880 resultados para Wine aroma


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In recent years, Russia has experienced significant economic growth. The wine industry is among those most affected by increases in disposable income. As a consequence, Russian wine importers have widened the range at the upper end of the quality spectrum. In the current scenario, some key questions arise concerning consumer attitudes toward wine and the way it is perceived in this evolving market. This article attempts to investigate such concerns through a choice experiment approach conducted by means of a questionnaire-based survey submitted to 388 Russian households located in the country's three largest cities (Moscow, Saint Petersburg, and Novosibirsk). In the experiment, respondents were asked to choose their favorite wine among seven dry red wines. The stated choices are analyzed using a random utility model to obtain an estimation of the price effect through a triangular distribution. Our results indicate the presence of three distinct market segments in the Russian wine market: a segment with only high-quality, highly priced Italian and French wines, a medium-quality segment currently limited to Spanish wines, and a much lower quality segment of wines in which demand for alcohol is essentially satisfied.

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We report the results of a study based on revealed and stated preference data on choice of Prosecco wines in retail stores close to the origin of production in Northern Italy. Emphasis is placed on ability to reconcile the utility structure of stated preference data with that underlying revealed preference data. We extend the analysis to cover nonattendance of key attributes, such as price and certification of origin, while controlling for the large range of brand effects.

