IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Effect of mannoproteins extracted from Torulaspora delbrueckii on wine flavanol composition and on flavanol-salivary protein interactions

Effect of mannoproteins extracted from Torulaspora delbrueckii on wine flavanol composition and on flavanol-salivary protein interactions

Abstract

Global climate change is exerting an influence on vine phenology, leading to a decoupling of technological and phenolic maturity of grapes. This results in the modification of berry chemical composition, which can translate into wines with excessive astringency. The addition of mannoproteins (MP) to wine has been proposed as a way of mitigating this problem, since some studies have shown that MPs can modulate wine astringency. However, the mechanism underlying the astringency modulation effect of MPs is not well known and it seems to be dependent on the compositional and structural characteristics of the MP.

MPs are highly glycosylated proteins located in the outermost layer of the yeast cell wall. They are naturally released to the wine by actively growing yeast during alcoholic fermentation and by yeast autolysis during aging on lees. The commercial MP preparations, often used in an empirical way, are obtained from the cell wall of Saccharomyces cerevisiae, the main oenological yeast, to improve wine technological and sensory properties.

In wine, non-Saccharomyces yeasts, such as Torulaspora genre, predominate over S. cerevisiae during the initial phases of spontaneous alcoholic fermentations. However, little is known about the MPs of non-Saccharomyces yeasts and, unlike S. cerevisiae, they have never been considered as a possible source of MPs of oenological interest.

Thus, the objective of this work was to isolate and characterize MPs from the cell wall of Torulaspora delbrueckii and evaluate their effect on red wine astringency. The MPs were obtained from a commercial strain of T. delbrueckii (Lallemand, Inc.) by means of different treatments: induced autolysis and enzymatic and chemical hydrolysis. The MP extracts were characterized as follows. The protein content was determined by Lowry method and the (glycol)protein profile was analyzed by SDS-PAGE. The molecular weight of the MPs was determined by HRSEC-RID and its monosaccharide composition was analyzed after MP hydrolysis and derivatization followed by HPLC-DAD-MS analysis. To evaluate the possible effect of the obtained MPs on astringency, they were added to a red wine and changes in flavanol composition were assessed by HPLC-DAD-MS. In addition, the molecular basis of the MPs effect was also evaluated by studying the interactions between MPs, flavanols and salivary proteins by ITC.

The results showed differences in the structure and composition of the MPs extracted by the application of different treatments. Likewise, the study of the wine flavanol profile and of the MP-flavanol-salivary protein interactions suggested that T. delbrueckii can be a good source of mannoproteins with technological properties to modulate the wine flavanolic composition and the organoleptic properties related to these compounds.

DOI:

Publication date: June 27, 2022

Issue: IVAS 2022

Type: Poster

Authors

García-Estévez Ignacio1, Oyón-Ardoiz María1, Manjón Elvira1 and Escribano-Bailón M.Teresa1

1Grupo de Investigación en Polifenoles – University of Salamanca

Contact the author

Keywords

mannoproteins, flavanols, non-Saccharomyces yeasts, Torulaspora delbrueckii, red wine

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

A predictive model of spatial Eca variability in the vineyard to support the monitoring of plant status

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...

Updating the Winkler index: An analysis of Cabernet sauvignon in Napa Valley’s varied and changing climate

This study aims to create an updated, agile viticultural climate index (similar to the Winkler Index) by performing in-depth analyses of current and historical data from industry partners in several major winegrowing regions. The Winkler Index was developed in the early twentieth century based on analysis of various grape-growing regions in California. The index uses heat accumulation (i.e. Growing Degree Days) throughout the growing season to determine which grape varieties are best suited to each region. As viticultural regions are increasingly subject to the complexity and uncertainty of a changing climate, a more rigorous, agile model is needed to aid grape growers in determining which cultivars to plant where. For the first phase of this study, 21 industry partners throughout Napa Valley shared historical phenology, harvest, viticultural practice, and weather data related to their Cabernet sauvignon vineyard blocks. To complement this data, berry samples were collected throughout the 2021 growing season from 50 vineyard blocks located throughout 16 American Viticultural Areas that were then analyzed for basic berry chemistry and phenolics. These blocks have been mapped using a Geographic Information System (GIS), enabling analysis of altitude, vineyard row orientation, slope, and remotely sensed climate data. Sampling sites were also chosen based on their proximity to a weather station. By analyzing historical data from industry partners and data specifically collected for this study, it is possible to identify key parameters for further analysis. Initial results indicate extreme variability at a high spatial resolution not currently accounted for in modern viticultural climate indices and suggest that viticultural practices play a major role. Using the structure of data collection and analyses developed for the first phase, this project will soon be expanded to other wine regions globally, while continuing data collection in Napa Valley.

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

Local adaptation tools to ensure the viticultural sustainability in a changing climate

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...

Underpinning terroir with data: rethinking the zoning paradigm

Agriculture, natural resource management and the production and sale of products such as wine are increasingly data-driven activities. Thus, the use of remote and proximal crop and soil sensors to aid management decisions is becoming commonplace and ‘Agtech’ is proliferating commercially; mapping, underpinned by geographical information systems and complex methods of spatial analysis, is widely used. Likewise, the chemical and sensory analysis of wines draws on multivariate statistics; the efficient winery intake of grapes, subsequent production of wines and their delivery to markets relies on logistics; whilst the sales and marketing of wines is increasingly driven by artificial intelligence linked to the recorded purchasing behaviour of consumers. In brief, there is data everywhere!

Opinions will vary on whether these developments are a good thing. Those concerned with the ‘mystique’ of wine, or the historical aspects of terroir and its preservation, may find them confronting. In contrast, they offer an opportunity to those interested in the biophysical elements of terroir, and efforts aimed at better understanding how these impact on vineyard performance and the sensory attributes of resultant wines. At the previous Terroir Congress, we demonstrated the potential of analytical methods used at the within-vineyard scale in the development of Precision Viticulture, in contributing to a quantitative understanding of regional terroir. For this conference, we take this approach forward with examples from contrasting locations in both the northern and southern hemispheres. We show how, by focussing on the vineyards within winegrowing regions, as opposed to all of the land within those regions, we might move towards a more robust terroir zoning than one derived from a mixture of history, thematic mapping, heuristics and the whims of marketers. Aside from providing improved understanding by underpinning terroir with data, such methods should also promote improved management of the entire wine value chain.