uva, o sabor e o aroma do vinho. Os fatores extrínsecos, como a região produtora e as características agroclimáticas, foram considerados atributos importantes nos vinhos com indicação geográfica. Os resultados apontam, ainda, boa confiabilidade e a validação de sete estilos de decisão entre os onze da escala avaliada para consumidores de vinhos com IG. A análise de clusters confirmou a formação de quatro grupos a partir dos sete estilos de decisão considerados inicialmente. Os consumidores que participaram desse estudo estão classificados no cluster constituído pelos estilos de decisão: Perfectionist, High-quality conscious; Habitual, brand-loyal e Local brand conscious, os quais são os que dão maior importância aos principais fatores associados à percepção de qualidade de vinhos com IG encontrados nesse estudo, que são: características próprias da região de origem (terroir); qualidade da matéria-prima (uvas); transmissão da cultura e história da região; características sensoriais dos vinhos e a tradição da vinícola. / A geographical indication of wines provides the market segmentation based on the value of the characteristics of their place of origin, which gives them an identity, and distinguish them in relation to their counterparts in the market. In this sense, the general objective of this thesis was to assess factors related to the quality perception of wine consumers with Geographical Indication (GI) and their purchase decision-making styles. To this end, four studies are presented: the first aimed at the understanding of the variables that influence the purchasing decisions of wines consumers with geographical indication or regional attributes. The second study was aimed to identify the aspects that are related to the quality perception and which characteristics are associated with wines with geographical indication for consumers. The third study assessed the CSI (Consumer Style Inventory) scale adapted to food by Cankurt et al. (2013), investigating the decision-making styles of wine consumers with GI in Brazil. The fourth study sought to identify specific consumer groups formed from seven selected styles based on Cankurt et al model. (2013), and to verify its relationship with some characteristics associated with the quality perception of wine consumers with a geographical indication. The methodological approach initially presents a systematic review of the literature focused on the topic in international journals in the ISI Web of Science, Scopus and Science Direct portals, in addition to a survey of national and international theses, dissertations, and journals. A Survey was made afterwards involving 2.621 participants in the National Tour tasting of Brazilian Institute of Wine in 2014. For data analysis, descriptive statistical analyzes were used (averages and frequencies), variance test analysis - ANOVA, multiple comparison test - DMS, Dunnet T3 at a significance level of 5% and Mann-Whitney comparison test, as well as exploratory and confirmatory factor analysis, cluster analysis, discriminant analysis and analysis of variance - ANOVA of clusters. The results show that consumers of wines with geographical indication or regional attributes have been valuing the sensory quality, typicality and prestige of wines, providing greater credibility to the products. Consumers that usually purchase wines with geographical indication, have been associated it to in product quality, recognizing the intrinsic factors such as the grape quality, flavor and aroma of the wine. Extrinsic factors, such as producing region and climatic characteristics have been considered important attributes in wines with geographical indication. The results also show good reliability and validation of seven decision styles among the eleven evaluated scale consumer of wine with the GI. Cluster analysis confirmed the formation of four groups from the seven decision styles considered initially. Consumers who participated in this study are classified as cluster consists of the decision styles: Perfectionist, High-quality conscious; Habitual, brand-loyal and Local brand conscious, which are those who give more importance to the main factors associated with perception of quality wines with GI found in this study, which are characteristics of the source region (terroir); quality of raw material (grape); transmission of culture and history of the area; sensory characteristics of the wines and the tradition of wine.

