Macrowine 2021
IVES 9 IVES Conference Series 9 A combination of biotechnology tools and coopers elements for an alternative the addition of SO2 at the end of the malolactic fermentation in red wines or at the “mutage” for the “liquoreux” wines

A combination of biotechnology tools and coopers elements for an alternative the addition of SO2 at the end of the malolactic fermentation in red wines or at the “mutage” for the “liquoreux” wines

Abstract

In red wines the post-MLF SO2 addition is an essential event. It is also the case for the “mutage” during the elaboration of the “liquoreux”. At these moments SO2 plays an antimicrobial action and an antioxidant effect. But at current pH of wines, ensuring a powerful molecular SO2 has become very difficult. Recent work on Brettanomyces strains have also shown that some strains are resistant up to 1.2 mg / L of molecular SO2. It’s also the case of the some Saccharomuces or Zygosaccharomyces strains suitable to re-ferment “liquoreux” wines after the “mutage”. Biotechnological products are now available for effective antimicrobial actions. Lysozyme inhibits the lactic acid bacteria. Chitosan also acts on the lactic acid bacteria but also efficiently on Brettanomyces. Acid sorbic can be a help to control the development of the undesirable strains yeast strains. On the antioxidant effect oak wood could potentially play a protective role. The development of an electrochemical sensor was used to estimate the influence of different cooperage factors on the antioxydant capacity(CaOx)suitable to be transmit by the wood at the wine. For red wines, during two successive vintages in two different wineries, tests compared classical post-MLF SO2 additions (5 g/hL) in classic new barrels to a treatment with a mixture of lysozyme and chitosan in CaOx optimized barrels. Microbiological monitoring has been done like chemical assays and wines tasted by expert panels. Barrels were also fitted with an innovative device allowing to measure dissolved oxygen without to have to open the barrel. In two different “Sauternes” wineries, test have been done to compare a classic mutage (between 10 and 25 g/hL of SO2) in classic barrels to a half a dose of SO2 and adding a supplement chitosan and sorbic acid in in CaOx optimized barrels. The impact on the microbial flora were investigated as well as the impact on the quality of wine. The innovative device for measuring dissolved oxygen was also used. All these wines were followed until the end of the harvest of breeding, ie on breeding periods of 6-18 months to understand the stability over time of the results. The results show that the test wines are microbiologically more stable than control wines. In the most of the case, always for the wine experiments and often for the “liqoureux”, the dissolved oxygen levels are also lower. Some metabolites (volatile phenols, diacetyl, and acetaldehyde) are less concentrated and colors are more intense and more stable. At the end, the combination of biotechnology tools and CAOX appears of a very efficient has emerged as a very effective technique to reduce the amount of total SO2 in wine as currently requested by consumers and by legislators.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Vincent Renouf*, Marie Mirabel

*Chêne & Cie

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

Nitrogen – Lipid Balance in alcoholic fermentations. Example of Champagne musts

Nutrient availability – nitrogen, lipids, vitamins or oxygen – has a major impact on the kinetics of winemaking fermentations. Nitrogen is usually the growth-limiting nutrient and its availability determines the fermentation rate, and therefore the fermentation duration. In some cases, in particular in Champagne, grape musts have high nitrogen concentrations and are sometimes clarified with turbidity below 50 NTU. In these conditions, lipid deficiencies may occur and longer fermentations can be observed. To better understand this situation, a study was realized using a synthetic medium simulating the composition of a Champagne must : 180 g/L of sugar, 360 mg/L of assimilable nitrogen and a lipid content ranging from 1 to 8 mg/L of phytosterols (mainly β-sitosterol).

Fingerprinting the origin of rosé wines with a new high throughput polyphenomics method

Wine is a widely consumed alcoholic beverage with a high commercial value. More specifically, the worldwide consumption of rosé wine has increased by 20% since 2002[1]. But because of its high commercial value, it can become a subject of fraud, and authenticity control is necessarily required. More than one hundred polyphenols have been recently quantified in various rosé wines [2]. They are key components defining color, taste and quality of wines. Their amount and composition depend on many different factors such as grape variety, winemaking and age of the wine. In this study, the influence of geographic origin of some rosé French wines was investigated. An original and very fast UPLC-QTOF-MS method was developed and used to predict the geographic origin authenticity of rosé wines.

Sensory and nephelometric analysis of tannin fractions obtained by ultrafiltration of red wines

The assessment of red wine mouthfeel relies primarily on the sensory description of its tannic properties. This evaluation could be improved by gaining a better understanding of the physicochemical properties of these tannins. Hence, the objectives of the present study were threefold: (1) to gain an insight into the sensory properties of subpopulations of proanthocyanidic tannins of different molecular sizes obtained through several ultrafiltration steps, (2) to quantify the kinetics of haze formation of these proanthocyanidic tannins in a dynamic polyvinylpyrrolidone (PVP) precipitation test, (3) to determine whether a correlation exists between the sensory and the precipitation data.

Towards multi-purpose valorisation of polyphenols from grape pomace: Pressurized liquid extraction coupled to purification by membrane processes

Grape by-products (including skins, seeds, stems and vine shoots) are rich in health promoting polyphenols. Their extraction from winery waste and their following purification are of special interest to produce extracts with high added value compounds. Meanwhile, the growing concern over environmental problems associated with economic constraints, require the development of environmentally sustainable extraction technologies. The extraction using semi-continuous subcritical water, as a natural solvent at high temperature and high pressure a technology is promising “green” technology that is environmentally friendly, energy efficient and improve the extraction process in plant tissues.

Efficiency of alternative chemical and physical treatments in reducing Brettanomyces Bruxellensis from oak wood

Oak barrels form an integral part of wine production, especially that of high quality wines. However, due to its porosity, wood presents an ecological niche for microbial proliferation and is highly susceptible to microbial spoilage which could cause considerable economic losses. Brettanomyces bruxellensis, the most commonly encountered microorganism responsible for spoilage during barrel ageing, can remain in barrels after barrel sanitation to contaminate new batches of wine after refilling. Therefore, effective sanitation treatments are of utmost importance to prevent recurring wine spoilage.