Grape-derived aroma and flavor precursors exist partially as non-volatile, sugar-bound glycosides. Hydrolysis of these compounds may modify sensory attributes and potentially enhance wine quality. In the first study, four levels of shoot thinning (control, 20, 25, and 30 shoots per meter) with and without basal leaf removal (2-4 leaves per shoot) were established on mid-wire (90 cm), bilateral cordon-trained, mature Cabernet Sauvignon (Vitis vinifera L.) grapevines in eastern Virginia in 1996 to determine the effects on grape chemistry, glycoconjugates, and conjugate fractions. Reduced shoot density generally resulted in higher berry weight and lower soluble solids (°Brix) at each sampling date. Titratable acidity and pH were generally unaffected by shoot thinning. The 25 shoots per meter treatment displayed the greatest rate of increase in total, red-free, and phenolic-free glycoconjugates, expressed as glycosides (μmol).. Leaf removal resulted in increased pH, total phenolics, and total anthocyanins at each sampling date and a higher concentration of total, red-free, and phenolic-free glycosides. In a second study, three crop levels [high (6.4 and 5.3 kg/vine), medium (5.1 and 4.9 kg/vine), and low (3.2 and 2.6 kg/vine) ] were established on mature Cabernet Sauvignon grapevines during the 1995 and 1997 seasons, respectively. Cluster thinning of vines trained to a mid-wire (90cm), bilateral cordon-system was performed by hand three weeks post-bloom to determine the effects on grape glycoconjugates and conjugate fractions (expressed as glycosyl-glucose). In 1995, reduced crop level resulted in higher soluble solids concentration, pH, and total and red-free glycosides but did not affect berry weight or titratable acidity. In 1997, the reduced crop level treatment had higher berry weight and lower soluble solids, sugar per berry, and anthocyanins compared with the high treatment throughout the sampling period. The low treatment had the highest concentration of total, red-free, and phenolic-free glycosides per gram of fresh fruit weight on the last sampling date and the highest total, red-free, and phenolic-free glycosides per gram of fresh fruit weight when compared at similar soluble solids concentrations. Duo-trio significance testing resulted in no sensory differences among the treatments in 1997. In a third study, Pinot noir (Vitis vinifera L.) wines were inoculated with one of six genetically different strains of Brettanomyces intermedius (Ave, M, 216, Vin 1, Vin 4, and Vin5). Wines stored sur lie and those racked immediately following the completion of secondary fermentation were analyzed to determine the influence of B. intermedius strains on total, red-free, and phenolic-free glycoside concentrations (estimated by the analysis of glycosyl-glucose), and on selected free volatiles. Sur lie wines inoculated with strain Vin 4 and racked wines inoculated with Vin 4 and Vin 5 had the lowest total glycoside concentration. Hydrolysis of red-free glycosides appeared greatest in sur lie wines inoculated with Vin 4 and racked wines inoculated with Vin 4 and Vin 5. Wines stored sur lie that were inoculated with M and Vin 1 and racked wines inoculated with Vin 1, Vin 4, and Vin 5 had the lowest concentration of phenolic-free glycosides. Wines were analyzed for volatile compounds known to be produced by Brettanomyces spp. Inoculated wines were found to have detectable concentrations of ethyl-2-methylbutyrate, isoamyl alcohol, ethyldecanoate, isovaleric acid, guaiacol, 2-pheylethanol, 4-ethylguaiacol and 4-ethylphenol. There were significant differences in the concentrations of these compounds among strains. Duo-trio testing demonstrated sensory differences between the control and all inoculated wines. Differences were also found between wines inoculated with strains Ave and Vin 5, strains M and 216, and strains M and Vin 4. / Master of Science

