IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Composition and molar mass distribution of different must and wine colloids

Composition and molar mass distribution of different must and wine colloids

Abstract

A major problem for winemakers is the formation of proteinaceous haze after bottling. Although the exact mechanisms remain unclear, this haze is formed by unfolding and agglomeration of grape proteins, being additionally influenced by numerous further factors. For instance, increased levels of polyphenols and sulfate ions, high pH and ionic strength, and increased storage temperatures have been discussed to promote haze formation. In contrast, organic acids and polysaccharides appear to inhibit protein agglomeration (Albuquerque et al. 2021). To avoid haze formation, winemakers use bentonite to reduce protein levels in the wine before bottling. However, the bentonite treatment imposes negative side effects such as losses in wine quantity and quality, as well as costs of bentonite waste disposal (van Sluyter et al. 2015). To better understand haze formation and to find alternative procedures for protein removal e.g. by enzymatic treatments, detailed insights into the composition of the wine colloids might be helpful.
Prior to characterization, colloids were isolated from five different musts (four varieties from five vineyards, three with pectinase treatment) and their corresponding wines by ultrafiltration (10 kDa cut-off) and freeze-drying. Protein and carbohydrate composition were determined after hydrolysis by ion chromatography and high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), respectively. Molar mass distribution of colloids was determined by size exclusion chromatography with multi angle light scattering in combination with an UV and RI detector (SEC-UV-MALS-RI).
Colloids were found to contain a wide range of 8.9 to 67.1 g protein and 28.1 to 78.0 g carbohydrates per 100 g dry matter. Thus, protein concentrations in must and wine were been between 0.06 and 0.40 g/L and carbohydrate concentrations between 0.17 and 0.65 g/L. While there were just minor differences in the amino acid composition between the musts and wines, the carbohydrate composition was different in the samples. For instance, arabinose and galactose were the main sugars found in all hydrolyzed must colloids, while galacturonic acid was present in higher amounts in those not treated with pectinase. After fermentation, mannose was found to be the main sugar in hydrolyzed wine colloids. SEC-UV-MALS-RI showed that the colloids contained three main fractions. Two carbohydrate-rich fractions with average molar masses from 931 to 22,617 kDa and from 80 to 495 kDa as well as a proteinaceous fraction with an average molar mass between 16 to 44 kDa.
Our results indicate that colloid concentration and composition in wine is heavily influenced by variety, vineyard and oenological practices. The isolated colloids and the analytical methods will in the future be used to screen for enzyme preparations suitable to degrade proteins in must and wine to avoid haze formation.

References

Albuquerque, Wendell; Seidel, Leif; Zorn, Holger; Will, Frank; Gand, Martin (2021): Haze Formation and the Challenges for Peptidases in Wine Protein Fining. In: Journal of Agricultural and Food Chemistry 69, S. 14402–14414.
van Sluyter, Steven C.; McRae, Jacqui M.; Falconer, Robert J.; Smith, Paul A.; Bacic, Antony; Waters, Elizabeth J.; Marangon, Matteo (2015): Wine Protein Haze: Mechanisms of Formation and Advances in Prevention. In: Journal of Agricultural and Food Chemistry 63 (16), S. 4020–4030.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Poster

Authors

Seidel Leif1, Albuquerque Wendell2, Happel Katharina3, Gand Martin2, Zorn Holger2,3, Schweiggert Ralf1 and Will Frank1

1Department of Beverage Research, Geisenheim University
2Institute of Food Chemistry and Food Biotechnology, Justus Liebig Giessen 
3Fraunhofer Institute for Molecular Biology and Applied Ecology, Giessen, Germany

Contact the author

Keywords

wine colloids, proteins, carbohydrates, molar mass

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Effect of fertigation strategies to adapt PGI Côtes de Gascogne production to hot vintage

The development of fertigation could be a possible solution to adapt PGI Côtes de Gascogne (south-western France) wine production to climate change. The goal would be to limit the negative effects of water stress on yield performance expectation (around 15 tons per hectare) and to make the use of fertilizers more efficient. This study aimed to compare the effects of three strategies of water and minerals supply on grapes and wines qualities. Two fertigation practices were compared to a rainfed control which is the current standard of the local grape growing production. The fertilizers (nitrogen and potassium) were (i) fully brought by irrigation pipe during the season, (ii) partially brought by irrigation pipe and partially on the soil or (iii) fully brought on the soil at the beginning of the season for the non-irrigated control (local standard). The trial was run on cv. Colombard trained on spur pruned with vertical shoot positioning system on a sandy-silty-clay soil over the 2020 vintage which was particularly hot for the region. Moderate to strong water deficit appeared during the growing period of the berries and held on after veraison. Irrigation strategies allowed for maintaining grapevine without water deficit and being significantly different from the control water status. Grapevine with fully or partial fertigation strategies produced 25% more yield mainly due to the increase of the bunch weight. Also, the fully fertigation showed the best ratio between yield and maturity and brought 30% less of fertilizers (both nitrogen and potassium) than the two other strategies. Finally, the analysis of aromatic compounds in Colombard wines, varietal thiols family, showed the same level of concentrations for the 3 treatments, confirming that the yield performance did not impact the aromatic potential in this trial.

