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Published: 4 June 2021
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1

Coetzee, Carien. "Oxidation treatments affecting Sauvignon blanc wine sensory and chemical composition." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86321.

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Thesis (PhD(Agric))--Stellenbosch University, 2014.
ENGLISH ABSTRACT: This study focussed on the effect of oxygen on the chemical and sensory evolution of Sauvignon blanc wine under controlled oxidation conditions. The sensorial interactive effects between Sauvignon blanc varietal aroma compounds and compounds that typically arise during oxidation of white wines were also investigated. In the first research chapter the sensorial interactive effects of Sauvignon blanc impact compounds with aldehydes typically originating from oxidation of white wines were investigated. Four compounds, 3‐ mercaptohexan‐1‐ol (3MH), 3‐isobutyl‐2‐methoxypyrazine (IBMP), 3‐(methylthio)‐propionaldehyde (methional) and phenylacetaldehyde were added together in a model wine medium at varying concentrations. The concentrations chosen were according to those reported in literature to occur in Sauvignon blanc wines. The sensory effects of these compounds were profiled using a trained sensory panel. Compounds were first profiled individually and results showed that the change in comcpound concentration not only led to a change in intensity ratings but also in some cases a change in the descriptor. All four compounds in the same sample showed complicated interactive effects. Data were statistically analysed using relatively novel techniques such as statistical networks that allowed deeper insights into the interactions involved. Various observations were made such as the contribution of 3MH to the ‘green’ character of the wine, the potent suppressing abilities of methional on 3MH and IBMP and the additive effect of methional and IBMP contributing to the ‘cooked’ character of the sample. In the second research chapter the effect of repetitive oxidation on a fresh and fruity style Sauvignon blanc wine was investigated. Results showed the progress and evolution of aromatic and non‐aromatic compounds during an oxidative aging period. A large range of chemical analyses were conducted together with extensive sensory profiling. Results showed a decrease in volatile thiols responsible for the fruity nuances and an increase in oxidation‐related compounds, such as acetaldehyde, during the course of the oxidation. Sensory profiling showed the evolution of the wine aroma during oxidation. The wine evolved from a fresh and fruity wine to slight oxidation and then developed extreme oxidative characteristics. The Control samples (no oxygen added) developed a ‘cooked’ character which could indicate the formation of reductive compounds in these wines. Conversely, the wines that received a single dose of oxygen did not develop this flavour and were perceived to be more fresh and fruity than the Control samples. The evolution of the wine colour was also monitored using a spectrophotometer as well as a sensory panel and results suggest that the colour of the wine evolved before the disappearance of the pleasant aroma. The advantages and disadvantages of oxygen exposure to this type of wine style are discussed as well as the complexity of the wine matrix and sensory interactions occurring in the specific wine. The aim of the third research chapter was again to investigate further sensory interactions between Sauvignon blanc varietal aroma compounds and an oxidation‐related compound. After the observations reported in the second research chapter, the inclusion of acetaldehyde in an interaction study seemed to be of critical importance. Acetaldehyde can reach significant concentrations during oxidation and can have a detrimental effect on wine aroma. This interaction study included three compounds, 3MH, IBMP and acetaldehyde. Acetaldehyde was able to effectively mask the ‘green’ character of the sample, while it also enhanced certain fruity nuances when present at specific concentrations. 3MH was able to suppress the oxidising character of acetaldehyde when present at sufficient concentrations. The results from this study clearly showed the complexity of the wine medium and the interactions involved. It also highlighted the importance of performing these types of sensory studies in a simple medium opposed to a complex matrix such as wine. The effect of oxygen on various aspects of the wine was investigated and the combination of chemical and sensory data delivered some interesting conclusions also involving interactions that occurred. This study paved the way for future investigations on the sensory relationships of Sauvignon blanc aroma compounds and the role of proper oxygen management in the production of quality wines.
AFRIKAANSE OPSOMMING: Die doelwit van die studie was om die effek van gekontroleerde oksidasie op die ontwikkeling en verloop van verskeie chemiese komponente asook die ontwikkeling van die sensoriese profiel van ‘n Sauvignon blanc wyn te ondersoek. Bykomende studies ondersoek die interaksie/wisselwerking tussen aromakomponente in ‘n eenvoudige matriks. Interaksies tussen spesifieke Sauvignon blanc kultivargeassosieerde aromakomponente en komponente wat normaalweg tydens die oksidasie van witwyne ontwikkel, word ondersoek. Die eerste navorsingshoofstuk het ten doel om die interaksie tussen tipiese Sauvignon blanc aromakomponente (of impakkomponente) met aldehiede wat normaalweg tydens oksidasie van witwyne ontwikkel, na te vors. Vier komponente is in ‘n modelwyn gevoeg teen verskeie konsentrasies, wat oor die algemeen in die literatuur gerapporteer is om voor the kom in Sauvignon blanc wyne. Die komponente wat ondersoek is, is: 3‐merkaptoheksanol (3MH), 3‐isobutiel‐2‐metoksiepirasien (IBMP), 3‐ (metieltio)‐propionaldehied (methional) en fenielasetaldehied. Die sensoriese effekte van die komponente is deur ‘n opgeleide sensoriese paneel geëvalueer. Komponente is eers individueel geanaliseer en die resultate het getoon dat dat die intensiteit van die spesifieke aroma verander namate die konsentrasie verander. In sommige gevalle het die beskrywende woord vir die aroma ook verander. Deur al vier komponente in dieselfde monster te voeg word die ondersoek gekompliseer. Die data is statisties geanaliseer deur gebruik te maak van relatiewe nuwe tegnieke soos statistiese netwerke wat dieper insig in die betrokke interaksies bewerkstellig. Verskeie waarnemings word gerapporteer onder andere die bydrae van 3MH tot die ‘groen’ karakter van die wyn, die kragtige onderdrukkingsvermoë van methional op 3MH en IBMP asook die opbouende effek van methional en IBMP wat bydra tot die ‘gekookte’ karakter van die monster. Die tweede navorsingshoofstuk is daarop gemik om die effek van herhalende oksidasie op 'n vars en vrugtige styl Sauvignon blanc wyn te ondersoek en om die vordering en ontwikkeling van aromatiese en nie‐aromatiese komponente gedurende hierdie tydperk te analiseer. ‘n Wye reeks chemiese komponente is geanaliseer tesame met omvangryke sensoriese analise. ‘n Afname in die vlugtige tiole, wat verantwoordelik is vir die vrugtige geure, is gevind tesame met ‘n toename in oksidasie‐verwante komponente (soos asetaldehied). Sensoriese ondersoeke toon ook die evolusie van die wynaroma tydens oksidasie. Die wyn het ontwikkel van ‘n vars en vrugtige styl na effense oksidasiegeure waarna ekstreme oksidasiekarakters waargeneem is. Die Kontrole monsters het ‘n ‘gekookte’ karakter ontwikkel wat ‘n aanduiding van die ontwikkeling van ‘reduktiewe’ komponente in hierdie wyn kan wees. Aan die ander kant het wyne wat een suurstofdosering ontvang het, geen van hierdie geure ontwikkel nie en die wyn is as varser en vrugtiger beskryf in vergelyking met die Kontrole monsters. Die ontwikkeling van die wynkleur is ook gemonitor deur gebruik te maak van ‘n spektrofotometer asook 'n sensoriese paneel. Resultate stel voor dat die kleur van die wyn ontwikkel voor die aangename geure begin verdwyn. Die voor‐ en nadele van suurstofblootstelling aan hierdie tipe wynstyl word bespreek asook die kompleksiteit van die wynmatriks en sensoriese interaksies wat in hierdie spesifieke wyn voorkom. Die derde navorsingshoofstuk is weereens daarop gemik om die sensoriese interaksie tussen tipiese Sauvignon blanc kultivar‐geassosieerde aromakomponente en nog ‘n oksidasie‐geassosierde aromakomponent te ondersoek. Die resultate vanuit die tweede navorsingshoofstuk het die insluiting van asetaldehied in die interaksiestudie genoodsaak. Asetaldehied kan betekenisvolle konsentrasies tydens oksidasie behaal en kan ook nadelige effekte op wynaroma hê. Hierdie interaksiestudie het die volgende drie komponente ingesluit: 3MH, IBMP en asetaldehied. Asetaldehied het die ‘groen’ karakter van IBMP effektief gemaskeer terwyl dit die waarneming van die vrugtige aroma ondersteun en selfs verhoog het wanneer dit teen sekere konsentrasies teenwoordig was. 3‐Merkaptoheksanol het die oksidasiekarakter van asetaldehied onderdruk wanneer dit teen genoegsame konsentrasies teenwoordig was. Die kompleksiteit van wyn as ‘n navorsingsmedium is duidelik vanuit die studie veral in die ondersoeking van interaksie‐effekte tussen komponente. Die belangrikheid van die gebruik van 'n eenvoudige medium teenoor ‘n komplekse medium vir soortgelyke studies is dus duidelik. Die effek van suurstof op verskeie aspekte van witwyn is ondersoek en die kombinasie van chemiese en sensoriese data het interessante gevolgtrekkings gelewer. Die studie het die pad vir toekomstige studies gebaan in terme van sensoriese interaksies met betrekking tot Sauvignon blanc aroma. Die belangrikheid van oordeelkundige suurstofbestuur tydens die produksie van kwaliteit wyne is ook uitgelig.
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2

Fernandes, Gabriella Vanderlinde. "Ecofisiologia da videira (Vitis vinifera L.) sob cultivo protegido, variedades Sauvignon blanc, Cabernet sauvignon e Merlot." reponame:Repositório Institucional da UFSC, 2014. https://repositorio.ufsc.br/xmlui/handle/123456789/123373.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Florianópolis, 2014.
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O Estado de Santa Catarina tem se destacado no cenário nacional pelo potencial na produção de vinhos finos de qualidade, em função da altitude. No entanto, algumas regiões de Santa Catarina, como o município em estudo, Rancho Queimado, apresentam elevada pluviosidade no período de maturação e colheita, além de riscos de ocorrência de geadas e granizos, o que compromete a qualidade da uva. A cobertura plástica dos vinhedos surge como uma opção para o controle destas adversidades climáticas, principalmente, para evitar a ação do excesso de precipitação durante a maturação das uvas. No entanto, a utilização e o conhecimento desta técnica é incipiente em uvas destinadas à vinificação. Portanto, é importante a caracterização climática e a definição dos parâmetros ecofisiológicos de vinhedos sob cobertura para que seja explorado ao máximo o potencial vitícola e enológico destes locais. O objetivo desse trabalho foi avaliar as influências microclimáticas estabelecidas pela cobertura plástica sobre a fisiologia, o potencial produtivo e a qualidade vitienológica da videira (Vitis vinifera L.). As variedades avaliadas foram Sauvignon Blanc, Cabernet Sauvignon e Merlot, no município de Rancho Queimado-SC (altitude de 1000 metros, latitude de 27°42' 26" S, longitude 49°04' 17? W), durante os ciclos 2011/2012 e 2012/2013. O vinhedo foi implantado no ano de 2009 em sistema de condução espaldeira, sobre porta-enxerto Paulsen 1103, com espaçamento de 3,0 m x 1,0 m. As variáveis climáticas avaliadas foram: temperatura do ar (ºC); precipitação pluviométrica (mm); umidade relativa do ar (%); radiação solar global (Wm-2) e radiação fotossintética ativa (µmol fótons m-2s-1). As análises ecofisiológicas compreenderam as avaliações fenológicas entre a brotação e a colheita, área foliar, teores foliares de clorofila, avaliação das trocas gasosas e rendimento. Na colheita foram avaliados o teor de sólidos solúveis totais, acidez total titulável, pH, índice de polifenóis totais e antocianinas manoméricas totais, trans-resveratrol, catequina e epicatequina. Com relação à temperatura, as máximas diárias são as que mais sofrem influência do uso da cobertura plástica, com aumento em média de 2?C. As médias das temperaturas máximas, mínimas e médias, assim como a amplitude térmica e o somatório térmico em graus-dia são superiores no vinhedo coberto quando comparados ao descoberto. Enquanto que a radiação global, a radiação fotossinteticamente ativa, a umidade relativa do ar e a precipitação pluviométrica foram maiores no vinhedo descoberto. A presença da cobertura plástica reduz em 28% a radiação fotossinteticamente ativa incidente sobre o dossel vegetativo, e em 32% a radiação solar global em todo o ciclo da videira. Devido ao aumento no somatório de graus-dia, a cobertura plástica sobre o vinhedo antecipou o início da brotação e demais eventos fenológicos até a mudança de cor das bagas. Entretanto, a redução da radiação solar proporcionou o prolongamento do processo de maturação das uvas. Uvas das variedades Cabernet Sauvignon e Merlot produzidas na área coberta apresentaram menores teores de acidez e maiores teores de sólidos solúveis totais, pH, polifenóis totais, catequinas e epicatequinas. Uvas cobertas de Merlot apresentram maiores teores de antocianinas manoméricas totais e de resveratrol. Houve incremento no teor de sólidos solúveis totais em uvas Sauvignon Blanc sob cobertura plástica. O teor de resveratrol foi reduzido em uvas das variedades Cabernet Sauvignon e Sauvignon Blanc cobertas, enquanto o conteúdo de catequinas e epicatequinas foram superiores em comparação as uvas do vinhedo descoberto. As uvas produzidas a partir do vinhedo coberto apresentam melhor qualidade do que em céu aberto, como consequência da melhor sanidade dos cachos. Os resultados obtidos na avaliação das trocas gasosas sugerem que o processo fotossintético foi beneficiado pelo microclima propiciado pela cobertura, e isto foi refletido na maior produtividade das plantas. Houve aumento das concentrações dos pigmentos nas folhas de plantas cobertas das variedades Cabernet Sauvignon na fase de maturidade e Sauvignon Blanc no ciclo 2012/13. As plantas cobertas das três variedades avaliadas mantiveram suas folhas cerca de 28 dias a mais do que as plantas descobertas. A presença da cobertura plástica aumenta a produtividade das variedades Cabernet Sauvignon em 54% e Sauvignon Blanc em 30%. E melhora a relação área foliar:produtividade de todas as variedades avaliadas.

Abstract : In last years viticulture in high altitude regions of Santa Catarina State has been highlighted for producing wines of unique quality in Brazil. Some regions of Santa Catarina State, as the city under study, Rancho Queimado, have high rainfall in maturation and harvest period, as well as risk of occurrence of frosts and hail, which compromises grape quality. The plastic cover is an option to control weather adversities especially to avoid excessive rainfall during the grape ripening. However, the use and knowledge of this technique is incipient to grapes for winemaking. The objective of this study was to evaluate the microclimate influences established by the plastic cover on the physiology, production potential and enological quality of the vine (Vitis vinifera L.). The varieties evaluated were Sauvignon Blanc, Cabernet Sauvignon and Merlot in the city of Rancho Queimado - Santa Catarina State (latitude 27 ° 42 '26 "S, longitude 49 ° 04' 17" W, altitude 1,000 meters), during seasons 2011/2012 and 2012/2013. The vineyard was planted in 2009, trained in vertical shooting positioning trellis, grafted on 1103P and spacing 3.0 x 1.0 m. Climatic data evaluated were precipitation (mm), relative humidity (%), maximum, air temperature (°C), global radiation (Wm-2) and photosynthetically active radiation (µmol photons m-2s-1). Ecophysiological analyzes were: phenological assessments between budbreak and maturity, leaf area, leaf chlorophyll content, leaf gas exchanges and yield. At harvest were evaluated total soluble solids, total acidity, pH, total polyphenols, total monomeric anthocyanins, trans-resveratrol, catechin and epicatechin. Regard to temperature, daily maximum suffers the greatest influence by the use of plastic cover, with an average increase of 2°C. The maximum, minimum and mean temperatures as well as thermal amplitude and heat summation (growing degree-days) are higher in the covered vineyard. While global radiation, photosynthetically active radiation, relative humidity and precipitation are higher in the uncovered vineyard. Due to the increase in the heat summation, the plastic cover antecipates budbreak and other phenological events until veraison. However, the reduction of solar radiation prolong the maturation process. Cabernet Sauvignon and Merlot produced under plastic cover present lower acidity and higher total soluble solids, pH, total polyphenols and catechins. Merlot produced under plastic cover presents higher contents of total monomeric anthocyanins and trans-resveratrol. Sauvignon Blanc under plastic cover presents higher contents of total soluble solids. The resveratrol content is reduced in covered Cabernet Sauvignon and Sauvignon Blanc, while the content of catechins and epicatechins are higher in the uncovered vineyard. The presence of the plastic cover reduces 28% of photosynthetically active radiation incident on the canopy, and 32% of global solar radiation throughout the cycle of the vine. The grapes produced in the covered vineyard have better quality as a result of better cluster sanity. The plastic cover influences vine phisiology. The results obtained in the evaluation of leaf gas exchange suggest that the photosynthetic process is benefited by the microclimate afforded by the cover, and this is reflected in higher plant yield. The plastic cover also increases the pigments concentrations in the leaves of Cabernet Sauvignon and Sauvignon Blanc (season 2012/13). The plants covered from the three varieties keep their leaves about 28 days longer than the uncovered ones. The plastic cover increases 54% of Cabernet Sauvignon yield and 30% of Sauvignon Blanc yield. And also improves the leaf area:yield ratio of all tested varieties.
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3

Harsch, Michael Johannes. "Identification of yeast genes involved in sauvignon blanc aroma development." Thesis, University of Auckland, 2009. http://hdl.handle.net/2292/5293.

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The grape variety Sauvignon Blanc (SB) is the flagship of New Zealand’s wine industry and accounted for over 75 % of the value of total wine exports in 2008. Two volatile thiols, 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl-acetate (3MHA), reminiscent of grapefruit and passion fruit respectively, are critical for the main varietal characters in New Zealand SB. These aromatic thiols are not present in the grape juice, but are synthesized and released by the yeast during alcoholic fermentation from non-aromatic precursors. The aim of this work was to elucidate the underlying genetics of volatile thiol synthesis in yeast (Saccharomyces cerevisiae) during alcoholic fermentation of grape juice. A gene-deletion strategy was chosen for the investigation of putative genes influencing 3MH and 3MHA release. The first part of this thesis optimized fermentation conditions in grape-juice-based media, which enabled auxotrophic laboratory strains, derived from S288C, to ferment grape juice to completion with high efficiency. Key steps to achieving this goal were the supplementation of the grape juice with higher than recommended amounts of amino acids, which increased the fermentation rate of auxotrophic yeast strains. Lysine auxotrophic strains especially benefited from this measure. In combination with the dilution of SB grape juice by 25 % with synthetic grape juice without sugars, the auxotrophic laboratory yeast BY4743 was able to metabolize all sugars in the grape juice-based media in a time frame similar to that of a commercial wine yeast. The key properties of the resulting wine were comparable to wine made with a commercial wine yeast under the same conditions. In the second part, these newly developed fermentation conditions were employed to screen 69 single-gene deletion strains in the laboratory yeast background BY4743. The list of the 69 candidate genes was compiled by combining existing knowledge about thiol production in yeast with the mining of several biological databases. Screening of the single-gene deletions revealed 17 genes which caused biologically relevant increases or decreases in volatile thiol production, but none abolished it. The majority of the 17 genes were related to the sulfur and nitrogen metabolism in yeast. A subset of these thiol-influencing genes were also deleted in a wine yeast, and were overexpressed in both wine yeast and laboratory yeast, to gain more insight in their regulatory effects. The findings confirmed that sulfur and nitrogen metabolism in yeast were important in regulating 3MH and 3MHA synthesis. Different sulfur and nitrogen sources were added to the grape must prior to fermentation and their effect on thiol release was studied. It was found that nitrogen sources urea and DAP, as well as, the sulfur compound S-ethyl-L-cysteine (SEC) increased 3MH and 3MHA concentrations in the resulting wines. The addition of cysteine to grape juice fermented with wine yeast deleted in genes CYS3 and CYS4 more than doubled total thiol production. Mapping approaches to investigate thiol production in yeast were employed in the final part of this thesis. Genetically mapped F2 progeny of a cross between a low thiol-producing yeast strain and a high-thiol producer were screened for their thiol phenotype. The 3MH and 3MHA phenotypes across 48 screened F2 progeny resembled normal distributions, indicating a quantitative trait. Subsequent mapping identified a locus on chromosome 14 with a small effect on the 3MHA phenotype, but no obvious candidate genes were evident in the region. Another approach to investigate the evolution of volatile thiols in yeast included the use of SEC, a thiol compound resembling the cysteinylated precursor of 3MH, as a sole nitrogen source in a yeast growth assay. It was found that most wine yeast, European yeast isolates and laboratory yeasts could utilize SEC as a nitrogen source, whereas various other S. cerevisiae isolates could not. Crosses between three pairs of Sec- and Sec+ yeast strains strongly indicated that this trait was monogenically inherited. However, no direct correlation between the SEC phenotype and volatile release could be observed. Genetic mapping experiments in one SEC-segregating yeast population linked this SEC phenotype to the leu2-D0 deletion in a cross between a Leu+ and Leu- yeast strain. It was shown that leucine auxotrophy most likely caused the Sec- phenotype. In a second F2 population of a cross between prototrophic Sec+ and Sec- strains, strong linkage was established to a region on chromosome 6 containing two candidate genes, DUG1 and IRC7. DUG1 was proved not to be the cause of the SEC phenotype, whereas IRC7 remains a strong candidate gene.
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4

Treurnicht, Jeanne. "Authentication of Sauvignon blanc wine in terms of added flavourings." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6594.