Grape maturity is a critical attribute impacting potential wine quality. Maturity evaluation is difficult due to the many interrelated factors that impact physicochemical changes and limitations in the understanding of these factors. Current methods of assessing grape maturity are destructive, expensive, time consuming, subjective, and do not always strongly correlated to potential wine quality. This study evaluated the applicability of a conducting polymer-based electronic nose to monitor grape maturity by analyzing headspace volatiles. In the first part of the study, system and experimental parameters affecting the electronic nose operation were investigated to optimize detection of wine grape aroma. In the second part, the ability of an electronic nose to classify Cabernet Sauvignon (Vitis vinifera L.) grapes based on maturity was investigated. Maturity of samples collected at different weeks post-bloom was evaluated by measuring berry weight, pH, Brix, titratable acidity, total phenols, color intensity, hue, total anthocyanins, and total and phenol-free glycosides. Results were compared, using discriminant and canonical discriminant analysis, with analysis of headspace volatiles via the hand-held electronic nose. The electronic nose was able to determine the difference between the sample groups. Field measurements demonstrated the potential for the electronic nose as a rapid, non-destructive tool for evaluating grape maturity. / Master of Science

Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2017-12-01T12:56:57Z No. of bitstreams: 1 PGCS15MA129.pdf: 879531 bytes, checksum: e78ae25345fc9732cf6389f2d2af1fb2 (MD5) / Made available in DSpace on 2017-12-01T12:56:57Z (GMT). No. of bitstreams: 1 PGCS15MA129.pdf: 879531 bytes, checksum: e78ae25345fc9732cf6389f2d2af1fb2 (MD5) Previous issue date: 2015-04-28 / Capes / Cover crops can be grown in the vineyards to erosion control and also as an alternative to prevent over vegetative vigor, due to competition for water and nutrients. The objective of this study was to evaluate the effects of cultivation and management of cover crops in vineyard of Cabernet Sauvignon in the Southern Brasilian Higlands. They were determined soil chemical properties and its correlation with the leaf nutrient content and also the dry matter production (DM) of cover plants and vine branches. The evaluations were in the 2013/14 season, in an experiment started in 2009. The treatments were composed by a control, the succession of annual species, buckwheat (Fagopyrum esculentum) and ryegrass (Lolium multiflorum), the perennial specie fescue (Festuca arundinacea) and wild plants, in addition to managements with and without transfer the cultural residue from the line to the leading vine. The leaves sampling was performed at "veraison" stage, while the soil sampling was made at three layers (0 - 5, 5 - 10, 10 - 15 cm) in the stage of ripening berries. In general, cover crops and their management did not affect the pH, Al, Ca and Mg in the soil. But the annual increased available P in the layer 0 - 5 cm, while the perennial generally increased the exchangeable K in layers up to 15 cm relative to the control. The fescue reduced the P and K leaf content compared to other treatments, N compared to annual and native plants and Mg compared to annual plants. The exchangeable K and the K/Mg ratio in the soil correlated positively with the K content and with the K/Mg ratio and negatively with Ca and Mg content in the leaves. The soil Ca content correlated positively with K leaf content, as well as soil Mg, with the K and P leaf content. The K/Mg soil rate correlated negatively with Ca and Mg, and positively with the K/Mg ratio in the leaves. The succession of annual species produced higher DM than perennial, but this resulted in lower dry branches mass relative to the control. Overall, the management of cover crops was little influence in the evaluated variables / Plantas de cobertura do solo podem ser cultivadas nos vinhedos para controle da erosão e também como alternativa para evitar o excesso de vigor vegetativo, devido à competição por água e nutrientes. O objetivo deste trabalho foi avaliar os efeitos do cultivo e do manejo dos resíduos das plantas de cobertura em vinhedo da cultivar Cabernet Sauvignon na região do Planalto Sul Catarinense. Foram determinados os atributos químicos do solo e sua correlação com os teores foliares de nutrientes e também a produção de massa seca (MS) das plantas de cobertura e dos ramos da videira. As avaliações foram realizadas na safra 2013/14, em um experimento iniciado em 2009. Os tratamentos foram compostos por um testemunha, pela sucessão de espécies anuais, o trigo mourisco (Fagopyrum esculentum) e o azevém (Lolium multiflorum), pela