Upscaling the integrated terroir zoning through digital soil mapping: a case study in the Designation of Origin Campo de Borja

homogeneous zones by intersecting several partial zonings of major factors that influence vineyard growth. Each of them follows specific process from their corresponding disciplines. Soil zoning specifically refers to a Soil Resource Inventory map that has traditionally been generated by conventional soil mapping methods. These methods have shortcomings in reaching fine cartographic and categorical details and involve significant expenses, which undermines their applicability. A new framework named Digital Soil Mapping has introduced quantitative models by statistical techniques to establish soil-landscape relationships and is able to provide intensive scale cartography.

In the present study, a microzoning at 1:10.000 scale is generated from an initial zoning, where the conventional soil map with polytaxic map units is replaced by a new one from digital techniques that disaggregates them. The comparison between the zonings considers a quantitative evaluation of capability for each Homogeneous Terroir Unit by means of the Viticultural Quality Index and its categorization based on its distribution by map. The spatial intersection of both maps gives rise to a confusion matrix in which the flows of class variations after the substitution are assessed.

The results show a five-fold increase in the number of Homogeneous Terroir Units identified and a larger differentiation among them, evidenced by a wider range in the capability index distribution. Both elements are accompanied by an increase in the detection of areas of higher potential within previously undervalued uniform zones.These features are a direct effect of the improvements brought by Digital Soil Mapping techniques and would verify the advantages of their implementation in the Integrated Terroir zoning. Eventually, such new highly detailed terroir units would benefit precision viticulture and sustainable management practices.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares

Mapping and tracking canopy size with VitiCanopy

Understanding vineyard variability to target management strategies, apply inputs efficiently and deliver consistent grape quality to the winery is essential. However, despite inherent vineyard variability, the majority are managed as if they are uniform. VitiCanopy is a simple, grower-friendly tool for precision/digital viticulture that allows users to collect and interpret objective spatial information about vineyard performance. After four years of field and market research, an upgraded VitiCanopy has been created to achieve a more streamlined, technology-assisted vine monitoring tool that provides users with a set of superior new features, which could significantly improve the way users monitor their grapevines. These new features include:
• New user interface
• User authentication
• Batch analysis of multiple images
• Ease the learning curve through enhanced help features
• Reporting via the creation of colour maps that will allow users to assess the spatial differences in canopies within a vineyard.
Use-case examples are presented to demonstrate the quantification and mapping of vineyard variability through objective canopy measurements, ground-truthing of remotely sensed measurements, monitoring of crop conditions, implementation of disease and water management decisions as well as creating a history of each site to forecast quality. This intelligent tool allows users to manage grapevines and make informed management choices to achieve the desired production targets and remain profitable.

Assessment of climate change impacts on water needs and growing cycle on grapevine in three DOs of NE Spain

This study assessed the suitability of grapevine growing in three DOs (Empordà, Pla de Bages and Penedès) of Catalonia (NE Spain) over the 21st century. For this purpose, an estimation of water needs and agroclimatic and phenological indicators was made. Climate change impacts were estimated at 1 km pixel resolution using temperature and precipitation projections from several general circulation models (GCM) and two climate change scenarios: RCP 4.5 (stabilization scenario) and RCP 8.5 (worst-case scenario). Potential crop evapotranspiration (following FAO procedure) and a daily water balance considering soil water holding capacity were used to estimate actual evapotranspiration of vines and, finally, water needs. Dynamics would be similar in the three DOs studied although the magnitude of impact differs. Water needs would be 2 and 3 times greater (ranging from 0 to more than 1500 m3/ha) than current water needs at both climate change scenarios. Moreover, blooming date would advance from 3 to 6 weeks, harvest date from 1 to 2.5 months, resulting in growing cycles from 10 to 80 days shorter. It should also be noted that frost risk would decrease from 6 to 76%, the number of days with temperatures above 30ºC during ripening would rise from 48 to 500% and tropical nights (minimum temperature >20ºC) at ripening would increase from 28 to 150%, depending on the scenario and the DOs. The impacts of climate change in the three DOs could result in significant limitations for grapevine cultivation and wine production if adaptive strategies are not applied. This result could serve as a basis for the design of specific and particular adaptation strategies to improve and maintain vineyards in the DOs studied and could be extrapolated to similar DOs and regions.