The overall objective of this work was to increase the knowledge regarding American hybrid grapes and wine-making techniques relevant to the State of Texas, specifically to investigate grape chemistry of hybrid grapes, to evaluate the effects of micro-oxygenation on wine chemistry, and to elucidate anti-cancer effects of wine compounds and extract in colon cancer cells in vitro. The methods used include HPLC-PDA-EIS-MSn and molecular bioassays. The American hybrid grapes, Black Spanish (Vitis aestivalis hybrid) and Blanc Du Bois (Vitis aestivalis hybrid), were compared to Cabernet Sauvignon and Merlot (Vitis vinifera) in their phytochemical composition. Total phenolics were similar in red grape varieties, but lower in white grapes. In Black Spanish grapes, anthocyanins and antioxidant capacity (ORAC) exhibited the highest values. Non-anthocyanin polyphenolics did not show qualitative differences in the four grape varieties. The presence of anthocyanins diglucosides was unique to Black Spanish grapes. The second experiment involved application of micro-oxygenation with oak inner staves to evaluate the effect of this new vinification technology on the stability of anthocyanins. Overall, anthocyanins exhibited significant decreases over time in the following order: control, wine with oak pieces, oak barrel, and micro-oxygenation. The anti-cancer effect of a combination of wine compounds, resveratrol/quercetin (RQ), and a polyphenolic extract from Black Spanish wine were investigated in colon cancer cells HT-29. RQ reduced the generation of reactive oxygen species (ROS), whereas the ORAC increased. RQ reduced cancer cell viability and proliferation, induced caspase-3-cleavage, and increased PARP-cleavage. Additionally, Sp1, Sp3, Sp4, and survivin were down-regulated at mRNA and protein levels. Furthermore, RQ decreased microRNA-27a (miR-27a) and induced ZBTB10, suggesting that RQ interactions with the miR-27a-ZBTB10-axis play a role in Sp down-regulation. Similar results were obtained for the wine extract. This work will provide valuable information regarding grape varieties, potential health benefits of wine, and wine production techniques to the wine industry in Texas and beyond.

The technique of micro-oxygenation involves the deliberate addition of continuous, metered amounts of oxygen into a vessel of bulk wine during the maturation period (between the end of fermentation and bottling). The aim of the process is to improve the sensory properties of red wine, particularly the mouthfeel characteristics associated with the various polyphenol constituents. The success of the process appears to depend strongly on the ability to control the rate of oxygen dosage. The effect of dosage rate on the chemical and corresponding sensory changes of a red wine is the central theme of this thesis. A method of dosing oxygen (at typical micro-oxygenation rates) into small volumes of wine (<100 litres) was developed using a dense polymer membrane diffuser. It was clearly demonstrated that wine could be reliably oxygenated at very low rates using a coiled length of FEP as the diffuser material. Oxygen dosage was regulated by adjusting the oxygen pressure inside the tube. The advantage with a dense polymer diffuser is that no bubbles are generated and the oxygenation efficiency is 100%. The diffuser was fully modeled and characterised for use in the laboratory scale trials detailed in Chapters Four and Six. The small scale oxygenation equipment was used to conduct a fully replicated experiment to investigate the evolution of a Cabernet Sauvignon wine under four oxygenation treatments at dosage rates of 0, 10, 23 and 36 mg/L/mth. The total period of the trial was 105 days. HPLC analysis indicated that the rate change of low molecular weight polyphenols is directly related to the oxygen dosage rate. The concentration of the majority of the identifiable monomers, most notably the anthocyanins decreased throughout the course of the trial. The rate of decrease was directly related to oxygen dosage rate. Thiolysis results showed an increase in mDP for all treatments over the course of the trial until day 77 when they were observed to decrease for all treatments. The decrease in mDP coincided with an addition of SO2 which was investigated in a subsequent trial. Spectrophotometric results indicated that the rate of formation of non-bleachable pigments was directly related to the rate of oxygen dosage with significant differences between the high rates (23 and 36 mg/L/mth) and the low rates (0 and 10 mg/L/mth). The trend for all treatments was for increased levels of stable pigments. The sensory results show that the measured organoleptic temporal development exhibits a similar oscillatory behaviour compared to the anecdotally derived curve presented in figure 1-2. The distinction between the respective phases described in section 1.1.1 was, however less clear. The most significant factor in the model weighting was mouthfeel and astringency which correlates with