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Kinetic study of browning caused by laccase activity using different substrates

AIM: To our knowledge all the studies about laccase kinetics and its inhibition have been performed with substrates and conditions very different from those of real grape juice. Moreover, none of these researches really measure enzymatic browning, since they have not taken into account what happens after the oxidation of o-diphenols in o-diquinones and their […]

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Adsorption capacity of phenolics compounds by polyaniline materials in model solution

AIM: The aim of this work was to study the trapping capacity of four polyaniline polymers towards phenolic compounds in wine-like model solutions. METHODS: The model wine solution was composed of 12% (v/v) and 4 g/L of tartaric acid adjusted to pH = 3.6. A series of centrifuge tubes (15 mL) were filled with 10 […]

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Influence of must fining on wine pinking: relationship between electrochemical and colorimetric measurements and pinking attitude of wine

AIM: “Pinking” is a term used to define an abnormal pink coloration assumed by white wines in certain cases. Despite the are many hypotheses about the causes of this phenomenon, pinking still represents an issue for the wine industry. In the absence of reliable preventive strategies, wineries often rely on treatments such as charcoal fining, […]

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Enzyme treatments during pre-fermentative maceration of white winegrapes: effect on volatile organic compounds and chromatic traits

AIM: Volatile organic compounds (VOCs) are very important for the characterisation and quality of the final white wine. An oenological practice to increase the extraction of aroma compounds is the cold pre-fermentative maceration [1,2], although it may also release phenolic compounds that confer darker chromatic traits to white wines, not appreciated by consumers. This practice […]

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Whole bunch fermentation: adding complexity, or just making ‘green’ wine?

AIM: Certain grape varieties contain negligible levels of isobutyl methoxypyrazine (IBMP) in grapes. However, it has long been known that grape stems may have a high concentration of IBMP. The study aimed to discover the extent to which whole bunch addition during fermentation contributes to ‘capsicum’ (green) flavour and aroma in wine by imparting IBMP. It […]

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Kinetic investigations of the sulfite addition on flavanols

Sulfonated monomeric and dimeric flavan-3-ols are recently discovered in wine and proved to have great importance in understanding wine chemistry and quality [1, 2]. Since the mechanism of their formation is still unknown, the aim of this work was to investigate the behaviour of wine monomeric and oligomeric and polymeric flavanols in the presence of […]

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Winemaking options for the improvement of the attributes of the wines from grapes with different oenological potential and sanitary status

The aim of this work was to study winemaking alternatives that will optimize the quality of the Tannat wines, taking advantage of the grape’s oenological potential. Alternatives of winemaking were studied using Tannat grapes with different composition and sanitary status. The grapes were harvested at technological maturity. The sanitary status of the grapes was evaluated […]

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Improvement of non-Saccharomyces yeast dominance during must fermentation by using spontaneous mutants resistant to SO2, EtOH and high pressure of CO2

AIM: A genetic study of four wine T. delbrueckii strains was done. Spore clones free of possible recessive growth‐retarding alleles with enhanced resistance to winemaking stressing conditions were obtained from these yeasts. METHODS: The genetic marker of resistance to cycloheximide (cyhR) allows easy monitoring of the new mutants obtained from these yeasts. Identity of the […]

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Microwaves, an auxiliary tool to improve red wine quality in warm climates

AIM Current winery efforts in Spanish warm climate regions, as Andalusia, are aimed at red wine production in spite of sub-optimal climatological conditions. This climate, characterized by high temperatures and sunlight, result in fast and heterogeneous ripening and, as a consequence, a lower polyphenolic concentration is detected in some grape varieties, thus leading to poor […]

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Identification of γ-nonalactone precusor in Merlot and Cabernet-Sauvignon grapes

Wine flavor results on complexes interactions of odorous components, which come from different aromatic families like esters, thiols, aldehydes, pyrazines or lactones. Varietal lactones identified in red wines contribute to cooked fruity flavors such as dried peach, apricot, figs and dried prune. Recent studies have demonstrated the key impact of the harvest date on the […]

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