A ocratoxina (OTA) é uma micotoxina que possui propriedades nefrotóxicas, hepatotóxicas, teratogênicas e carcinogênicas. No Brasil, o limite máximo permitido de OTA em vinhos foi estabelecido em 2011 e é 2 μg/L. A ocorrência desta toxina em vinhos está relacionada principalmente à presença de fungos do gênero Aspergillus nas uvas usadas para a vinificação. Deste modo, o objetivo deste estudo foi verificar a influência das etapas de elaboração de vinho Cabernet Sauvignon sobre os níveis de OTA, através de dois diferentes experimentos: (A) vinho elaborado a partir de uvas inoculadas com fungo ocratoxigênico e (B) vinho elaborado com uvas naturalmente contaminadas com OTA. Para os dois experimentos, amostras das etapas mosto, fermentação/maceração, descuba, pós-fermentação, trasfega e maturação foram coletadas em triplicata, durante um período de 5 meses. A OTA foi detectada através da técnica de cromatografia líquida de alta eficiência com detector de fluorescência (CLAE-FL) e o limite de detecção e quantificação foi de 0,06 μg/L e 0,6 μg/L, respectivamente. Durante a vinificação, as etapas que apresentaram maior percentual de redução da toxina foram descuba, pós-fermentação e trasfega. Reduções significativas nos níveis de OTA foram observadas após a conclusão da vinificação. No vinho elaborado com uvas inoculadas com fungo ocratoxigênico observou-se uma redução de 92,6%. Valor similar (92%) foi verificado no vinho produzido com uvas naturalmente contaminadas por OTA. Considerando todo o processo de vinificação, pode-se sugerir que a diminuição dos níveis de OTA foi observada principalmente, devido à adsorção da toxina à parede celular das leveduras. Além disso, a adsorção da toxina aos sólidos em suspensão presentes no vinho durante a elaboração pode ter ocorrido. / The ochratoxin A (OTA) is a mycotoxin with nephrotoxic, hepatotoxic, teratogenic and carcinogenic properties. In Brazil, the permitted maximum limits for the OTA in wines was established in 2011 and is 2 μg/L. The occurence of this toxin in wines is due mainly for presence of fungi from Aspergillus genera in grapes used for winemaking. In this way, the aim of this study was to check the influence of stages of the winemaking process of Cabernet Sauvignon grape on the OTA levels through two different experiments: (A) wine made from grapes inoculated with ochratoxigenic fungi and (B) wine made from grapes naturally contaminated with OTA. For the two experiments, samples of must, fermentation/maceration, drawn-off wine, after fermentation, racking and maturation stages were collected in triplicate, during 5 months. The OTA was detected using high-performance liquid chromatography with fluorecence detector (HPLC-FL) and the limit of detection and limit of quantitation were 0.06 and 0.6 μg/L, respectively. During the winemaking, the stages that show higher toxin reduction were drawn-off wine, after alcoholic fermentation and racking. Significant reductions in OTA levels were observed when winemaking was finished. A reduction of 92.6% was observed in wine made from grapes inoculated with ochratoxigenic fungi. Similar value (92%) was verified in wine made from grapes naturally contaminated with OTA. Considering all winemaking process, we may suggest that the decreasing of OTA levels was observed mainly due to adsorption of the toxin in cell wall of yeast. Furthermore, the adsorption of the toxin in suspended solids present in wine during the winemaking may be occurred.