the observed changes occurring in the wine polypenols during maturation. Overall the laboratory scale trial showed that the chemical polyphenol development was directly related to the oxygen dosage rate. The sensory evolution also appeared to be accelerated with higher oxygen dosage rates, although the oscillatory nature of the sensory response given a single linear input indicates a complex underlying mechanism driving the changes. The effect of SO2 on the development of wine polyphenols with and without oxygen was also investigated. The presence of SO2 was found to have a significant effect on both mDP and the concentration of non-bleachable pigments. mDP was observed to decrease over the six week trial period irrespective of whether oxygen had been added or not. The mDP for the treatments without SO2 increased steadily over the course of the trial. Similarly the formation of non-bleachable pigments was suppressed and even retarded with SO2 present whereas for the treatments without SO2 a steady increase was observed. The implication of these results is that SO2 may have a much larger effect on tannin development than oxygen. The use of electrochemical micro-oxidation (or ELMOX) was examined ostensibly to determine proof of concept and also compare the performance of glassy carbon and titanium as electrode materials against traditional micro-oxygenation. Notable transformations occurred with titanium showing higher levels of ethanal than the other treatments both chemically and by sensory measure. A greater rate of stable pigment formation was also observed for the titanium compared to the other treatments. The respective dosage rates for the glassy carbon ELMOX and traditional micro-oxygenation treatments were too low to be able to discriminate any significant differences compared to the control wine. / AGMARDT Doctoral Scholarship

The technique of micro-oxygenation involves the deliberate addition of continuous, metered amounts of oxygen into a vessel of bulk wine during the maturation period (between the end of fermentation and bottling). The aim of the process is to improve the sensory properties of red wine, particularly the mouthfeel characteristics associated with the various polyphenol constituents. The success of the process appears to depend strongly on the ability to control the rate of oxygen dosage. The effect of dosage rate on the chemical and corresponding sensory changes of a red wine is the central theme of this thesis. A method of dosing oxygen (at typical micro-oxygenation rates) into small volumes of wine (<100 litres) was developed using a dense polymer membrane diffuser. It was clearly demonstrated that wine could be reliably oxygenated at very low rates using a coiled length of FEP as the diffuser material. Oxygen dosage was regulated by adjusting the oxygen pressure inside the tube. The advantage with a dense polymer diffuser is that no bubbles are generated and the oxygenation efficiency is 100%. The diffuser was fully modeled and characterised for use in the laboratory scale trials detailed in Chapters Four and Six. The small scale oxygenation equipment was used to conduct a fully replicated experiment to investigate the evolution of a Cabernet Sauvignon wine under four oxygenation treatments at dosage rates of 0, 10, 23 and 36 mg/L/mth. The total period of the trial was 105 days. HPLC analysis indicated that the rate change of low molecular weight polyphenols is directly related to the oxygen dosage rate. The concentration of the majority of the identifiable monomers, most notably the anthocyanins decreased throughout the course of the trial. The rate of decrease was directly related to oxygen dosage rate. Thiolysis results showed an increase in mDP for all treatments over the course of the trial until day 77 when they were observed to decrease for all treatments. The decrease in mDP coincided with an addition of SO2 which was investigated in a subsequent trial. Spectrophotometric results indicated that the rate of formation of non-bleachable pigments was directly related to the rate of oxygen dosage with significant differences between the high rates (23 and 36 mg/L/mth) and the low rates (0 and 10 mg/L/mth). The trend for all treatments was for increased levels of stable pigments. The sensory results show that the measured organoleptic temporal development exhibits a similar oscillatory behaviour compared to the anecdotally derived curve presented in figure 1-2. The distinction between the respective phases described in section 1.1.1 was, however less clear. The most significant factor in the model weighting was mouthfeel and astringency which correlates with the observed changes occurring in the wine polypenols during maturation. Overall the laboratory scale trial showed that the chemical polyphenol development was directly related to the oxygen dosage rate. The sensory evolution also appeared to be accelerated with higher oxygen dosage rates, although the oscillatory nature of the sensory response