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Thesis (MSc (Wine Biotechnology))--University of Stellenbosch, 2011.
Includes bibliography.
ENGLISH ABSTRACT: The varietal character of Sauvignon blanc wine is mostly defined by the balance between tropical and green vegetative flavour nuances. Grape derived methoxypyrazines are the main aroma contributors towards green vegetative flavours. Methoxypyrazines are heat and light sensitive. Due to warm climatic conditions in South Africa, methoxypyrazine levels decrease during grape ripening. The addition of food flavourings to Sauvignon blanc wine, a practice known as spiking, has occurred in the past to improve the green character of the wines. Adding flavourings to wine and selling the wine as natural certified wine is illegal in South Africa. Currently, adulterated Sauvignon blanc wines are identified using gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS) methods to quantify methoxypyrazines and compare levels to an established database. Although of high sensitivity, GC-MS and LCMS methods are costly and time consuming, therefore not optimal for routine screening of wines. Hence the need for the development of a fast and cost effective method for routine screening of large amounts of wines to identify adulteration. Small scale vinification practices were used to prepare experimental Sauvignon blanc wine. Flavourings were added to Sauvignon blanc grape juice before fermentation, during the preparation of experimental spiked wines. Control wines, containing no flavouring, were also prepared. Commercial wines were spiked after fermentation and bottling. Each wine was only spiked with a single flavouring. The flavourings added were the juice of homogenised fresh green peppers and commercially available flavourings for wine. The following commercial flavourings were used: green pepper, asparagus, grassy and tropical. The above mentioned wines were analyzed using Fourier transform infrared (FT-IR) spectroscopy, GC-MS, LC-MS and descriptive sensory analysis. The FT-IR techniques used were Fourier transform mid infrared (FT-MIR) transmission, FT-MIR attenuated reflection and Fourier transform near infrared (FT-NIR) reflection spectroscopy. The data was interpreted using the following multivariate statistical techniques: principal component analysis (PCA), partial least squares discrimination (PLS-D) and conformity testing. Multivariate models constructed from FT-MIR and FT-NIR data were able to discriminate between spiked and control wines. Sensory analysis results clearly showed differences between non-spiked wines and spiked wines with 3-isobutyl-2-methoxypyrazine concentrations 10 times higher than naturally occurring in wine. Differences between control and spiked wines with concentrations of 3-isobutyl-2-methoxypyrazine similar to concentrations naturally occurring in wines could not be detected to prove adulteration conducting sensory analysis. However, differences between control and spiked wines with levels of 3-isobutyl-2-methoxypyrazine similar to levels naturally occurring in wines could be detected using FT-IR data in conjunction with multivariate statistics. This study showed that, FT-IR spectroscopy in conjunction with multivariate statistical methods can be a possibility for the screening and identification of wines suspected of adulteration in terms of added flavourings. Descriptive sensory analysis also proved to be a potentially useful tool. However screening and training of potential panel members are time consuming.
AFRIKAANSE OPSOMMING: Die variëteitskarakter van Sauvignon blanc wyn word grotendeels gedefinieer deur die balans tussen tropiese en groen vegetatiewe aromas. Metoksipirasiene is die hoof aroma verbindings wat verantwoordelik is vir groen vegetatiewe aromas. Metoksipirasien is hitte- en ligsensitief. Warm klimaatsomstandighede in Suid-Afrika het tot gevolg dat metoksipirasien konsentrasies daal tydens druif rypwording. Sauvignon blanc wyne is in die verlede vervals deur middel van die byvoeging van vars groen soetrissies om die groen vegetatiewe karaktereienskappe van die wyne te bevorder. Die byvoeging van geurmiddels of plantekstrakte by wyn en verkoop van daardie wyn as gesertifiseerde natuurlike wyn is onwettig in Suid-Afrika. Tans word vervalsde wyne met behulp van gaschromatografie-massaspektrometrie (GC-MS) en vloeistofchromatografie-massaspektrometrie (LC-MS) opgespoor. Kwantifisering van metoksiepirasien konsentrasies in wyne en druiwesappe word vergelyk met konsentrasies in ‘n bestaande databasis. Alhoewel GC-MS en LC-MS hoë sensitiwiteitsmetodes is, is dit duur en tydrowende metodes, dus nie optimaal vir roetine sifting nie. Dus word ‘n koste- en tydseffektiewe roetine metode benodig om vervalsing van wyne op te spoor. Eksperimentele wyne is op klein skaal berei. Geurmiddels is voor fermentasie by die druiwesap gevoeg. Kontrole wyne waarby geen geurmiddels gevoeg is nie, is ook berei. Kommersiële wyne is gegeur na fermentasie en bottelering. Elke wyn is met ‘n enkele geurmiddel gegeur. Gehomogeniseerde vars groen soetrissie asook kommersieel beskikbare geursels vir wyn is gebruik. Die volgende kommersiële geursels is gebruik: groen soetrissie, aspersie, gras en tropiese geursel. Die volgende analitiese tegnieke is gebruik vir analisering van bogenoemde wyne: Fourier transformasie infrarooi (FT-IR) spektroskopie, GC-MS, LC-MS en beskrywende sensoriese analise. Die spesifieke FT-IR tegnieke wat gebruik is, is: Fourier transformasie mid-infrarooi (FT-MIR) transmissie, FT-MIR verswakte weerskaatsing en Fourier transformasie naby-infrarooi (FT-NIR) reflektansie. Die volgende multiveranderlike statistiese tegnieke is gebruik ter interpretasie van data: hoof komponent analise (PCA), parsiële kleinste kwadraat diskriminant analise (PLS-D) en gelykvormigheidstoetsing. Multiveranderlike modelle, bereken met behulp van FT-MIR en FT-NIR data, kon diskrimineer tussen gegeurde en kontrole wyne. Resultate wat verkry is tydens sensoriese analises het duidelike verskille uitgewys tussen gegeurde en kontrole wyne met betrekking tot 3-isobutiel-2- metoksipirasien konsetrasies waar 3-isobutiel-2-metoksipirasien konsentrasies 10 keer hoër was as wat natuurlik voorkom in wyn. Geen beduidende verskille kon waargeneem word in gevalle waar wyne vervals is met laer konsentrasies van geurmiddels deur sensoriese data te ontleed nie. Nietemin, statisitiese verskille tussen kontrole en vervalsde wyne kon waargeneem word vir lae-konsentrasie-geurmiddel vervalsde wyne deur FT-IR data met behulp van multiveranderlike statisitiese metodes te ontleed. Hierdie studie het gewys dat FT-IR in kombinasie met multiveranderlike statistiese tegnieke spesifiek hoof komponent analise (PCA) en parsiële kleinste kwadraat diskriminant analise (PLS-D) asook gelykvormigheidstoetsing bruikbare tegnieke is om te onderskei tussen kontrole (egte natuurlike) en vervalsde wyne ten opsigte van die byvoeging van geurmiddels. Beskrywende sensoriese analise kan ook nuttig gebruik word, alhoewel keuring en opleiding van paneellede tydrowend is.
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Silva, Tatiane Carine da. "Crescimento vegetativo e diferenciação floral em videiras 'sauvignon blanc' e 'cabernet sauvignon' cultivadas em São Joaquim - SC." reponame:Repositório Institucional da UFSC, 2015. https://repositorio.ufsc.br/xmlui/handle/123456789/135648.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Florianópolis, 2015.
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A viticultura catarinense é uma atividade econômica em plena expansão e, nos últimos anos, vem buscando a melhoria dos vinhedos para produção de uvas e vinhos de alta qualidade. Nas regiões de altitude de Santa Catarina, a vitivinicultura ainda é muito recente e pouco se sabe sobre o comportamento ecofisiológico das plantas cultivadas. Dentre as variedades de maior importância econômica na região estão a Sauvignon Blanc e a Cabernet Sauvignon. Este estudo teve como objetivos caracterizar o crescimento vegetativo e os níveis de hormônios endógenos em ápices dos ramos, e caracterizar a diferenciação floral morfológica em gemas das videiras  Sauvignon Blanc e  Cabernet Sauvignon , cultivadas em São Joaquim-SC, no ciclo fenológico 2013/2014. A área experimental está localizada em um vinhedo comercial conduzido em sistema espaldeira, em altitude de 1.293m (28º15'13"S e 49º57'02"W). O delineamento experimental utilizado foi o completamente casualizado (DCC). Durante o ciclo foi realizado o acompanhamento da fenologia e das variáveis meteorológicas. As avaliações e coletas foram realizadas quinzenalmente. A partir da brotação foi acompanhada a evolução do crescimento vegetativo de 20 plantas por variedade, medindo-se o comprimento dos ramos da base até o ápice. Foram coletados aleatoriamente no vinhedo, ápices dos ramos das videiras para identificação e quantificação de hormônios endógenos (GA3 e GA4, AIA, ABA, cZ e tZ, SA e JA), através de Cromatografia Líquida de Ulltra Performance (UPLC) e Electrospray Ionization - Mass Spectrometry/Mass Spectrometry (ESI-MS/MS). Foram coletadas as cinco gemas basais de oito ramos por variedade para observação, em estereomicroscópio e microscopia eletrônica de varredura (MEV), dos estádios iniciais da diferenciação floral. Pode-se observar que o padrão de crescimento dos ramos foi similar para as duas variedades estudadas, sendo a maior taxa de crescimento observada no final da primavera, na primeira quinzena de dezembro (11/12/2013), após a plena floração. A paralisação do crescimento dos ramos ocorreu no verão, durante o período de maturação das bagas, no início de fevereiro (04/02/2014) para a Cabernet Sauvignon e em meados de fevereiro (18/02/2014) para a Sauvignon Blanc. A paralisação do crescimento foi induzida pela diminuição do fotoperíodo. As baixas temperaturas (<10°C) parecem estar associadas a uma resposta adicional no processo de aclimatação ao frio. As concentrações de ABA, SA e JA nos ápices dos ramos aumentaram durante a evolução do ciclo vegetativo, tendo suas máximas concentrações durante o período inicial de formação das bagas, antes da véraison. Os níveis hormonais nos ápices dos ramos apresentaram comportamento similar ao longo do ciclo para ambas as variedades. A  Cabernet Sauvignon apresentou concentrações maiores dos hormônios: ABA, SA e JA em comparação com a  Sauvignon Blanc . As concentrações de tZ não variaram significativamente ao longo do ciclo da  Cabernet Sauvignon e este fitormônio não foi quantificado para a  Sauvignon Blanc . Não foi possível quantificar os hormônios: GA3, GA4, AIA e cZ nos ápices de ambas as variedades. O início da diferenciação floral nas gemas ocorreu antes da floração para ambas as variedades, sendo 25 dias antes da plena floração (30/10/2013) para a  Sauvignon Blanc e 8 dias antes da plena floração (12/11/2013) para a  Cabernet Sauvignon . O primórdio de inflorescência totalmente desenvolvido foi identificado para a  Sauvignon Blanc antes da véraison, enquanto para a  Cabernet Sauvignon após a mudança de cor das bagas. Os resultados deste estudo possibilitaram a melhor compreensão do efeito das condições climáticas e do controle hormonal sobre o crescimento vegetativo da videira cultivada em São Joaquim-SC. Neste trabalho também identificou-se as fases fenológicas em que ocorreram os estágios iniciais da diferenciação floral das variedades na região.

Abstract : Santa Catarina viticulture is an expanding economic activity which is seeking in the last years to improve the vineyards for production of higher quality grapes and wines.The grapevine and wine production in Santa Catarina Highlands is still recent and little is known about grapes ecophysiological behavior. Sauvignon Blanc and Cabernet Sauvignon are among varieties of greater economic importance in this region. This study aimed to characterize the vegetative growth and the endogenous hormones levels in shoots apexes, and to characterize the morphological floral differentiation in grapevine buds of  Sauvignon Blanc and  Cabernet Sauvignon grown in São Joaquim/SC, at phonological cycle 2013/2014. Experimental area is located in a commercial vineyard conducted in VSP system (vertical shoot positioned), at 1.293m altitude (28º15'13"S and 49º57'02"W). The experimental design was completely randomized blocks. Phenology and weather variables were monitored during the season. Analysis and samples were taken every two weeks. From budburst on, shoot growth was assessed in 20 plants per variety, measuring the length from the base to the shoot apex. Aapexes of shoots were collected randomly for endogenous hormones (GA3 and GA4, AIA, ABA, cZ and tZ, SA and JA) identification and quantification using Ultra Performance Liquid Chromatography (UPLC) and Electrospray Ionization - Mass Spectrometry / Mass spectrometry (ESI-MS / MS). For floral differentiation analysis, five basal buds from eight shoots per variety were collected, and observations of the early stages of floral differentiation in stereomicroscope and scanning electron microscopy (SEM) were performed. It was observed similar pattern of shoot growth for both varieties, with higher growth rate in late spring, on the first half of December (12/11/2013), after full bloom. Shoot growth cessation occurred in the summer, during grape berry ripening, in early February (02/04/2014) for  Cabernet Sauvignon and in mid-February (18/02/2014) for  Sauvignon Blanc . Growth cessation was induced by photoperiod decrease. Low temperatures (<10°C) seem to be associated to an additional response in the process of cold acclimation. ABA, SA and JA concentration in apexes of the shoots increased during the course of the season, with maximum levels in the initial period of berry formation, before véraison. Hormone levels in shoot apexes showed similar behavior during cycle for both varieties.  Cabernet Sauvignon presented higher concentration of hormones (ABA, SA and JA) compared to  Sauvignon Blanc . For both varieties, changes in hormones levels in the apexes during the growth cycle had similar behavior. Concentrations of tZ did not present significant variation for  Cabernet Sauvignon and this plant hormone could not be quantified for  Sauvignon Blanc . It was not possible to quantify GA3, GA4, AIA and cZ in the apexes of shoots for both varieties. The beginning of floral differentiation in buds occurred before flowering for both varieties, 25 days before full bloom (10/30/2013) for 'Sauvignon Blanc' and 8 days before full bloom (12/11/2013) for  Cabernet Sauvignon . The fully development of inflorescence primordium was identified for 'Sauvignon Blanc' before véraison, while for  Cabernet Sauvignon it was after berries color change . Results of this study provided a better understanding of the effect of weather conditions and hormonal control over the vegetative growth of grapevine grown in São Joaquim-SC. In this work it was also identified the phenological phases when the early stages of floral differentiation of varieties in the region occurred.
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Herrmann, Lukas Karl. "Effects of must turbidity on fermentative aroma development in Sauvignon blanc." Master's thesis, ISA-UL, 2016. http://hdl.handle.net/10400.5/13010.

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Mestrado Vinifera Euromaster - Viticulture and Enology - Instituto Superior de Agronomia - UL / Institut National d'Etudes Superieures Agronomiques de Montpellier
In many ways New Zealand has become an ideal for a New World wine country. With the first commercial Sauvignon blanc only released in 1974, Sauvignon blanc fought its way to become not only the flagship of New Zealand`s wine industry, holding around 66 % of the country’s total grape production at the 2015 harvest, but also made its way to be recognized for its outstanding quality all over the world. For some critics, New Zealand Sauvignon blanc is arguably the best in the world and others called the Marlborough wine region the best place to grow Sauvignon blanc in New Zealand. Even though testimonies like that may be subjective as taste lies on the tongue of the beholder, New Zealand Sauvignon blanc clearly came a way plastered with success leading to an export value of $1.424 billion NZD in 2015. Key to this success is that the industry found a way to distance itself from its French archetype, world famous Sauvignon blanc originated from the Loire valley, and reinvented itself, introducing a unique winestyle that does not need to shy any comparison. In the heart of this winestyle aroma compounds of the thiol group play an important role. Derived during yeast activity during fermentation from non-odorous precursors found in grapejuice, the two most important thiols that have been related with Marlborough Sauvignon blanc are 3MH and 3MHA. These deliver exotic nuances reminiscent of grapefruit, passionfruit, gooseberry, guava and boxtree. Due to the high oxidability of thiols, several strategies have been adapted by the industry to preserve these key compounds and their non-odorous precursors during the processing of grapes, which includes harvesting, transportation, processing and storage. Although a lot of research has been carried out to further understand the relations between precursors, thiols and their preserving, and to be able to continuously contrast New Zealand Sauvignon blanc from competitors, many questions still remain unclear at the present day. One of them is the effect of juice turbidity on aroma development during fermentation. Research has revealed a broad idea on the positive and negative effects, caused by micronutrients and physical parameters of grape solids derived during process steps leading to juice extraction from the berries on fermentation kinetics and general aroma development. To my best knowledge no research has been published to the present day that focuses on the effect of juice turbidity on the thiol development and expression in Sauvignon blanc ferments. This masterthesis in hand, with the title “Effects of must turbidity on fermentative aroma development in Sauvignon blanc” is supposed to give an overview over the state of research on Sauvignon blanc with a further focus on the question about possible effects and practical applications of juice turbidity. Finally, this work tries to improve the small scale winemaking protocol of Plant and Food Research, Blenheim, where this research has been conducted.
N/A
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Lund, Cynthia M. "Investigation of New Zealand Sauvignon Blanc Wine Using Trained Sensory Panels." Thesis, University of Auckland, 2009. http://hdl.handle.net/2292/5168.

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ABSTRACT A core tool of sensory science is the use of trained descriptive panels. This research describes an investigation into the role of motivation in the performance of trained panels and the use of a trained panel to develop a better understanding of the perception of Sauvignon blanc wines. Substantial investment in time and money is directed towards ensuring trained panels perform optimally. Having selected a panel, the panel leader needs to ensure that panellists provide accurate, reliable data. Panellist motivation is also an important factor to consider. While performance psychology, education and sport science fields have researched motivation extensively, knowledge about panellist motivation within sensory science is limited. However, findings from existing research in these other areas - which suggest an important role for autonomy, competence and relatedness - can be applied to sensory panels in order to increase intrinsic motivation. The initial part of the research investigated the fundamental factors that affect and influence panellists’ motivation and participation. A survey (n=74) revealed that extra income and a general interest in food were the key drivers in inspiring people to become panellists, whilst enjoyment in being a panellist, interest in food, and extra income were key drivers for people to remain panellists. In a second survey, the intrinsic motivation of seven trained panels from four countries (n=108) was assessed. External panels were found to be more intrinsically motivated than internal panels. Experienced panellists had an increased perception of competence, which is a key factor for people to be intrinsically motivated. Understanding motivational frameworks currently used in other research fields and integrating them into existing panel training protocols may enhance and sustain panellists’ intrinsic motivation. A trained panel (n=14) was then used in the second part of the thesis to identify key flavours in Sauvignon blanc wines from Australia, France, New Zealand, Spain, South Africa and USA. Sixteen characteristics were identified and measured, including sweet sweaty passionfruit, capsicum, passionfruit skin/stalk, boxwood/cat’s urine, grassy, mineral/flinty, citrus, bourbon, apple lolly/candy, tropical, mint, fresh asparagus, canned asparagus, stonefruit, apple and snowpea. Principal component analysis was used to describe differences between regions and countries. Sauvignon blanc wines from Marlborough, New Zealand (NZ), were described by tropical and sweet sweaty passionfruit characteristics, while French and South African Sauvignon blanc wines were described as having flinty/mineral and bourbon-like flavors. Chemical analyses of these wines also showed that Marlborough, NZ wines had more methoxypyrazine and thiol compounds. A consumer study (n=109) showed that New Zealanders significantly prefer New Zealand style Sauvignon blanc. The final part of this research focused on using trained panellists to explore the interactions between volatile and non-volatile wine compounds and their effects on the aroma profile of New Zealand Sauvignon blanc wine. Four volatile aroma compounds that are important in New Zealand Sauvignon blanc wine were studied (isobutyl methoxypyrazine [MIBP], 3-mercaptohexanol [3MH], 3-mercaptohexanol acetate [3MHA], and ethyl decanoate). Each of these four aroma compounds were assessed in combination with three non-volatile polyphenolic compounds commonly found in Sauvignon blanc wine: catechin, caffeic acid and quercetin. Results showed each polyphenol had a unique effect when blended with a specific aroma compound, either suppressing, accentuating, or showing little effect on the perception of the aroma compounds. The perception of MIBP, 3MH, and ethyl decanoate were largely suppressed by the added polyphenols, with a few exceptions. The perception of 3MH was accentuated with the addition of caffeic acid, and the perception of 3MHA was accentuated with the addition of catechin. The interactive effects of aroma compounds with polyphenols likely reflect non-covalent associations in the wine solution that reduce the volatility of the aroma compounds. With an understanding of the interactive effects of volatile and non-volatile compounds in wine, winemakers might optimize the impact of selected volatile compounds by managing polyphenol levels, supporting their efforts to attain desirable wine aroma profiles.
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Van, Wyngaard Elizma. "Volatiles playing an important role in South African Sauvignon blanc wines." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80274.