espécie perene festuca (Festuca arundinacea) e por plantas espontâneas, além dos manejos com e sem a transferência do resíduo cultural da linha para a entrelinha da videira. A amostragem das folhas foi realizada na fase de “veraison”, enquanto a do solo foi feita em três camadas (0 - 5, 5 - 10 e 10 - 15 cm) na fase da maturação das bagas. Em geral, as plantas de cobertura e seu manejo não afetaram o pH, os teores de Al, Ca e Mg trocáveis no solo. Porém as anuais aumentaram o P extraível na camada 0 - 5 cm, enquanto a perene em geral aumentou o K extraível nas camadas até 15 cm, relativamente à testemunha. A festuca reduziu os teores foliares de P e K relativamente aos demais tratamentos, de N relativamente às plantas anuais e nativas e, de Mg relativamente às anuais. O K extraível e a relação K/Mg do solo correlacionaram-se positivamente com o teor de K e com a relação K/Mg e, negativamente com os teores de Ca e Mg nas folhas. O Ca do solo correlacionou-se positivamente com o teor de K foliar, assim como o Mg do solo, com os teores de K e P foliares. A relação K/Mg do solo correlacionou-se negativamente com os teores de Ca e Mg e, positivamente com a relação K/Mg foliares. A sucessão de anuais produziu maior MS do que a perene, porém essa resultou em menor MS de ramos relativamente à testemunha. Em geral, houve pouca influência do manejo das plantas de cobertura nas variáveis avaliadas

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

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The rate of nitrogen (N) in grapevines in the Rio Grande do Sul (RS) State, Southern Brazil, is established considering N content in leaves or leaves petioles and yield expectation limits. Once N fertilization needs have been diagnosed, the N is applied in indefinite times. However, N fertilization recommendations don t consider the impact of N fertilization in the yield, the consequences on grape composition and the contribution of N of crop residues to mineral nutrition of grapevines. The objective of this work was to estimate the recovery and accumulation of N in grapevines and the effect in the yield and grape composition. Three studies were carried on. Study 1, recovery, distribution and accumulation of N fertilizer was studied, in Cabernet Sauvignon grapevines, located at Bento Gonçalves city, area of the Serra Gaúcha (experiment 1), and Santana do Livramento city, area of the Campanha (experiment 2), in RS, Southern Brazil. In the experiment 1 and 2 the plants were fertilized with 15N in four forms and, when grapes were mature, plants were fractionated, oven-dried, weighted and analysed for total N and 15N enrichment. Study 2, grape yield and composition of grapevines treated with different amounts of N were studied, in the vineyards of the Study 1. Grapes were collected when ripe and yield was evaluated. Must soluble solids, pH, total acidity, tartaric acid, malic acid, total phenols, anthocyanins and N ammonia were evaluated in part of the berries. The remaining berries were triturated and total N, P, K, Ca and Mg were evaluated. Study 3, decomposition and nutrient release by aerial organs of Lolium perenne (LP) and Trifolium repens (TR) (experiment 1), and grapevines uptake of the N derived from decomposing material (experiment 2) were studied in Chardonnay grapevines located at the experimental Station of the University of Bologna, Italy. In experiment 1, 2 g (DW) of 15N-labelled litter of LP and TR were placed into litter bags which were placed on the vineyard soil surface. Collection of bags LP and TR was performed 8 (June) and 16 (August) weeks from the deposition. Remaining biomass, 15N, N, C, P, K, Ca, Mg and S concentrations were determined. In experiment 2, 30 g plant-1 of dry litter of LP and TR were placed on the herbicided soil under the grape plants. Grapevine leaves were collected 8 and 16 weeks from litter deposition; after 16 weeks, one year (including bunches) and two years shoots were collected, oven-dried, weighted and analysed for total N and 15N enrichement. Results showed that the absorbed N is distributed and accumulated especially in leaves and that most of the N found in the plant was not derived from the fertilizers but from the organic matter already present in the soil. However, N fertilization increased grape yield in the Serra