Dans l’optique de comprendre et maitriser le vieillissement des vins, en particulier des vins blancs, il est nécessaire d’approfondir nos connaissances sur les mécanismes physico-chimiques d’oxydation liés aux processus d’oxygénation. Pour cela, il est important d’avoir des outils permettant la quantification de la capacité antioxydante des vins blancs, et l’identification des composés impliqués dans celle-ci, afin de pouvoir anticiper l’aptitude au vieillissement d’un vin.Lors de cette étude, des analyses de la capacité antioxydante par DPPH et Résonnance Paramagnétique Electronique (RPE) ont été réalisées sur un grand nombre de vins en cours d’élevage et issus de plusieurs millésimes. En parallèle des analyses métabolomiques, principalement par Chromatographie Liquide couplée à la Spectrométrie de Masse (UPLC-Q-TOF-MS) mais également par Spectrométrie de Masse à Résonance Cyclotronique des Ions et à Transformée de Fourier (FT-ICR-MS) ont été réalisées.L’optimisation de la méthode DPPH, pour l’analyse des vins blancs a révélé une réactivité importante des composés soufrés, avec des capacités antioxydantes similaires à celles des composés phénoliques. La comparaison de cette méthode optimisée à la méthode de référence du laboratoire (RPE) sur plus de 106 vins, a montré la complémentarité de l’information apportée par ces deux différentes méthodes de mesure de capacité antioxydante. Le traitement statistique des corrélations avec les analyses métabolomiques réalisées sur 287 vins a permis de révéler une liste de 380 marqueurs moléculaires associés à la capacité antioxydante des vins. Une méthode alternative de mesure du potentiel antioxydant des vins blancs a également été développée, qui repose sur l’identification de composés nucléophiles naturellement présents et susceptibles de piéger les quinones formées au cours de mécanismes d’oxydation. Outre des composés soufrés, nous avons montré que différents peptides ayant des propriétés antioxydantes présentent de telles propriétés nucléophiles. Dans un second temps, l’étude de différentes pratiques œnologiques (élevage, hyperoxygénation ou sulfitage) a permis de déterminer leurs impacts sur la capacité antioxydante des vins mais également sur les marqueurs moléculaires associés. Il apparait ainsi une augmentation significative de la capacité antioxydante des vins au cours de l’élevage. De plus, cette augmentation de la capacité antioxydante est associée à une consommation de peptides en début d’élevage, ainsi qu’à l’apparition de nouveaux composés dans les vins et ce indépendamment du millésime. Les composés qui apparaissent semblent être majoritairement des composés phénoliques provenant potentiellement du bois ou de l’autolyse des levures. Les vins issus de moûts protégés par l’ajout précoce de sulfites ont une capacité antioxydante plus élevée par rapport aux vins issus de moûts hyperoxygénés. De plus, la protection du moût à un impact important sur la composante moléculaire soufrée retrouvée dans les vins. Ainsi, il a été observé une quantité beaucoup plus faible de composés soufrés (peptides ou non) dans les vins issus de moûts hyperoxygénés montrant donc une consommation de ces composés dans les mécanismes d’oxydation du vin. En résumé, ces résultats révèlent pour la première fois l’importance des composés soufrés dans les mécanismes de protection des vins blancs de Bourgogne vis-à-vis de l’oxydation, par leur capacité de piégeur de radicaux mais également de piégeur de quinones. / In order to understand and control the aging of wines, particularly white wines, it is necessary to deepen our knowledge about the physico-chemical mechanisms of oxidation related to oxygenation processes. For this, it is important to have tools to quantify the antioxidant capacity of white wines, and to identify the compoiunds involved, in order to anticipate the aging ability of a wine.In this study, analyzes of the antioxidant capacity by DPPH and Electron Paramagnetic Resonance (EPR) were carried out on a large number of wines during aging and from several vintages, in parallel with metabolomic analyzes, mainly carried out by Liquid Chromatography Coupled to Mass Spectrometry (UPLC-Q-TOF-MS) but also by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS).Optimization of the DPPH method for the analysis of white wines, showed a high reactivity of sulfur compounds with similar antioxidant capacities to those of phenolic compounds. The comparison of this optimized method with the laboratory reference method (EPR) on more than 106 wines, showed the complementarity of the information provided by these two different methods of measuring an antioxidant capacity.Combining antioxidant capacity measurements and metabolomic analyzes, it was possible to determine a list of molecular markers related to the antioxidant capacity of white wines. During this study, a focus on nucleophilic compounds present in wines has also been realized, these compounds being able to react with the quinones formed during oxidation and thus to play a role in the oxidation mechanisms of white wines. Besides sulfur compounds, we showed that several peptides with antioxidant properties could exhibit such nucleophilic behavior. In a second step, the study of different oenological practices (aging, hyperoxygenation or adding SO2 to must) allowed to determine their impacts on the antioxidant capacity of wines but also on the associated molecular markers. It thus appears a significant increase in the antioxidant capacity of the wines during aging. In addition, this increase in antioxidant capacity is associated with a consumption of peptides at the beginning of aging, but also with the appearance of compounds in wines, regardless of the vintage. The compounds that appear are potentially phenolic compounds which can come from wood or lees autolysis. Wines from protected musts with sulfites addition, have a higher antioxidant capacity compared to wines from hyperoxygenated musts. In addition, the protection of musts has a significant impact on the sulfur component found in wines. Thus, a much smaller amount of sulfur compounds (peptides or not) has been observed in wines derived from hyperoxygenated musts, showing a consumption of these compounds in the oxidation mechanisms. Overall, these results reveal for the first time the importance of sulfur compounds in the mechanisms of protection of white wines from Burgundy against oxidation, by radical scavenging capacity and quinone trapping.