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Thesis (MScAgric)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: Sauvignon blanc wines have become progressively more important in the commercial market. Extensive research is being done in various countries to gain more understanding about the aroma compounds found in Sauvignon blanc wines and the interactions between them. Sauvignon blanc wines often have either have a green or tropical style. The green style is caused by the methoxypyrazines while the volatile thiols are important contributing compounds to the tropical style. Various international studies have focussed on measuring the chemical composition of Sauvignon blanc wines. However, more research is required on South African Sauvignon blanc wines. Little is known of the volatile thiols content of South African Sauvignon blanc wines, although the methoxypyrazine content has been extensively reported on. Although methoxypyrazines and volatile thiols are seen as the most important aroma compounds contributing to Sauvignon blanc character, other compounds contribute as well. Esters, monoterpenes and phenols have been found to influence Sauvignon blanc aroma and interact with the methoxypyrazines and volatile thiols. The complex interaction between the compounds responsible for the aroma of Sauvignon blanc wines are still not fully understood and further research is thus needed. The first part of the current study investigated the interaction between a specific methoxypyrazine and volatile thiol. Five different concentrations of 2-isobutyl-3- methoxypyrazine (ibMP) and 3-mercaptohexan-1-ol (3MH) were spiked in dearomatize, neutral Sauvignon blanc wine. The single compounds as well as every possible combination of the range of concentrations were evaluated using sensory descriptive analysis. It was found using various statistical approaches that ibMP suppressed the tropical attributes associated with 3MH and that 3MH suppressed the green attributes that correlated with ibMP. The concentrations at which the suppression occurred and the degree of suppression was different for each attribute. The second part of the current study focussed on commercial South African Sauvignon blanc wines. Sensory descriptive analysis and chemical analysis were used to assess the wines and measure the volatile thiol and methoxypyrazine concentrations. The concentrations of volatile thiols and methoxypyrazines were found to be in line with international Sauvignon blanc wines. It was also shown for the first time that the mutually suppressive trend between the volatile thiols and methoxypyrazines can be seen in commercial Sauvignon blanc wines as well. Future work is needed to fully understand the complex interaction between the various compounds in Sauvignon blanc wines. Further research could focus on investigating the mechanism of interaction between the volatile thiols and methoxypyrazines as well as other aroma compounds.
AFRIKAANSE OPSOMMING: Sauvignon blanc-wyne word toenemend belangriker in die kommersiële mark. Omvattende navorsing word in etlike lande gedoen om meer begrip te ontwikkel van die aromaverbindings wat in Sauvignon blanc-wyne teenwoordig is, asook van die interaksies tussen hulle. Sauvignon blanc-wyne het in baie gevalle óf ’n groen óf ’n tropiese styl. Die groen styl word veroorsaak deur metoksipirasiene, terwyl die vlugtige tiole belangrike bydraende verbindings is wat aanleiding gee tot die tropiese style. Verskeie internasionale studies het reeds gefokus op die meet van die chemiese samestelling van Sauvignon blanc-wyne, maar meer navorsing is nodig oor Suid-Afrikaanse Sauvignon blanc-wyne. Min is bekend oor die inhoud van vlugtige tiole in Suid-Afrikaanse Sauvignon blanc-wyne, hoewel daar reeds op groot skaal oor die metoksipirasieninhoud verslag gedoen is. Hoewel metoksipirasiene en vlugtige tiole die belangrikste aromaverbindings is wat tot Sauvignon blanc-karakter bydra, is daar ook ander verbindings wat ’n bydrae maak. Esters, monoterpene en fenole het almal ’n invloed op Sauvignon blanc-aroma en reageer op die metoksipirasiene en vlugtige tiole. Die komplekse interaksie tussen die verbindings wat vir die aroma van Sauvignon blanc-wyne verantwoordelik is, word nog nie volledig begryp nie en verdere navorsing is nodig. Die eerste deel van die huidige studie het die interaksie tussen ’n spesifieke metoksipirasien en vlugtige tiol ondersoek. Vyf verskillende konsentrasies van 2-isobutiel-3-metoksipirasien (ibMP) en 3-merkaptoheksaan- 1-ool (3MH) is by ontgeurde, neutrale Sauvignon blanc-wyn gevoeg. Die enkel verbindings, asook elke moontlike kombinasie van die reeks konsentrasies, is deur middel van beskrywende sensoriese analise geëvalueer. Daar is met behulp van verskillende statistiese benaderings gevind dat ibMP die tropiese eienskappe wat verband hou met 3MH onderdruk het, terwyl 3MH die groen eienskappe wat verband hou met ibMP onderdruk het. Die konsentrasies waarteen die onderdrukking plaasgevind het en die vlak van onderdrukking het vir elke eienskap verskil. Die tweede deel van die studie het gefokus op kommersiële Suid-Afrikaanse Sauvignon blancwyne. Beskrywende sensoriese analise en chemiese analise is gebruik om die wyne te assesseer en die konsentrasies van vlugtige tiole en metoksipirasiene te meet. Die konsentrasies vlugtige tiole en metoksipirasiene was in lyn met dié van internasionale Sauvignon blanc-wyne. Daar is ook vir die eerste keer gewys dat die wedersyds onderdrukkende tendens tussen die vlugtige tiole en metoksipirasiene ook in kommersiële Sauvignon blanc-wyne gevind word. Toekomstige werk sou kon fokus op ’n begrip van die komplekse interaksie tussen die verskillende verbindings in Sauvignon blanc-wyne. Verdere navorsing sou ook kon fokus op ’n ondersoek van die meganisme van interaksie tussen die vlugtige tiole en metoksipirasiene, sowel as ander aromaverbindings.
The South African Wine Industry (Winetech), THRIP and the NRF for financial support
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Coetzee, Zelmari. "Site and vintage response of malic and tartaric acid in Vitis vinifera L. cv’s Cabernet Sauvignon and Sauvignon blanc." Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85736.

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Thesis (MScAgric)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: Acids are one of the major components that originate largely from the berry, that are found in wine, and that influence the sensory perception. The presence of organic acids in adequate concentrations in the grape berry, of which tartaric- and malic acid are the main organic acids present, is important as this determines the potential of a must to produce a good and stable wine. The effect of temperature on the organic acid content of the must is widely discussed with higher temperatures in general being associated with lower quantities of organic acids present in the juice, and lower temperatures during ripening associated with higher quantities, specifically in the case of malic acid. Due to the topographical diversity of the Stellenbosch Wine of Origin district and the closeness of the ocean and the occurrence of sea breezes, the mesoclimate differs greatly over short distances. Sixteen sites, consisting of eight Sauvignon Blanc and Cabernet Sauvignon sites respectively, were selected from a broader terroir study site network. Three vintages with complete climatic datasets were selected for vintage comparisons. Climate in the study area was monitored on differing scales, and data from a weather station network, as well as from mesoclimatic dataloggers within the sites were available. The available data was firstly compared to determine the variability of the data, not only between the two climatic scales, but also between the sites. Different climate classification indices and parameters available in literature were thereafter compared and evaluated for the best representation in this area. The Huglin index was found to be a better representation regarding the thermal climatic indices. Due to the great differences between temperatures noted for the mesoclimatic loggers and the nearest automatic weather station, the use of mesoclimatic logger data was preferred, and is advised in future studies where this scale of data is available. Malic and tartaric acid has a definite synthesis period up until véraison, after which the content of tartaric acid remains constant in the berry and the content of malic acid decreases until harvest due to mainly respiration. The temperature data was therefore separated in a synthesis period from flowering to véraison, and a ripening period from véraison to harvest. In this study, clear differences were firstly seen in the climate as expected, not only between sites per vintage, but in addition between vintages and between vintages per site. The phenological differences between the sites could be largely attributed to the differences in temperature as phenology and temperature was found to be highly correlated in this study. Differences in the ripening parameters were noticed in addition to the contents of the organic acids between sites, although no definite contribution of temperature was shown to affect the contents of these compounds at either véraison or harvest. These differences may be attributed to other factors such as the soil water content and the canopy architecture. In addition, these factors all contribute in differing percentages to the differences found in the contents per site. It was found though that temperature can be used as an indicator of the organic acid content in the grape berry, considering that the temperature data is available on a mesoclimatic scale, separated in a synthesis and period of degradation, and the number of hours within the temperature thresholds are determined. Differences seen in the organic acid contents can however not only be attributed to the differences in topography and the temperature as discussed in this study.
AFRIKAANSE OPSOMMING: Sure is belangrike druifkomponente wat grootliks hul oorsprong in die korrel het, in die wyn voorkom, en die sensoriese persepsie van die wyn beïnvloed. Die voorkoms van organiese sure in genoegsame konsentrasies in die korrel, waarvan wynsteensuur en appelsuur die hoof organiese sure is, is belangrik aangesien dit die potensiaal van die sap om ʼn goeie en stabiele wyn te produseer, bepaal. Hoe temperatuur die inhoud van organiese sure in die druiwesap affekteer is gereeld onder bespreking, met hoër temperature in die algemeen geassosieer met ʼn laer inhoud van organiese sure, terwyl laer temperature geassosieer word met ʼn hoër inhoud van organiese sure in die sap, veral in die geval van appelsuur. As gevolg van die topografiese diversiteit van die Stellenbosch Wyn van Oorsprong distrik, asook die nabyheid van die oseaan met die gepaardgaande voorkoms van die seebries, verander die mesoklimaat aansienlik oor klein afstande in hierdie area. Vir die studie was sestien wingerde, wat bestaan het uit agt Sauvignon Blanc en agt Cabernet Sauvignon wingerde, geselekteer vanuit ʼn groter terroir studie. Verder was drie seisoene, met volledige klimaatsdatastelle, geselekteer vir die vergelyking van data tussen die seisoene. Klimaat was op verskillende skale binne die studie area gemonitor en data van ʼn weerstasie netwerk, sowel as van mesoklimaat dataversamelaars binne die wingerde, was beskikbaar. Die beskikbare datastelle was vergelyk, asook geëvalueer, om die mees verteenwoordigende datastel vir die area te bepaal. Met die oorweging van die termiese indekse was daar gevind dat die Huglin indeks beter verteenwoordigend van die area was. Verder, as gevolg van die groot verskille wat gevind is tussen die temperature gemeet met die mesoklimaat dataversamelaars en die naaste outomatiese weerstasie, was daar besluit dat die gebruik van die mesoklimaat data verkies is en is dit ook aan te beveel vir die gebruik in toekomstige navorsing indien die tipe data beskikbaar is. Wynsteen- en appelsuur het beide ʼn definitiewe sintese periode tot en met véraison, waarna die hoeveelheid wynsteensuur in die korrel relatief konstant bly en die hoeveelheid appelsuur afneem hoofsaaklik as gevolg van respirasie. Die temperatuur data was dus verdeel in ‘n periode van sintese vanaf blom tot en met véraison, en ʼn rypwordingsperiode vanaf véraison tot en met oes. In hierdie studie was daar eerstens groot verskille waargeneem in die klimaat soos wat daar verwag is. Hierdie verskille was nie net waargeneem as tussen die seisoene nie, maar ook tussen die wingerde binne ʼn seisoen. Die fenologiese veskille tussen die wingerde wat ook waargeneem is, kon hoofsaaklik aan die verskille in die temperatuur toegeskryf word en ʼn goeie korrelasie tussen temperatuur en fenologie is opgemerk. Merkwaardige verskille in die rypwordingsparameters, asook in die inhoud van die organiese sure, was waargeneem, alhoewel die bydrae van temperatuur op die inhoud van hierdie komponente by véraison of oes nie as definitief getoon is nie. Dit kan toegeskryf word aan die bydrae van ander faktore, soos byvoorbeeld die grondwaterinhoud en die lowerargitektuur, op die inhoud van hierdie komponente. Die addisionele faktore dra egter in verskillende persentasies by tot die verskille waargeneem tussen die wingerde.
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10

Bocker, Caroline. "Recherche sur les précurseurs du 3-sulfanylhexanol des vins de Sauvignon blanc." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0412/document.

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La mise au point de techniques de fractionnement des moûts de Sauvignon blanc par chromatographie de partage centrifuge et par chromatographie Flash, a permis de mettre en évidence la présence de deux « nouvelles » formes précurseurs du 3SH (le S-3-(hexan-1-al)-glutathion et l'acide S-3-glutathionyl-hydroxyhexanesulfonique). L’ensemble de ces résultats a permis de confirmer la contribution majeure des S-conjugués au potentiel en 3SH des moûts. Le S-3-(hexan-1-ol)-L-cystéine, le S-3-(hexan-1-ol)-glutathion ainsi que les deux nouvelles formes identifiées, permettent d’expliquer près de 65% du 3SH libéré dans les vins. Par ailleurs, nous avons montré que l’ensemble des formes précurseurs appartenait à la même voie d’assimilation de la levure et que le S-3-(hexan-1-ol)-L-cystéine est un intermédiaire indispensable à la biotransformation des S-conjugués au glutathion, précurseurs du 3-sulfanylhexanol. De plus, le pourcentage de biotransformation des différents S-conjugués en 3SH semble directement lié à leur position dans le flux métabolique
The development of fractionation techniques in Sauvignon Blanc musts such as centrifugal partition chromatography and flash chromatography, permitted to identify two precursor forms of 3-sulfanylhexanol : the S-3-(hexan-1-al)-glutathione, and the S-3-glutathionyl-hydroxy hexanesulfonic acid. These results confirmed the major contribution of S-conjugates in the potential liberation of 3-sulfanylhexanol in musts. The two newly identified forms along with S-3-(hexan-1-ol)-L-cysteine and S-3-(hexan-1-ol)-glutathione, explain up to 65% of the total release of 3-sulfanylhexanol. Futhermore, we showed that all precursor forms belonged to the same assimilation pathway of yeast and the S-3-(hexan-1-ol)-L-cysteine is an essential intermediate in the metabolism of S-glutathione conjugates, which is a precursor of 3-sulfanylhexanol . Finally, the biotransformation percentage of different S-conjugates of 3-sulfanylhexanol seems directly related to their position in the metabolic flow
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11

Bezerra, Iglesias de Lacerda. "Caracterização estrutural e estudo do potencial anti-inflamatório de polissacarídeos estraídos dos vinhos Cabernet Franc, Cabernet Sauvignon e Sauvignon Blanc." reponame:Repositório Institucional da UFPR, 2016. http://hdl.handle.net/1884/41909.

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Orientador : Prof. Dr. Guilherme Lanzi Sassaki
Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Ciências : Bioquímica. Defesa: Curitiba, 25/02/2016
Inclui referências : f. 90-108
Resumo: Existem poucos trabalhos sobre caracterização de polissacarídeos de vinhos. A estrutura e as quantidades de polissacarídeos liberados dependem do processo de vinificação e podem influenciar as propriedades sensoriais, a qualidade dos vinhos e possivelmente os benefícios para a saúde. No entanto, não foram encontrados na literatura científica, estudos que mostrem alguma relação entre os polissacarídeos encontrados nos vinhos e atividades biológicas, como a anti-inflamatória. Com isso, esse trabalho teve como objetivo a caracterização estrutural dos polissacarídeos encontrados em três tipos de vinhos: Cabernet Franc (ACF), Cabernet Sauvignon (ACS) e Sauvignon Blanc (ASB) e avaliação da capacidade das amostras estudadas de inibirem mediadores inflamatórios in vitro. Os vinhos foram concentrados e os polissacarídeos foram obtidos por meio de precipitação etanólica seguida de centrifugação, diálise, liofilização, congelamento e degelo, precipitação de Fehling e fracionamento por coluna de troca iônica. Os polissacarídeos foram caracterizados estruturalmente por métodos químicos, por ressonância magnética nuclear (RMN) 1D e 2D de 1H e 13C, cromatografia gasosa acoplada à espectrometria de massas de ionização eletrônica (GC-MS), análise de metilação e cromatrografia líquida de exclusão estérica acoplada à índice de refração de espalhamento de luz laser em multiângulos (HPSEC-MALLS). Os rendimentos dos polissacarídeos dos vinhos foram: 0,16% (ACF), 0,05% (ACS) e 0,02% (ASB). A composição monossacarídica mostrou a presença de Gal, Ara, Rha, GalA, Glc, 2-O-metil-Xyl, 2-O-metil-Fuc e Man em diferentes concentrações. Todas as frações apresentaram teor de <1% de proteínas. As frações apresentaram um perfil de eluição heterogênea em HPSEC-MALLS, sugerindo uma mistura de polissacarídeos. Através da RMN heteronuclear de 2D-HSQC e a análise de metilação foi possível identificar a presença de arabinogalactanas do tipo II, ramnogalacturananas do tipo I e II, mananas e dextrinas. O potencial anti-inflamatório dos polissacarídeos foi avaliado através da inibição de NF-?B em células RAW-Blue. Todas as frações estudadas apresentaram propriedade anti-inflamatória quando testadas in vitro na dose 100 ?g/mL. Os resultados das análises químicas, espectrométricas e espectroscópicas forneceram um "fingerprint" molecular para os polissacarídeos de cada tipo vinho, uma vez que os polissacarídeos dos vinhos apresentaram rendimentos e quantidades diferentes, podendo auxiliar na determinação de uma assinatura dos vinhos analisados. Palavras-chave: vinhos, polissacarídeos, inflamação.
Abstract: There are few works about characterization of polysaccharides of wines. The structure and amounts of polysaccharides released depend on the wine-making process and can influence the sensory properties, quality of the wines and benefits for health. However, there were not found in scientific literature, studies showing a relationship between the polysaccharides found in wines and biological activities. This work aimed structural characterization of the polysaccharides found in three types of wines: Cabernet Franc (ACF), Cabernet Sauvignon (ACS) and Sauvignon Blanc (ASB). The wines were concentrated and the polysaccharides were obtained via ethanolic precipitation followed centrifugation, dialysis, freeze dry, freezing-thawing, fehling precipitation and fractionation with ion exchange columnn. The polysaccharides have been characterized structurally by chemical methods, nuclear magnetic resonance (NMR) 1D and 2D ¹H and ¹³C NMR, gas chromatography-mass spectrometry electron ionization (GC-MS), methylation analysis and liquid cromatrografia coupled steric exclusion the laser light scattering refractive index in multi angles (HPSEC-MALLS). The anti-inflammatory potential of the polysaccharides through inhibition of NF-?B in Raw-Blue cells. Polysaccharide yields were: 0,16% (ACF), 0,05% (ACS) and 0,02% (ASB). The fractions showed monosaccharide composition containing Ara, Rha, GalA, Glc, Gal, Man, Xyl e Fuc in different concentrations. All fractions have <1% content of protein. All the samples showed a heterogeneous elution profile, suggesting the presence of polysaccharide mixture. By heteronuclear NMR 2D-HSQC and methylation analysis was possible to identify the presence of type II arabinogalactan, type I and II rhamnogalacturanans, mannans, and dextrins. The anti-inflammatory potential of the polysaccharides was evaluated through the inhibition of NF-?B in RAW-blue cells. All samples showed anti-inflammatory property when tested in vitro in a dose100 ?g/mL. The results of chemical, spectrometric and spectroscopic analyzes can furnish a fingerprint for each wine, since the profile of the mixtures had different yields and quantities, aiding for a non-volatile based singular signature. Keywords: wines, polysaccharides, inflammation.
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Würz, Douglas André. "Desempenho viti-enológico das variedades cabernet sauvignon e sauvignon blanc em regiões de altitude em função da época de desfolha." Universidade do Estado de Santa Catarina, 2016. http://tede.udesc.br/handle/handle/2384.

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Capes
Highland regions of Santa Catarina State, Brazil, have been acquiring great importance due to the high potential for wine production from Vitis vinifera L. cultivars, but due to highlands of Santa Catarina State are being in an emergent wine grown region fundamental investigations into vineyard practices are necessary. This work aims to contribute to the generation of data that can direct the management of leaf removal in the vineyards in order to develop a differentiated quality wine, determining times of leaf removal in the varieties Cabernet Sauvignon and Sauvignon Blanc, and evaluate the its effect on vegetative, productive aspects, enological potential of grape wine quality, and the occurrence of bunch rot. The results of this study show the importance of management of leaf removal grapes wines, demonstrating its benefits in relation to technological and phenolic maturity indices, providing better quality grape, higher productivity and better vegetative balance. And the leaf removal, held between phenological full flowering stage and grain pea resulted in a significant reduction in the incidence and severity of bunch rot of Cabernet Sauvignon and Sauvignon Blanc grown in high altitudes of Santa Catarina. It is evident that the removal leaf vine is indispensable for obtaining a grape of high quality and sanity
As regiões de altitude de Santa Catarina vem despertando interesse de investidores, pela sua característica de elaborar vinhos de elevada qualidade. Porém, por ser uma atividade ainda recente nessas regiões, há uma grande demanda pela geração de informações técnicas adequadas, visto que possui características distintas das demais regiões vitícolas do Brasil. A presente dissertação visa contribuir na geração de informações que possam direcionar o manejo da desfolha nos vinhedos, a fim de elaborar um vinho de qualidade diferenciada, determinando o efeito de diferentes épocas de desfolha nas variedades Cabernet Sauvignon e Sauvignon Blanc sobre aspectos vegetativos, produtivos, potencial enológico da uva, qualidade do vinho, e na ocorrência de podridão cinzenta (Botrytis cinerea Pers) nos cachos. Os resultados deste estudo evidenciam a importância do manejo da desfolha da videira, demonstrando seus beneficios em relação aos índices de maturação tecnológica e fenólica, propiciando melhor qualidade da uva, maior produtividade e melhor equilíbrio vegeto:produtivo. Além disso, a realização de uma desfolha precoce, realizada entre os estádios fenológicos plena florada e grão ervilha resultaram em redução da incidência e severidade de podridão cinzenta (Botrytis cinerea) nos cachos das variedades Cabernet Sauvignon e Sauvignon Blanc cultivadas em elevadas altitudes de Santa Catarina. Evidencia-se que o manejo da desfolha da videira é indispensável para obtenção de uma uva de elevada qualidade e sanidade
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13

Martins, João Duarte Victor Franco. "Previsão da produção na casta Sauvignon Blanc com base nas componentes do rendimento." Master's thesis, ISA/UTL, 2011. http://hdl.handle.net/10400.5/4131.