Gaúcha grapevines. The rate can be split 25% at the beginning of bud burst + 25% at bud burst + 25% at flowering + 25% at growth berries; 50% at the beginning of bud burst + 50% at bud burst and 50% at flowering + 50% at growth berries. Moreover, N fertilization altered the grape composition, especially decrease the amount of anthocyanins. LP and TR residues decomposed at the same rate, but nutrient release was different between the two species and varied according with mineral element. The amount of N that grapevines recovered from the decomposing litter was low and similar for LP and TR residues. / No Rio Grande do Sul (RS), a dose de nitrogênio (N) para a videira é definida a partir do seu teor total na folha inteira ou no pecíolo, e na expectativa de produção. Quando diagnosticada a necessidade de aplicação, recomenda-se o seu parcelamento em épocas incertas. Entretanto, essa recomendação não infere informações sobre o impacto do N aplicado na produção e na composição da uva. Também não se considera a contribuição do N dos resíduos de plantas de cobertura depositados na superfície do solo. O presente trabalho teve como objetivo estudar a recuperação e acumulação de N em videiras e seu efeito na produtividade e na composição da uva e do mosto. Foram conduzidos três estudos: Estudo 1, realizado para estimar a recuperação, distribuição e a acumulação de N aplicado ao solo pela videira. Esse foi composto por dois experimentos: Experimento 1, implantado em um vinhedo de Cabernet Sauvignon na Embrapa Uva e Vinho, Bento Gonçalves (RS), e o experimento 2, instalado na Empresa Pernod Ricard Brasil/Almadén, Santana do Livramento (RS). Nos experimentos 1 e 2 as videiras foram submetidas à aplicação de uma dose de N com 3% de átomos de 15N, em quatro modos de parcelamento. Na maturação da uva, as plantas foram colhidas, fracionadas, secas, determinada a matéria seca (MS) e analisado os totais de N e 15N. O Estudo 2 foi realizado para avaliar a produtividade e a composição da uva e do mosto, em videiras submetidas à aplicação de N. O Estudo 2 foi formado por dois experimentos: Experimento 1, implantado no vinhedo do experimento 1 do Estudo 1, as videiras receberam cinco doses de N e o experimento 2, instalado no vinhedo do experimento 2 do Estudo 1, as videiras foram submetidas à aplicação de seis doses de N. Nos experimentos 1 e 2 a uva foi colhida, determinada a produção e no seu suco avaliado os sólidos solúveis totais, o pH, a acidez total, o ácido tartárico e málico, os polifenóis totais, as antocianinas e o N amoniacal. Além disso, na baga foram analisados os totais de N, P, K, Ca e Mg. O Estudo 3 foi realizado para determinar a contribuição de N derivado da decomposição de resíduos de azevém (Lolium perenne) e trevo branco (Trifolium repens) para a videira. Esse compreendeu dois experimentos instalados em vinhedo de Chardonnay, em Bologna, Itália. No experimento 1, os resíduos de azevém perene e de trevo branco foram colocados no interior de bolsas teladas e depositados no solo. Ao longo do ciclo das videiras as bolsas teladas foram coletadas, determinada a MS remanescente e analisado os totais de 15N, N, C, P, K, Ca, Mg e S. No experimento 2, os resíduos das espécies foram colocados na superfície do solo e na maturação da uva as videiras foram colhidas, fracionadas, secas, determinado a MS e analisado os totais N e 15N. Os resultados obtidos mostram que o N adicionado e absorvido no ano é distribuído e acumulado, preferencialmente, nas folhas, mas a maior parte do N presente na videira é derivada de outras formas, que não a do fertilizante. Entretanto, existe aumento na produção quando da aplicação de N na Serra Gaúcha, podendo a dose ser parcelada 25% no início da brotação+25% na brotação+25% na floração+25% no crescimento das bagas; 50% no início da brotação+50% na brotação e 50% na floração+50% no crescimento das bagas. A aplicação de N altera a composição da uva, especialmente, diminui a quantidade de antocianinas no mosto. Os resíduos de azevém perene e trevo branco depositados na superfície do solo são decompostos com a mesma taxa no ciclo vegetativo e produtivo da videira, porém liberam nutrientes em taxas diferentes. No entanto, isso tem pouca importância, pois as plantas recuperam porcentagens pequenas e iguais de N derivado dos resíduos das duas espécies.