A ocratoxina (OTA) é uma micotoxina que possui propriedades nefrotóxicas, hepatotóxicas, teratogênicas e carcinogênicas. No Brasil, o limite máximo permitido de OTA em vinhos foi estabelecido em 2011 e é 2 μg/L. A ocorrência desta toxina em vinhos está relacionada principalmente à presença de fungos do gênero Aspergillus nas uvas usadas para a vinificação. Deste modo, o objetivo deste estudo foi verificar a influência das etapas de elaboração de vinho Cabernet Sauvignon sobre os níveis de OTA, através de dois diferentes experimentos: (A) vinho elaborado a partir de uvas inoculadas com fungo ocratoxigênico e (B) vinho elaborado com uvas naturalmente contaminadas com OTA. Para os dois experimentos, amostras das etapas mosto, fermentação/maceração, descuba, pós-fermentação, trasfega e maturação foram coletadas em triplicata, durante um período de 5 meses. A OTA foi detectada através da técnica de cromatografia líquida de alta eficiência com detector de fluorescência (CLAE-FL) e o limite de detecção e quantificação foi de 0,06 μg/L e 0,6 μg/L, respectivamente. Durante a vinificação, as etapas que apresentaram maior percentual de redução da toxina foram descuba, pós-fermentação e trasfega. Reduções significativas nos níveis de OTA foram observadas após a conclusão da vinificação. No vinho elaborado com uvas inoculadas com fungo ocratoxigênico observou-se uma redução de 92,6%. Valor similar (92%) foi verificado no vinho produzido com uvas naturalmente contaminadas por OTA. Considerando todo o processo de vinificação, pode-se sugerir que a diminuição dos níveis de OTA foi observada principalmente, devido à adsorção da toxina à parede celular das leveduras. Além disso, a adsorção da toxina aos sólidos em suspensão presentes no vinho durante a elaboração pode ter ocorrido. / The ochratoxin A (OTA) is a mycotoxin with nephrotoxic, hepatotoxic, teratogenic and carcinogenic properties. In Brazil, the permitted maximum limits for the OTA in wines was established in 2011 and is 2 μg/L. The occurence of this toxin in wines is due mainly for presence of fungi from Aspergillus genera in grapes used for winemaking. In this way, the aim of this study was to check the influence of stages of the winemaking process of Cabernet Sauvignon grape on the OTA levels through two different experiments: (A) wine made from grapes inoculated with ochratoxigenic fungi and (B) wine made from grapes naturally contaminated with OTA. For the two experiments, samples of must, fermentation/maceration, drawn-off wine, after fermentation, racking and maturation stages were collected in triplicate, during 5 months. The OTA was detected using high-performance liquid chromatography with fluorecence detector (HPLC-FL) and the limit of detection and limit of quantitation were 0.06 and 0.6 μg/L, respectively. During the winemaking, the stages that show higher toxin reduction were drawn-off wine, after alcoholic fermentation and racking. Significant reductions in OTA levels were observed when winemaking was finished. A reduction of 92.6% was observed in wine made from grapes inoculated with ochratoxigenic fungi. Similar value (92%) was verified in wine made from grapes naturally contaminated with OTA. Considering all winemaking process, we may suggest that the decreasing of OTA levels was observed mainly due to adsorption of the toxin in cell wall of yeast. Furthermore, the adsorption of the toxin in suspended solids present in wine during the winemaking may be occurred.