given a single linear input indicates a complex underlying mechanism driving the changes. The effect of SO2 on the development of wine polyphenols with and without oxygen was also investigated. The presence of SO2 was found to have a significant effect on both mDP and the concentration of non-bleachable pigments. mDP was observed to decrease over the six week trial period irrespective of whether oxygen had been added or not. The mDP for the treatments without SO2 increased steadily over the course of the trial. Similarly the formation of non-bleachable pigments was suppressed and even retarded with SO2 present whereas for the treatments without SO2 a steady increase was observed. The implication of these results is that SO2 may have a much larger effect on tannin development than oxygen. The use of electrochemical micro-oxidation (or ELMOX) was examined ostensibly to determine proof of concept and also compare the performance of glassy carbon and titanium as electrode materials against traditional micro-oxygenation. Notable transformations occurred with titanium showing higher levels of ethanal than the other treatments both chemically and by sensory measure. A greater rate of stable pigment formation was also observed for the titanium compared to the other treatments. The respective dosage rates for the glassy carbon ELMOX and traditional micro-oxygenation treatments were too low to be able to discriminate any significant differences compared to the control wine. / AGMARDT Doctoral Scholarship

The technique of micro-oxygenation involves the deliberate addition of continuous, metered amounts of oxygen into a vessel of bulk wine during the maturation period (between the end of fermentation and bottling). The aim of the process is to improve the sensory properties of red wine, particularly the mouthfeel characteristics associated with the various polyphenol constituents. The success of the process appears to depend strongly on the ability to control the rate of oxygen dosage. The effect of dosage rate on the chemical and corresponding sensory changes of a red wine is the central theme of this thesis. A method of dosing oxygen (at typical micro-oxygenation rates) into small volumes of wine (<100 litres) was developed using a dense polymer membrane diffuser. It was clearly demonstrated that wine could be reliably oxygenated at very low rates using a coiled length of FEP as the diffuser material. Oxygen dosage was regulated by adjusting the oxygen pressure inside the tube. The advantage with a dense polymer diffuser is that no bubbles are generated and the oxygenation efficiency is 100%. The diffuser was fully modeled and characterised for use in the laboratory scale trials detailed in Chapters Four and Six. The small scale oxygenation equipment was used to conduct a fully replicated experiment to investigate the evolution of a Cabernet Sauvignon wine under four oxygenation treatments at dosage rates of 0, 10, 23 and 36 mg/L/mth. The total period of the trial was 105 days. HPLC analysis indicated that the rate change of low molecular weight polyphenols is directly related to the oxygen dosage rate. The concentration of the majority of the identifiable monomers, most notably the anthocyanins decreased throughout the course of the trial. The rate of decrease was directly related to oxygen dosage rate. Thiolysis results showed an increase in mDP for all treatments over the course of the trial until day 77 when they were observed to decrease for all treatments. The decrease in mDP coincided with an addition of SO2 which was investigated in a subsequent trial. Spectrophotometric results indicated that the rate of formation of non-bleachable pigments was directly related to the rate of oxygen dosage with significant differences between the high rates (23 and 36 mg/L/mth) and the low rates (0 and 10 mg/L/mth). The trend for all treatments was for increased levels of stable pigments. The sensory results show that the measured organoleptic temporal development exhibits a similar oscillatory behaviour compared to the anecdotally derived curve presented in figure 1-2. The distinction between the respective phases described in section 1.1.1 was, however less clear. The most significant factor in the model weighting was mouthfeel and astringency which correlates with the observed changes occurring in the wine polypenols during maturation. Overall the laboratory scale trial showed that the chemical polyphenol development was directly related to the oxygen dosage rate. The sensory evolution also appeared to be accelerated with higher oxygen dosage rates, although the oscillatory nature of the sensory response given a single linear input indicates a complex underlying mechanism driving the changes. The effect of SO2 on the development of wine polyphenols with and without oxygen was also investigated. The presence of SO2 was found to have a significant effect on both mDP and the concentration of non-bleachable pigments. mDP was observed to decrease over