Thesis (M.Inst.Agrar.(Agricultural Economics, Extension and Rural Development))--University of Pretoria, 2008. / Abstract in English. Includes bibliographical references.

Thesis (MSc Food Sc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: In this study an industry-selected and diverse range of South African red wines were analysed for sensory and chemical attributes, as well as degree of liking using a target group of black South African consumers. Segments of consumers that differed in degree of liking were then tested for their response to intrinsic (sensory) and extrinsic (non-sensory) cues. The selection of wines included eighteen dry and natural sweet red wines, representing low-end inexpensive wines together with high-end, top quality wines. Sensory profiles for all samples were established using Quantitative descriptive analysis (QDA). The results revealed that cultivar specific dry red wines associated with a wide range of sensory descriptors such as woody, vegetative and fruity, while the sweet red wines associated with the fruity and sweet-associated attributes. Chemically there was a significant variation between wines regarding the alcohol and sugar content. Gas chromatography with flame ionisation detection (GC-FID) indicated the major volatile constituents present in the wine, i.e. esters, alcohols and fatty acids. When investigating the association between the chemical and sensory data, it was revealed that the red blends were driven by the presence of alcohols and esters, and sensory descriptors such as high roast oak, coffee and mixed spice, whereas the red cultivar wines were mostly driven by fatty acids and esters and the sensory descriptors, green bean and asparagus. The sweet red blends were closely associated with acids and the sensory descriptors sweet-associated and floral. Degree of liking of a subset of 18 wines was investigated based on the preferences of black consumers from the Western Cape area, South Africa. These consumers predominantly preferred the sweet red wines with high sugar content, in a blind tasting session. Purchase intent was also evaluated by viewing actual photographs of packaging formats of the respective wines and the results indicated that the consumers preferred the well-known cultivar wines with a perception of value and style. Cluster analysis was furthermore performed to ascertain whether these consumers differed in their degree of liking of the intrinsic character of the respective wines. Four different clusters of consumers were identified: 1) Consumers preferring both dry and sweet red wines equally, 2) Consumers who strongly favoured sweet red wines and moderately liked dry red wines, 3) Consumers who strongly favoured sweet red wines with little preference for dry red wines; and 4) Consumers preferring dry red wines. Consumers were also probed on their general opinions or perceptions on the extrinsic character of the wines, and thus factors that influence the purchasing process. It was found that black consumers who don‟t consume wine often, preferred wines that they are familiar with, while consumers that drink wine more frequently enjoy to broaden their horizons by experimenting with more expensive wine brands. Extrinsic or non-sensory cues such as alcohol content, label, vintage, price and cultivar were found to be the most important considered factors when purchasing red wines, while awards and type of closure were regarded as the least important. It was also found that the discerning consumers, who purchase high-end wines, took