Memoria para optar al título de Ingeniero en Alimentos / Se ha estudiado el efecto del contacto con la madera en forma de chips de tres especies nativas chilenas (Roble Ruil, Acacia Dealbata y Roble Blanco) y de Roble Francés en la composición química y sensorial de los vinos tintos de las cepas Cabernet Sauvignon y Carménère. Los chips fueron adicionados en una dosis de 4g/L tras la fermentación maloláctica de los vinos y mantenidas en maceración durante 45 días. Las muestras de vino se evaluaron sensorialmente cada 15 días hasta completar los 45 días de maceración. En paralelo, se realizaron análisis convencionales, determinación de compuestos fenólicos totales y análisis de color. Durante los 45 días de maceración, las maderas nativas resultaron ser mejores al Roble Francés en cuanto a la percepción sensorial del color rojo en la cepa Carménère. Para el resto de los parámetros medidos y para la cepa Cabernet Sauvignon, no se encontraron diferencias significativas entre las maderas. A través del paso de los días los compuestos fenólicos, Intensidad colorante, pH, acido málico y grado alcohólico fueron disminuyendo, por otro lado la acidez total y volátil, parámetros CIELAB y tonalidad fueron en aumento. Estos resultados ponen de manifiesto cómo las maderas nativas chilenas, en la dosis ensayada, son una alternativa viable al Roble Francés para su utilización en la industria enológica / Wines of Carménère and Cabernet Sauvignon strains, after malolactic fermentation, were inoculated and fermented with chips of three Chilean native woods to determine the impact that these may have on their chemical and sensory characteristics, compared to a french oak chips pattern. The wine samples were assessed every 15 days for up to 45 days of maceration. In parallel, conventional analyses, determination of total phenolic compounds and color analysis were performed. During the 45 days of maceration, native woods were found to be better than French oak in terms of sensory perception of red in the Carménère strain. For the rest of the parameters measured, no significant differences were found among the woods. Through the passage of the days the phenolic compounds, color intensity, pH, malic acid and alcoholic degree were declining, on the other hand, total and volatile acidity, CIELAB parameters and tonality were increasing. These results show how the Chilean native woods in the dosage tested are a viable alternative to French oak for use in the wine industry

Cabernet sauvignon is the most widely planted red wine grape in California and is valued in the hundreds of millions of dollars. Cabernet sauvignon grapes, when severely vigorous or overcropped, can contain vegetal aromas and flavors when harvested. 3-alkyl-methoxypyrazines are the volatile compounds responsible for this effect and can lower the perceived quality of the wine. Resveratrol is a phytoalexin that has many medical and health benefits and can be found in red wines. An experiment was conducted in Paso Robles, CA to assess the effects of five yield levels, manipulated through cluster thinning, on methoxypyrazine and resveratrol concentrations. Berry weights and chemistry were also measured, in the form of ºBrix, pH, and TA. In 2009 and 2010, no significant statistical differences were found in methoxypyrazines in the harvested grapes. In 2009, resveratrol concentrations were below the detection limits in the wine produced. In 2010, berry weight and chemistry measurements were not significantly different, except for grapes from lightly- and greatly-thinned vines which varied in pH at harvest. The 2009 wines were subjected to discrimination and preference testing by trained tasters. No significant difference was found in the discrimination test and no difference was found using the Friedman and Kramer’s Rank test for the preference test. Only a very slight difference was found between the wines made from unthinned and greatly-thinned vines according to Tukey’s Multiple Comparison Test. The findings of this thesis suggest that cluster thinning does not affect methoxypyrazine and resveratrol concentrations or sensory analysis in Cabernet sauvignon grown on the east side of Paso Roble, CA.

Vineyard management practices are known to affect fruit composition and resultant wines, in part, by altering fruit volatiles. Methods currently used to evaluate the impact of vineyard practices on grape/wine composition include measuring physico-chemistry indices and performing wine sensory analyses. These activities are both time-consuming and destructive. Two electronic nose (ENose) systems: a hand-held conducting polymer-based and a portable surface acoustic wave-based systems were investigated as grape monitoring tools. Vineyard treatments included the effect of canopy side (East vs. West and North vs. South), cluster thinning (unthinned, 1 cluster/shoot, and 1 & 2 cluster/shoot) and ethanol spray (5% v/v) on Cabernet franc, Merlot and both varieties respectively. ENose data were obtained in the field (over two growing seasons for canopy side and in 2008 for cluster thinning and ethanol spray) and laboratory (2007 for canopy side), across different sampling dates and compared with nine-grape/eight-wine chemistry assays, GC/MS (cluster thinning) and wine aroma sensory evaluations (triangular difference testing). ENose results demonstrated 100% significant differences between all Cabernet franc and Merlot treatments. Grape/wine chemistry indices, for both Cabernet franc and Merlot, did not differ among treatments (except ethanol treatment) across sampling dates or growing seasons and vineyard management practices. Wine aroma sensory evaluations demonstrated only limited differences (3 out of 8 comparisons: East vs. West, 1 cluster/shoot vs. 1 & 2 clusters/shoot and 1 cluster/shoot and 1 & 2 clusters/shoot). The high level of discrimination by ENose systems may provide opportunities to enhance the understanding of vineyard management activities. / Master of Science in Life Sciences