La connaissance de la composition phénolique du Cabernet-Sauvignon (CS) et du Merlot (M) dans la région vitivinicole du bordelais a un intérêt majeur pour définir la structure et la qualité tannique (astringence et amertume) des raisins et des vins. La composition en tanins et anthocyanes de raisins et de vins issus du Cabernet Sauvignon et du Merlot ainsi que leur perception tannique ont été recherchées. L’étude raisins a été réalisée pour cinq parcelles de la région bordelaise (Pauillac, Margaux, Saint Emilion (1), Saint Emilion (2) Côtes de Bourg) pour trois millésimes consécutifs : 2006, 2007 et 2008 et différents types de sol : Limoneux, Sableux, Limono-Sableux 1, Limono-Sableux 2, Limon argilo-sableux pour le M et Limono-argileux, Sablo-limoneux 1, Limono-sableux, Sablo-limoneux 2 et Limoneux pour le CS. Les monomères [(+)-catéchine (C), (-)-épicatéchine (EC), (-)-épicatéchine-O-gallate] et les oligomères (dimères: B1, B2, B3, B4 et trimère Cat-Cat-Epi) des procyanidines, ont été identifiées et quantifiées pour les extraits de raisins (pépins et pellicules) et pour les vins par CHLP-UV-Fluo. Le pourcentage de galloylation (%G), le pourcentage de prodelphinidines (%P) ainsi que le degré moyen de polymérisation (DPm) des tanins oligomères des raisins et des tannins de vin ont été déterminés par CHLP-UV-SM. L’intensité d’astringence et d’amertume des tanins oligomères des raisins (pépins et pellicules) et des vins ont été estimées par analyse sensorielle. Les anthocyanes monoglucosides [cyanidine-3-O-glucoside (Cy), delphinidine-3-O-glucoside (Dp), paeonidine-3-O-glucoside (Pn), malvidine-3-O-glucoside (Mv), petunidine-3-O-glucoside (Pt)] et les anthocyanes acétylées (paeonidine-3-O-glucoside, malvidine-3-O-glucoside) et coumaroylées (paeonidine-3-O-glucoside, malvidine-3-O-glucoside) ont été identifiées et quantifiées par CLHP-UV-SM dans les extraits de pellicules et dans les vins. L’influence du sol, du millésime, et du cépage (pour les raisins et les vins) ont été explorés. Le millésime, dans les deux cas (raisins et vins), a un effet très significatif et domine celui du cépage (raisins et vins) et celui du sol (raisins) sur la plupart des variables étudiées. Selon le type de sol et le millésime, la qualité tannique des raisins est évaluée. Les pépins de CS issus du sol Limono-sableux présentent une grande variabilité au niveau du DPm (3,8 à 7,2) et au niveau du % G (19,0 à 51,3). Ceux-ci sont plus astringents et amers que les pépins issus des autres types de sols. Les pépins (CS) du millésime 2006 sont plus astringents et amers que ceux des autres millésimes, même s’ils sont caractérisés par des valeurs de DPm et % G deux fois moins élevées que ceux de 2007. Pour les sols Limono-sableux, les pellicules (CS) possèdent les valeurs moyennes de DPm (30,89) et de % G (5,07) les plus élevées et sont perçues comme les plus astringentes. Les pépins de M issus du sol Limono-sableux 1 et du sol Limoneux présentent des DPm maximums de 3,20 et 3,03 ; avec des intensités moyennes d’astringence et d’amertume les plus élevées pour le sol Limono-sableux 1. Pour les pépins de M, les intensités d’astringence sont du même ordre pour les 3 millésimes. Les pépins (M) de 2007 possèdent le % G le plus élevé (33,34) et sont perçus plus amers par rapport aux autres millésimes. Les pellicules de M des sols sableux sont plus astringentes avec une variation forte du % P (3,8 à 14,0). Pour le M, les pellicules issues du sol Limoneux sont moins astringentes et se caractérisent par un DPm moins élevé (10,42) par rapport aux autres sols. Pour les pépins, le CS présente un DPm (4,15) et un % G (26,12) plus élevés que celui du M (2,74 et 21,22 %). Pour les pellicules, le CS se caractérise par un DPm (22,85), un % G (3,24 %) et un % P (14,99 %) plus élevés que ceux de M (DPm = 19,42, % G = 1,31 %, % P= 5,54). Pour les trois millésimes étudiés, le cépage n’a influencé ni l'amertume ni l'astringence pour les pépins et les pellicules. Les différences significatives et consécutives sur la composition en anthocyanes entre CS et M pour les trois millésimes portent sur : la Cy, la Pt, la Pn, la Mv et les anthocyanes acétylées et coumaroylées. Les teneurs en anthocyanes acétylées sont deux fois plus élevées