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…

Micro-meteorological, compositional and transcriptional study of corvina grape color during ripening

Grape anthocyanin content and composition could affect the quality and the production strategies of red wines. Differences in the pigment composition modify the color properties in terms of hue, extractability and stability. Thus, for the production of a highly qualitative wine such as “Amarone”, variations in the pigment composition are not negligible. The aim of this work was the investigation of the anthocyanin profile changes during ripening in Corvina grapes, the main cultivar for the “Amarone” production. The experiment took place in 2015, in two vineyards located in Valpollicella (Italy).

Contribution of Piperitone to the mint nuances perceived in the aging bouquet of red Bordeaux wines

During the tasting of a fine, old wine, the aromas generated in the glass are intertwined in an intimate, complex manner, expressing the fragrance of the aging bouquet. This aging bouquet, which develops during bottle storage through a complex transformation process, may result in a broad palette of nuances. Among these, undergrowth, truffle, toasted, spicy, licorice, fresh red- and black-berry fruit and mint descriptors were recently identified as features of its olfactory representation for red Bordeaux wines. Although a targeted chemical approach focusing on volatile sulfur compounds revealed the role played by dimethyl sulfide, 2-furanmethanethiol, and 3-sulfanylhexanol as molecular markers of the typicality of the wine aging bouquet of red Bordeaux wines, its chemical transcription has only partially been elucidated.

Red wine substituted esters involved in fruity aromatic expression: an enantiomeric approach to understand their sensory impact and their pathway formation

Among red wines ethyl esters, those from short hydroxylated and branched-chain aliphatic acids constitute a family with a particular behavior and sensory importance. They have been previously discussed in the literature [1] and recent studies have established that some of them were strongly involved in of red wines’ fruity aroma [2]. As some among them have an asymmetrical carbon atom, it seemed important to separate their different enantiomers to obtain an accurate assessment of their organoleptic impact. Three chiral esters have been identified, presenting alkyl and/or hydroxyle substituants: ethyl 2-hydroxy-4-methylpentanoate, ethyl 2-methylbutanoate, and ethyl 3-hydroxybutanoate.

Impact of some agronomic practices on grape skins anthocyanin content

Wine colour is the first quality characteristic to be assessed, especially regarding red wines. Anthocyanins are very well known to be the main responsible compounds for red wine colour. Red cultivars can synthesize and accumulate anthocyanins in berry skin to express their colour. However, anthocyanin accumulation is often influenced by a series of factors, such as genetic regulation, phytohormones, environmental conditions and viticultural management.

Trans-resveratrol concentrations in wines Cabernet Sauvignon from Chile

This study evaluated the levels of trans-resveratrol in commercial wines made from Cabernet Sauvignon grapes from different valleys of Chile stilbenes. The Cabernet Sauvignon is the most planted variety in Chile, being 38% of the total vineyard country. Chile is the fourth largest wine exporter in the world, so it is important to evaluate the Cabernet-Sauvignon wines in their concentration levels of trans-resveratrol and its relation to the benefits provided to human health in moderate consumption. Evaluation comprises commercial wines from different valleys of Chile and its relationship with climatic characteristics, soil and vineyard handling.