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O vinho tinto é uma importante fonte de compostos fenólicos com atividade antioxidante e que estão relacionados com a prevenção de doenças cardiovasculares e cancro. Estes compostos são um sub-produto do processo de destilação vínica utilizado para produzir aguardente necessária para a produção de Vinho do Porto. Esta tese tem como objetivo valorizar os compostos fenólicos resultantes das destilarias de vinho, através do estudo da sua composição, das interações com o material polimérico do vinho, da sua estabilidade durante o armazenamento e avaliação dos seus potenciais efeitos biológicos in vitro. Isto irá permitir definir aplicações para estes compostos como ingredientes alimentares com propriedades funcionais. Dois vinhos tintos (RW1 e RW2) foram utilizados como fonte de compostos fenólicos. A fim de estudar estes compostos, cada vinho foi evaporado à pressão atmosférica, permitindo obter o respetivo vinho desalcolizado (DW1 e DW2). Os polissacarídeos e compostos fenólicos presentes nos vinhos desalcolizados foram fracionados por extração em fase sólida utilizando cartuchos C18 sep-pak. A fração hidrofóbica, rica em compostos fenólicos, foi separada em frações ricas em ácidos fenólicos, em procianidinas e em antocianinas, as quais foram usadas para avaliar a sua contribuição para a atividade antioxidante total e caracterização fenólica detalhada dos DW. Foram obtidas quantidades comparáveis de compostos fenólicos totais (1.3 g/L para RW1 e DW1, e 3.1 para RW2 e DW2), de taninos (1.2 g/L para RW1 e DW1 e 1.6 para RW2 e DW2) e de antocianinas (0.24 g/L para RW1 e DW1 e 0.41 para RW2 e DW2) para os vinhos e para os respetivos vinhos desalcolizados. A determinação da atividade antioxidante de RW e DW pelos métodos do DPPH e ABTS também originou valores semelhantes, permitindo inferir que o processo de destilação realizado não promoveu uma perda relevante de compostos fenólicos. A atividade antioxidante total de vinho deveu-se essencialmente à fração rica em antocianinas. Os dois DW foram dialisados para se obter o material polimérico dos vinhos (WPM1 e WPM2). O WPM1 e WPM2 apresentavam 1.1 e 1.3 g/L de material sólido, respetivamente. O WPM (WPM1 e WPM2) era composto por polissacarídeos (31 e 36%), proteínas (10 e 12%) e também por compostos fenólicos (32 e 43%). A análise de açúcares mostrou que as manoproteínas e as arabinogalactanas eram os principais polissacarídeos presentes. A extração do WPM com metanol deu origem a um material insolúvel em metanol (PMi) e a uma fração solúvel em metanol, que continuava a conter hidratos de carbono e compostos fenólicos, mostrando uma forte interação entre estes compostos. Para determinar a energia de ativação (Ea) da libertação dos compostos fenólicos de fracções de material polimérico do vinho, foram realizadas diálises do DW, WPM e PMi, utilizando-se quatro concentrações diferentes, a cinco temperaturas (5-40 °C). O valor da Ea foi 25 para o WPM e 61 kJ/mol para o PMi, mostrando que os compostos fenólicos do vinho podem estar associados de forma diferente à matriz polimérica e que uma fração pode estar, ainda, fortemente associada a esta matriz. A fim de avaliar a possível existência de interações seletivas com os compostos fenólicos, o WPM foi fracionado, permitindo a obtenção de uma fração rica em manoproteínas (MP), através de uma cromatografia de afinidade com concanavalina A e 3 frações ricas em arabinogalactanas (AG0, AG1 e AG2) obtidas por cromatografia de troca aniónica. Foi avaliada a difusão de nove antocianinas monoméricas através de uma membrana de diálise, em presença do WPM, e das frações ricas em MP e em AG. A diálise dos compostos fenólicos livres do vinho foi realizada como ensaio em branco. Todas as frações poliméricas mostraram capacidade para reter as antocianinas, embora em diferente extensão. Foi observada uma capacidade de retenção maior para as antocianinas acilglucosiladas do que para as antocianinas glucosiladas. A fração rica em AG teve uma maior contribuição para a capacidade de retenção das antocianinas pelo material polimérico vinho do que a fração rica em MP, principalmente quando as antocianinas estavam acetiladas. Com o objetivo de estudar formas para preservar, a longo prazo, as propriedades antioxidantes dos compostos fenólicos, o extrato de compostos fenólicos (PCE), em pó, foi armazenado em diferentes condições de luz e atmosfera, à temperatura ambiente durante 1 ano. Observou-se que o PCE armazenado no escuro, dentro de um exsicador sob atmosfera de azoto, preservou 95% da atividade antioxidante inicial. Também foram avaliadas as melhores condições para preservar as antocianinas quando em solução, armazenadas a duas temperaturas (5 e 30 ºC) durante 3 meses. A adição de 0.5 g/L de uma fração rica em polissacarídeos a um vinho armazenado a 30 ºC promoveu a proteção das antocianinas, especialmente das antocianinas cumaroiladas. Os potenciais efeitos biológicos dos compostos fenólicos foram avaliados em diferentes sistemas celulares in vitro utilizando as seguintes frações: WPM, WPS (polissacarídeos do vinho), WPC (compostos fenólicos do vinho), PA-E (fração rica em ácidos fenólicos), PR-E (fração rica em procianidinas) e APP-E (fração rica em antocianinas e procianidinas poliméricas). Foi observada uma maior viabilidade celular quando as células do carcinoma do cólon HT-29 foram expostas a dois agentes oxidantes (radiação UV e H2O2) em presença das frações PR-E e APP-E. Além disso, os extratos WPS, WPC, PR-E e APP-E mostraram propriedades anti-inflamatórias, avaliadas pela inibição da produção de NO por células de macrófagos RAW264.7, sendo o extrato APP-E (0.19 mg/mL) o que exibiu a maior capacidade anti-inflamatória. A fim de elucidar as propriedades antioxidantes dos extratos do vinho em células humanas, os glóbulos vermelhos (RBC) foram selecionados como um modelo metabolicamente simples. Os extratos WPM, WPS, WPC, PR-E, e APP-E mostraram efeito anti-hemolítico para a hemólise dos RBC provocada pelo peróxido de hidrogénio (H2O2) e pelo di-hidrocloreto de 2,2'-azo-bis(2-diaminopropano) (AAPH). Os resultados obtidos permitem concluir que o processo de desalcoolização dos vinhos à pressão atmosférica, preservou as principais características antioxidantes dos compostos fenólicos. Estes compostos podem contribuir para a defesa das células contra agentes oxidantes, nomeadamente por terem um potencial de atividades anti-inflamatória e anti-hemolítica, promovendo a viabilidade celular. A interação dos compostos fenólicos do vinho com o material polimérico permite inferir uma dosagem contínua e gradual das antocianinas vinho tinto após a sua ingestão, contribuindo para um período mais longo da sua exposição e, como consequência, dos seus potenciais benefícios para a saúde.

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The production of color/flavor compounds in wine is the result of different interrelated mechanism reactions. Among these, the oxidation phenomenon and the Maillard reaction stands out with particular relevance due to their large impact on the sensory quality of wines and consequently on the product shelflife. The aim of this thesis is to achieve a global vision of wine degradation mechanisms. The identification of mediators’ reactions involved in oxidative browning and aromatic degradation will be attempted based on different detectors. Two approaches are implemented in this work: a “non-target” approach by which relevant analytical tools will be used to merge the information of cyclic voltammetry and Diode-Array (DAD) detectors, allowing a broader overview of the system and the note of interesting compounds, and a “target” approach by which the identification and quantification of the different compounds related to the wine degradation process will be performed using different detectors (HPLC-UV/Vis, LC-MS, GC-MS, and FID). Two different patterns of degradation will be used in this study: wines generated by O2 and temperature perturbations, and synthetic solutions with relevant wine constituents for mechanisms validation. Results clearly demonstrate a “convolution” of chemical mechanisms. The presence of oxygen combined with temperature had a synergistic effect on the formation of several key odorant compounds.The results of this work could be translated to the wine-making and wine-storage environment from the modelling of the analysed compounds.