the six week trial period irrespective of whether oxygen had been added or not. The mDP for the treatments without SO2 increased steadily over the course of the trial. Similarly the formation of non-bleachable pigments was suppressed and even retarded with SO2 present whereas for the treatments without SO2 a steady increase was observed. The implication of these results is that SO2 may have a much larger effect on tannin development than oxygen. The use of electrochemical micro-oxidation (or ELMOX) was examined ostensibly to determine proof of concept and also compare the performance of glassy carbon and titanium as electrode materials against traditional micro-oxygenation. Notable transformations occurred with titanium showing higher levels of ethanal than the other treatments both chemically and by sensory measure. A greater rate of stable pigment formation was also observed for the titanium compared to the other treatments. The respective dosage rates for the glassy carbon ELMOX and traditional micro-oxygenation treatments were too low to be able to discriminate any significant differences compared to the control wine. / AGMARDT Doctoral Scholarship

The technique of micro-oxygenation involves the deliberate addition of continuous, metered amounts of oxygen into a vessel of bulk wine during the maturation period (between the end of fermentation and bottling). The aim of the process is to improve the sensory properties of red wine, particularly the mouthfeel characteristics associated with the various polyphenol constituents. The success of the process appears to depend strongly on the ability to control the rate of oxygen dosage. The effect of dosage rate on the chemical and corresponding sensory changes of a red wine is the central theme of this thesis. A method of dosing oxygen (at typical micro-oxygenation rates) into small volumes of wine (<100 litres) was developed using a dense polymer membrane diffuser. It was clearly demonstrated that wine could be reliably oxygenated at very low rates using a coiled length of FEP as the diffuser material. Oxygen dosage was regulated by adjusting the oxygen pressure inside the tube. The advantage with a dense polymer diffuser is that no bubbles are generated and the oxygenation efficiency is 100%. The diffuser was fully modeled and characterised for use in the laboratory scale trials detailed in Chapters Four and Six. The small scale oxygenation equipment was used to conduct a fully replicated experiment to investigate the evolution of a Cabernet Sauvignon wine under four oxygenation treatments at dosage rates of 0, 10, 23 and 36 mg/L/mth. The total period of the trial was 105 days. HPLC analysis indicated that the rate change of low molecular weight polyphenols is directly related to the oxygen dosage rate. The concentration of the majority of the identifiable monomers, most notably the anthocyanins decreased throughout the course of the trial. The rate of decrease was directly related to oxygen dosage rate. Thiolysis results showed an increase in mDP for all treatments over the course of the trial until day 77 when they were observed to decrease for all treatments. The decrease in mDP coincided with an addition of SO2 which was investigated in a subsequent trial. Spectrophotometric results indicated that the rate of formation of non-bleachable pigments was directly related to the rate of oxygen dosage with significant differences between the high rates (23 and 36 mg/L/mth) and the low rates (0 and 10 mg/L/mth). The trend for all treatments was for increased levels of stable pigments. The sensory results show that the measured organoleptic temporal development exhibits a similar oscillatory behaviour compared to the anecdotally derived curve presented in figure 1-2. The distinction between the respective phases described in section 1.1.1 was, however less clear. The most significant factor in the model weighting was mouthfeel and astringency which correlates with the observed changes occurring in the wine polypenols during maturation. Overall the laboratory scale trial showed that the chemical polyphenol development was directly related to the oxygen dosage rate. The sensory evolution also appeared to be accelerated with higher oxygen dosage rates, although the oscillatory nature of the sensory response given a single linear input indicates a complex underlying mechanism driving the changes. The effect of SO2 on the development of wine polyphenols with and without oxygen was also investigated. The presence of SO2 was found to have a significant effect on both mDP and the concentration of non-bleachable pigments. mDP was observed to decrease over the six week trial period irrespective of whether oxygen had been added or not. The mDP for the treatments without SO2 increased steadily over the course of the trial. Similarly the formation of non-bleachable pigments was suppressed and even retarded with SO2 present whereas for the treatments without SO2 a steady increase was observed. The