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Optimizing the use of bentonite for better control of haze formation In white and rosé wines

In winemaking, the appearance of turbidity in white and wine is a serious visual defect, which lowers significantly its commercial value. A major cause of the formation of turbidity in wine is attributed to the presence of temperature-sensitive proteins. The proteins undergo slow conformational changes, leading to aggregation and flocculation phenomena. The process can be […]

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Foamability of bentonite treated wines: impact of new acacia gum fractions obtained by ionic exchange chromatography (IEC)

Foam is a key aspect of quality of sparkling wines. Bentonite is usually added to the wine to prevent protein haze, but reducing its foamability [1]. New skills are searching to avoid this undesirable event [2]. Acacia senegal gum (Asen) is an exudate from Acacia trees, which can be used to stabilize red wine color. […]

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Grape seed powder as an alternative to bentonite for wine fining

PR proteins can cause haze in wines, and the risk is to keep the wine unsold. Generally, in winemaking bentonite solves this problem by removing proteins, but it is not a renewable resource, has poor settling, which means difficulty in filtering after use and a considerable loss of wine, it is not a specific adsorbent […]

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Use of antisense RNA technology to modulate gene expression in Œnococcus oeni

Œnococcus oeni is a wine-associated lactic acid bacterium performs the malolactic fermentation, which improves the taste and aromatic complexity of many wine. Although, wine exhibits harsh and challenging conditions (low pH, low temperature, nutrient-poor and presence of ethanol), O. oeni possesses a remarkable adaptability to those physiochemical conditions.  Mechanisms for responding to environmental changes are […]

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Nitrogen metabolism in Kluyveromyces marxianus and Saccharomyces cerevisiae: towards a better understanding of fermentation aroma production

During wine alcoholic fermentation, yeasts produce volatile aroma compounds from sugar and nitrogen metabolism. Some of the metabolic pathways leading to these compounds have been known for more than a century. Yet, the differences in compound yield and nature between species remain poorly understood. Using a two-pronged approach of isotopic filiation and transcriptome analysis, this […]

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Mathematical modeling of fermentation kinetics: a tool to better understand interactions between Torulaspora delbrueckii and Saccharomyces cerevisiae in mixed cultures

Nowadays the use of Torulaspora delbrueckii is more and more common in winemaking. However, its behavior in presence of Saccharomyces cerevisiae is not always predictable. Indeed, the interactions existing between the two yeasts are still not well characterized and can lead to a bad control during their implementation in mixed cultures. The objective of the […]

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Impact of non-Saccharomyces in malolactic fermentation of white and red winemaking

Nowadays the use of non-Saccharomyces as starters of alcoholic fermentation (AF) has increased because of the modulation of the organoleptic profile of wines. Additionally, these wines can undergo a malolactic fermentation (MLF) driven out by lactic acid bacteria, mainly Oenococcus oeni. Since MLF is usually performed after AF, MLF is highly influenced by the metabolism […]

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Genetic causes of SO2 consumption in Saccharomyces cerevisiae

SO2 is used during winemaking for its anti-oxidative and anti-microbial properties. A high SO2 concentration in the wine has negative impacts by hiding wine aromas and delaying malolactic fermentation. SO2 concentration is also a source of health concerns and is therefore legally regulated. During the alcoholic fermentation SO2 can be produced or consumed by the […]

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Fungal resident flora of a new winery: colonization, dynamics and potential persistence capacities

Through the years, extensive studies have been conducted on fungal biodiversity during the winemaking process: from the vineyard until aging. More recently, and as previously described for Saccharomyces cerevisiae, the persistence of winery resident flora (non-Saccharomyces yeasts) over time and its contribution to the alcoholic fermentation have been demonstrated. Also, winery surfaces were described as […]

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Aroma chemical profiles characterization of wines produced with moristel grapes harvested at different time points

The wine aroma is constituted by hundred of volatile chemical compounds that depend on many viticultural and oenological factors. One of the most important factors that will unequivocally affect the final wine pro-perties is the grape maturity level. Grape ripening is an extremely complex process, in which the metabolites and precursors concentrations change significantly with […]

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