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A method for the determination of some pesticide residues in must and wine samples was developed using solid-phase microextraction (SPME) and gas chromatography – electron capture detection (GC/ECD). The procedure only needs dilution as sample pre-treatment and is therefore simple, fast and solvent-free. Eight fungicides (vinclozolin, procymidone, iprodione, penconazole, fenarimol, folpet, nuarimol and hexaconazole), one insecticide (chlorpyriphos) and two acaricides (bromopropylate and tetradifon) can be quantified. Good linearity was observed for all the compounds in the range 5–100 µg/L. The reproducibility of the measurements was found acceptable (with RSD’s below 20%). Detection limits of 11 µg/L, on average, are sufficiently below the proposed maximum residue limits (MRL’s) for these compounds in wine. The analytical method was applied to the determination of these compounds in Portuguese must and wine samples from the Demarcated Region of Alentejo, where any residues could be detected.

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Phenolic compounds constitute a diverse group of secondary metabolites which are present in both grapes and wine. The phenolic content and composition of grape processed products (wine) are greatly influenced by the technological practice to which grapes are exposed. During the handling and maturation of the grapes several chemical changes may occur with the appearance of new compounds and/or disappearance of others, and consequent modification of the characteristic ratios of the total phenolic content as well as of their qualitative and quantitative profile. The non-volatile phenolic qualitative composition of grapes and wines, the biosynthetic relationships between these compounds, and the most relevant chemical changes occurring during processing and storage will be highlighted in this review.

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Dissertation presented to obtain the Ph.D degree in Biochemistry, Plant Physiology

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Companhia das Quintas, Limited Company wishes to conquer the Chinese market with its wines. For that, it decided to enter in a partnership with a local importer and distributor. This project analyses the macroeconomic factors of the country, the local market and the consumer behavior, using on-site research that included interviews with professionals of the industry, unstructured observation of the consumer and existing statistical data analysis. Finally, the project presents a marketing plan to make this partnership a success.

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Wine Tourism is gaining importance in today’s world and more destinations and establishments have been arising. After understanding the importance of this economic activity and the factors it must have to succeed, a new project was conceived for Central Alentejo taking into account its potential. This project is an example of how to take advantage of Wine Tourism in wine regions that are underexplored, such as Aldeias de Montoito, the village near Redondo to which a Business Plan will be created, explaining the strategies to pursue in order to have a successful Wine Tourism destination.

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Double degree

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The adapted metabolic response of commercial wine yeast under prolonged exposure to concentrated solutes present in Icewine juice is not fully understood. Presently, there is no information regarding the transcriptomic changes in gene expression associated with the adaptive stress response ofwine yeast during Icewine fermentation compared to table wine fermentation. To understand how and why wine yeast respond differently at the genomic level and ultimately at the metabolic level during Icewine fermentation, the focus ofthis project was to identify and compare these differences in the wine yeast Saccharomyces cerevisiae KI-Vll16 using cDNA microarray technology during the first five days of fermentation. Significant differences in yeast gene expression patterns between fermentation conditions were correlated to differences in nutrient utilization and metabolite production. Sugar consumption, nitrogen usage and metabolite levels were measured using enzyme assays and HPLC. Also, a small subset of differentially expressed genes was verified using Northern analysis. The high osmotic stress experienced by wine yeast throughout Icewine fermentation elicited changes in cell growth and metabolism correlating to several fermentation difficulties, including reduced biomass accumulation and fermentation rate. Genes associated with carbohydrate and nitrogen transport and metabolism were expressed at lower levels in Icewine juice fermenting cells compared to dilute juice fermenting cells. Osmotic stress, not nutrient availability during Icewine fermentation appears to impede sugar and nitrogen utilization. Previous studies have established that glycerol and acetic acid production are increased in yeast during Icewine fermentation. A gene encoding for a glycerollW symporter (STL1) was found to be highly expressed up to 25-fold in the i Icewine juice condition using microarray and Northern analysis. Active glycerol transport by yeast under hyperosmotic conditions to increase cytosolic glycerol concentration may contribute to reduced cell growth observed in the Icewine juice condition. Additionally, genes encoding for two acetyl CoA synthetase isoforms (ACSl and ACS2) were found to be highly expressed, 19- and II-fold respectively, in dilute juice fermenting cells relative to the Icewine juice condition. Therefore, decreased conversion of acetate to acetyl-CoA may contribute to increased acetic acid production during Icewine fermentation. These results further help to explain the response of wine yeast as they adapt to Icewine juice fermentation. ii