implication of these results is that SO2 may have a much larger effect on tannin development than oxygen. The use of electrochemical micro-oxidation (or ELMOX) was examined ostensibly to determine proof of concept and also compare the performance of glassy carbon and titanium as electrode materials against traditional micro-oxygenation. Notable transformations occurred with titanium showing higher levels of ethanal than the other treatments both chemically and by sensory measure. A greater rate of stable pigment formation was also observed for the titanium compared to the other treatments. The respective dosage rates for the glassy carbon ELMOX and traditional micro-oxygenation treatments were too low to be able to discriminate any significant differences compared to the control wine. / AGMARDT Doctoral Scholarship

[ES] El mercado actual del vino tinto demanda vinos de gran potencia visual, elevada concentración aromática y que no resulten excesivamente astringentes ni amargos. Asimismo, el consumidor final demanda cada vez más vinos que se desarrollen en una viticultura más orgánica que garantice la sostenibilidad del cultivo. Para cumplir con estas expectativas, se está limitando la utilización de compuestos químicos en el viñedo, sustituyéndolos por otros naturales con menor impacto medioambiental, y se están utilizando en bodega técnicas como la maceración prefermentativa, que contribuye a la extracción de antocianos y aromas, o la microoxigenación, que permite estabilizar los compuestos polifenólicos en un tiempo reducido. El color de los vinos depende de su concentración en antocianos, pero también la forma y el estado en que éstos se encuentren en el vino, que depende de diferentes factores, siendo uno de ellos el fenómeno de la copigmentación como paso anterior a la polimerización y estabilización. Además, el oxígeno juega un papel crucial en la evolución del color, así como en la oxidación de los polifenoles y en la formación de complejos más estables. El aroma también es muy importante en los vinos, ya que es uno de los primeros aspectos que percibimos. Por ello, es de gran importancia la utilización de técnicas de vinificación que permitan extraer el mayor potencial aromático de los precursores que se encuentran en las uvas. Para conseguir incrementar la calidad de los vinos tintos elaborados con la variedad Monastrell, estableciendo una metodología de elaboración que permita mejorar la concentración polifenólica y aromática de estos vinos, se ha estudiado el efecto de la aplicación en la uva, 10 días antes de la vendimia, de sustancias copigmentantes, tales como, extractos vegetales (romero, trigo sarraceno y té verde) y copigmentos puros (ácido cafeico, rutina y catequina). Asimismo, los copigmentos puros también se aplicaron a la entrada en bodega. Se ensayaron dos técnicas enológicas diferentes: la vinificación tradicional y la maceración prefermentativa en frío (6-8ºC), seguida de vinificación tradicional. Por último, una vez concluida la fermentación maloláctica, los vinos obtenidos fueron sometidos a una adición controlada de acetaldehído durante 45 días, seguido de un proceso de conservación en botella de 12 meses. Los resultados mostraron que los tratamientos con copigmentos, especialmente con extractos vegetales ricos en copigmentos, incrementaron la concentración de antocianos polimerizados y totales, y de compuestos aromáticos favorables para la calidad, destacando el extracto de romero por su acción directa sobre el color de los vinos de Monastrell. Utilizar la maceración prefermentativa en la elaboración de los vinos procedentes de tratamientos de copigmentación, ha permitido incrementar la concentración de polifenoles totales y taninos condensados, así como la de ésteres y acetatos. La microoxigenación, mediante la aplicación de acetaldehído durante la conservación de los vinos tratados previamente con copigmentos, dio lugar a un incremento del porcentaje de antocianos polimerizados, de la concentración de antocianos, de taninos condensados y de polifenoles totales, no afectando a la composición aromática de los vinos. Por todo ello, se puede establecer que la combinación de tratamientos de copigmentación en el campo, especialmente con extractos vegetales, de maceración prefermentativa durante la elaboración, y de microoxigenación durante la conservación, permite elaborar vinos de Monastrell con un color más estable, mayor concentración de compuestos polifenólicos, y mayor concentración de ésteres y acetatos, compuestos relacionados con aromas positivos florales, frutales y especiados. / [CA] El mercat actual del vi negre demana vins de gran potència visual, elevada concentració aromàtica i que no siguen excessivament astringents ni amargs. Així mateix, el consumidor final demana cada vegada més vins que es desenvolupen en una viticultura més orgànica que garanteisca la sostenibilitat del cultiu. Per complir amb aquestes expectatives, s'està limitant la utilització de compostos químics a la vinya, substituint-los