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Mestrado em Viticultura e Enologia - Instituto Superior de Agronomia
With the objective of finding estimated yield models, it was collected data from yield components of a Sauvignon Blanc vineyard variety from Quinta do Pinto, Merceana, Denomination of Origin Alenquer, Lisboa wine region. The method was based on the sampling of 32 spaces that correspond to 192 vines in four different phenological stages (separated flowers, berry pea-size, veraison and ripe bunch). The data obtained was then submitted to an statistical analysis in order to find the correlation coefficients between the several variables and yield. The results indicate significant allometric relations between the inflorescences and bunches variables measured. The number of bunches explains most of the production variability (58%). Based on a stepwise regression, two models were obtained for yield estimation: One based on three variables measured during the berry pea-size stage which explains 57% of the yield variability and other based on two variables measured during the veraison that explain 76%. The model produced at veraison seems to be the more robust and includes fast and easy to determine on the field variables. These models, when adjusted, tend to be an useful tool, allowing early previsions in an easy and economical way.
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Kilby, Michael W. "Pruning Methods Affect Yield and Fruit Quality of 'Merlot' and 'Sauvignon Blanc' Grapevines." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/220579.

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One red and one white cultivar of winegrapes grown in Southern Arizona was pruned to four different methods. The red cultivar was 'Merlot' and the white was 'Sauvignon Blanc'. The pruning methods were 2 bud spur, 4 bud spur, cane and basal buds only. The basal bud treatment was eliminated for 'Sauvignon Blanc'. The 4 bud spur method resulted in significantly greater yield when compared to the other methods. Fruit produced from the basal bud only treatment resulted in fruit that was significantly greater in pH and acid content. The 'Sauvignon Blanc' cultivar had significantly higher yield with cane pruning with no difference in fruit quality.
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15

Sala, Solé Rodrigo Ignacio. "Caracterización química, física y sensorial de vinos comerciales chilenos del cultivar sauvignon blanc." Tesis, Universidad de Chile, 2011. http://repositorio.uchile.cl/handle/2250/148411.

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Memoria para optar al Título Profesional de Ingeniero Agrónomo Mención: Enología y Vitivinicultura
El objetivo del presente estudio consistió en caracterizar química, física y sensorialmente, 15 vinos chilenos del cultivar Sauvignon Blanc de las vendimias 2007 y 2008, obtenidos directamente en el mercado chileno. Las muestras fueron sometidas a análisis de acidez total, pH, azúcares reductores, intensidad colorante y pardeamiento. Además se determinaron y cuantificaron los compuestos fenólicos de bajo peso molecular por Cromatografía Líquida de Alta Eficacia acoplada a un detector de fotodiodos alineados (HPLC-DAD). Cada una de las muestras de vino fue evaluada por un panel de expertos, relacionados directamente en la elaboración de vinos, quienes realizaron el análisis sensorial para los atributos de franqueza aromática, intensidad aromática, armonía aromática, dulzor, consistencia, acidez, intensidad gustativa y percepción del nivel de alcohol, además de realizar una selección única para las tipicidades aromáticas de herbáceo, cítrico, tropical, frutoso, floral y otros, con los descriptores aromáticos para la tipicidad seleccionada. Se pudo observar que en los análisis químicos y físicos existieron diferencias entre las muestras, presentando amplios rangos de valores en todas las determinaciones. En la evaluación sensorial no se encontraron diferencias significativas en la mayoría de las muestras y se evidenció una gran heterogeneidad en las respuestas de los evaluadores para cada una de las muestras.
The objective of this study consisted in characterizing chemical, physical and sensory, 15 Chilean Sauvignon Blanc wines of vintages 2007 and 2008, directly obtained in the chilean trade. The samples were subjected to analysis of total acidity, pH, reducing sugars, color intensity and browning. Additionally were identified and quantified the low molecular phenolic compounds by High Performance Liquid Chromatography coupled to a diode array detector (HPLC-DAD). Each of the wine samples were evaluated by an experts panel, directly related to the wine production, who performed the sensory analysis for the attributes of aromatic frankness, aromatic intensity, aromatic harmony, sweetness, consistency, acidity, flavor intensity and perceived level of alcohol, in addition to a forced selection for aromatic typicality herbaceous, citrus, tropical, fruity, floral and others, with the aromatic descriptors for the typicality selection. It was observed that the chemical and physical analysis shown differences among the samples, showing wide ranges of values in all determinations. In the sensory evaluation no significant differences were found in most samples and showed a large heterogeneity in the evaluators responses for each of the wine samples.
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Jouanneau, Sara. "Survey of aroma compounds in Marlborough sauvignon blanc wines: regionality and small scale winemaking." Thesis, University of Auckland, 2011. http://hdl.handle.net/2292/7960.

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Marlborough is the largest wine region in New Zealand and Sauvignon blanc cultivars represented about 60 % of the vineyard area in 2009. The main compounds responsible for the most intense aromas in Sauvignon blanc wines had been assumed to be methoxypyrazines, responsible for the herbaceous, capsicum and asparagus aromas, and varietal thiols, responsible for fruity aromas such as grapefruit, citrus or passion fruit. However, the aromatic potential of Sauvignon blanc wines is too complex to be limited to just these two families of compounds. This study has shown that further groups of aroma compounds (esters, terpenes, C6- and higher alcohols, fatty acids, C13- norisoprenoids, cinnamates and anthranilates) could also be involved in the characteristic aroma of these wines. Winemakers divide the Marlborough Sauvignon blanc growing area into 7 sub-regions, and ascribe different aroma profiles to wines coming from these regions. An extensive study of the compounds that impact on Sauvignon blanc aroma has been undertaken with over fifty important impact aroma compounds quantified in 54 wines from different sub-regions within Marlborough. Some important variations with regard to the Marlborough sub-regions have been revealed, and the extent to which these differences in chemical composition can impact on wine sensory differences has been assessed. A further aim of this research was to assess the optimum small scale winemaking protocol in order to obtain aroma composition results in research wines comparable to those found in commercial wines. Different conditions in the early stages of the winemaking process were studied: destemming and crushing of the grapes, differences between hand-picked and machine-harvested grapes, and the use of maceration enzymes. The results have shown that both destemming and crushing of the grapes are needed to obtain wines with an aroma composition similar to the commercial wines.
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Coetzee, Carien. "Oxygen and sulphur dioxide additions to Sauvignon blanc : effect on must and wine composition." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6733.

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Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2011.
Includes bibliogaphy.
ENGLISH ABSTRACT: Sauvignon blanc wines have become increasingly popular in South Africa as it is a cultivar that can be easily manipulated in the vineyard and cellar to produce a range of wine styles. These wines are usually given aroma descriptors such as green pepper, grassy and asparagus; while other more tropical aromas include passion fruit and guava. These aromas are thought to be mainly caused by methoxypyrazines and volatile thiols. These compounds are known to be character impacting compounds of Sauvignon blanc and are present in the grapes in the aromatic form (methoxypyrazines) or as non‐aromatic precursors (thiols) that can be released by the yeast during fermentation. Other aroma compounds such as esters, higher alcohols, fatty acids and monoterpenes are compounds that could potentially influence the aroma bouquet of a wine significantly. These aroma compounds exist either as precursors in the grapes (monoterpenes) or arise due to yeast metabolism during fermentation (esters, higher alcohols, fatty acids) and often display fruity, floral and pleasant aromas. In the cellar, winemaking practices can be manipulated to a certain extent to achieve the desired wine style. Winemaking tools such as temperature, skin contact, pressing conditions, oxygen (O2), sulphur dioxide (SO2) and yeast strain are only a few factors influencing the outcome of a wine. In general, South African winemakers maintain a very reductive environment during Sauvignon blanc wine production by using inert gasses, thereby causing the production costs to increase. There is sufficient evidence to support the reductive handling of white wine, however there seems to be a lack of information as to why the must should be treated reductively before fermentation. The over all goal of this study was thus to investigate the effect of different O2 and SO2 additions to Sauvignon blanc must before settling, specifically focussing on the typical aroma compounds often found in these wines. Chapter 2 gives an overview of the oxidation reactions occurring in must (enzymatic oxidation) and wine (chemical oxidation). This chapter also reports the origin of the specific Sauvignon blanc aroma compounds and their reaction to different must and wine treatments with a focus on oxidation. Chapter 3 reports research results focussing on the effect of the different must treatments on the character impacting compounds of Sauvignon blanc wines, specifically the methoxypyrazines and the volatile thiols. The effect of the treatments on the polyphenols and glutathione content in the must and wine was also investigated. Oxidation in the absence of SO2 led to a decrease in glutathione and certain phenolic compounds in the must. In general, volatile thiols were protected against oxidation by SO2, even when O2 was present in the must. Methoxypyrazines concentrations were not significantly influenced by the treatments. Chapter 4 elucidates the effect of the treatments on other yeast and grape derived aroma compounds often found in Sauvignon blanc wines, such as the esters, higher alcohols, fatty acids and monoterpenes. In general, the effect of SO2 seemed to have the greatest influence on the produced aroma compounds. The results reported in this thesis could possibly change the way South African Sauvignon blanc musts are handled in future during the winemaking process. It is clear that O2 and SO2 management in the cellar is of critical importance for the winemaker to produce wines of high quality. Future work is important to fully understand the mechanisms and evolution of important aroma compounds of Sauvignon blanc wines during the winemaking process.
AFRIKAANSE OPSOMMING: Sauvignon blanc wyn aroma word gewoonlik beskryf met terme soos groen rissie, grasagtig en aspersie terwyl ander tropiese aromas soos grenadella en koejawel ook dikwels voorkom. Die manipulasie van Sauvignon blanc in die wingerd en in die kelder tydens wynmaak, gee die wynprodusent die vryheid om ‘n wye reeks wyn style te produseer. Dit maak Sauvignon blanc baie populêr in die Suid‐Afrikaanse wynindustrie. Die bogenoemde aromas word waargeneem in die wyn as gevolg van die teenwoordigheid van sekere aroma komponente genaamd metoksipirasiene en vlugtige tiole. Hierdie komponente lewer ‘n unieke bydrae tot die aroma samestelling van Sauvignon blanc wyne en kom voor in die druiwe in die aromatiese vorm (metoksipirasiene) of as nie‐aromatiese voorlopers (tiole) wat tydens alkoholiese fermentasie deur die gis vrygestel kan word. Komponente soos esters, hoër alkohole, vetsure en monoterpene kan ook ‘n potensiële bydra lewer tot die algehele aroma van Sauvignon blanc wyne en kom voor in die druiwe (monoterpene) of ontstaan as gevolg van gis metabolisme gedurende alkoholiese fermentasie (esters, hoër alkohole, vetsure). Hierdie geur komponente word dikwels beskryf as vrugtig, blomagtig en oor die algemeen aangenaam. Tydens wynmaak kan die wyn tot ‘n mate gemanipuleer word om ‘n spesifieke wynstyl te bekom. Hulpmiddels soos temperatuur, dopkontak, pers omstandighede, suurstof (O2), swawel dioksied (SO2) en gisras is slegs ‘n paar faktore wat die algemene uitkoms van ‘n wyn kan beïnvloed. Oor die algemeen word Sauvignon blanc in Suid‐Afrika baie reduktief behandel tydens wynbereiding. Dit vereis sekere hulpmiddels, soos die gebruik van inerte gas, wat die produksiekoste dikwels verhoog. Navorsing ondersteun die reduktiewe behandeling van wit wyn, maar dit wil voorkom asof daar ‘n tekort aan navorsing is wat die reduktiewe behandeling van die sap voor fermentasie regverdig. Die algemene doel van die studie is dus om die effek van verskillende O2 en SO2 byvoegings tot Sauvignon blanc sap (voor afsak) te ondersoek met die fokus op die tipiese aroma komponente wat in die wyn voorkom. Hoofstuk 2 lewer ‘n algemene oorsig van die tipes oksidasie reaksies wat voorkom in sap (ensiematiese oksidasie) en wyn (chemiese oksidasie). Spesifieke Sauvignon blanc aroma komponente word ook ondersoek in terme van die oorsprong van die komponente asook die reaksie wat plaasvind met verskillende mos en wyn behandelings, met ‘n fokus op oksidasie. In hoofstuk 3 word die effek van die verskillende mos behandelings op tipiese Sauvignon blanc aroma komponente, spesifiek metoksipirasiene en vlugtige tiole, ondersoek. Die effek van die behandelings op die polifenole en glutatioon inhoud in die mos en wyn word ook gerapporteer. Oksidasie van die sap in die afwesigheid van SO2, het ‘n afname in glutatioon en sekere polifenol konsentrasies veroorsaak. Dit wil voorkom asof die produksie van vlugtige tiole oor die algemeen beskerm word teen oksidasie indien daar genoegsame SO2 teenwoordig is. Hierdie effek word ondervind selfs as die sap met suursof versadig word. Die effek van die behandelings op die konsentrasies van metoksipirasiene was nie beduidend nie. Hoofstuk 4 rapporteer die effek van die behandelings op ander aroma komponente soos esters, hoër alkohole, vetsure en monoterpene. Oor die algemeen wil dit voorkom asof die effek van SO2 beduidend was en waarskynlik die grootste invloed op die produksie van hierdie aroma komponente het. Na aanleiding van die resultate bevind in hierdie tesis, is daar ‘n moontlikheid dat die manier waarop Sauvignon blanc wyne geproduseer word in Suid‐Afrika, moontlik kan verander in die toekoms. Vir die wynmaker om hoë kwaliteit Sauvignon blanc wyne te produseer, is O2 en SO2 bestuur in die kelder van kardinale belang. Verdere navorsing moet steeds gedoen word om die meganisme en evolusie van belangrike aroma komponente in Sauvignon blanc wyne tydens die wynmaakproses, ten volle te verstaan.
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18

Peyrot, des Gachons Catherine. "Recherches sur le potentiel aromatique des raisins de Vitis vinifera L. Cv. Sauvignon blanc." Bordeaux 2, 2000. http://www.theses.fr/2000BOR20799.

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Le développement d'une méthode de dosage par dilution d'isotopes stables, de trois S-conjugués à la cystéine, précurseurs de thiols volatils responsables de l'arôme du Sauvignon, permet d'apprécier le potentiel aromatique des raisins de ce cépage. Cette méthode est un dosage indirect des précurseurs cystéinylés, basée sur l'analyse des thiols volatils correspondants, libérés par percolation du moût sur une colonne de tryptophanase immobilisée. Au cours de la maturation, l'évolution des teneurs en précurseurs cystéinylés du raisin varie en fonction du S-conjugué à la cystéine considéré et des conditions climatiques du millésime L'alimentation en eau joue un rôle essentiel sur le potentiel aromatique des raisins. La distribution des précurseurs cystéinylés dans la baie diffère selon le précurseur considéré : 80 % des S-4-(4-méthylpentan-2-one)-L-cystéine et S-4-(4-méthylpentan-2-ol)-L-cystéine se situent dans le jus et plus de 50 % du S-3-(hexan-1-ol)-L-cystéine (P-3MH) sont dans la pellicule. Par conséquent, la macération pelliculaire améliore le potentiel aromatique du moût mais a une incidence essentiellement sur le P-3MH. Les thiols volatils sont libérés à partir de leur précurseur sous l'action de la levure. La révélation du potentiel aromatique du sauvignon dépend donc entièrement de la fermentation alcoolique. Le taux de transformation des précurseurs cystéinylés en arôme est très faible. De plus, le taux de dégradation des S-conjugués à la cystéine varie en fonction de la souche de levure inoculée, mais il est davantage influencé par la composition du moût. L'identification du S-3-(hexan-1-ol) glutathion dans le moût de sauvignon fournit des indications sur la voie de biosynthèse du P-3MH dans la vigne, car les S-conjugués au glutathion sont généralement impliqués dans les voies de détoxification chez les organismes vivants.
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19

Serughetti, Alessandro. "Influences of the amino acids during alcoholic fermentation and development of aroma compounds in Sauvignon blanc." Master's thesis, ISA, 2017. http://hdl.handle.net/10400.5/15840.

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Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL / Universitá degli Studi di Torino
In recent years, New Zealand in terms of production has expressed a certain respect and attention towards Sauvignon Blanc for its organoleptic chemical characteristics. In this project seven different amino acids were used, two blend of amino acids and the DAP (di-ammonium phosphate) used in wineries, with the aim of investigating the effect of different levels of nitrogenous source of musts from the two different vineyards ( Omaka Vineyard and Gifford's Creek Vineyard), on the progress of fermentation and the impact on the aromatic component, with the use of the "New Zealand Grape and Wine Research Program" winemaking protocols, with all the processes being reduced to improve the aromatic quality of Sauvignon Blanc in the Marlborough region of New Zealand. This experimental thesis project with the title "Influences of amino acids during alcoholic fermentation and the development of aromatic compounds in Sauvignon Blanc", observes the single amino acids added starting from two musts, with different initial nitrogenous source, and examines the reaction from the yeast during alcoholic fermentation, with reference to the type of free aromatic compounds and their concentration
N/A
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20

Sutherland, M. J. "The influence of vine vigour and canopy ideotype on fruit composition and aroma of Sauvignon Blanc." Diss., Lincoln University, 2009. http://hdl.handle.net/10182/1270.

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The influence of soil texture on canopy growth, vine yield, and fruit composition of Sauvignon blanc were assessed on a mature vineyard from the Rapaura area in Marlborough. The subject vines were mature Sauvignon blanc in a commercial vineyard trained to four cane VSP and planted with a north south orientation. Row and vine spacings were typical of the area at 3m x 1.8m. Four areas of different soil texture were identified using trunk circumference measurements, visual assessment of the surface soil and aerial photographs to identify changes in vine growth. Soil pits were excavated at a later date to determine root numbers and record the soil texture in the different areas. Two crop treatments were imposed on half of the plots at approximately 50% veraison: unthinned crop and 50% crop. A shading treatment was also imposed at 50% veraison where three sets of tagged shoots had bunches that were exposed to sunlight, bunches that had some natural shading from leaves or bunches that had paper bags fastened over each to provide a completely shaded environment. Vine vegetative vigour for each plot was assessed during the growing season using the Point Quadrat method and at pruning using bud counts and pruning weights. Thirty berry samples were collected from the 32 plots and analysed weekly for soluble solids and berry weight. Harvest of bunches from the tagged shoots occurred on two different dates with the first harvest picked when fruit from one soil and crop treatment had reached 21 °Brix. The second picking took place just before the commercial harvest, which coincided with last soil and crop treatment reaching 21 °Brix. Bunches from each tagged shoot were weighed, frozen and later analysed for soluble solids, pH, organic acids, and methoxypyrazines. Vines on very stony textured soils had small trunk circumferences with a high root density and yield to pruning weight ratio compared to those growing on deep silt soils. Vines on deep silt soils had more vigorous canopies with large shoots and a higher leaf layer number. The target soluble solids was reached first by the vines on the very stony plots despite the higher crop load with soil texture appearing to be a dominant factor by influencing the time of flowering. Cluster shading decreased soluble solids, consistent with other studies, whilst crop thinning resulted in an earlier harvest. This was contrary to popular opinion that crop thinning at veraison would have no impact on sugar accumulation. pH and organic acids were unaffected by shading or bunch thinning. Vines growing on deep silt soils had a significantly higher level of total acidity and malic acid than those on the stony soils. At harvest, methoxypyrazine levels were very low compared to previously reported figures for Marlborough, which may have been a result of sample preparation. IBMP was significantly higher on deep silt soils, however, with no impact from the shading or crop treatment. The findings are consistent with the hypothesis that IBMP synthesis may be increased by the number of leaves surrounding bunches (Roujou de Boubee, 2003). The results suggest that soil texture plays a dominant role in influencing Sauvignon blanc flavour and aroma and due consideration should be given to vineyard layout and site selection prior to new plantings taking place.
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21

Anfang, Nicole. "Wine yeasts of New Zealand : an investigation into their distribution, contribution to sauvignon blanc aroma and interaction in co-ferments /." Thesis, University of Auckland, 2010. http://hdl.handle.net/2292/5834.

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22

Ford, Rebecca Jane. "The effect of shading and crop load on flavour and aroma compounds in Sauvignon blanc grapes and wine." Master's thesis, Lincoln University. Agriculture and Life Sciences Division, 2007. http://theses.lincoln.ac.nz/public/adt-NZLIU20080523.100013/.