pour le CS (6,99 mg/g), alors que le M présente des teneurs en anthocyanes coumaroylées (3,31 mg/g) plus élevées que celles du CS (1,99 mg/g). L’étude de la qualité tannique sur vins, a été réalisée pour 24 millésimes issus de CS et 7 millésimes issus de M. Les teneurs en composés phénoliques, en anthocyanes, en tanins totaux, en monomères des tanins (C+EC), la teinte, l’IC’ (intensité colorante), le % G, le % P et le DPm ainsi que l’intensité de l’astringence apparaissent comme des données pertinentes pour différencier les vins en fonction du millésime. Des corrélations entre l’âge des vins et : le DPm, la teinte, l’astringence, les teneurs en composés phénoliques totaux, en monomères de tanins (C+EC) et en tanins totaux ont pu être obtenues. La caractérisation qualitative des tanins et des vins est établie par corrélation entre l’astringence et le DPm (R2 = 0,509, p = 0,051, CS ; R2 = 0,780, p = 0,000, M). De plus, le DPm apparaît être un marqueur du millésime (R2 = 0,796, p = 0,000 ; CS et R2 = 0,946, p = 0,000 ; M). Nous proposons une échelle reliant le DPm des vins en fonction du millésime et de la perception tannique (astringence). Les vins issus du M sont caractérisés par une moindre richesse en composés phénoliques totaux, en tanins, en anthocyanes, en DPm, en % G, en % P ainsi que par une intensité d’astringence moins importante par rapport a ceux de CS. Le TAV (titre alcoométrique volumique, % vol) semble être positivement corrélé à l’amertume (r = 0,39, p < 0,05). / Cabernet-Sauvignon (CS) and Merlot (M) phenolic composition is of paramount importance to grapes and red wines structure and quality (astringency and bitterness) in Bordeaux winegrowing region. Tannins and anthocyanins composition as well as tannin perception have been studied for Cabernet-Sauvignon and Merlot grapes and wines. Grapes study was carried out with samples from five vineyards located in Bordeaux (Pauillac, Margaux, Saint Emilion (1), Saint Emilion (2)and Côtes de Bourg) for three consecutive vintages (2006, 2007 and 2008) and for different soil types (Silty, Sandy, Silty-sandy 1, Silty-sandy 2, Silty clay-sandy for M and Clay-loam, Sandy-silty 1, Silty-sandy, Sandy-silty 2 and Silty for CS). The proanthocyanidin monomers [(+)-catechin (C), (-)-epicatechin (EC), (-)-epicatechin-O-gallatte] and oligomers [dimers: B1, B2, B3, B4 and trimer Cat-Cat-Epi] from grape extracts (seed and skin) and wine were identified and quantified by HPLC-UV-Fluo. Percentage of galloylation (%G), percentage of prodelphinidins (%P) as well as mean degree of polymerization (mDP) of grape tannins oligomers and wine tannins were determined by HPLC-UV-MS. Sensory analysis concerning astringency and bitterness intensity of grape tannins oligomers (skins and seeds) and wines was also performed. The anthocyanic composition of glucosides [cyanidin-3-O-glucoside (Cy), delphinidin-3-O-glucoside (Dp), paeonidin-3-O-glucoside (Pn), malvidin-3-O-glucoside (Mv), petunidin-3-O-glucoside (Pt)] acetylated glucosides (paeonidin-3-O-glucoside, malvidin-3-O-glucoside]) and coumarylic glucosides (paeonidin-3-O-glucoside, malvidin-3-O-glucoside) of skins extracts and wines were analysed by HPLS-MS. Soil, vintage and grape variety influence on the above parameters are explored. The vintage in both cases (grapes and wines), has a significant effect and dominates that of grape variety (grape and wine) and soil (grape). Depending on soil type and vintage, tannins grapes quality is evaluated. CS seeds from Silty-sandy soil present a great variability on mDP (3.8 to 7.2) and on % G (19.0 to 51.3). The above seeds are more astringent and bitter than those from other soil types. The 2006 seeds (CS) are more astringent and bitter than these from the other vintages, even if they are characterized by G % and mDP values two times lower than these of 2007. Skins (CS) of Silty-sandy soils, have the highest mDP (30.89) and % G (5.07) average values and are perceived as more astringent. M seeds from Silty-sandy 1 and Silty soil have the maximum mDP values (3.20 and 3.03); Silty-sandy 1 M seeds present the highest astringency and bitterness intensities. For M seeds, astringency intensities present the same values for the 3 vintages. The 2007 seeds (M) have the highest % G (33.34) and are perceived bitter than those from the other vintages. M skins from Sandy soils are the most astringent with a strong variation on % P (3.8 to 14.0). M skins from Silty soils are less astringent and are characterized by lower mDP values (10.42) than these from other soils. In seeds, CS presents a mDP (4.15) and a % G (26.12) higher than M (2.74 and 21.22 %). CS skins are also characterized by higher mDP (22.85), % G (3.24 %) and % P (14.99 %) values than M (mDP = 19.42, % G = 1.31 % and %, P = 5.54 %). For all three vintages studied, the grape variety does not affect the astringency and bitterness intensity in both skin and seed tannins extracts. The consistent differences between CS and M for the three vintages on anthocyanin composition are on : Cy, Pt, Pn, Mv, acetylated and coumarylic anthocyanin levels. Acetylated anthocyanins values are two times highest for CS (6.99 mg/g), while M presents (3.31 mg/g) coumarylic anthocyanin levels higher than CS (1.99 mg/g). The study concerning wine tannin quality, was conducted for 24 vintages for CS and for 7 vintages for M. Total phenolic compounds, total anthocyanins, total tannins, tannin monomers (C+EC), hue, IC' (color intensity), % G, % P, mDP and astringency intensity differentiate wines according to vintage. The correlation between wine age and: mDP, hue, astringency, total phenolic compounds, tannin monomers (C+EC) and total tannin levels are obtained. The qualitative tannin and wine characterization is established by correlation between astringency and mDP (R 2 = 0.509, p = 0.051, CS; R2= 0.780, p = 0.000, M). In addition, the mDP appears to be vintage marker (R 2 = 0.796, p = 0.000; CS and R2 = 0.946, p = 0.000; M). Scale patterns between wine mDP and both ageing and tannin perception (astringency) are proposed. M wines are characterized by lower levels of total phenolic compounds, tannins, anthocyanins, mDP, % G, % P % levels as well as by lower astringency intensity than CS wines. Ethanol level seems to be positively correlated to bitterness (r = 0.39, p < 0.05).

The research project, Optimization of an array of Peptidic Indicator Displacement Assays for the Discrimination of Cabernet Sauvignon Wines, describes the multiple step lab trials conducted to optimize an array of ensembles composed of synthesized peptides and PCV:Cu+2 complexes for the differentiation of seven Cabernet Sauvignon wines with different tannin levels. This report also includes the methods and analysis used. The analysis interpreted by principal component analysis. / text

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Florianópolis, 2009. / Made available in DSpace on 2012-10-24T20:45:59Z (GMT). No. of bitstreams: 1 267503.pdf: 1118454 bytes, checksum: 7fe62f8046bba8b89ab866da76b52d6e (MD5)

The research in this diploma thesis aims on the comparison of quantitative and qualitative characteristics of selected clones of variety Sauvignon blanc. For selected clones were compared phenological phases, uvological characteristics, analysis of grape must, wine analysis and sensory evaluation. The experiment was carried out in the vineyards of the company Ampelos a.s. It was observed eight clones of variety Sauvignon Blanc. It was observed phenological phases in the same conditions of given clones. It was then determined uvological characteristics of bunch of grapes which was aimed on the average weight of bunch of grapes, the average weight of berries, the average weight of berry, the average weight of stem, the average number of berries and the average size of bunch of grapes (length x width). In the grape must were measured the analytical values, such as the sugar content, the amount of titratable acid, pH, the assimilable nitrogen content. From the results, it was clear that clones from Czech selection are much better adapted to the Czech climatic conditions. It was also observed that not all clones from Czech selection achieved better results than clones from abroad. This was confirmed in the case of clone 29/68 which has got the worst results from the all observed clones. As an ideal option for producing high quality wines is a planting composed from multiple clones with different characteristics.

