Macrowine 2021
IVES 9 IVES Conference Series 9 Interest and impact of PVP/PVI (Polyvinylpyrrolidone/ Polyvinylimidazole) on winemaking and final quality of wines

Interest and impact of PVP/PVI (Polyvinylpyrrolidone/ Polyvinylimidazole) on winemaking and final quality of wines

Abstract

Consumers’ health and security force authorities to limit, in wine as in others food industry products, the concentration in « dangerous » molecules. Therefore the legal limit in heavy metals keeps on decreasing. As per proof EU regulation just decrease the stain concentration in wine from 0,2 to 0,15 mg/l. Certain changes , such as sodium arsenite treatment in vines, disappearance of brass in wineries to the benefit of stainless steel, limit even more the concentration of heavy metals in wines. But the use of copper derivates in vines treatments is difficult to replace. In the case of wine and its elaboration, the problem is even more complex. Indeed, regulation forces the wine producers to control the concentration of certain heavy metals in final wines. But most of the time the measured concentration is largely under legal limit (copper < 1 mg/l) with an average of 0 à 0,2 mg/l of CU, this has the consequence to let consider the wine producers that they have no problem. Unfortunately they are wrong ! This lecture will demonstrate that a major part of musts contain a copper concentration over 0,5 mg/l. The gap between must and wine is majorly do to the alcoholic fermentation that eliminate partially copper. This high concentration has a direct impact on winemaking and final wines quality. Copper is a known antiseptic, and it can have some toxic effects on micro-organisms (this effect is strain / species dependant). This leads to fermentations problems from slugglish to suck AF or difficult MLF. In addition heavy metals have an impact that can cause over 50% of “destruction” of certain aromatic compounds of grapes such as free thiols. Copper is also taking an active part in oxidation mechanisms that forms quinones and conduct to an increase of yellow length in wines colour. It increases bitterness of wines and also limit SO2 action ( copper is trapping free fraction). As for conclude this lecture will demonstrate the interest and impact PVP/PVI (only or in formulation) during winemaking as a solution to heavy metal presence such as copper. 

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Christophe Morge*, Céline Sparrow

*SOFRALAB

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

The effect of cropload on the volatile aroma characteristics of ‘Beihong’ and ‘Beimei’ red wine

Beihong and Beimei were bred as winemaking cultivars released by Institute of Botany, the Chinese Academy of Sciences in 2008. The cultivars are selected from the population of ‘Muscat Hamburg’ (Vitis vinifera) ×V. amurensis. They are extended to most provinces in North of China because they have strong resistance to cold and disease and need not be buried in soil in winter. To better understand the effect of cropload on volatile compounds during wine-making, we surveyed volatiles composition and content of different cropload level in 3-years-old ‘Beihong’ and ‘Beimei’ vines which planted in east foot of Helan mountain of Ningxia (EHN).

HEAT BERRY : Sensitivity of berries ripening to higher temperature and impact on phenolic compounds in wine

The grapevine is an important economical crop that is very sensitive to climate changes and microclimate. The observations made during the last decades at a vineyard scale all concur to show the impact of climate change on vine physiology, resulting in accelerated phenology and earlier harvest (Jones and Davis 2000). It is well-known that berry content is affected by the ambient temperature. While the first experiences were primarily conducted on the impact of temperature on anthocyanin accumulation in the grape, few studies have focused on others component of phenolic metabolism, such as tannins.

Influence of methyl jasmonate foliar application to vineyard on grape volatile composition over three consecutive vintages

An alternative to improve grape quality is the application to the vineyard of elicitors. Although these compounds were first used to increase resistance of plants against pathogens, it has been found that they are also able to induce mechanisms involved in the synthesis of phenolic compounds and some amino acids. However, researches about the influence of elicitors on grape volatile composition are scarcely. Therefore, the aim of this work was to study the influence of methyl jasmonate (MeJ) foliar application on grape aroma composition over three consecutive vintages. MeJ was applied to Tempranillo grapevines at a concentration of 10 mM in 2013, 2014, and 2015 years. Control plants were sprayed with water.

Defining the mechanisms and impact of winemaking treatments on tannin and polysaccharides in red wine: recent progress in creating diverse styles

Tannin and polysaccharide concentration and composition is important in defining the texture of red wines, but can vary due to factors such as cultivar, region, grape ripeness, viticultural practices and winemaking techniques. However, the concentration and composition of these macromolecules is dependent not only on grape tannin and polysaccharide concentration and composition, but also their extractability and, in the case of polysaccharides, their formation by yeast. Through studies into the influence of grape maturity, winemaking and sensory impacts of red grape polysaccharides, seed and skin tannins, recent research in our laboratory has shown that the processes involved in the extraction of these macromolecules from grapes and their retention in wine are very complex.

Proteomic and activity characterization of exocellular laccases from three Botrytis cinerea strains

Botrytis cinerea is a fungus that causes common infection in grapes and other fruits. In winemaking, its presence can be both considered desirable in the case of noble rot infection or undesirable when grey rot is developed. This fungus produces an extracellular enzyme known as laccase which is able to cause oxidation of phenolic compounds present in must and wine, causing most of the times a decrease in its quality and problems during the winemaking process [1]. Material and methods: Three B. cinerea strains (B0510, VA612 and RM344) were selected and grown in a liquid medium adapted from one previously described [2]. The enzyme was isolated by tangential ultrafiltration of the culture medium using a QuixStand system equipped with a 30 KDa filtration membrane.