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The effects of crop load and berry exposure on the composition of Marlborough Sauvignon blanc grapes and wine from the Brancott vineyard, Blenheim, were explored. Commercially grown, 2-cane and 4-cane Sauvignon blanc vines were used with a row orientation of north-south. Two exposure treatments were imposed in the following manner: complete leaf removal was undertaken in the fruit zone and 50% shade cloth was erected to give a uniform shading treatment to half the trial vines. Weekly thirty-berry and whole bunch samples were taken from each of the 32 plots with the exception of the veraison period when two samples per week were taken. Vine vigour was assessed using pruning and leaf area per vine data. Harvest occurred on different dates for 2-cane and 4-cane pruned vines so that fruit attained from both treatments had similar °Brix. Fruit was processed at the Lincoln University winery. Must analysis and wine analysis were undertaken. As expected, 4-cane vines had almost double the yield of 2-cane vines. Higher crop load significantly reduced leaf area per shoot and shoot thickness. Lower leaf area to fruit ratio for 4-cane berries resulted in delayed onset of veraison and slowed the rate of sugar accumulation. Crop load, which limited leaf area to fruit ratio, appeared to be the dominant factor in determining timing of grape physiological ripeness as expressed by °Brix over other factors such as fruit exposure. Malic acid, tartaric acid, IPMP (iso-propylmethoxypyrazine) and IBMP (iso-butyl-methoxypyrazine) were lower at equivalent °Brix in 4-cane compared with 2-cane berries. Significantly higher concentrations of quercetin were found in exposed compared to shaded berries. Must analysis showed a significant influence of crop load on berry titratable acidity and pH, reflecting berry ripening results. Exposure significantly increased the concentrations of nitrogenous compounds in 4-cane must yet showed no influence on 2-cane must. After wine processing lower malic acid concentrations in wines made from 100% exposed fruit became evident in lower wine titratable acidity but showed no influence on wine pH. Bentonite addition to wines had a small but statistically significant influence on wine by reducing pH, titratable acidity and alcohol. Bound sulphur concentrations were significantly higher in 4-cane versus 2-cane wines. At harvest, methoxypyrazine levels in grapes and wines were very low; IBMP concentrations where significantly lower than those normally found in Sauvignon blanc wines from Marlborough. This was attributed to the absence of basal leaves from the shoots of ripening berries. The results suggest that leaf area to fruit ratio is a powerful determinant of grape and wine quality.
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23

Ford, R. J. "The effect of shading and crop load on flavour and aroma compounds in Sauvignon blanc grapes and wine." Lincoln University, 2007. http://hdl.handle.net/10182/498.

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The effects of crop load and berry exposure on the composition of Marlborough Sauvignon blanc grapes and wine from the Brancott vineyard, Blenheim, were explored. Commercially grown, 2-cane and 4-cane Sauvignon blanc vines were used with a row orientation of north-south. Two exposure treatments were imposed in the following manner: complete leaf removal was undertaken in the fruit zone and 50% shade cloth was erected to give a uniform shading treatment to half the trial vines. Weekly thirty-berry and whole bunch samples were taken from each of the 32 plots with the exception of the veraison period when two samples per week were taken. Vine vigour was assessed using pruning and leaf area per vine data. Harvest occurred on different dates for 2-cane and 4-cane pruned vines so that fruit attained from both treatments had similar °Brix. Fruit was processed at the Lincoln University winery. Must analysis and wine analysis were undertaken. As expected, 4-cane vines had almost double the yield of 2-cane vines. Higher crop load significantly reduced leaf area per shoot and shoot thickness. Lower leaf area to fruit ratio for 4-cane berries resulted in delayed onset of veraison and slowed the rate of sugar accumulation. Crop load, which limited leaf area to fruit ratio, appeared to be the dominant factor in determining timing of grape physiological ripeness as expressed by °Brix over other factors such as fruit exposure. Malic acid, tartaric acid, IPMP (iso-propylmethoxypyrazine) and IBMP (iso-butyl-methoxypyrazine) were lower at equivalent °Brix in 4-cane compared with 2-cane berries. Significantly higher concentrations of quercetin were found in exposed compared to shaded berries. Must analysis showed a significant influence of crop load on berry titratable acidity and pH, reflecting berry ripening results. Exposure significantly increased the concentrations of nitrogenous compounds in 4-cane must yet showed no influence on 2-cane must. After wine processing lower malic acid concentrations in wines made from 100% exposed fruit became evident in lower wine titratable acidity but showed no influence on wine pH. Bentonite addition to wines had a small but statistically significant influence on wine by reducing pH, titratable acidity and alcohol. Bound sulphur concentrations were significantly higher in 4-cane versus 2-cane wines. At harvest, methoxypyrazine levels in grapes and wines were very low; IBMP concentrations where significantly lower than those normally found in Sauvignon blanc wines from Marlborough. This was attributed to the absence of basal leaves from the shoots of ripening berries. The results suggest that leaf area to fruit ratio is a powerful determinant of grape and wine quality.
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24

Panzeri, Valeria. "Influence of vineyard posts type on the chemical and sensorial composition of Sauvignon blanc and Merlot noir wines." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80197.

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Thesis (MScAgric)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: In recent years South African wines have been under the spotlight due to references in the international wine media to a distinctive ‘burnt rubber’ character. Many winemakers and wine experts argued that the peculiar character could be ascribed to winemaking errors linked to mismanaged fermentation. An alternative possible source of the taint was identified in the coal tar creosote used as a wood preservative in vineyard trellis systems. South African regulations allow for the use of creosoted utility poles in agricultural land, but in Europe and USA their usage has been highly regulated and even banned for certain applications. Contamination of foodstuff by polycyclic aromatic hydrocarbons (PAHs) is one of the major motives for the banning of creosote in Europe and USA. Some of the compounds in the creosote mixture display very strong odour characteristics and for this reason it became the focus of attention for the present study. The overall aim of this study was to determine if vines trellised with creosoted posts could accumulate or absorb the various malodorous compounds deriving from the wood treatment onto the grape berries. These compounds could then be extracted from the grape berries into the wine during alcoholic fermentation, creating quality and sensory problems. Chapter 2 of this thesis gives an overview of the extensive literature that deals with methods of analysis of PAHs and malodorous phenols using both Gas Chromatography (GC), as well as High Performance Liquid Chromatography (HPLC). New methods for sample preparation, as well as analysis of PAHs using HPLC-Diode Array Detector (DAD), were developed and the results reported in Chapter 3. It was demonstrated that Sauvignon blanc experimental wines contained only chrysene at very low levels. The concentrations of chrysene found in the experimental wines are within the prescribed parameters as established by The Commission of the European Communities. Since no other PAH compounds were found in the samples analysed, it was concluded that the experimental wines were safe for human consumption and complied with EU regulations. The effect of vineyard posts on the sensorial characteristics of wine is discussed in Chapter 4. Creosoted poles were found to be responsible for an off-flavour described as ‘burnt rubber’ and ‘tarry’ in Merlot wines produced from grapes grown in close proximity to the posts. Following some of the reported findings, new guidelines have been introduced in the Integrated Production of Wine certification, which advise against the use of creosoted poles for vineyard trellising. This preliminary but important guideline will bring the South African wine industry a step closer to the fulfilling the obligations for food safety as required by the legislation of our major export partners. Future investigations are recommended to completely understand and evaluate the cumulative effect of creosoted posts in a fully trellised vineyard.
AFRIKAANSE OPSOMMING: Oor die afgelope paar jaar is Suid-Afrikaanse wyne onder die soeklig geplaas as gevolg van verwysings in die internasionale wynmedia na ‘n duidelike ‘gebrande rubber’-karakter. Baie wynmakers en wyndeskundiges het aangedui dat hierdie besonderse karakter toegeskryf kan word aan wynbereidingsfoute wat verband hou met gisting wat wanbestuur is. ‘n Alternatiewe moontlike oorsprong van die smaak is geïdentifiseer in die koolteer wat as ‘n houtpreserveermiddel in wingerdopleistelsels gebruik word. Suid-Afrikaanse regulasies maak voorsiening vir die gebruik van kreosoteerde nutspale in landbougrond, hoewel hulle gebruik in Europa en die VSA hoogs gereguleerd en in sommige gevalle selfs verbied is. Die besmetting van kossoorte deur polisikliese aromatiese koolwaterstowwe (polycyclic aromatic hydrocarbons (PAHs)) is een van die vernaamste redes vir die verbanning van kreosoot in Europa en die VSA. Sommige van die verbindings in die kreosootmengsel het baie sterk geurkenmerke en daarom is dit die fokus van die huidige studie. Die oorhoofse doelwit van hierdie studie was om te bepaal of wingerde wat op kreosoteerde pale opgelei is, die verskillende onwelriekende verbindings afkomstig van die houtbehandeling in die druiwekorrels kan akkumuleer of absorbeer. Hierdie verbindings sou dan tydens alkoholiese gisting uit die druiwekorrels in die wyn geëkstraheer kon word, wat aanleiding sou gee tot kwaliteits- en sensoriese probleme. Hoofstuk 2 van hierdie tesis verskaf ‘n oorsig van die breedvoerige literatuur wat handel oor metodes om PAH’s en onwelriekende fenole met behulp van beide gaschromatografie (GC) en hoëdrukvloeistofchromatografie (HPLC) te analiseer. Nuwe metodes is ontwikkel om monsters voor te berei en om PAH’s met behulp van ‘n HPLC-diode array detector (DAD) te analiseer. Die resultate word in Hoofstuk 3 gerapporteer. Daar is aangetoon dat die eksperimentele Sauvignon blanc-wyne chriseen teen baie lae vlakke bevat het. Die konsentrasies van chriseen wat in die eksperimentele wyne gevind is, is binne die voorgeskrewe parameters van die Kommissie van die Europese Gemeenskap. Aangesien daar nie ander PAHverbindings in die geanaliseerde monsters gevind kon word nie, is daar tot die gevolgtrekking gekom dat die eksperimentele wyne veilig is vir menslike verbruik en aan die EG-regulasies voldoen. Die effek van wingerdpale op die sensoriese kenmerke van wyn word in Hoofstuk 4 bespreek. Kreosoteerde pale is gevind wat verantwoordelik is vir ‘n wangeur in Merlot-wyne afkomstig van druiwe wat naby die pale gegroei het en wat as ‘gebrande rubber’ en ‘teeragtig’ beskryf is. Op grond van sommige van die gerapporteerde bevindings, is nuwe riglyne ingesluit in die sertifisering vir die Geïntegreerde Produksie van Wyn, wat aanbeveel dat kreosoteerde pale nie vir wingerdoplei gebruik word nie. Hierdie voorlopige, maar belangrike riglyn sal die Suid-Afrikaanse wynbedryf al beter in staat stel om te voldoen aan die voedselveiligheid regulasies wat vereis word deur die wetgewing van ons belangrikste uitvoervennote. Toekomstige ondersoeke moet aangewend word om die kumulatiewe effek van kreosoteerde pale in volledig opgeleide wingerde ten volle te verstaan en te evalueer.
Indaba Scholarship and Winetech for their financial support
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25

Sánchez, Fuenzalida Marcelo Alejandro. "Uso de fuentes nitrogenadas en fermentación alcohólica y su efecto en el aroma de un vino sauvignon blanc." Tesis, Universidad de Chile, 2014. http://repositorio.uchile.cl/handle/2250/148413.

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Memoria para optar al Título Profesional de Ingeniero Agrónomo
El objetivo del presente estudio consistió en evaluar el uso de cuatro fuentes nitrogenadas diferentes en un mismo mosto del cultivar Sauvignon Blanc proveniente del valle de Leyda de la temporada 2012. El mosto fue sometido a análisis de FAN, pH, acidez total, acidez volátil, densidad, sulfuroso libre, sulfuroso total para verificar que correspondiera a las condiciones buscadas y los vinos obtenidos en cada tratamiento fueron caracterizados a través de la medición de pH, acidez total, acidez volátil, densidad, sulfuroso libre, sulfuroso total, grado alcohólico y azúcar residual. Además se determinó la evolución de fermentación alcohólica midiendo diariamente la densidad y temperatura de todos los tratamientos. Cada una de las muestras obtenidas fue evaluada por un panel entrenado con previa experiencia en el análisis de la variedad Sauvignon Blanc, quienes tuvieron que analizar solo el aroma de las muestras midiendo los descriptores de intensidad aromática, aroma a cítrico, aroma a durazno, aroma a pimentón verde, aroma a frutos tropicales, aroma a pera y aroma a miel. En el comportamiento de la fermentación alcohólica se pudo observar que el tratamiento 3 es significativamente diferente respecto de los otros tratamientos. En la evaluación sensorial se encontró diferencias significativas solo en el aroma a pera y se evidenció una gran heterogeneidad en las respuestas de los evaluadores para cada una de las muestras.
The aim of this study was to evaluate the use of four different nitrogen sources in Sauvignon Blanc of Valley Leyda of the 2012 season. The must was subjected to analysis of FAN, pH, total acidity, volatile acidity, density, free sulfur, total sulfur to verify that correspond to the conditions sought and wines produced in each treatment were characterized by the measurement of pH, acidity total volatile acidity, density, free sulfur, total sulfur, high alcohol and residual sugar. Further evolution was determined by measuring daily fermentation the density and temperature of all treatments. Each of the samples obtained was evaluated by a trained panel with prior experience in the analysis of Sauvignon Blanc, they had to analyze only the aroma of the samples by measuring the descriptors of aromatic intensity, citrus aroma, aroma of peach, aroma of green pepper , tropical fruit aroma, aroma of pear and honey aroma. The behavior of the alcoholic fermentation, it was observed that treatment 3 is significantly different from other treatments. The sensory evaluation found significant differences only in the aroma of pear and showed a high heterogeneity in the responses of the evaluators for each of the samples.
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26

Apablaza, Álvarez Claudia Andrea. "Efecto del ácido abscísico exógeno sobre las características de bayas de vitis vinifera L. cv. sauvignon blanc y chardonnay." Tesis, Universidad de Chile, 2012. http://www.repositorio.uchile.cl/handle/2250/113689.

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Memoria para optar al título profesional de Ingeniera Agrónoma
Autorizada por el autor, pero con restricción para ser publicada a texto completo hasta diciembre de 2013
En diversos estudios, se ha demostrado que el ácido abscísico (ABA) se encuentra relacionado con el inicio de la maduración de las bayas de vid. Aplicaciones exógenas de este regulador cercanas a la época de envero, han adelantado el proceso de maduración, ya que se acelera el metabolismo primario y secundario de las bayas tratadas, tales efectos han sido demostrados en la totalidad de los ensayos realizados, en variedades de uva tinta, de mesa y para vino. Sin embargo, aún no se ha estudiado el efecto de este fitoregulador sobre variedades blancas. Con la intención de establecer el efecto del ABA sobre bayas de las var. Sauvignon Blanc y Chardonnay, se determinaron 3 tratamientos: (i) 50 mgL-1 ABA; (ii) 100 mgL-1 ABA; (iii) testigo con agua y Tween 20 al 0,1% (v/v). Se realizaron dos aplicaciones, -2 y +1 días después de pinta (DDP) para la var. Chardonnay y -7 y -4 días después de pinta (DDP) para la var. Sauvignon Blanc. Mediante muestreos semanales, se determinó el avance en la maduración de las bayas junto con la evolución del volumen y peso total de las bayas, peso de hollejos, sólidos solubles, pH, acidez titulable, fenoles totales, taninos totales, clorofilas y carotenos. En este ensayo las aplicaciones de ABA, modificaron el volumen y peso total de las bayas, en ambas variedades. Además se vieron afectados la acumulación de sólidos solubles, el pH y la concentración de ácidos orgánicos en la var. Sauvignon Blanc, lo que no sucedió en la var. Chardonnay, presumiblemente por una aplicación más tardía del regulador. Cabe señalar que las modificaciones se observaron al inicio del periodo de maduración y que hacia el final de éste tendieron a alinearse con el testigo. Para los demás parámetros medidos no se observaron efectos del ABA sobre ninguna de las variedades que incluye este estudio.
In diverse previous studies, it has been demonstrated that the abscisic acid (ABA) is related to the beginning of the berry maturation. Exogenous applications of this plant growth regulator near veraison, have advanced the maturation process, since the primary and secondary metabolism of the treated berries is accelerated, such effects have been demonstrated in the totality of the realized tests, in red and black cultivars, nevertheless not yet the effect of this plant growth regulator has studied on white varieties. With the intention to establish the effect of the ABA on berries of Sauvignon Blanc and Chardonnay, determined 3 treatments: (I) 50 mgL-1 ABA; (II) 100 mgL-1 ABA; (III) Control, with water and Tween 20 to 0.1% (v/v). Two applications, -2 and +1 were realized days after veraison (DAV) for the Chardonnay grapes and -7 and -4 days after veraison (DAV) for the Sauvignon Blanc grapes. By means of weekly samplings, the advance in the maturation of the berries along with the evolution of the berry size, berry and skin weight, soluble solids, pH, acidity, phenols, tannins, chlorophylls and carotenes was determined. In this test the applications of ABA modified the volume and berry weight in both varieties. In addition they were affected the soluble solid accumulation, the pH and the concentration of organic acids in the Sauvignon Blanc grapes, which did not happen in the Chardonnay grapes, is speculated on that by a delayed application but of the regulator. It is possible to indicate that the modifications were observed the beginning of the period of maturation and that towards the end of this they tended to align itself with the control. For the other measured parameters effects of the ABA were not observed on any of the varieties that this study includes.
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Von, Mollendorff Anke. "The impact of wine yeast strains on the aromatic profiles of Sauvignon blanc wines derived from characterized viticultural treatments." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80181.

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Thesis (MScAgric)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: Grape must is a complex medium, and during wine production numerous biochemical pathways and metabolic reactions are taking place simultaneously to produce a specific taste and aroma. Microorganisms, specifically yeast, play a key role in the formation of metabolites formed during alcoholic fermentation. Sauvignon blanc, a well studied grape cultivar, is known to have a versatile range of aroma profiles ranging from “green” to “tropical”. It has been broadly stated that a “green” Sauvignon blanc can be created in the vineyard and a “tropical” Sauvignon blanc can be created by selecting a specific yeast strain, and that the balance between “green” and “tropical” characters is essential for the final aroma profile. Except for grape-derived varietal aromatic compounds such as methoxypyrazines (green), volatile thiols (tropical) and monoterpenes (floral), yeast derived volatile compounds including esters, higher alcohols, fatty acids and carbonyl compounds will also contribute to the final wine aroma. The main aim of this study was to assess how viticultural treatment-derived differences in grape must, can impact on aroma production when this grape must is fermented with different commercial wine yeast strains. The viticulture treatment focused on light intensity modulated through canopy treatment. Volatile aroma differences were compared for canopy and yeast treatments, specifically focusing on the fermentation derived bouquet (esters, higher alcohols, volatile fatty acids, carbonyl compounds and monoterpenes). Results showed significant differences between initial must compositions, including titratable acidity, malic acid and yeast assimilable nitrogen. The volatile aroma compounds were also significantly impacted although no noticeable effect on the overall fermentation kinetics was observed. Depending on the yeast strain differences in volatile compounds varied. A clear vintage effect is noticeable between volatile compounds affected by the treatments. Data generated in 2012 shows clear differences between ethyl- and acetate esters and could clearly be grouped according to yeast strain through multivariate analysis. Sensory evaluation results could clearly be distinguished according to canopy treatment and to a lesser degree according to yeast strain used. This indicates that although yeast has a more prominent impact on the fermentative bouquet that develops during alcoholic fermentation the overriding aroma is primarily derived from grape-derived metabolites which can be manipulated by canopy treatments. None the less the difference in fermentation bouquet does add to the complexity of the wine especially in the case of fermentation derived “tropical” aromas including guava and passion fruit. In some cases where shaded grapes had higher ester concentrations, the resultant wine also had higher aroma quality. This study has contributed to a better understanding of the complex relationships between canopy manipulation and yeast selection on aroma formation. The analysis of volatile aroma alone however is not enough to understand the final perception of wine taste and further indepth studies of the viticultural and oenological factors is needed. In particular, this project has focused on a single vineyard over only two vintages. The general validity of the conclusions derived from this study therefore will require additional data sets.
AFRIKAANSE OPSOMMING: Druiwemos is ‘n komplekse medium en tydens wynbereiding is daar verskeie biochemiese weë en metaboliese reaksies wat gelyktydig plaasvind om ‘n spesifieke smaak en aroma te produseer. Mikro-organismes, veral gis, speel ‘n sleutelrol in die vorming van metaboliete tydens alkoholiese gisting. Sauvignon blanc, ‘n goed bestudeerde druifkultivar, besit ‘n veelsydige reeks aromaprofiele wat wissel van “groen” tot “tropies”. Oor die algemeen word dit voorgehou dat ‘n “groen” Sauvignon blanc in die wingerd geskep word, terwyl ‘n “tropiese” Sauvignon blanc geskep kan word deur ‘n spesifieke gisras te selekteer, en die balans tussen “groen” en “tropiese” karakters is noodsaaklik vir die finale aromaprofiel. Behalwe vir druifafgeleide kultivarafhanklike aromatiese verbindings soos metoksipirasiene (groen), vlugtige tiole (tropies) en monoterpene (blomagtig), sal gisafgeleide vlugtige komponente, waaronder esters, hoër alkohole, vetsure en karbonielverbindings, ook tot die finale wynaroma bydra. Die hoofdoelwit van hierdie studie was om te bepaal hoe verskille in druiwemos wat afkomstig is van wynkundige behandeling ‘n impak op aromaproduksie kan hê wanneer hierdie druiwemos met verskillende kommersiële wyngisrasse gegis word. Die wynkundige behandeling het gefokus op ligintensiteit wat deur lowerbehandeling gereguleer is. Vlugtige aromaverskille is op grond van lower- en gisbehandelings vergelyk, met ‘n spesifieke fokus op die gistingsafgeleide boeket (esters, hoër alkohole, vlugtige vetsure, karbonielverbindings en monoterpene). Die resultate het beduidende verskille getoon tussen aanvanklike mossamestellings, waaronder titreerbare suurheid, appelsuur en gis-assimileerbare stikstof. Daar was ook ‘n noemenswaardige impak op die vlugtige aromaverbindings, hoewel geen merkbare effek op die algehele gistingskinetika waargeneem kon word nie. Die verskille in vlugtige verbindings het gewissel op grond van die gisras. ‘n Duidelike oesjaareffek was merkbaar tussen vlugtige verbindings wat deur die behandelings geaffekteer is. Data wat in 2012 gegenereer is, toon duidelike verskille tussen etiel- en asetaatesters en kon duidelik m.b.v. meervariantanalise volgens gisras gegroepeer word. Die resultate van die sensoriese evaluering kon duidelik volgens lowerbehandeling onderskei word, en tot ‘n mindere mate volgens die gisras wat gebruik is. Dít dui daarop dat hoewel gis ‘n meer prominente impak het op die gistingsboeket wat tydens alkoholiese gisting ontwikkel, is die oorheersende aroma hoofsaaklik afgelei van druifafgeleide metaboliete wat deur lowerbehandelings gemanipuleer kan word. Nietemin dra die verskil in gistingsboeket by tot die kompleksiteit van die wyn, veral in die geval van gistingsafgeleide “tropiese” aromas, insluitend koejawel en grenadella. In sommige gevalle waar beskadude druiwe hoër esterkonsentrasies gehad het, het die gevolglike wyn ook ‘n hoër aromakwaliteit gehad. Hierdie studie dra by tot ‘n beter begrip van die effek van die komplekse verhoudings tussen lowermanipulasie en gisseleksie op aromavorming. ‘n Analise van vlugtige aroma alleen is egter nie voldoende om die finale persepsie van wynsmaak te begryp nie en bykomende diepgaande studies van die wingerdkundige en wynkundige faktore word benodig. Hierdie projek het in die besonder gefokus op ‘n enkele wingerd oor slegs twee oesjare. Die algemene geldigheid van die afleidings wat van hierdie studie gemaak word, sal dus bykomende datastelle vereis.
The National Research Foundation and Postgraduate Merit Bursary for financial support
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28

Garrido, Jerez Alvaro Rodrigo. "Efecto sobre la copigmentación en mezclas de vinos de las variedades Carménère con Pinot Noir y Syrah con Sauvignon Blanc." Tesis, Universidad de Chile, 2006. http://www.repositorio.uchile.cl/handle/2250/101833.

