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


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.


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.


Publication date: June 23, 2022

Issue: IVAS 2022

Type: Poster


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


wine colloids, proteins, carbohydrates, molar mass


IVAS 2022 | IVES Conference Series


Related articles…

Comparison of plant nutrients in the soil solution and bleeding sap of grapevine cvs

In this study macro and micro nutrients of plants (N = NH4 + NO3 , P, K, Ca, Na, Zn, Mn, Fe and Cu) were determined both in soil solution and bleeding sap and compared each other. Bleeding sap was collected from the nine varieties of grapevine Cvs. grafted on 5BB rootstock and grown in different soil conditions. For all varieties, plant nutrients content in bleeding sap as higher than in soil solution except for Ca and Na. While in soil solution Ca content was found at 10209 ppm, this value in bleeding sap was 49.20 ppm (Kozak Beyazy), 55.38 ppm (Trakya Ylkeren), 50.37 (Cardinal) and 74.27 ppm (Tekirdaô Çekirdeksizi) respectively. For the same varieties the Na values were as follows : 7.16 ppm (in soil solution) : 4.8, 3.23, 4.21,4.58 ppm (in bleeding sap) respectively. K content in bleeding sap was higher than in soil solution for a few varieties, and lower in some varieties. Traces of Fe and Cu were found in both media.


The interest in indigenous non-Saccharomyces yeast for use in wine production has increased in recent years because they contribute to the complex character of the wine. The aim of this work was to investigate the fermentation products of ten indigenous strains selected from a collection of native yeasts established at the Institute for Adriatic Crops and Karst Reclamation in 2021, previously isolated from Croatian Maraština grapes, belonging to Hypopichia pseudoburtonii, Metschnikowia pulcherrima, Metschnikowia sinensis, Metschnikowia chrysoperlae, Lachancea thermotolerans, Pichia kluyveri, Hanseniaspora uvarum, Hanseniaspora guillermondii, Hanseniaspora pseudoguillermondii, and Starmerella apicola species, and compare it with commercial non-Saccharomyces and Saccharomyces strains.

Advancing grapevine science through genomic research

The seminar will examine the complexities and prospects of genomic research on Vitis species, characterize by exceptionally high heterozygosity and common interspecific gene flow. The seminar will showcase case studies highlighting the critical role of diploid genome references in grape research, specifically in areas such as aroma development, disease resistance, and domestication traits. It will also address the emerging focus on pangenomes within the Vitis genus, particularly in the context of genetic studies on naturally interbreeding populations.


Phenolic, volatile and nitrogen compounds are key to wine quality. On one hand, phenolic compounds are related to wine color, mouthfeel properties, ageing potential. and are associated with beneficial health properties. On the other hand, wine aroma is influenced by hundreds of volatile compounds. Fermentative aromas represent, quantitatively, the wine aroma, and among these volatile compounds, esters, higher alcohols and acids are mainly responsible for the fermentation bouquet.

Aroma quality of fortified wines from different Moscato cv. Cultivated in sicily

AIM: Vitis vinifera L. cv. Moscato includes different varieties, mainly white grapes with a medium-sized berry, spheroidal or slightly flattened in shape, yellow greenish color which becomes golden yellow or amber when exposed to the sun. Moscato varieties are mainly used for the production of sweet aromatic wines