per altres naturals amb menor impacte mediambiental, i s'estan utilitzant al celler tècniques com la maceració prefermentativa, que contribueix a l'extracció d'antocians i aromes, o la microoxigenació, que permet estabilitzar els compostos polifenòlics en un temps reduït. El color dels vins depèn de la seua concentració en antocians, però també en la forma i l'estat en que aquests es troben en el vi, que depèn de diferents factors, siguent un d'ells el fenòmen de la copigmentació com pas anterior a la polimerització i l'estabilització. A més a més, l'oxígen juga un paper crucial en l'evolució del color, així com en l'oxidació dels polifenols i en la formació dels complexos més estables. L'aroma també és molt important en els vins, ja que és un dels primers aspectes que percebem. Per això, és de gran importància la utilització de tècniques de vinificació que permeten extraure el major potencial aromàtic dels precursors que es troben al raïm. Per aconseguir augmentar la qualitat dels vins negres elaborats amb la varietat Monastrell, establint una metodologia d'elaboració que permeta millorar la concentració polifenòlica i aromàtica d'aquests vins, s'ha estudiat l'efecte de l'aplicació en el raïm, 10 dies abans de la verema, de substàncies copigmentants, com ara, extractes vegetals (romer, blat negre i te verd) i copigments purs (àcid cafeic, rutina i catequina). Així mateix, els copigments purs també es van aplicar a l'entrada al celler. Es van assajar dos tècniques enològiques diferents: la vinificació tradicional i la maceració prefermentativa en fred (6-8ºC), seguida de vinificació tradicional. Finalment, una vegada conclosa la fermentació malolàctica, els vins obtinguts van ser sotmesos a una addició controlada d'acetaldehid durant 45 dies, seguit d'un procés de conservació en ampolla de 12 mesos. Els resultats van mostrar que els tractaments amb copigments, especialment amb extractes vegetals rics en copigments, van augmentar la concentració d'antocians polimeritzats i totals, i de compostos aromàtics favorables per a la qualitat, destacant l'extracte de romer per la seua acció directa sobre el color dels vins de Monastrell. Utilitzar la maceració prefermentativa en l'elaboració dels vins procedents de tractaments de copigmentació, ha permès augmentar la concentració de polifenols totals i tanins condensats, així com la d'èsters i acetats. La microoxigenació, mitjançant l'aplicació d'acetaldehid durant la conservació dels vins tractats prèviament amb copigments, va donar lloc a un augment del percentatge d'antocians polimeritzats, de la concentració d'antocians, de tanins condensats i de polifenols totals, no afectant a la composició aromàtica dels vins. Per tot això, es pot establir que la combinació de tractaments de copigmentació en el camp, especialment amb extractes vegetals de maceració prefermentativa durant l'elaboració, i de microoxigenació durant la conservació, permet elaborar vins de Monastrell amb un color més estable, més concentració de compostos polifenòlics, i major concentració d'èsters i acetats, compostos relacionats amb aromes positus florals, fruitals i especiats. / [EN] The current red wine market demands wines with high visual power, great aromatic concentration and that are not excessively astringent or bitter. Furthermore, the final consumer increasingly demands developed wines in a more organic viticulture in order to ensure the sustainability of the crop. To meet these expectations, the use of chemical compounds in the vineyard is being limited, replacing them by another natural ones with less environmental impact, and techniques such as pre-fermentation maceration are being used in the winery, which contributes to the extraction of anthocyanins and aromas, or micro-oxygenation, that allows polyphenolic compounds to be stabilized in a reduced time. The colour of wines depends on their concentration in anthocyanins, but also the form and state in which they are found in the wine, which depends on several factors, one of them being the phenomenon of copigmentation as a previous step to polymerization and stabilization. In addition, the oxygen has a crucial role in colour's evolution, as well as, in the oxidation of polyphenols and in the formation of more stable complexes. Aroma is also very important in wines, due to the fact that is one of the first aspects that we perceive. For this reason, the use of vinification techniques that allow extracting the greatest aromatic potential of the precursors found in the grapes, is of great importance. In order to increase the quality of red wines made with the Monastrell variety, establishing a production methodology that allows improving the polyphenolic and aromatic concentration of these wines, the effect of the application on the grape, 10 days before harvest, has been studied, of copigmenting substances such as plant extracts (rosemary, buckwheat and green tea) and pure copigments (caffeic acid, rutin and catechin). Likewise, pure copigments were also