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Thibon, Cécile. "Recherches sur les précurseurs cystéinylés de l'arôme variétal des vins de Sauvignon blanc : Approche analytique et étude de leur biotransformation par Saccharomyces cerevisiae." Bordeaux 2, 2006. http://www.theses.fr/2006BOR21406.

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La combinaison de méthodes analytiques (RMN, IR, SM, CPG-SM) a permis l'élucidation des changements structuraux associés au pH, du S-4 (4-méthylpentan-2-one)-L-cystéine, (P-4MMP). A un pH compris entre 5,5 et 8, le P-4MMP présente une tautométrie céto-énolique induisant une cyclisation intramoléculaire. Une méthode de dosage rapide par CPG-SM du potentiel aromatique (P-4MMP et S-3-(hexan-1-ol)-L-cystéine, P-3MH), sous forme de dérivés, a pu être entreprise. Par ailleurs, la mise en place d'une méthode stéréo-sélective de dosage du P-3MMH a permis de dévoiler une distribution des diastéréoisomères en faveur de la forme S, dans les raisins touchés par la pourriture noble. Ce travail a contribué à la compréhension des mécanismes impliqués dans la biotransformation des S-conjugués à la cystéine par S. Cerevisiae. La teneur en azote peut moduler la libération des thiols. Par une approche génétique, le gène URE 2, impliqué dans la NCR, modulateur de la libération des thiols a été identifié
The combination of analytical methods (NMR, IR, MS, GC/MS) allowed the elucidation of structural changes at different pH of S-4 (4-methylpentan-2-one)-L-cysteine, (P-4MMP). From pH 5,5 to 8, the P-4MMP is present as keto-enol tautomeric mixture and leads to intermolecular cyclisation. A GCMS method measurement of the aroma potential (P-4MMP and S-3-(hexan 1-ol)-L-cysteine, P-3MH), under derivative form began. The development of a stereo-selective method of P-3MH assay revealed a distribution in favour of S confifuration for the P-3MH diastereoisomers, in the Bordeaux white must infected by B. Cinerea. This study has also permitted the understanding of biotransformation mechanisms of S-conjugates in volatile thiols by S. Cerevisiae. The nitrogen concentration can modulate the thiols release. By genetic study, the URE2 gene (NCR) of release regulation was identified
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Opazo, Pavez Rodrigo Antonio. "Efecto de distintos niveles de deshoje sobre la fotoinhibición en pieles de bayas de la cepa sauvignon blanc (Vitis vinífera L.)." Tesis, Universidad de Chile, 2013. http://repositorio.uchile.cl/handle/2250/148805.

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Tesis para optar al Grado de Magíster en Enología y Vitivinicultura
La absorción de la luz ocurre gracias a los pigmentos de clorofila del tipo a y b, que se asocian a complejos de proteínas en los tilacoides, denominados fotosistema I y II (PSI y PSII). En los fotosistemas están presentes los carotenoides que pueden absorber la radiación luminosa, actuando como pigmento auxiliar, pero también tienen un papel transcendental en la fotoprotección. Prácticas como el deshoje, que buscan mejorar las condiciones de aireación e iluminación de los racimos, generan diferentes comportamientos en las pielesde las bayas. En este trabajo se realizaron dos ensayos, uno con racimos con exposición Este y otro con exposición Oeste, en donde se evaluaron los efectos de los tratamientos de oscuridad, sin deshoje, deshoje al estado de tamaño arveja y deshojes en envero, sobre el comportamientode la fotosíntesis, composición de pigmentos de clorofilas a y b, y carotenoides en las pieles de las bayas de la cepa Sauvignon Blanc. Los distintos regímenes lumínicos afectaron con diferencias significativas la morfología de la baya, durante su crecimiento y desarrollo.En relación a la fotosíntesis, en ambos ensayos,los tratamientos deshojados presentaron fotoinhibición desde posenvero, en donde los tratamientos con deshoje en envero presentaron Fv/Fm más bajos, con valores que oscilaron entre 0,79 y 0,38 en el ensayo Este, y entre 0,37 y 0,29 en el ensayo Oeste.Al comienzo de los ensayos, la concentración de las clorofilas presentaron diferencias significativas, fundamentalmente en el ensayo de la orientación Este, luego las clorofilas disminuyeron en los cuatro tratamientos hasta el final de la temporada. Los carotenoides totales aumentaron el contenido en el tiempo, además los tratamientos provocaron una activacióndel ciclo de las xantofilas en los fotosistemas. El alto grado de exposición de los racimos provocó dañosen los fotosistemas, evidenciados en la disminución de Fv/Fm. Sin embargo, aumentó el contenido de carotenoides al final de la temporada, lo que puede ser beneficioso, ya que podría conducir a la mayor formación de compuestos aromáticos.
The absorption of light occurs due to the chlorophyll pigments of the type a and b, which are associated with protein complexes in thylakoids, called photosystem I and II (PSI and PSII). Within the photosystems it is possible to find the Carotenoids. Carotenoids can absorb light radiation, acting as auxiliary pigment, but also having a transcendental role in photoprotection process. Procedures such as defoliation, seeking to improve the conditions of ventilation and illumination of clusters, generate different behaviors in the skin of the berries.In this work, two experiments were done, one bunch with East orientation and one with West orientation. The researchers evaluated the effect of the treatment dark, without leaf removal, leaf removal to pea state and leaf removal from veraison, on the behavior of photosynthesis and pigment composition of chlorophylls a and b, and carotenoids in the skins of the berries of Sauvignon Blanc. The different light patterns, affected with significant differences in the morphology of the berry, during their growth and development. In relation to photosynthesis, in both trials showed photoinhibition treatments from postenvero leafless, where defoliation treatments at veraison showed Fv/Fm lower, with values ranging between 0,79 and 0,38 in the test this, and between 0,37 and 0,29 in the Western assay. At the beginning of the trials, the chlorophylls showed significant differences, mainly in the trial with east orientation. Then, the chlorophylls decreased in the four treatments until the end of the season. Total Carotenoids increased their content during the time. Morover, treatments caused the activation of xanthophylls cycle in photosynthetic systems. High exposure of clusters caused damage photosynthetic systems, as evidenced by declining Fv/Fm. However, increased the carotenoid content at the end of the season, which be can beneficial as it could lead to increased formation of aromatics.
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31

Trindade, Annielly Mayara Gomes da. "Caracterização de vinhos orgânicos sauvignon blanc elaborados a partir de diferentes fases de maturação das uvas no Vale do São Francisco." reponame:Repositório Institucional da UFSC, 2013. https://repositorio.ufsc.br/xmlui/handle/123456789/130884.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia de Alimentos, Florianópolis, 2013.
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O objetivo do presente trabalho foi caracterizar vinhos elaborados a partir de uvas produzidas de cultivo orgânico, da cultivar Sauvignon Blanc, colhidas em diferentes fases de maturação. O experimento foi desenvolvido em área pertencente à Adega Bianchetti Tedesco Ltda., localizada no Distrito de Irrigação Senador Nilo Coelho, na cidade de Petrolina-PE. As plantas estão instaladas em sistema de condução do tipo latada e irrigadas por gotejamento. As uvas foram acompanhadas durante todo ciclo fenológico e colhidas entre janeiro e fevereiro/2012. Foram vinificadas pelo método tradicional, em cubas de vidro de 9 L cada, feitos em três repetições. As fermentações foram realizadas com a adição de leveduras comerciais, ocorrendo em temperatura controlada e acompanhadas diariamente. Os vinhos foram estabilizados a frio por 30 dias e engarrafados manualmente. Foram analisados após 45 dias de estabilização em garrafas onde se analisou o teor de álcool, pH, acidez total e volátil, SO2 livre e total, densidade, extrato seco, atividade antioxidante total, açucares totais, antocianinas totais, índice de polifenois totais, minerais e perfil aromático. Observou-se que durante a maturação das uvas houve o aumento dos sólidos solúveis, pH e atividade antioxidante e diminuição da acidez. De um modo geral a composição mineral mostrou-se semelhante, com exceção do teor de potássio. Nas análises químicas houve diferenças estatisticamente significativas entre as amostras avaliadas relativas à: acidez total, extrato seco total, índice de polifenois totais e teor de açúcares. Os compostos olfativos variaram estatisticamente entre os tratamentos, com perfis aromáticos diferentes dependendo da época de colheita das uvas. Os resultados obtidos mostram que existe influência das fases de maturação sobre a composição físico-química dos vinhos tropicais orgânicos Sauvignon Blanc elaborados no Vale do São Francisco, sendo que a prática da colheita escalonada permite aumentar a gama de produtos e melhorar a tipicidade dos vinhos tropicais na região.

Abstract : The aim of this study was to characterize wines produced from grapes grown in organic cultivation, cultivar Sauvignon Blanc, harvested at different stages of maturation. The experiment was conducted in an area belonging to the Cellar Bianchetti Tedesco Ltda., Located in the Irrigation District Senator Nilo Coelho, in the city of Petrolina-PE. The plants are located in the conduction system of the type trellis and drip irrigated. The grapes were followed during the entire phenological cycle and harvested between January and fevereiro/2012. Were vinified by the traditional method, in glass tanks each 9L, made in triplicate. The fermentations were carried out with the addition of commercial yeasts occurred in controlled temperature and monitored daily. The wines were cold stabilized for 30 days and bottled by hand. They were analyzed after 45 days of stabilization in bottles where they analyzed the alcohol content, pH, total and volatile acidity, free and total SO2, density, solids, total antioxidant activity, total sugars, total anthocyanins, total polyphenols index , minerals and aromatic profile. It was observed that during the ripening of the grapes was increased soluble solids, pH and antioxidant activity and decreased acidity. Generally the mineral composition was similar, except for potassium. Chemical analyzes were statistically significant differences between the analyzed samples concerning: total acidity, fixed acidity, total solids, total polyphenols index and sugar content. The olfactory compounds varied significantly among the treatments, with different aromatic profiles depending on the time of harvest of the grapes. The results show that there is influence of maturation stages on the physical and chemical composition of organic tropical Sauvignon Blanc wines produced in the São Francisco Valley, and the practice of scaled harvests will increase the product range and improve the typicality of tropical wines in the region.
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Medel, González Rodolfo André. "Estudio de los efectos de distintos manejos de cosecha y maceración prefermentativa en la composición química del mosto del cv. sauvignon blanc." Tesis, Universidad de Chile, 2012. http://www.repositorio.uchile.cl/handle/2250/116353.

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Memoria para optar al Titulo Profesional de Ingeniero Agrónomo mención Enología y Vitivinicultura
Dentro de las primeras operaciones realizadas en la elaboración de vinos, se encuentran la cosecha y la maceración prefermentativa. Estas labores están dentro de aquellas que proporcionarán el máximo potencial del producto final. Es por esto que esta investigación se enfoca en resolver la problemática asociada a la toma de decisiones relacionadas con estas labores claves en la producción de vinos y su impacto sobre su calidad final. Los objetivos del presente estudio fueron describir física y químicamente mostos del cv. Sauvignon Blanc obtenidos de bayas cosechadas de forma mecánica y manual, además del efecto de la maceración prefermentativa sobre la composición del mismo. El estudio se realizó con mosto obtenido de bayas cosechadas en la viña Veramonte, ubicada en el valle de Casablanca, Región de Valparaíso, Chile. Durante el programa de prensado se tomó una muestra en cada etapa de éste, con el fin de observar la evolución del mosto a medida que se aumenta la presión sobre las bayas. Las muestras fueron sometidas a análisis de acidez total, pH, sólidos solubles, SO2 libre y total, taninos totales, fenoles totales, intensidad colorante, y pardeamiento. Además se cuantificaron compuestos fenólicos de bajo peso molecular a través de Cromatografía Líquida de Alta Eficacia (HPLC). Si bien se encontraron diferencias entre los tratamientos referidos al tipo de cosecha, éstas no fueron determinantes como podría suponerse, esto debido a lo severo de la cosecha mecanizada; es decir, a pesar de que la cosecha manual entrega mostos con una acidez relativamente superior y con un pardeamiento menor al momento de analizarlo en la etapa de escurrido, no es posible afirmar con certeza que la cosecha mecánica genere mostos y por consecuencia vinos de una calidad enológica menor. En cuanto a los resultados del ensayo de maceración prefermentativa, los mostos provenientes de ésta presentaron como característica una disminución en la acidez y un aumento relativo en el pardeamiento. Sin embargo, obtiene valores superiores en cuanto a extracción de compuestos fenólicos, lo que genera beneficios al momento de elaborar vinos con una mayor complejidad sensorial, no obstante aumenta el riesgo de obtener oxidaciones no deseadas.
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33

Díaz, Gutiérrez Catalina Alejandra. "Contenido de proteínas patogénicas e inestabilidad proteica de jugos de uva blanca cv. sauvignon blanc y chardonnay (Vitis vinifera L.) : diferencia entre clones, variedades y zonas de producción." Tesis, Universidad de Chile, 2012. http://repositorio.uchile.cl/handle/2250/147882.

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Memoria para optar al Título Profesional de Ingeniero Agrónomo, mención Enología y Vitivinicultura.
Las proteínas de tipo taumatina y las quitinasas, familias de proteínas solubles presentes en la baya de Vitis vinifera son responsables de la formación de turbidez y sedimentos en vinos blancos embotellados. En consecuencia, estas proteínas relacionadas a la patogénesis tienen una gran influencia en la calidad del vino. El principal objetivo de este estudio fue determinar el contenido de proteínas totales y específicas (taumatina y quitinasa), y la estabilidad proteica en jugos de uvas que fueron cosechadas en diferentes etapas de desarrollo (entre envero y cosecha). El estudio se realizó en variedades Sauvignon blanc (clon 1, 107 y 242) y Chardonnay (clon 4, 5 y Mendoza) provenientes de dos zonas de producción del Valle de Casablanca, Chile. El contenido de proteínas totales fue determinado mediante el método de Bradford y el contenido de proteínas específicas (tipo taumatina y quitinasa) fue detectado por RP-HPLC. La formación de turbidez o sedimentos en el jugo de uva libre es indicador de inestabilidad térmica. Los resultados indicaron que el contenido de proteínas totales y el contenido de proteínas específicas fueron proporcionales a la formación de turbidez o inestabilidad proteica del jugo obtenido durante todo el período de maduración estudiado, independiente de la variedad, clon, o zona de producción. En la mayoría de los casos el contenido de las proteínas taumatina y quitinasa aumenta con el tiempo de desarrollo de la baya.
Thaumatin-like proteins and chitinases, two soluble protein families occurring in Vitis vinifera grapes, have been associated to hazing in bottled white wines. Thus, these pathogenesis-related proteins have a major influence on wine quality. The main aim of this study was to determine the content of total protein and the content of specific proteins (thaumatin-like and chitinase) as well as protein stability in the juice of grapes that were collected at various ripening stages between véraison and harvest. The study was conducted on the Sauvignon blanc (clones 1, 107 and 242) and Chardonnay (clones 4, 5 and Mendoza) V. vinifera varieties from two different production zones in the Casablanca Valley, Chile. Total protein content was determined by spectrophotometry using the Bradford’s method. Contents of thaumatin-like and chitinase proteins were obtained by RP-HPLC analysis. Hazing and sedimentation in the grape juice indicates thermal instability. In the study we observed that both the content of total protein and the content of the specific proteins in the grape juices vary in direct relationship with hazing or protein instability throughout the ripening period, regardless the grape variety, clone or production zone. Contents of thaumatin-like and chitinase proteins were usually found to increase with grape maturation.
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Tominaga, Takatoshi. "Recherches sur l'arôme variétal des vins de Vitis vinifera L. Cv. Sauvignon blanc et sa genèse à partir de précurseurs inodores du raisin." Bordeaux 2, 1998. http://www.theses.fr/1998BOR20599.

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La mise au point de méthodes d’extraction spécifique des thiols volatils a permis d’analyser l’arôme caractéristique des vins de Sauvignon. Elles utilisent conjointement la combinaison des thiols d’un extrait organique avec le p-HMB et des procédés appropriés pour purifier le complexe obtenu. Outre la 4-mercapto-4-méthylpentan-2-one, déjà connue dans les vins de Sauvignon, quatre nouveaux thiols volatils odorants, dont la présence n’avait jamais été signalée jusqu’ici dans les vins, ont ainsi été identifiés : la 4-mercapto-4-méthylpentan-2-ol, le 3-mercapto-3-méthylbutan-1-ol, le 3-mercaptohexan-1-ol et l’acétate de 3-mercaptohexyl. Les concentrations de ces composés dans les vins et leurs propriétés organoleptiques ont été déterminés. Ces thiols volatils contribuent également à l’arôme d’autres fruits ou plantes dont l’odeur est parfois comparée à celle des vins de Sauvignon. Ces composés participent aussi à l’arôme des vins d’autres cépages, en particulier certains cépages alsaciens. Ces différents thiols volatils apparaissent dans les vins au cours de la fermentation alcoolique sous l’action du métabolisme de la levure. La 4-mercapto-4-méthylpentan-2-one, le 4-mercapto-4-méthylpentan-2-ol, le 3-percaptohexan-1-ol, proviennent de précurseurs non volatils et inodores du raisin, ayant la structure de S-conjugués à la cystéine : S-4-(méthylpentan-2-one), S-4-(4-méthylpentan-2-ol) et S-3-(hexan-1-ol), -L-cystéine. De tels précurseurs d’arômes n’avaient jamais été mis en évidence auparavant. Ces différents thiols peuvent être libérés in vitro par percolation du moût sur une colonne de tryptophanase immobilisée. Basé sur ce principe, un prodédé de dosage du potentiel aromatique des moûts de Sauvignon a été mis au point. La S-3-(hexan-1-ol)-L-cystéine a également été identifiée dans le fruit de la passion. Les S-conjugués à la cystéine sont donc une nouvelle catégorie de précurseur d’arômes des fruits.
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35

Hart, Rodney Sebastian. "Proteomic and metabolomic characterisation of novel wine yeasts: towards the evaluation and improvements of their ability to produce aromatic sauvignon blanc wines." University of the Western Cape, 2017. http://hdl.handle.net/11394/5913.

