 IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Chemical diversity of 'special' wine styles: fortified wines, passito style, botrytized and ice wines, orange wines, sparkling wines 9 Impact of winemaking processes on wine polysaccharides, improving by qNMR

Impact of winemaking processes on wine polysaccharides, improving by qNMR

Abstract

AIM: Today the knowledge in terms of molecular composition of the colloidal matrix is not enough in order to control its stability, according to the number of winemaking and wine stabilization processes. The physico-chemical processes during the winemaking change the composition and quantity of wine macromolecules. The goal today is to determine which analytical techniques will allow to discriminate these winemaking processes in order to better understand their impact on colloidal matrix stability as well as which molecules are responsible for its instabilities.

METHODS: Wines obtained after conventional winemaking were subjected to different fining and chemical stabilization treatments. Different methods were used to investigate the wine macromolecular composition and stability after chemical stabilization, including quantitative and qualitative analyzes of total soluble polysaccharides by extraction under acidified ethanol, and by size exclusion separation as well as qNMR metabolomics.

RESULTS: Observation of a slight difference at the quantitative level using classical analysis between the winemaking processes was observed as well as a strong discrimination by qNMR metabolomics.

CONCLUSIONS:

Analyses of total soluble polysaccharide of wine after different treatment shows different types and amount of these molecules. The qNMR metabolomics confirme the discrimination between each treatment. It allows a strong discrimination and is a step towards in the identification of winemaking processes. More investigations still require to determine which are the key parameters involved the wine colloidal stability as well as the right stabilization products, physicochemical winemaking processes, depending on the wine. The qNMR allows to understand, improve and choose the vinifications processes and the physicochemical stabilization of the colloidal matrix of wines, while respecting the quality and typicity of the most Bordeaux wines.

DOI:

Publication date: September 15, 2021

Issue: Macrowine 2021

Type: Article

Authors

Jean Martin-Pernier

PhD student at UR oenology- ISVV, at univerité de Bordeaux,Ines Le MAO, PhD student at UR oenology- ISVV, at Université de Bordeaux Wiame EL-BATOUL, trainee at UR oenology- ISVV, at Université de Bordeaux Michael JOURDES, Maître de Conférences at Université de Bordeaux Tristan RICHARD, Professor at Université de Bordeaux Virginie MOINE, scientific director at BioLaffort Arnaud MASSOT, scientific officer at BioLaffort Gregory Da COSTA, associate professor at Université de Bordeaux Soizic LACAMPAGNE, research engineer at UR oenology- ISVV

Contact the author

Keywords

process, winemaking, nmr, macromolecules, wine, polysaccharide

Citation

An automated cooling system to mitigate thermal and radiative stresses in Pignoletto white grapes

In the context of increasingly hot and dry summers, the adoption of innovative irrigation technologies has become essential for maintaining grape production while minimizing water use.

EFFECT OF DIFFERENT TEMPERATURE AND WATER-LOSS DEHYDRATION CONDITIONS ON THE PATTERN OF FREE AND GLYCOSYLATED VOLATILE METABOLITES OF ITALIAN RED GRAPES

Post-harvest grape berries dehydration/withering are worldwide applied to produce high-quality sweet and dry wines (e.i., Vin Santo, Tokaji, Amarone della Valpolicella). Temperature and water loss impact grape metabolism [1] and are key variables in modulating the production of grape compounds of oenological interest, such as Volatile Organic Compounds (VOCs), secondary metabolites responsible for the aroma of the final wine.
The aim of this research was to assess the impact of post-harvest dehydration on free and glycosylated VOCs of two Italian red wine grapes, namely Nebbiolo and Aleatico, dehydrated in tunnel under controlled condition (varied temperature and weight-loss, at constant humidity and air flow). From these grapes Sforzato di Valtellina Passito DOCG and Elba Aleatico Passito DOCG, respectively.

Evaluation of colloidal stability in white and rosé wines investing Dynamic Light Scattering technology

Proteins constitute one of the three main components of grape juice and white wine, phenolic compounds and polysaccharides being the others. A specific group of the total grape-derived proteins resists degradation or adsorption during the winemaking process and remains in finished wine if not removed by the commonplace commercial practice of bentonite fining. While bentonite is effective in removing the problematic proteins, it is claimed to adversely affect the quality of the treated wine under certain conditions, through the removal of colour, flavor and texture compounds. A number of studies have indicated that different protein fractions require distinct bentonite concentrations for protein removal and consequent heat stabilization.

Visualization of wine origin, quality level and terroir by the landscape

The communication of the aims of a viticulture under the premise of terroir is presently discussed in a lot of wine-growing regions around the world. To encourage this discussion the differences in knowledge, understanding, and preference concerning wine and landscape should be regarded more closely: the wine should be perceived as a representative of its region and one of the most characteristic features of a region is the landscape.

Do high temperature extremes impact berry tannin composition?

Flavonoids, including flavonols, anthocyanins, and tannins, are important contributors to grape and wine quality, and their biosynthesis is strongly influenced by bunch microclimate.