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The first objective of this study was to identify appropriate sensory descriptors to assess the astringent sub-qualities of red wine. The influence of pH and ethanol on the sensation of astringency in red wine was evaluated, using a de-alcoholized red wine. A portion of the wine was adjusted to the pH values of 3.2, 3.4, 3.6 and 3.8, and another portion was adjusted to ethanol concentrations of 0%, 6%, 12%, and 15%. In addition, the pH 3.4 and 3.6 treatments were adjusted to an ethanol concentration of 12% and 15% all wines were then assessed sensorially and seventeen terms were identified, through panel discussion, to describe the mouth-feel and taste qualities: velvet, aggressive, silk/satin, dry, fleshy, unripe, pucker viscosity, abrasive, heat, chewy, acidity, grippy/adhesive, bitter, balance, overall astringency, and mouth-coat. Descriptive analysis profiling techniques were used to train the panel and measure the intensity of these attributes. It was found that decreasing pH values (averaged across all ethanol concentrations) showed an increase in the overall astringency of the wine. The combined treatments of ethanol and pH, real wine parameters (pH 3.4 and 3.6; 12% and 15% ethanol) did not have an effect on the perception of the astringent sub-qualities of the wine. A time intensity study was also included using the pH and ethanol adjusted wines, which showed that as the ethanol level of the wines increased so did the time to maximum intensity. The second objective was to identify appropriate sensory descriptors to evaluate the influence of grape maturity and maceration technique (grape skin contact) on the astringency sub-qualities of red vinifera wines from Niagara. The grapes were harvested across two dates, representing an early harvest and a late harvest. A portion of the Cabernet Sauvignon grapes wine was divided into three maceration treatments of oneweek maceration, standard two-week maceration, three-week maceration, and MCM. Another portion of both the early and late harvest Cabernet Sauvignon grapes were chaptalized to yield a final ethanol concentration of 14.5%. The wines were assessed sensorially and thirteen terms were identified, through panel discussion, to describe the mouth-feel and taste qualities: carbon dioxide, pucker, acidity, silk/chamois, dusty/chalky/powdery, sandpaper, numbing, grippy/adhesive, dry, mouthcoat, bitter, balance and, overall astringency. Descriptive analysis techniques were used to train the panel and measure the intensity of these attributes. The data revealed few significant differences in the mouth-feel of the wines with respect to maturity; which included differences in overall astringency and balance. There were varietal differences between Cabernet Sauvignon, Cabernet Franc, and Pinot Noir and differences for Cabernet Sauvignon wines due to the length and manner of maceration and as a result of chaptalization. Statistical analysis revealed a more complex mouth-feel for the Pinot Noir wines; and an increase in the intensity of the astringent sub-qualities as a result of the addition of sugar to the wines. These findings have implications for how processing decisions, such as optimum grape maturity and vinification methods may affect red wine quality.

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Investigations of 2-alkyl-3-methoxypyrazines (2-isopropyl-3-methoxypyra2ine, 2- secbutyl-3-methoxypyrazine and 2-isobutyl-3-niethoxypyrazine) in ladybug species {Coleoptera: Coccinellidae) and wine samples have been conducted. Headspace sampling coupled with gas chromatography-mass spectrometry was used to determine amounts of 2-alkyl-3-methoxypyra2ines in the ladybug species. Hippodamia convergens had the highest amount of alkybnethoxypyrazines, followed by Harmoma axyridis and the least in Coccinella septempunctata. Using a solvent extraction method, the precoccinelline alkaloid was found present in Hippodamia convergens and Coccinella septempunctata but not Harmonia axyridis. Steam distillation followed by a soHd phase extraction method as a sample preparation technique, enhanced detection while the isotope dilution method afforded accurate quantitation of the alkyknethoxypyrazines in the wine samples. Both ladybug-tainted and commercial wine samples were found to contain the 2- alkyl-3-methoxypyrazines. Wine samples prepared in 2001 generally contained higher levels than the corresponding 2003 samples. Levels of the 2-alkyl-3-methoxypyrazines found in the commercial wines ranged from a minimum value of 6 ng/L to 260 ±10 ng/L. Analyses revealed that for both ladybug species and wine samples, the 2- isopropyl-3-methoxypyrazine had the highest concentration, followed by 2-isobutyl- 3-methoxypyrazine and the least being the 2-secbutyl-3-methoxypyrazine. Possible contamination of the wine samples by ladybugs is thoroughly discussed. Furthermore, attempts to remove or reduce the levels of the alkylmethoxypyrazines with molecularly imprinted polymers from wine samples are presented in detail.