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Philosophiae Doctor - PhD (Biotechnology)
Wine yeast Saccharomyces cerevisiae and wild yeasts e.g. Torulaspora delbrueckii forms an integral part of wine production by converting relatively 'neutral' flavoured Sauvignon blanc grape must into varietal aromatic wines. Yeast derived and mediated metabolites which contribute to Sauvignon blanc wine aroma and flavour, are regulated by yeast proteins (enzymes) that are differentially expressed during the course of fermentation. Inoculation with an appropriate yeast strain can, therefore, increase commercial wines sales as resultant wines will have sought-after aromas and flavours. Likewise, inoculation with the incorrect strain can have an undesirable effect on wine quality. Subsequently, the development of yeasts for the production of varietal aromatic Sauvignon blanc with lower volatile acidity (VA) was also identified as a South African industry priority. Although genetic modification can address this, the use of genetically modified organisms (GMO) is illegal.
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Flores, Valdivia Daniela Alejandra. "Efecto del color de la botella de vidrio sobre la composición química de un vino del cv. Sauvignon blanc durante su almacenamiento." Tesis, Universidad de Chile, 2011. http://www.repositorio.uchile.cl/handle/2250/112301.

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Memoria para optar al Título Profesional de Ingeniero Agrónomo Mención Enología
El presente trabajo tuvo por objetivo evaluar el efecto de la coloración de la botella de vidrio sobre las características físicas, químicas y sensoriales de un vino comercial del cv. Sauvignon blanc, almacenado por un período de siete meses, bajo condiciones de luz artificial y temperatura constante. Se utilizaron botellas de vidrio de cuatro coloraciones diferentes: incolora, verde, verde hoja seca y ámbar. El primer análisis realizado correspondió al tiempo 0, durante el cual las muestras se mantuvieron en oscuridad. Posteriormente se procedió, mensualmente, con análisis básicos, fenólicos y sensoriales, durante un período de siete meses, en donde las botellas de vino estuvieron almacenadas en repisas, expuestas durante 16 horas al día a una fuente de luz artificial. Se pudo observar que el vino contenido en la botella incolora presentó bajos valores tanto en intensidad colorante y pardeamiento oxidativo, como en croma y componente amarilla. Por su parte el vino contenido en botella verde y ámbar presentó valores más altos en los parámetros antes mencionados, lo cual diferenció significativamente el tratamiento de botella incolora con los de envase oscuro. Por otro lado, el vino contenido en botella incolora mantuvo una alta luminosidad con respecto a los otros tratamientos, sin embargo, presentó la mayor pérdida de fenoles totales. Los análisis químicos y sensoriales mostraron resultados coincidentes, lo cual demostró que el vino contenido en la botella incolora presentó el menor desarrollo de pigmentación amarillo-pardo. Por lo tanto, el color de la botella afectó las características físicas, químicas y sensoriales del vino del cv. Sauvignon blanc durante el almacenamiento en botella de siete meses.
The objective of the present work was to evaluate the effect of the glass bottle colour over physicals, chemicals and sensory parameters of commercial Sauvignon blanc wines, stored along seven month, under both artificial light and constant temperature conditions. It was used four different types of bottles with different glass colour: colourless, green, dry leaf green and amber. The first analysis was carried out to the samples at time 0, without exposition of them to the light. Following this, basics, phenolics and sensory analysis was applied once a month along a seven month period, where wine bottles were shelf stored, exposed during 16 hours a day to artificial light. It was observed that the wine bottled in a colourless glass bottle showed lower values in both color intensity and oxidative browning, as in chrome and yellow component. The wine bottled in a green and amber glass bottles showed higher values at mentioned parameters, which indicated significant difference among colourless and dark bottles. In other hand, the wine bottled in a colourless glass bottle exhibited a higher luminosity than the dark bottles, however, it showed the highest lost of total phenol content. The chemical and sensory analysis showed coincident results, which demonstrated that wine bottled in a colourless glass bottle presented the lower browning development. Therefore, the glass bottle colour affected the physicals, chemicals and sensory parameters of Sauvignon blanc wine during seven month of bottle storage.
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37

Swart, Ewarda. "The effect of region, yeast strain and ascorbic acid on the development of a sulphur-like aroma and on Sauvignon blanc wine quality." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51968.

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Thesis (MSc Food Sc )--University of Stellenbosch, 2000.
ENGLISH ABSTRACT: Highly valued Sauvignon blanc wines, with the distinctive cultivar-typical aromas, reminiscent of grassy, green pepper or asparagus-like, are produced in some South African regions. Quite often, however, neutral and sulphur-like, low quality Sauvignon blanc wines are produced and this phenomenon is of great concern to wine producers and consumers, and affects our competition on overseas markets, negatively. The aim of this study was to investigate the effect of region, ascorbic acid/S02 treatments and yeast strain on Sauvignon blanc wine aroma and quality. Wines were produced from grapes obtained from the warmer Robertson and the relatively cooler Stellenbosch regions (1998 season). The juices were treated with different combinations of ascorbic acid/S02 treatments [commercially available ascorbic acid/meta preparate, S02 (control), pure ascorbic acid/S02] and Saccharomyces cerevisiae yeast strains (Vin 13, VL3C, NT 116). The wines were analysed for esters, higher alcohols, monoterpenes and 2-methoxy-3-isobutylpyrazine (ibMP). The wines were also sensorially evaluated for wine aroma intensities (fruity/ester, sulphur-like, grassy/green pepper) and overall quality. Additionally, the synergistic action of ibMP and the sulphur-containing component, 4-mercapto-4-methylpentan-2- one (MMP), considered to be the most important impact components of Sauvignon blanc, was studied. The two components were added, separately and in combinations at increasing concentrations, to different media. The nuances perceived, varied from dusty, grassy to green pepper for ibMP and from guava, sulphur-like to cat urine or "conifer" for MMP. Significant differences were observed between the wines treated with the different combinations of ascorbic acid/S02 treatments and fermented with different yeast strains, irrespective of region. The highest quality, cultivar-typical Sauvignon blanc wines were produced from the pure ascorbic acid/S02 treatment in combination with yeast strains Vin 13 and NT 116. This coincided with high ester and low higher alcohol concentrations, which did not overpower the typical Sauvignon blanc character. The treatments had, in some cases, a significant effect on monoterpene levels, but it was concluded that these differences were not big enough to affect wine quality. Levels of ibMP were too low and could not be reliably measured. Low quality wines, with prominent, undesirable sulphur-like aromas, were produced from juices, treated with the commercially available ascorbic acid/meta preparate and the French yeast strain, VL3C. Techniques, followed to identify the aroma components causing the sulphur-like offflavours, as MMP or as other sulphur-containing components, were gas chromatography/mass spectrometry, solid phase microextraction and sniffing. However, these tests were not successful and studies to identify these off-flavours should be continued. It was succeeded in this study to produce Sauvignon blanc wines without the undesirable, sulphur-like aromas. Although this investigation showed that a newly developed, commercially available ascorbic acid/meta preparate did not yield any sulphur-like off-flavours, quite often Sauvignon blanc wines with such off-flavours are still produced. Further research is needed to clarify this phenomenon.
AFRIKAANSE OPSOMMING: Hoë kwaliteit Sauvignon blanc wyne, met kenmerkende kultivar-tipiese, gras-, groenrissie- of aspersie-agtige aromas, word in sekere streke van Suid Afrika geproduseer. Die gereelde produksie van neutrale, en swawelagtige lae kwaliteit Sauvignon blanc wyne, wek egter nie net groot kommer by wynprodusente en verbruikers nie, maar het ook 'n negatiewe impak op kompetisie met oorsese markte. Die doel van hierdie studie was dus om die effek van streek, askorbiensuur/Sóbehandelings en gisras op Sauvignon blanc wynaroma en kwaliteit vas te stel. Wyne is berei met druiwe wat verkry is van die warmer Roberston en relatief koeler Stellenbosch streke (1998 seisoen). Verskillende kombinasies askorbiensuur/So, behandelings [kommersieel-beskikbare askorbiensuur/meta preparaat, S02 (kontrole), suiwer askorbiensuur/So-l en Saccharomyces cerevisiae gisrasse (Vin 13, VL3C, NT 116) is gebruik tydens die wynbereidingsproses. Spesifieke ester-, hoër alkohol-, monoterpeen- en 2-metoksi-3-isobutiel metoksipirasienkonsentrasies (ibMP) is in die wyne bepaal. Die wyne is ook sensories vir wynaroma intensiteite (vrugtig/ester, swaweiagtig, gras/groenrissie-agtig) en algehele kwaliteit geëvalueer. Die sinergistiese aksie van ibMP en die swawelbevattende komponent, 4-merkapto- 4-metielpenta-2-oon (MMP), wat beskou word as die belangrikste impakkomponente in Sauvignon blanc, is addisioneel bestudeer. Hierdie komponente is in toenemende konsentrasies, individueel en in kombinasies, tot verskillende media gevoeg. Die nuanses wat waargeneem is, het van stowwerig, gras-, groenrissie-agtig vir ibMP, tot koejawelagtig, swaweiagtig, katurine, konifeer vir MMP, gevarieer. Ongeag streke, is betekenisvolle verskille tussen die wyne wat berei is met die verskillende kombinasies van askorbiensuur/So- behandelings en gisrasse, waargeneem. Hoër kwaliteit, kultivar-tipiese Sauvignon blanc wyne is berei met suiwer askorbiensuur/So- in kombinasie met gisras Vin 13 of NT 116. Alhoewel die hoë ester- en lae hoër alkohol- konsentrasies, hierdie resultate bevestig het, is die tipiese Sauvignon blanc karakter nie hierdeur oorheers nie. Sommige behandelings het wel 'n betekenisvolle invloed of monoterpeenkonsentrasies gehad het, maar was te min om 'n effek op wynkwaliteit uit te oefen nie. Die konsentrasievlakke van ibMP swawelagtige aromas, het egter voorgekom in wyne wat met die kommersieelbeskikbare askorbiensuur/meta preparaat en die Franse gisras, VL3C, berei is. Verskeie tegnieke soos gaschromatografie/massa spektrometrie, soliede fase mikroekstraksie en "sniffing", is gebruik om die komponent, MMP, wat moontlik verantwoordelik vir hierdie ongewensde swawelagtige wangeure was, te identifiseer. Die identifikasie hiervan was egter onsuksesvol, en verdere studies is nodig om die komponent(e) verantwoordelik vir hierdie wangeure, te identifiseer. Die suksesvolle produksie van Sauvignon blanc, sonder ongewensde swaweiagtig aromas, was wel moontlik. Alhoewel hierdie studie ook duidelik getoon het dat daar geen swawelagtige wangeure in die wyne wat met die nuut ontwikkelde, kommersieel-beskikbare askorbiensuur/meta preparaat berei was, voorgekom het nie, vind die produksie van Sauvignon blanc wyne met van hierdie wangeure nog steeds plaas. Verdere navorsing rakende hierdie aspek is nodig.
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38

Sarrazin, Elise. "Recherches sur l'arôme des vins liquoreux de pourriture noble issus des cépages Sémillon et Sauvignon blanc : caractérisation de composés clés et étude de leur génèse." Bordeaux 2, 2007. http://www.theses.fr/2007BOR21466.

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Les vins liquoreux de pourriture noble sont réputés pour la complexité et la diversité de leurs arômes. Toutefois, les composés associés à leurs nuances caractéristiques sont encore peu connus. Après avoir vérifié l'existence d'un arôme typique des vins liquoreux de cépages Sémillon et Sauvignon blanc, notre travail s'est ciblé sur la caractérisation de rnolécules clés. L'analyse par CPG-O et CPG-SM de vins blancs secs et liquoreux a permis la qualification et la hiérarchisation de zones odorantes associées aux nuances typiques des vins liquoreux, dont certaines 3(2H)-furanones (furaneol*, homofuraneol et norfuraneol) aux odeurs de sucre cuit, le phénylacétaldéhyde aux nuances miellées et le méthional. Les notes zestées sont pour la plupart associées à des thiols volatils. Le rôle clé du 3-sulfanylhexan-l-ol avait déjà été décrit. De plus, trois thiols ont été identifiés pour la première fois dans le vin : le 3-sulfanylpentan-1-ol, le 3-sulfanylheptan-1-ol et le 2-méthyl -3-sulfanylbutan-1-ol. La participation de ces différents composés à l'arôme caractéristique des vins liquoreux a été étudiée en déterminant leurs seuils de perception olfactive et en les dosant. Paradoxalement, ces composés sont déjà retrouvés dans les vins blancs secs. Néanmoins, nous montrons qu'ils présentent des teneurs accrues dans les vins élaborés à partir de raisins botrytisés et prouvons I'intérêt de la pourriture noble pour amplifier le bouquet aromatique des vins liquoreux. Par ailleurs, notre travail a permis de démontrer indirectement la présence du disulfure du 3-sulfanylhexan-1-ol dans les vins de pourriture noble, et ainsi, de confirmer la cornposition singulière de ces vins.
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39

Alberts, P. "Development of a novel LC-MS/MS method for the detection of adulteration of South African sauvignon blanc wines with 3-alkyl-2-methoxypyrazines." Thesis, Link to the Internet, 2008. http://hdl.handle.net/10019/805.

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40

Roland, Aurélie. "Influence des phénomènes d'oxydation lors de l'élaboration des moûts sur la qualité aromatique des vins de Melon B. et de Sauvignon Blanc en Val de Loire." Thesis, Montpellier, SupAgro, 2010. http://www.theses.fr/2010NSAM0016/document.

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Afin de caractériser les moûts de Melon B. et de Sauvignon Blanc en composition et de modéliser leur profil d'oxydation, diverses méthodologies analytiques quantitatives ont été développées et validées. La quantification par dilution isotopique des précurseurs de thiols a nécessité la synthèse de molécules marquées qui ont également servies de traceurs lors d'études de filiation dans des milieux complexes. Ainsi, au cours de la fermentation alcoolique, nous avons pu démontrer que le S-3-(hexan-1-ol)-glutathion (G3MH) et la S-4-(4-méthylpentan-2-one)-glutathion (G4MMP) sont métabolisés par la levure et libèrent le 3-mercaptohexan-1-ol (3MH) et la 4-méthyl-4-mercaptopentan-2-one (4MMP) avec des rendements de conversion molaires proches de 4,4 % et 0,3 % respectivement. La modélisation des phénomènes d'oxydation à l'échelle laboratoire a permis par ailleurs de vérifier, comme le laissaient supposer leurs structures chimiques, que les précurseurs de thiols ne sont pas dégradés par les mécanismes oxydatifs affectant les moûts. Au contraire, une formation de G3MH concomitante avec le pic de production du Grape Reaction Product (GRP) est observée. La validation de ces observations à l'échelle industrielle a été conduite par comparaison des pressurages traditionnel et inerté. L' élaboration d'un moût de Melon B. sous gaz inerte n'est pas favorable à la production de G3MH d'origine pré-fermentaire, et a pour conséquence une diminution des teneurs en 3MH dans les vins correspondants, sans pour autant, déprécier les qualités organoleptiques des vins jeunes. Pour le Sauvignon Blanc, le potentiel aromatique de type thiol n'est pas affecté par le type de pressurage, mais une diminution très significative en 3MH dans les vins issus des cuvées obtenues sous gaz inerte est observée. La voie du (E)-2-hexènal qui est certainement impliquée, pourrait expliquer cette perte aromatique. Ainsi, de manière globale, dans nos conditions expérimentales, une oxydation ménagée et raisonnée des moûts de Melon B., et dans une moindre mesure de Sauvignon Blanc, est favorable à la qualité aromatique des vins du Val de Loire
In order to characterize Melon B. and Sauvignon Blanc musts in composition and to study their oxidation profiles, several analytical methodologies have been developed and validated. The quantification of thiols precursors by Stable Isotope Dilution Assay required the synthesis of labeled molecules, which have been used either as analytical standards or as tracers for relationship studies in complex matrices. Thus, we established that, during the alcoholic fermentation, the S-3-(hexan-1-ol)-glutathione (G3MH) and the S-4-(4-méthylpentan-2-one)-glutathione (G4MMP) are metabolized by the yeast to release the 3-mercaptohexan-1-ol (3MH) and the 4-méthyl-4-mercaptopentan-2-one (4MMP) with molar conversion yields close to 4.4 % and 0.3 % respectively. Oxidation mechanisms study at laboratory scale demonstrated that aromatic potential was not affected by oxidative reactions, as expected in regard to their chemical structures. On the contrary, the G3M H was produced in the same time as the Grape Reaction Product peak (GRP). The validation of these observations at industrial scale was conducted by comparing traditional and inerted pressing systems. The elaboration of a Melon B. must under inert gas was not in favor of a G3MH pre-fermentary production, which induced a decrease of 3MH concentration in wine without affecting the organoleptic qualities of young wines. For Sauvignon Blanc must, the aromatic potential was not affected by the kind of pressing systems but a significant decrease in 3MH was observed in the wines obtained with juices from the beginning of pressing. The E-(2)-hexenal pathway could certainly explain such aromatic losses. Thus, under our experimental conditions, a mild and controlled oxidation of Melon B. must and, in a certain extend of Sauvignon Blanc must, is in favor of the aromatic quality of wines from Loire Valley
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41

Silva, Moreno Enrique Esteban. "Efecto del macerado y prensado sobre el contenido de proteínas patogénicas e inestabilidad protéica de jugo de uva y vino cv. sauvignon blanc : impacto sobre la dosis de bentonita usada en el vino." Tesis, Universidad de Chile, 2011. http://www.repositorio.uchile.cl/handle/2250/111135.

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Memoria para optar al Título Profesional de Ingeniero Agrónomo Mención: Enología y Vitivinicultura
La formación de turbidez y/o depósitos en vinos blancos embotellados, es uno de los principales problemas que aqueja la industria del vino. Se cree que el principal factor responsable de esto, sería la presencia de proteínas térmicamente inestables, llamadas también proteínas patogénicas. Para estudiar este problema, se evaluó el efecto que tienen sobre la abundancia de proteínas patogénicas del mosto de uva, distintos tratamientos de maceración y prensado a distintos tiempos y etapas respectivamente. Adicionalmente se evaluó la cantidad de bentonita necesaria para estabilizar un vino procedente de uva macerada y prensada, y uva solo prensada. La cantidad de proteínas patogénicas obtenidas después de los tratamientos de maceración fueron mayores a las encontradas en las muestras testigos, donde se observó que a mayor tiempo de maceración hubo una mayor cantidad de proteínas patogénicas. Esta tendencia se correlaciona con un aumento en la inestabilidad proteica de los mostos. El caso de los tratamientos de prensados (tres y seis etapas), no se observó una correlación entre la abundancia de proteínas patogénicas e inestabilidad proteica de los mostos. Finalmente, la cantidad de proteínas patogénicas encontradas en un vino elaborado a partir de uva macerada y prensada, fue mayor que las encontradas en un vino elaborado con uvas solo prensadas. De esta manera fue necesaria una adición de bentonita mayor en el vino con ambos tratamientos (20% mayor al vino con uva solo prensada).
The formation of turbidity and/or deposits in bottled white wines is one of the main problems facing the wine industry. It is believed that the main factor responsible for this, is the presence of thermally unstable proteins, also called pathogenic proteins. To study this problem, were evaluated the effects on protein abundance of grape-pathogenic, different maceration and pressing treatments at different times and stages respectively. Additionally, were evaluated the amount of bentonite required to stabilize a wine from macerated and pressed grape and grape just pressed. The number of pathogenic proteins obtained after maceration treatments were higher than those found in standard samples, where it was observed that the longer the maceration was a higher number of pathogenic proteins. This trend correlates with increased protein instability musts. The case of pressed treatments (three and six stages), there was a correlation between protein abundance and protein instability pathogenic musts. Finally, the number of pathogenic proteins found in a wine made from grapes macerated and pressed, was higher than those found in wine grapes pressed only. Thus it took a further addition of bentonite in wine with both treatments (20% higher than the wine pressed from grapes only).
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42

Choné, Xavier. "Contribution à l'étude des terroirs de Bordeaux : étude des déficits hydriques modérés, de l'alimentation en azote et de leurs effets sur le potentiel aromatique des raisins de Vitis vinifera L. cv. Sauvignon blanc." Bordeaux 2, 2001. http://www.theses.fr/2001BOR20917.

