Enoforum 2021
IVES 9 IVES Conference Series 9 Enoforum Web 9 Enoforum Web Conference 2021 9 Cellar session 9 Mannoprotein extracts from wine lees: characterization and impact on wine properties

Mannoprotein extracts from wine lees: characterization and impact on wine properties

Abstract

This study aims at exploiting an undervalued winemaking by-product, wine yeast lees, by developing efficient and food-grade methods for the extraction of yeast glycoproteins. These extracts were then supplemented to wine and their impact on wine properties assessed. White wine lees were produced by fermenting Sauvignon blanc grape juice with S. cerevisiae Uvaferm HPS strain. Three extraction methods were applied on lees using physical (autoclave and sonication) or enzymatic (Glucanex®, an industrial β-glucanases) approaches. Glycoproteins extracts were characterized by SEC-HPLC and SDS-PAGE. After their addition to wine (0.5 g/L), no alteration of wine clarity was detected. The ultrasonication and enzymatic extracts, containing a relatively low amount of glycoproteins, led to a significant decrease in wine protein haze formation upon heat test (-7%). Conversely, the autoclave extract was the richest in glycoproteins and had a positive impact on wine foaming properties, inducing an increase in foam’s maximum height and stability which were 2.6 and 3.6 times higher compared to a model wine. The autoclave extract improved tartrate stability as shown by a decrease in wine conductance (-11%) compared to the untreated wine. Results suggest that white wine lees could be considered a valuable source of glycosylated proteins with potential applications in winemaking. In this context, the autoclave appears as the more promising method in terms of both efficiency and extract’s effectiveness. The proposed food-grade exploitation approach could represent an important tool to improve the environmental and economical sustainability of the wine supply chain.

DOI:

Publication date: April 23, 2021

Issue: Enoforum 2021

Type: Article

Authors

Alberto De Iseppi1, Andrea Curioni1,2, Giovanna Lomolino1, Matteo Marangon1, Simone Vincenzi1,2 and Benoit Divol3

1Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Viale dell’Università, 16, 35020, Legnaro, Padova, Italy
2Centre for Research in Viticulture and Enology (CIRVE), Viale XXVIII Aprile 14, 31015, Conegliano, Italy
3South African Grape and Wine Research Institute, Department of Viticulture and Oenology, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa

Contact the author

Tags

Enoforum 2021 | IVES Conference Series

Citation

Related articles…

Reviewing the geometry of terraces in the Douro region towards sustainable viticulture

The Douro demarcated region constitutes just over 50% of the area of mountain vineyard in the world, i.e., vineyards with slope gradients of 30% or above. Among the different (terraced) vineyard layouts, the formerly preferred wider terraces supporting two rows of vines and the currently advocated narrower single vine row, dominate the vineyards’ planting layout. The slope of these terraces, in other words, the supporting earth ramp, is a key element in these vineyards’ construction.

The role of molecular ecophysiology in terroir expression

Terroir is a complex concept which associates soil, climate, grape variety and cultural practices that include the training system and oenological techniques. It is a type of social construction with man at its centre. The typicality of a wine is also a social construction which is the result of an agreement among specialists vis à vis a given quality of the wine whose references are the wine’s origins (e.g. terroir) and taste.

Teasing apart terroir: the influence of management style on native yeast communities within Oregon wineries and vineyards

Newer sequencing technologies have allowed for the addition of microbes to the story of terroir. The same environmental factors that influence the phenotypic expression of a crop also shape the composition of the microbial communities found on that crop. For fermented goods, such as wine, that microbial community ultimately influences the organoleptic properties of the final product that is delivered to customers. Recent studies have begun to study the biogeography of wine-associated microbes within different growing regions, finding that communities are distinct across landscapes. Despite this new knowledge, there are still many questions about what factors drive these differences. Our goal was to quantify differences in yeast communities due to management style between seven pairs of conventional and biodynamic vineyards (14 in total) throughout Oregon, USA. We wanted to answer the following questions: 1) are yeast communities distinct between biodynamic vineyards and conventional vineyards? 2) are these differences consistent across a large geographic region? 3) can differences in yeast communities be tied to differences in metabolite profiles of the bottled wine? To collect our data we took soil, bark, leaf, and grape samples from within each vineyard from five different vines of pinot noir. We also collected must and a 10º brix sample from each winery. Using these samples, we performed 18S amplicon sequencing to identify the yeast present. We then used metabolomics to characterize the organoleptic compounds present in the bottled wine from the blocks the year that we sampled. We are actively in the process of analysing our data from this study.

Exploring the influence of terroir on the sensorial and aroma profiles of wines – An application to red wines from AOC Corbières

The aromatic profile of a wine is the result of volatile molecules present in grapes (varietal or primary aromas) and those produced during the winemaking process of fermentation (secondary aromas) and during wine aging (tertiary aromas).

Practical Aspects of Viticultural Zoning In South Africa

Depuis 1973, une commission statutaire administre la législation qui régit le zonage vitivinicole en Afrique du Sud. La province «Le Cap de l’ouest» cerne toutes les zones viticoles sauf quatre unités. Pour la plupart, le Cap de l’ouest a un climat méditerranéen. Les zones viticoles – qui produisent les «vins d’origine» – sont des régions, des districts, des quartiers et des domaines. Les régions sont vastes, séparées par la topographie, par ex. des chaînes de montagnes et des fleuves. Généralement, chaque région représente une zone climatique. Le climat de chaque district est plus homogène. Les quartiers sont exactement délimités par le climat, la topographie et la géologie. Les domaines sont les plus petits. Chaque domaine doit avoir un seul propriétaire.