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Icewine is an intensely sweet, unique dessert wine fennented from the juice of grapes that have frozen naturally on the vine. The juice pressed from the frozen grapes is highly concentrated, ranging from a minimum of 35° Brix to approximately 42° Brix. Often Icewine fennentations are sluggish, taking months to reach the desired ethanol level, and sometimes become stuck. In 6 addition, Icewines have high levels of volatile acidity. At present, there is no routine method of yeast inoculation for fennenting Icewine. This project investigated two yeast inoculum levels, 0.2 gIL and 0.5 gIL. The fennentation kinetics of inoculating these yeast levels directly into the sterile Icewine juice or conditioning the cells to the high sugar levels using a step wise acclimatization procedure were also compared. The effect of adding GO-FERM, a yeast nutrient, was also assessed. In the sterile fennentations, yeast inoculated at 0.2 gIL stopped fennenting before the required ethanol level was achieved, producing only 7.8% (v/v) and 8.1 % (v/v) ethanol for the direct and conditioned inoculations, respectively. At 0.5 gIL, the stepwise conditioned cells fennented the most sugar, producing 12.2% (v/v) ethanol, whereas the direct inoculum produced 10.5% (v/v) ethanol. The addition of the yeast nutrient GO-FERM increased the rate of biomass accumulation, but reduced the ethanol concentration in wines fennented at 0.5 gIL. There was no significant difference in acetic acid concentration in the final wines across all treatments. Fennentations using unfiltered Icewine juice at the 0.5 gIL inoculum level were also compared to see if the effects of yeast acclimatization and micronutrient addition had the same impact on fennentation kinetics and yeast metabolite production as observed in the sterile-filtered juice fennentations. In addition, a full descriptive analysis of the finished wines was carried out to further assess the impact of yeast inoculation method on Icewine sensory quality. At 0.5 gIL, the stepwise conditioned cells fennented the most sugar, producing 11.5% (v/v) ethanol, whereas the direct inoculum produced 10.0% (v/v) ethanol. The addition of the yeast nutrient GO-FERM increased the peak viable cell numbers, but reduced the ethanol concentration in wines fennented at 0.5 gIL. There was a significant difference 7 in acetic acid concentration in the final wines across all treatments and all treatments affected the sensory profiles of the final wines. Wines produced by direct inoculation were described by grape and raisin aromas and butter flavour. The addition of GO-FERM to the direct inoculation treatment shifted the aroma/flavour profiles to more orange flavour and aroma, and a sweet taste profile. StepWise acclimatizing the cells resulted in wines described more by peach and terpene aroma. The addition of GO-FERM shifted the profile to pineapple and alcohol aromas as well as alcohol flavour. Overall, these results indicate that the addition of GO-FERM and yeast acclimatization shortened the length of fermentation and impacted the sensory profiles of the resultant wines.

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A study was devised to evaluate influences of irrigation and fertigation practices on Vitis vinifera and Vitis labruscana grapes in the Niagara Peninsula. A modified FAO Penman- Monteith evapotranspiration formula was used to calculate water budgets and schedule irrigations. Five deficit irrigation treatments (non-irrigated control; deficits imposed postbloom, lag phase, and veraison; fiiU season irrigation) were employed in a Chardonnay vineyard. Transpiration rate (4-7 /xg H20/cmVs) and soil moisture data demonstrated that the control and early deficit treatments were under water stress throughout the season. The fiiU season irrigation treatment showed an 18% (2001) and 19% (2002) increase in yield over control due to increased berry weight. Soluble solids and wine quality were not compromised, and the fiiU season treatment showed similar or higher °Brix than all other treatments. Berry titratable acidity andpH also fell within acceptable levels for all five treatments. Irrigation/fertigation timing trials were conducted on Concord and Niagara vines in 2001- 02. The six Concord treatments consisted of a non-irrigated control, irrigation fi^om Eichhom and Lorenz (EL) stage 12 to harvest, and four fertigation treatments which applied 70 kg/ha urea. The nine Niagara treatments included a non-irrigated control, two irrigated treatments (ceasing at veraison and harvest, respectively) and six fertigation treatments of various durations. Slight yield increases (ca. 10% in Concord; 29% in Niagara) were accompanied by small decreases in soluble solids (1.5°Brix), and methyl anthranilate concentrations. Transpiration rate and soil moisture (1 1.9-16.3%) data suggested that severe water stress was present in these Toledo clay based vineyards.