OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 The affinity of white wine proteins for bentonite is dependent on wine composition and is directly related to their thermal stability / sensitivity

The affinity of white wine proteins for bentonite is dependent on wine composition and is directly related to their thermal stability / sensitivity

Abstract

Bentonite fining is commonly used in oenology to remove all or parts of white wine proteins, which are known to be involved in haze formation. This fining is effective, but has disadvantages: it is not selective, thus molecules responsible for aroma are also removed, it causes substantial volume losses, and finally it generates wastes. Over the last decades, the knowledge of wine proteins has increased: they have been identified, their structures are known, some of them have been crystallized. 

However, haze formation is not only a question of protein composition and concentration. It depends on many other factors, such as pH, wine composition (polyphenols, polysaccharides,…). Heat or chemical tests used to adjust the bentonite dose often leads to an overestimation, because they aim at removing all the proteins, even the ones that are stable in the range 60-80 °C and are not involved in spontaneous haze. 

In this study, we analyzed and quantified the proteins in 7 white wines (3 varieties, 4 areas), treated with four bentonite doses ranging from 5 to 80 g/hL. In parallel, samples of wines were heated during 30 minutes at 40, 60 and 80 °C and the residual proteins analyzed. 

The wines differed in their protein composition. In each wine, when they were present, the proteins were adsorbed on bentonite in this order: chitinase and β-glucanase, Lipid Transfer Protein (LTP), Thaumatin Like (TL) 22 kDa, TL 19 kDa and Invertase. 

The adsorption of a given protein was wine dependent. This could be due to wine pH and ionic strength (different in the studied wines), which changes electrostatic interactions that drive the protein adsorption onto bentonite, but also to other differences in composition (ethanol, polysaccharides, polyphenols, metals…). Experiments performed at pH 2.5 indicated that pH is not the only cause of such different adsorption behaviours: indeed adsorption isotherms were different. 

Protein adsorption on bentonite was compared to their thermal sensitivity. It was ranked as previously: β-glucanase ~ Chitinase > TL22 > TL19 ~ Invertase > LTP. It is worth noting that the most thermostable proteins are the ones which need the highest doses of bentonite on a wide panel of wines. These stable proteins do not need to be removed and thus bentonite doses could be reduced. More specific tests, which would take into account only the most sensitive proteins need to be developed.

DOI:

Publication date: June 23, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Céline Poncet-Legrand (1), Eric Meistermann (2), Frédéric Charrier (3), Philippe Cottereau (4), Patrick Chemardin (1), Aude Vernhet (1)

1 UMR SPO- Univ Montpellier – INRA- Montpellier SupAgro – 2, place Pierre Viala, 34060 Montpellier cedex FRANCE 
2 Institut Français de la Vigne et du Vin, F-68000 Colmar 
3 Institut Français de la Vigne et du Vin, F-44120 Vertou 
4 Institut Français de la Vigne et du Vin, F-30230 Rodilhan 

Contact the author

Keywords

haze formation, fining, protein adsorption, wine matrix

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

A sensometabolomic approach to understand wine mouthfeel percepts

Targeted analytical methods can overlook compounds that are a priori unknown to play a role in the mouthfeel sensations. This limitation can be overcome with the information provided by untargeted metabolomic analysis using UPLC‐QTOF-MS. To this end, an untargeted metabolomic approach applied to 42 red wines has allowed development of a model with predictive capacity by cross-validation for the “dry”, “oily” and “unctuous” sensations perceived by a sensory panel. The optimal PLS model for “dry” retained compounds with positive regression coefficients (≥ 0.17) including a trimer procyanidin, a peptide, and four anthocyanins.

Les terroirs viticoles ont une histoire

The historian starts from a scientific, rigorous and recent definition of the wine-growing region. “A viticultural terroir is made up of several homogeneous units: geological and pedological elements (texture,
grain size, thickness, mineralogical nature, chemical components), geomorphological (altitude, slope, exposure), climatological (rainfall, temperature, insolation)”. Absent from this definition, the man is fortunately reintroduced a little further. By associating viticulture and winemaking, it forms a “couple” with the terroir and this couple.

The effects of perennial cover crop management on soil temperature and vine water status

The implications of perennial cover crop management on vine vigor and yield have been well documented. However, whereas multiple studies show that cover crop management affects grapevine dry matter production, water, and nutrient status, the specific effects of a new hybrid perennial cover crop on soil temperature and its relationship to vine water status in vineyards has not been explored. This study will compare 3 different perennial cover crop combinations and tillage practices with a no-till seeding of a new hybrid perennial, Poa bulbosa (Pb).

Sur la réalité du lien entre le terroir et le produit : de l’analyse sémantique à l’approche écologique

The reflections presented here are a synthesis of a set of research on the construction of a scientific logic concerning the relations between the terroir, the vine, the wine, and on the study of a product, the wine, considered as the resulting from many interactions between factors of various orders. This work has benefited greatly from discussions of an epistemological as well as a technical nature with all the researchers at URVV (Angers) and with our colleagues at the Institut National des Appellations d’Origine, over several years.

Adaptation to soil and climate through the choice of plant material

Choosing the rootstock, the scion variety and the training system best suited to the local soil and climate are the key elements for an economically sustainable production of wine. The choice of the rootstock/scion variety best adapted to the characteristics of the soil is essential but, by changing climatic conditions, ongoing climate change disrupts the fine-tuned local equilibrium. Higher temperatures induce shifts in developmental stages, with on the one hand increasing fears of spring frost damages and, on the other hand, ripening during the warmest periods in summer. Expected higher water demand and longer and more frequent drought events are also major concerns. The genetic control of the phenotypes, by genomic information but also by the epigenetic control of gene expression, offers a lot of opportunities for adapting the plant material to the future. For complex traits, genomic selection is also a promising method for predicting phenotypes. However, ecophysiological modelling is necessary to better anticipate the phenotypes in unexplored climatic conditions Genetic approaches applied on parameters of ecophysiological models rather than raw observed data are more than ever the basis for finding, or building, the ideal varieties of the future.