terclim by ICS banner
IVES 9 IVES Conference Series 9 EXPLORING THE INFLUENCE OF S. CEREVISIAE MANNOPROTEINS ON WINE ASTRINGENCY AND THE IMPACT OF THEIR POLYSACCHARIDE STRUCTURE

EXPLORING THE INFLUENCE OF S. CEREVISIAE MANNOPROTEINS ON WINE ASTRINGENCY AND THE IMPACT OF THEIR POLYSACCHARIDE STRUCTURE

Abstract

Mannoproteins (MPs) are proteoglycans from the outmost layer of yeast cell walls released into wine during alcoholic fermentation and ageing on lees processes. The use of commercial preparations of mannoproteins as additives to improve wine stability with regards to the crystallization of tartaric salts and to prevent protein haze in the case of white and rosé wines is authorized by the OIV.

Regarding red wines and polyphenols, mannoproteins are described as able to improve their colloidal stability and modulate the astringent effect of condensed tannins. The latter interact with salivary proteins forming insoluble aggregates that cause a loss of lubrication in the mouth and promote a drying and puckering sensation. However, neither the interaction mechanisms involved in mannoproteins capacity to impact astringency nor the structure-function relationships related to this property are fully understood.

The aim of this study was to evaluate the impact of high molecular weight mannoproteins on tannin-protein interactions. To this end, experiments were performed in a model wine using tannins purified from a red Syrah wine and BSA. Tannin-BSA aggregation kinetics were followed for 1 hour through Dynamic Light Scattering measurements in the absence and presence of mannoproteins. To progress in the identification of structure-function relationships and on the part played by the polysaccharide part, mannoproteins fractions from four yeast strains were extracted and purified. Yeast Strains were selected according to their origin and specific mannoprotein polysaccharide structure: a commercial enological strain (MP-LMD47), the wild-type BY4742 strain (MP-WT), and two of its mutants ΔMnn4 (MP-Mnn4, no mannosyl-phosphorylation) and ΔMnn2 (MP-Mnn2, linear N-glycosylation backbone). A thorough characterization of mannoprotein fractions confirmed the structural differences between mannoproteins from each yeast strain.

MPs were capable of delaying tannin-BSA aggregation kinetics by preventing the formation of micron-sized particles within the hour of measurement but did not avoid the long-term precipitation of tannin-BSA aggregates. Experiments indicated that mannoproteins interfere with tannin-BSA enlarged aggregation through the formation of a ternary MP-Tannin-BSA system. To be able to prevent tannin-BSA particle growth, the density/compactness of the polysaccharide moiety of MPs was a key factor.

 

1. Boulet, J.-C., Trarieux, C., Souquet, J.-M., Ducasse, M.-A., Caillé, S., Samson, A., … Cheynier, V. (2016). Models based on ultraviolet spectroscopy, polyphenols, oligosaccharides and polysaccharides for prediction of wine astringency. Food Chemistry, 190, 357–363. https://doi.org/10.1016/j.foodchem.2015.05.062
2. Cheynier, V. (2012). Phenolic compounds: from plants to foods. Phytochemistry Reviews, 11(2–3), 153–177. https://doi. org/10.1007/s11101-012-9242-8
3. Soares, S., Mateus, N., & de Freitas, V. (2012). Carbohydrates Inhibit Salivary Proteins Precipitation by Condensed Tannins. Journal of Agricultural and Food Chemistry, 60(15), 3966–3972. https://doi.org/10.1021/jf3002747
4. Vidal, S., Francis, L., Guyot, S., Marnet, N., Kwiatkowski, M., Gawel, R., … Waters, E. J. (2003). The mouth-feel properties of grape and apple proanthocyanidins in a wine-like medium. Journal of the Science of Food and Agriculture, 83(6), 564–573. https://doi.org/10.1002/jsfa.1394

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Article

Authors

Saul Assunção Bicca1,2, Céline Poncet-Legrand¹, Stéphanie Roi¹, Julie Mekoue², Thierry Doco¹ And Aude Vernhet¹

1. SPO Institut Agro, INRAE, Univ Montpellier, Montpellier, France.
2. Lallemand, SAS, 19 rue des Briquetiers, BP 59, 31702 Blagnac, France

Contact the author*

Keywords

Mannoproteins, Physico-chemical Interactions, Astringency, Condensed Tannins

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

MOUSY OFF-FLAVOURS IN WINES: UNVEILING THE MICROORGANISMS BEHIND IT

Taints and off-flavours are one of the major concerns in the wine industry and even if the issues provoked by them are harmless, they can still have a negative impact on the quality or on the visual perception of the consumer. Nowadays, the frequency of occurrence of mousy off-flavours in wines has increased.
The reasons behind this could be the significant decrease in sulphur dioxide addition during processing, the increase in pH or even the trend for spontaneous fermentation in wine. This off-flavour is associated with Brettanomyces bruxellensis or some lactic acid bacteria metabolisms.

NEW INSIGHTS INTO VOLATILE SULPHUR COMPOUNDS SCALPING ON MICROAGGLOMERATED WINE CLOSURES

The evolution of wine during bottle ageing has been of great interest to ensure consistent quality over time. While the role of wine closures on the amount of oxygen is well-known [1], closures could also play other roles such as the scalping phenomenon of flavour compounds. Flavour scalping has been described as the sorption of flavour compounds by the packaging material, which could result in losses of flavour intensity. It has been reported in the literature that volatile sulphur compounds (VSC) can be scalped on wine closures depending on the type of closure (traditional and agglomerated cork, screw-cap, synthetic [2]).

BIOSORPTION OF UNDESIRABLE COMPONENTS FROM WINE BY YEAST-DERIVED PRODUCTS

4-Ethylphenol (EP) in wine is associated with organoleptic defects such as barn and horse sweat odors. The origin of EP is the bioconversion reaction of p-coumaric acid (CA), naturally present in grapes and grape musts by contaminating yeasts of the genus Brettanomyces bruxellensis.
Yeast cell walls (YCW) have shown adsorption capacities for different compounds. They could be applied to wines in order to adsorb either CA and/or EP and thus reduce the organoleptic defects caused by the contaminating yeasts.

NEUROPROTECTIVE AND ANTI-INFLAMMATORY PROPERTIES OF HYDROXYTYROSOL: A PROMISING BIOACTIVE COMPONENT OF WINE

Hydroxytyrosol (HT) is a phenolic compound present in olives, virgin olive oil and wine. HT has attracted great scientific interest due to its biological activities which have been related with the ortho-dihydroxy conformation in the aromatic ring. In white and red wines, HT has been detected at concentrations ranging from 0.28 to 9.6 mg/L and its occurrence has been closely related with yeast metabolism of aromatic amino acids by Ehrlich pathway during alcoholic fermentation. One of the most promising properties of this compound is the neuroprotective activity against pathological mechanisms related with neurode-generative disorders including Alzheimer’s and Parkinson’s disease.

EXPLORING THE ROLE OF TRANSITION METAL IONS IN THE EVOLUTION OF ESTERS COMPOSITION OF YOUNG WHITE WINE DURING AGEING

Young white wines are typically released to the market a few months after harvest, to be consumed within a year, when their fresh fruity aromas are still dominant and appealing to modern consumers. Esters, particularly higher alcohol acetates (HAAs) and ethyl esters of fatty acids (EEFAs), play a central role in the fruity expression of young white wines [1]. However, these esters are known to undergo significant hydrolysis during the first months of aging [1, 2].