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

Vineyard management practices are known to affect fruit composition and resultant wines, in part, by altering fruit volatiles. Methods currently used to evaluate the impact of vineyard practices on grape/wine composition include measuring physico-chemistry indices and performing wine sensory analyses. These activities are both time-consuming and destructive. Two electronic nose (ENose) systems: a hand-held conducting polymer-based and a portable surface acoustic wave-based systems were investigated as grape monitoring tools. Vineyard treatments included the effect of canopy side (East vs. West and North vs. South), cluster thinning (unthinned, 1 cluster/shoot, and 1 & 2 cluster/shoot) and ethanol spray (5% v/v) on Cabernet franc, Merlot and both varieties respectively. ENose data were obtained in the field (over two growing seasons for canopy side and in 2008 for cluster thinning and ethanol spray) and laboratory (2007 for canopy side), across different sampling dates and compared with nine-grape/eight-wine chemistry assays, GC/MS (cluster thinning) and wine aroma sensory evaluations (triangular difference testing). ENose results demonstrated 100% significant differences between all Cabernet franc and Merlot treatments. Grape/wine chemistry indices, for both Cabernet franc and Merlot, did not differ among treatments (except ethanol treatment) across sampling dates or growing seasons and vineyard management practices. Wine aroma sensory evaluations demonstrated only limited differences (3 out of 8 comparisons: East vs. West, 1 cluster/shoot vs. 1 & 2 clusters/shoot and 1 cluster/shoot and 1 & 2 clusters/shoot). The high level of discrimination by ENose systems may provide opportunities to enhance the understanding of vineyard management activities. / 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

Current fruit-zone management recommendation in the eastern US aims for 1-2 basal shoot leaf layers after fruit set to limit fungal disease and sunburn incidence, and prevent extreme heating of grapes. The goal of this work was to assess if fruit-zone leaf removal to an uncommonly greater extent, and/or at an earlier phenological stage, would favorably alter yield components or fruit composition in three popularly grown, red-fruited, Bordeaux varieties – Cabernet franc, Petit Verdot, and Cabernet Sauvignon. Pre-bloom leaf removal to various extents reduced crop yield by 41-78% when compared to no leaf removal across seasons and varieties. Pre-bloom leaf removal implementation in consecutive seasons tended to further reduce crop yield components compared to implementation in the first year. Pre-bloom leaf removal tended to reduce cluster compactness and bunch rot incidence when compared to post-fruit set and no leaf removal. Basal leaf removal to the greatest extents inconsistently reduced soluble solids and titratable acidity across varieties and seasons. Pre-bloom and post-fruit set leaf removal to the greatest extent consistently increased total grape phenolics and anthocyanins compared to no leaf removal in Cabernet Sauvignon, but inconsistently increased total grape phenolics compared to no leaf removal in Cabernet franc and Petit Verdot. Basal leaf removal to the greatest extents tended to increase the synthesis and degradation of carotenoids more consistently than no leaf removal, and this was particularly true for zeaxanthin. Petit Verdot and Cabernet franc wine color and aroma were inconsistently distinguishable between leaf removal treatments, and color intensity was rated higher in wines made with fruit from pre-bloom leaf removal compared to modest post fruit-set leaf removal plots. Waiting until after fruit set to remove fruit-zone leaves maintained crop yield and offered comparable improvements in fruit composition to pre-bloom leaf removal. Pre-bloom leaf removal of no more than four leaves is recommended to limit crop yield reduction, and modestly improve fruit composition. This work showed that fruit-zone leaf removal does not need to be conservative in the eastern US, particularly because the climate does not appear to be detrimental to fruit composition, and open fruit-zones reduce grape fungal disease incidence. / Ph. D.