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La cartographie au 1/100 000 des sols de l'Entre-Deux-Mers géographique permet d'apprécier la diversité pédologique de cette région. Les déficits hydriques modérés de la vigne ont été étudiés avec le potentiel tige. Cette application de la chambre à pression est un indicateur plus discriminant des contraintes hydriques modérées que le potentiel foliaire de base pour les sols à humidité hétérogène. Contrairement au potentiel foliaire de base, le potentiel tige permet la détection de déficits hydriques après des épisodes pluvieux estivaux. On observe une diminution de la vitesse de croissance des rameaux pour une valeur de potentiel tige égale à 0,65 MPa. Cette valeur peut être considérée comme le seuil d'apparition d'une contrainte hydrique modérée de la vigne. La transpiration du feuillage et le potentiel tige sont fortement corrélés lors de période de déssèchement régulière du sol. Le potentiel aromatique d'un moût de Sauvignon blanc fait intervenir à la fois sa teneur en précurseurs d'arôme (P-4MMP, P4MMPOH, P3MH), en composés phénoliques et en composés réducteurs (glutathion). L'expression aromatique du vin sera d'autant plus intense que le moût est riche en précurseurs d'arôme et en glutathion et pauvre en composés phénoliques. Les carences en azote ont un effet négatif sur le potentiel aromatique du raisin, elles diminuent la teneur en précurseurs cystéinylés et en composés réducteurs, elles induisent une augmentation de la teneur en composés phénoliques du moût. Les déficits hydriques apparaissant environ 4 semaines avant la récolte acroissent le potentiel aromatique du raisin
Soil mapping of Entre-Deux-Mers area revealed various soil types. Vine water deficits have been studied with stem water potential measured with a pressure chamber. Stem water potential is a more discriminating indicator than predawn leaf water potential to assess moderate water deficits. Conversely to predawn leaf water potential, stem water potential can detect water deficit the days following summer rainfall. When water was whithholding, shoot growth speed decrease occured for stem water potential value of 0,65 MPa. This value can be considered as a threshold value of the occurence of moderate vine water deficit. Stem water potential and leaf transpiration rate are strongly linked during continuous soil dehydration. Aromatic potential of grape is upon the dependence on the precursor content (P-4MMP, P-4MMPOH, P-3MH), the glutathion content and the phenolic content. A marked nitrogen deficiency decreased the aromatic potential of the grape. Low nitrogen status is linked with high phenolic content and low glutathion and precursor content in the grape. Post veraison, moderate vine water deficit have positive effect on the aromatic potential of the grape
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43

Kritzinger, Engela Cornelia. "Winemaking practices affecting glutathione concentrations in white wine." Thesis, Stellenbosch: Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20295.

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Thesis (MScAgric)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Glutathione (GSH), a tripeptide consisting of glutamate, cysteine and glycine, is the most ubiquitous non‐protein intracellular thiol in a large variety of organisms, including plants, animals and fungi. The thiol moiety of the cysteine residue confers unique redox and nucleophilic properties. In plant cells, GSH fulfils an indispensible role in the antioxidant system, sulphur metabolism and detoxification of xenobiotics. Upon grape crushing, GSH is extracted into the juice where it exerts several protective effects during the vinification process. In must, it reacts with oxidized phenolic compounds to form the colourless grape reaction product (GRP) which limits must browning to a certain extent. During wine ageing, GSH impedes the decrease of important aroma compounds, including certain esters, terpenes and volatile thiols, while at the same time preventing the development of atypical ageing off‐flavours. GSH may also inhibit the yellowing of wine during ageing. It is thus evident that elevated GSH levels in wine, in particular white wine which is more sensitive to oxidation, may be highly valuable for wine quality. The reductive crushing and pressing of white grape varieties, which limits oxidation and the consequent incorporation of GSH into GRP, promotes higher GSH levels in the juice. The reductive handling of juice also limits the formation of oxidized glutathione (GSSG). However, during alcoholic fermentation and maturation, levels generally decrease as a result of assimilation by the yeast Saccharomyces cerevisiae, and inevitable oxidation that takes place during the vinification process. The principal focus of this study was to gain a better understanding of the fate of glutathione during alcoholic fermentation and to establish whether certain oenological applications could result in elevated wine GSH levels. The application studied, included choice of yeast strain, extended lees contact, nitrogen supplementation and supplementation with glutathione enriched inactive dry yeast preparations (GHS‐IDYs). In addition, the need for a rapid analytical method for the simultaneous quantification of both GSH and GSSG in must and wine which does not involve derivatization or require extensive sample preparation, led to the development of a novel UPLC‐MS/MS method. The method was also employed to determine intracellular GSH and GSSG contents of the yeast S. cerevisiae and was studied for the first time in winemaking conditions. It was shown that the GSH levels fluctuated during alcoholic fermentation, suggesting the uptake and release by yeast. At the end of alcoholic fermentation, levels were generally lower than those initially present in grape juice, but in some cases, concentration increases were also observed. This finding indicates that, in some cases, endogenously‐produced GSH may be secreted into must during alcoholic fermentation, contributing to higher GSH levels in wine. Albeit small, significant differences in GSH content could be seen in wines fermented with different yeast strains, implying that yeast strain may to a certain extent influence wine GSH levels. While the effects of lees ageing and nitrogen supplementation seem to be insignificant in contributing to higher GSH levels in wine, the supplementation of must with GSH‐IDYs could result in increased wine GSH levels, provided the supplementation is done early during fermentation. This study has broadened our knowledge of several oenological factors, influencing GSH levels in wine and provided a new baseline for future research studies.
AFRIKAANSE OPSOMMING: Glutatioon (GSH), ’n tripeptied bestaande uit glutamaat, sisteïen en glisien, is die mees algemene nieproteïenagtige intrasellulêre tiool in ‘n wye verskeidenheid organismes, insluitende plante, diere en fungi. Die tioolfunksiegedeelte van die sisteïenresidu verleen unieke redoks‐ en nukleofiliese eienskappe. GSH vervul ‘n onmisbare rol in die antioksidantsisteem, swaelmetabolisme en die ontgiftiging van xenobiotika in plantselle. Tydens die maal van druiwe word glutatioon in die sap geëkstraeer waar dit verskeie beskermende effekte tydens die wynbereidingsproses uitoefen. GSH reageer met geöksideerde fenoliese verbindings om die kleurlose druifreaksieproduk (DRP) te vorm wat die verbruining van mos in ‘n sekere mate beperk. GSH verminder ook die afname van belangrike aromaverbindings tydens wynveroudering, insluitende sekere esters, terpene en vlugtige tiole, terwyl dit terselfdertyd die vorming van atipiese verouderingswangeure belemmer. So ook kan GSH die vergeling van wyn tydens veroudering inhibeer. Dit is dus voor die hand liggend that verhoogde GSH‐vlakke in wyn, in die besonder witwyn, wat meer oksidasie‐sensitief is, van waarde kan wees vir wynkwaliteit. Die reduktiewe maal en pers van witdruifvariëteite wat oksidasie en gevolglike inkorporasie van GSH in DRP beperk, bevorder hoër GSH‐vlakke in sap. So ook beperk die reduktiewe behandeling van sap die vorming van geoksideerde glutatioon (GSSG). Gedurende alkoholiese gisting en veroudering neem GSH‐vlakke egter af as gevolg van assimilasie deur die gis, Saccaromyces cerevisiae, asook onvermydelike oksidasie wat gedurende die wynbereidingsproses plaasvind. Die hooffokus van die studie was om ‘n beter begrip van die lot van glutatioon tydens alkoholiese gisting te verkry en om vas te stel of sekere wynkundige praktyke verhoogde GSH‐vlakke in wyn tot gevolg kan hê. Die studie het gisraskeuse, verlengde gismoerkontak, stikstofaanvulling en aanvulling met glutatioon‐verrykte, onaktiewe droëgis ingesluit. Daarbenewens het die behoefte aan ‘n vinnige analitiese metode vir die gelyktydige kwantifisering van sowel GSH as GSSG in mos en wyn wat nie derivatisering of uitgebreide monstervoorbereiding vereis nie, gelei tot die ontwikkeling van ‘n nuwe UPLC‐MS/MS metode. Hierdie metode is ook gebruik om die intrasellulêre GSH‐ en GSSG‐inhoud van die gis S. cerevisiae te bepaal wat vir die eerste keer in wynbereiding bestudeer is. Daar is bewys dat GSH‐vlakke tydens alkolholiese gisting fluktueer, wat dui op die opname en vrystelling daarvan deur die gis. Die vlakke aan die einde van alkoholiese gisting was oor die algemeen laer as vlakke aanvanklik teenwoordig in die sap. In sommige gevalle is konsentrasietoenames egter ook waargeneem. Hierdie bevinding dui daarop dat intrasellulêr‐vervaardige GSH, in sommige gevalle, in die mos uitgeskei kan word, wat tot hoër GSH‐vlakke in wyn lei. Klein, dog beduidende verskille in GSHinhoud is waargeneem in wyne wat met verskillende gisrasse berei is, wat daarop dui dat gisras in ‘n sekere mate die GSH‐vlakke in wyn kan beïnvloed. Alhoewel die effek van gismoerveroudering en stikstofaanvulling onbeduidend is, kan die aanvulling van mos met glutatioon‐verrykte, onaktiewe droëgis tot verhoogde GSH‐vlakke in wyn lei, mits die aanvulling vroeg tydens alkoholiese gisting gedoen word. Hierdie studie verbreed ons kennis van verskeie wynkundige praktyke wat GSH‐vlakke in wyn beïnvloed en vorm ‘n nuwe basis vir toekomstige navorsingstudies.
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44

Šťastný, Radek. "Vliv termínu odlistění na aromatický profil vína Sauvignon blanc." Master's thesis, 2016. http://www.nusl.cz/ntk/nusl-363357.

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The purpose of the thesis on topic Effect of date of defoliation on aromatic profile ´Sauvignon blanc´ wine was to find out the effect of removing leaves from grapes zone on qualitative and quantitative parameter of grapes of this species. The practical part of the experiment with defoliation in different terms was carried out during 2015 on a vineyard in Svatobořice-Mistřín. Part of the practical experiment was the production of wines from different variants and and evaluated the sensory properties of wine.
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45

Bílková, Markéta. "Vliv termínu odlistění zóny hroznů na kvalitu a zdravotní stav hroznů." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-167758.

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46

Nováček, Tomáš. "Porovnání ruční a mechanizované defoliace a hodnocení vlivu na kvalitu hroznů." Master's thesis, 2019. http://www.nusl.cz/ntk/nusl-426578.

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The thesis deals with the issue of defoliation after quality grapes. The work deals with the comparison of mechanical and manual defoliation. The first part deals with searching and displaying information with this issue. The second part is about my experiment, its processing and its own recommendations. I was able to do this experiment on the Plaček vineyard in Moravské Branice where I used 11 lines of Sauvignon blanc variety for the experiment when every line indicates another experiment variation. Defoliation zone of grapes took place since 7.6.2018. Manual defoliation always removed 1-3 leafs and other part from defoliation zone. Since 15.6.2018 we used a mechanized defoliation using the defoliator. The following experimental variations were made in the same terms both manually and mechanically. The last mechanical defoliation was on 1.7.2018 and we performed a defoliation variant as a control. The last attempts were made between 26.7 and 2.8.2018 where we used another method of defoliation zone of grapes for a purpose to slown down the ripening. During the ripening of the grapes their health and quality was monitored. In four weeks carried out the evaluation of qualitative grapes. The berry sugar content, Ph value, acid content, nitrogen content and other defoliation-related parameters were measured. All measurements were taking place at a school laboratory in Lednice. All data have been evaluated and we written own recommendations for winemakers and vineyard oweners.
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47

Kozmon, Tomáš. "Vplyv termínu odlistenia zóny hrozna na kvalitu a zdravotný stav u odrody Savignon blanc." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-250106.

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The impact of the term of defoliation of the zone of grape on quality and condition of plant health for the Sauvignon blanc variety The focus of the Thesis is to evaluate the effect of the term of defoliation of the zone of grape on quality and condition of plant health for Sauvignon blanc variety. The introduction of the theoretical part briefly characterizes the issue of leaf area -- factors affecting it. The next sections describe the green work and the attention is focused primarily on defoliation of the zone of grape -- the impact, the terms and the intensity of defoliation. The factors determining the ripeness and quality of grapes are briefly described as well individual qualitative parameters. The practical section describes he methodology used in the evaluation of the experiment of defoliation on four different terms and the results of the examined variants of defoliation are interpreted.
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48

Kušický, Dávid. "Porovnání agrobiologických a kvalitativních vlastností klonů vybrané odrůdy révy vinné." Master's thesis, 2019. http://www.nusl.cz/ntk/nusl-426565.

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This diploma thesis compares the differences between clones of the Sauvignon variety, which are planted in the Central Slovakia wine region in the village of Veľký Krtíš and then evaluates the results of this comparison. Three clones from French and one clone from Tyrol are planted together in one vineyard track. The literary part of this thesis describes general information about Sauvignon variety, its clones and aromatic substances. In the vineyard were studied the phenological phases of the clones, uvological values and yield. From each clone has been made wine separately. For each wine were determined basic parameters and difference of aromatic substances using method of comprehensive two-dimensional gas chromatography. Based on the results of the expert committee were created the aromagrams and the position of the wines in the hundred-point table according to standards of the O.I.V.
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49

Žáková, Iveta. "Porovnání kvality hroznů a vína z ruční a mechanizované sklizně u odrůdy Sauvignon blanc." Master's thesis, 2016. http://www.nusl.cz/ntk/nusl-363251.

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Machine harvesting is the most widely expanded vineyard mechanization practices today. Foreign research into the effects of mechanization demonstrated that the grape quality was unaffected, in some cases, improved with the introduction of machine harvesting. In 2015 within the framework of this diploma work the experiment was performed by Sauvignon blanc. All data were subjected to Analysis of variance at P < 0,05. Although statistical differences were found in the grapes by total acidity and type of harvesting, statistical differences were not found in wine. Wine produced from machine grape harvesting were more fruity in sensory analysis.
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50

Wang, Xingchen. "Varietal Thiols and Precursors: Biogenesis, Reactivity, and Impact of Winemaking Practices." Thesis, 2022. https://hdl.handle.net/2440/136792.

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Over one thousand volatile compounds have been identified in wine and these arise from different chemical classes, varietal thiols are of one group which is particularly important given their substantial sensory impact on certain wine varieties. As such, furthering the understanding of thiol biogenesis through the analysis of known precursors and exploration of new ones, and reactivity of thiols based on factors related to viticulture, winemaking, and wine storage, is crucial to the manipulation of varietal thiols in wine and thus overall wine sensory profile. Additionally, exploring of other sulfur-containing volatile compounds in wine is one of the aims of the project, which could contribute to the appreciation of wine aroma complexity as a result of this important class of molecules. A review of the literature (Chapter 1) summarises the production and manipulation of varietal thiols in wine, including 3-sulfanylhexan-1-ol (3-SH), 3-sulfanylhexyl acetate (3-SHA), 4-methyl-4-sulfanylpentan-2-one (4-MSP), and 4-methyl-4-sulfanylpentan-2-ol (4-MSPOH), and considers the impact on non-volatile L-glutathione and L-cysteine conjugated precursors in grapes from viticultural and winemaking practices. Specialised analytical methods for studying such compounds are necessary given their chemical reactivity. The review also identified research gaps, namely knowledge regarding potential new precursors and reactivity of varietal thiols, given that the concentrations of varietal thiols in wine could not be adequately accounted for by the utilisation of known precursors. Impacts of some winemaking practices on the concentrations of thiol precursors in grape materials and varietal thiols in the resultant wines were proposed. The review highlighted the possibility of sulfur-containing volatile compounds awaiting discovery in wine, including grapefruit mercaptan and blackcurrant mercaptan, which are key contributors to the aroma of grapefruit and blackcurrant, respectively. Chapter 2 (prepared in manuscript format) reports a preliminary study aiming to identify new precursors to 4-MSP and 3-SH. 4-MSP can be released from its L-glutathionylated or L-cysteinylated conjugate (i.e., GSH-4-MSP and Cys-4-MSP) with mesityl oxide (MO) assumed to be their precursor but not been identified in grapes. It was hypothesised in Chapter 1 that one route could involve MO produced by soil bacteria near grapevine roots, with subsequent uptake and transformation of MO into 4-MSP precursors. To verify this, a feeding experiment was conducted by applying deuterium labelled MO to grape leaves and bunches of potted grapevines. Analysis of the grape tissues by HPLC-MS/MS showed the presence of deuterium labelled GSH-4-MSP or Cys-4-MSP, indicating that MO is the precursor of GSH-4-MSP and Cys-4-MSP in grapevines. However, further experiments should explore the existence of MO in vineyard soil as well as soil bacteria strains that could potentially yield MO. Additionally, this chapter studied the presence of a potential 3-SH precursor, namely the Nmalonylcysteine conjugated 3-SH (MalCys-3-SH), in Sauvignon blanc juice extracts. The extracts were screened after optimising MS parameters using an authentic MalCys-3-SH standard based on a published HPLC-MS/MS method for thiol precursors. Although MalCys- 3-SH was not identified at this stage, it cannot be concluded with the small sample set that this or other precursors are not present in juice. A greater number of grape samples should be analysed in the future, jointly with MS experiments that look for the loss of specific fragments associated with L-glutathione, for example. The research publication presented in Chapter 3 explores the reactivity of varietal thiols, particularly 3-SH. The recent identification of cis-2-methyl-4-propyl-1,3-oxathiane (cis-2-MPO) in wine was speculated to be the product of 3-SH reacting with acetaldehyde. In a continuation of this work, the evolution profile of cis-2-MPO during alcoholic fermentation was studied, revealing moderate to strong Pearson correlations with 3-SHA and acetaldehyde. Yeast strains significantly affected cis-2-MPO production during fermentation, but resulted in similar concentrations in the resultant wines. The instability of cis-2-MPO was illustrated by the continuous decline in a commercial Sauvignon blanc wine spiked with cis-2-MPO which was stored for one-year under various conditions (pH, temperature, presence of acetaldehyde or SO2). In this case, cis-2-MPO appeared to be preserved by lower pH, acetaldehyde addition, and 4 °C storage temperature. The research publication in Chapter 4 was based on the hypothesis that enantiomers of cis-2-MPO were produced from the corresponding 3-SH enantiomers upon their reaction with acetaldehyde. To verify this, a validated stable isotope dilution assay (SIDA) using gas chromatography coupled to mass spectrometry (GC-MS) with a chiral GC column stationary phase was developed and utilised to analyse wine samples. Chemical formation of cis-2-MPO from the co-spiking of 3-SH and acetaldehyde standards in a commercial wine was verified and used to confirm enantiomer elution order. cis-2-MPO was revealed to consist of (2R,4S)-2-MPO and (2S,4R)-2-MPO in wine, which had strong Pearson correlations with (3S)-3-SH and (3R)- 3-SH, respectively, upon analysing the thiol enantiomers. Additionally, one enantiomer of cis- 2,4,4,6-tetramethyl-1,3-oxathiane (cis-TMO), derived from the reaction of 4-MSPOH and acetaldehyde, was identified and quantified in a few white wine samples (≤ 28 ng/L). Although presenting below the odour detection threshold (14.9 μg/L) determined in this work, its presence demonstrated a pathway for the production of 1,3-oxathianes from acetaldehyde and varietal thiols bearing a 1,3-sulfanylalkanol substitution in their structures. Chapter 5 (prepared in manuscript format) reports the preliminary method development to resolve 4-MSPOH enantiomers and identify the proposed sulfur-containing volatile compounds in wine. Bearing a chiral centre, 4-MSPOH can conceivably consist of two enantiomers. However, the identification of a single cis-TMO enantiomer (Chapter 3) implied that only a single 4-MSPOH enantiomer might be present in wine. To examine this, an assessment of two chiral stationary phases (CSPs), column temperature, eluent composition, and mobile phase flow rate were performed to separate 4-MSPOH enantiomers by adapting a method involving thiol derivatisation and HPLC-MS/MS analysis with a CSP. Base line separation of 4-MSPOH enantiomers was not achieved with the columns on hand, but the method was adequate to verify the hypothesis, and different wine samples were screened. 4- MSPOH was not identified at this stage and further method optimisation using alternative CSPs along with analysing additional wines with a more sensitive instrument may provide more conclusive results. Chapter 5 also studied the potential presence of grapefruit mercaptan (GFM) and blackcurrant mercaptan (BCM) using a published HPLC-MS/MS method after thiol derivatisation. Calibration of BCM was undertaken and a selection of wines was analysed, but BCM was not detected. Further work with a broader set of wines is required to provide evidence about the presence and concentration of BCM. In contrast, GFM appears to be unstable under light or protic conditions and the degradation product was investigated, although additional study is required to verify its identity. Research manuscripts in Chapter 6 and Chapter 7 highlight the effect of a novel grape crushing technique, known as accentuated cut edges (ACE), on the release of thiol precursors and varietal thiols in Shiraz and Sauvignon blanc during winemaking. Other practices, including water dilution and skin contact time for Shiraz, and yeast strain and lactic acid bacteria for Sauvignon blanc, were also evaluated. Concentrations of thiol precursors in Shiraz grape must and varietal thiols in Shiraz wine were not significantly affected by ACE (Chapter 6, research publication). Nonetheless, as best as it can be ascertained, this was the first time that thiol precursors were identified in Shiraz grape must. Sauvignon blanc and Pinot noir wines made with ACE or conventional crushing on a commercial scale were also analysed, giving preliminary insight into the potential of ACE for increasing concentrations of varietal thiols in Sauvignon blanc, but causing a decrease of 3-SH in Pinot noir. The impact of ACE on varietal thiols may depend on grape variety was highlighted, which was pursued further with fermentation trials involving ACE and Sauvignon blanc (Chapter 7, research publication). Varietal thiols and their precursors in the Sauvignon blanc trials were markedly increased by ACE. However, the potential for browning of white wine was raised given the higher amounts of total phenolics and hydroxycinnamates in ACE treatments. The impact of crushing method, yeast strain, and malolactic fermentation on other volatile compounds was evaluated for the Sauvignon blanc fermentations. Interactions with other winemaking parameters were observed and discussed in Chapter 6 and Chapter 7. The overall sensory quality of the Shiraz and Sauvignon blanc wines was assessed with a rate-all-that-apply (RATA) methodology, revealing that the grape crushing method and other winemaking practices could modify the wine sensory profiles, with ACE playing a relatively minor role, as outlined in the respective chapters.
Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2022
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