applied in the cellar entrance. Two different enological techniques were tested: traditional vinification and cold pre-fermentation maceration (6-8ºC), followed by traditional vinification. Finally, once the malolactic fermentation was concluded, the wines obtained were subjected to a controlled addition of acetaldehyde for 45 days, followed by a 12-month bottle preservation process. The results showed that treatments with copigments, especially with plant extracts rich in copigments, increased the concentration of polymerized and total anthocyanins, and aromatic compounds favorable for quality, highlighting rosemary extract for its direct action on the colour of wines of Monastrell. Using pre-fermentation maceration in the production of wines from copigmentation treatments has made it possible to increase the concentration of total polyphenols and condensed tannins, as well as that of esters and acetates. Micro-oxygenation through the application of acetaldehyde during the conservation of wines previously treated with copigments gave rise to an increase in the percentage of polymerized anthocyanins, in the concentration of anthocyanins, in condensed tannins and in total polyphenols, without affecting the aromatic composition of the wines. For all of these reasons, it can be established that the combination of copigmentation treatments in the field, particularly with plant extracts, pre-fermentation maceration during production and micro-oxygenation during storage, allows the production of Monastrell wines with a more stable colour, higher concentration of polyphenolics, and higher concentration of esters and acetates, compounds related to positive floral, fruity and spicy aromas. / Anaya Martínez, JA. (2022). Efecto de la aplicación de copigmentos vegetales sobre la composición fenólica y aromática de vinos tintos de Monastrell elaborados con diferentes técnicas de vinificación [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/185126 / TESIS

La micro-oxygénation des vins, par la dispersion de bulles d’oxygène, est une pratique de plus en plus utilisée dans le domaine de l’œnologie. Cette technique n’est pas toujours convenablement maitrisée par manque de connaissances scientifiques sur les paramètres régissant le transfert de l’oxygène. La recherche s'est focalisée sur l'étude des coefficients de transfert en fonction des composés du vin (CO2, éthanol, sucrose, consommateurs d’oxygène) et des conditions opératoires (type de diffuseur, température, rapport entre hauteur et diamètre du contenant de liquide). Les résultats montrent que lors de la micro-oxygénation, le dioxyde de carbone dissous et le sucrose ont une incidence négative sur le transfert alors que la présence d’éthanol améliore le transfert. En ce qui concerne les conditions opératoires, l’augmentation de débit de gaz et l’augmentation de rapport entre la hauteur et le diamètre de la cuve de micro-oxygénation joue positivement sur le transfert d’oxygène La surface spécifique des bulles et le coefficient de transfert de matière ont pu être dissociés pour les vins. La nature tensio-active des composés du vin semble être un élément important sur le transfert de matière. Les connaissances acquises ont été appliquées à la micro-oxygénation au cours de deux étapes de l'élaboration des vins : la fermentation alcoolique avec la maitrise de l’apport d’oxygène et la simulation de la technique d’élevage en barrique par micro-oxygénation couplée à l’ajout de copeaux de bois. Une nouvelle approche concerne l'étude d'un contacteur membranaire qui permet le transfert d’oxygène par diffusion. / Micro-oxygenation of the wines, by the dispersion of oxygen bubbles, is a practice increasingly used in oenology. This technique is not always suitably controlled for lack of scientific knowledge on the parameters governing the transfer of oxygen. Research was focused on the study of transfer coefficients in function of wine components (CO2, ethanol, sucrose, consuming oxygen) and of operating conditions (type of diffuser, temperature, relationship between height and diameter of the container of liquid). The results show that during micro-oxygenation, the dissolved carbon dioxide and the sucrose have a negative incidence on the transfer whereas the presence of ethanol improves the transfer. As operating conditions are concerned, the increase in gas output and the increase in micro-oxygenation tank height/diameter ratio positively influence oxygen transfer. For wines, the specific surface of the bubbles and the mass transfer coefficient could be dissociated. The surfactant nature of wine components seems to be the most important factor in mass transfer. The knowledge so acquired was applied to micro-oxygenation during two stages of wine making: alcoholic fermentation with the oxygen yield control and the simulation of ageing technique in barrels coupled with the wood chips addition. A new approach relates to the study of a membrane contactor application allowing the oxygen transfer by diffusion.