more of the latter aspects into consideration, whereas consumers who purchase low-end wines considered a limited number of the non-sensory cues. / AFRIKAANSE OPSOMMING: In hierdie studie is 'n diverse reeks industrie-geselekteerde, Suid-Afrikaanse rooiwyne geanaliseer vir hul sensoriese en chemiese eienskappe. Verbruikersvoorkeur van die wyne is getoets, asook tot watter mate verbruikersvoorkeure beïnvloed word deur intrinsieke (sensoriese) en ekstrinsieke (nie-sensoriese) faktore. Die reeks van agtien wyne het bestaan uit droë en soet rooi wyne, wat op hul beurt verder verdeel kan word in goedkoper, kwaliteit wyne en duurder, ultra-premium wyne. Die sensoriese profiel van al die wyne is bepaal deur beskrywende sensoriese analise. Resultate het getoon dat die kultivar-spesifieke droë rooiwyne geassosieer word met 'n wye reeks sensoriese eienskappe soos houtagtig, kruidagtig en vrugtig, terwyl die soet rooiwyne beskryf is as vrugtige en soet-geassosieerd. In terme van die chemiese analises was daar betekenisvolle verskille betreffende die alkohol- en suikerinhoud van die wyne. Gas chromatografie gekoppel met vlam-ioniserende deteksie (GC-FID) het die mees vlugtige verbindings teenwoordig in die wyn aangedui, naamlik esters, alkohole en vetsure. Met die korrelasie van die chemiese en sensoriese data is gevind dat die droë versnitwyne gedryf word deur die teenwoordigheid van alkohole en esters, asook sensoriese eienskappe soos gehout, koffie, en gemengde spesery, terwyl die kultivar-spesieke wyne weer meestal gedryf word deur vetsure en esters en sensoriese eienskappe soos groenboontjie en aspersie. Die soet rooiwyne het chemies geassosieer met sure en sensoriese terme soos soet-geassosieerd en blomagtig. Die aanvaarbaarheid van 'n kleiner groepering wyne is bepaal deur gebruik te maak van swart verbruikers in die Wes-Kaap area, Suid-Afrika. Die verbruikers het in 'n blinde proesessie onderskeie wyne se wynverpakking besigtig en aangedui of hulle die wyne sou koop. Hierdie resultate het getoon dat die verbruikers bekende kultivarwyne verkies wat 'n persepsie van waarde en styl geïllustreer het. Segmentasie tegnieke is op die data uitgevoer ten einde te bepaal of verbruikers in groepe verdeel kan word, wat betref hul voorkeur van die sensoriese of intrinsieke eienskappe van die wyne. Vier verskillende groepe is geïdentifiseer, nl. verbruikers wat 1) droë en soet rooiwyne ewe veel verkies; 2) soet rooiwyne en tot 'n mate ook droë rooiwyne verkies; 3) soet rooiwyne en tot 'n mindere mate droë rooiwyne verkies; en laastens 4) slegs droë rooiwyne verkies. Verbruikers se algemene opinies en persepsies betreffende die ekstrinsieke eienskappe van die wyne is ook ondersoek, met ander woorde faktore wat die aankoop van wyne beïnvloed. Daar is gevind dat swart verbruikers wat nie gereeld wyn drink, bekende handelsmerke verkies, terwyl verbruikers wat gereeld wyn drink, daarvan hou om hul horisonne te verbreed en te eksperimenteer met 'n verskeidenheid handelsmerke. Ekstrinsieke of nie-sensoriese aspekte soos, alkohol-inhoud, etiket, oesjaar, prys en kultivar is die belangrikste faktore wat in ag geneem word wanneer rooiwyne gekoop word, terwyl wyntoekennings en die feit dat die wyn met kurke gebotteleer word, nie as belangrik beskou word nie. Daar is ook gevind dat die meer ingeligte verbruiker, wat hoë kwaliteit wyne koop, meer van die bogenoemde aspekte in ag neem tydens die aankoopproses, terwyl die verbruiker wat meer geneig is om goedkoper wyne te koop, slegs 'n paar ekstrinsieke faktore in ag neem.