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Florianópolis, 2010 / Made available in DSpace on 2013-07-16T04:07:47Z (GMT). No. of bitstreams: 1 280813.pdf: 3093511 bytes, checksum: 11d8705d75884caa56131666c66989c4 (MD5) / No Estado de Santa Catarina, as áreas de produção de videira (Vitis vinifera L.) var. Cabernet Sauvignon, variedade de uva mais exigente em frio, concentram-se nas regiões mais altas nos municípios de Bom Retiro, São Joaquim, Lages, Painel, Campos Novos, Tangará, Videira, Iomerê, Caçador e Água Doce. A viticultura está se tornando uma importante atividade econômica para o desenvolvimento dessas regiões. Além disto, o Estado é um dos principais produtores de uva e vinho do país. Portanto, o conhecimento do efeito dos sistemas atmosféricos e sua variabilidade e das mudanças climáticas na maturação dos frutos da videira (Vitis vinifera L.) traz segurança aos produtores e investimentos no setor. Os objetivos deste estudo foram: i) identificar e caracterizar o efeito de sistemas atmosféricos nas variáveis meteorológicas e na qualidade da uva; ii) identificar o impacto das mudanças climáticas na área potencial do cultivo da videira (Vitis vinifera L.) var. Cabernet Sauvignon no Estado de Santa Catarina. Foram utilizados dados de fenologia de cinco locais (São Joaquim, Bom Retiro, Campos Novos, Videira e Água Doce), em quatro safras diferentes (entre 2005/2006 a 2008/2009). A ocorrência dos sistemas atmosféricos e a intensidade das variáveis meteorológicas foram avaliadas para o período da maturação à colheita. Três cenários do zoneamento agroclimático foram elaborados: atual, 2050 e 2070. Para a geração dos cenários 2050 e 2070 foram utilizadas as saídas do sistema integrado de modelagem climática regional PRECIS ("Providing Regional Climates for Impacts Studies"). Na elaboração do zoneamento agrícola, foram utilizados os seguintes critérios: total anual de horas de frio ? 7,2°C e data de ocorrência de última geada. Os sistemas atmosféricos que ocorrem no período da maturação à colheita da videira (Vitis vinifera L.) var. Cabernet Sauvignon podem influenciar as variáveis meteorológicas. A ocorrência de jatos subtropicais diminui o total de precipitação, quando não estão associados às frentes frias. Os sistemas atmosféricos frentes frias e cavados invertidos aumentaram as temperaturas mínimas médias nesse período fenológico. A alta pressão aumentou o número de dias com amplitude superior a 12oC. Entretanto, não haverá efeito dos sistemas atmosféricos na quantidade de sólidos solúveis totais (oBrix). A amplitude térmica aumentou com a ocorrência de sistemas de alta pressão e essa variável teve um efeito significativo nos sólidos solúveis totais (Vitis vinifera L.) var Cabernet Sauvignon (oBrix). A variabilidade da ocorrência dos principais sistemas atmosféricos durante a fase da maturação à colheita de videira (Vitis vinifera L.) var. Cabernet Sauvignon é maior entre os anos agrícolas e menor entre as regiões no Estado. Frente fria e cavado invertido, baixa pressão, cavado e jato subtropical apresentaram diferenças nas frequências de ocorrência nos anos agrícolas. Somente o jato subtropical apresentou diferenças entre as regiões estudadas. As projeções de aumento de temperatura para os cenários 2050 e 2070 no cultivo da videira (Vitis vinifera L.), no Estado de Santa Catarina, mostraram uma drástica redução da área potencial, um deslocamento da área potencial de cultivo para áreas mais frias do Estado, uma antecipação e a redução da duração do período da maturação à colheita e uma tendência de diminuição de sólidos solúveis totais nos frutos, o que impacta na qualidade dos vinhos.