IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Asymmetrical flow field-flow fractionation with online multidetection is a viable tool to investigate colored red wine colloids

Asymmetrical flow field-flow fractionation with online multidetection is a viable tool to investigate colored red wine colloids

Abstract

Despite its relevance for wine quality and stability, red wine colloids have not still been sufficiently investigated, an occurrence due to the lack of suitable analytical techniques to study them as they are present in wine. Recently, asymmetrical Flow Field-flow Fractionation (AF4) with online multidetection has been tested as a new analytical tool to this aim, revealing its suitability for quantification, fractionation, and characterization of wine colloids in native state [1]. With the aim to characterize red wines in relation to their colloidal composition, AF4 technique was applied to 24 monovarietal Italian wines kept in bottles for 2 years and produced without any filtration, oak contact, fining treatments, malolactic fermentation or ageing on yeast lees. AF4 analysis allowed to quantify wine colloids, and to characterize them in terms of dimensions (by MALS) and absorbance (A280 & A520 nm). MALS revealed that each wine contained several colloids’ populations of different sizes (from 10 to 130 nm), but most of them showed sizes in the range 20 – 40 nm. The comparison by AF4 analysis of the A280-absorbing species present in whole wines with that of wines containing only species larger than 5 kDa (which were considered as colloids) allowed to calculate for each wine the percentage of molecules involved in the assembly of colloidal particles. This calculation showed that in the different samples the percentage of colloids varied from 1 to 44% of the total A280 absorbing compounds, indicating the diversity of the wines. Given that the A280 signal is mostly due to phenolics and proteins, these data indicate that very different percentages of these compounds participate in the formation of particles in the 20 – 40 nm size range. This means that phenolics necessarily need to be associated with other wine components to form particles of those dimensions. This association should involve proteins and polysaccharides [1]. The A520 data indicated the presence of pigments in the colloidal fraction. These pigments are likely to be constituted of tannin-anthocyanins complexes (polymeric pigments). Therefore, given the absence of species with sizes <20 nm, an association of these colored complexes with other colloidal-forming compounds seems necessary, the obvious candidate being proteins as they are known to strongly interact with tannins. Our results suggest that the color of red wines is due, in addition to free oligomeric pigments, also to colloidal particles formed by these latter bound to proteins, and that the quantity of these particles is highly variable in wines from different origin. How the presence of proteins affects the stability and evolution of red wines’ color remains to be investigated, keeping into consideration also the contribution of wine polysaccharides, which have been previously found to be part of the red wine colloidal particles [1].

References

[1] Marassi, et al. Food Hydrocoll 2021;110:106204.
Acknowledgments: MIUR project PRIN n.20157RN44Y

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Marangon Matteo1, Marassi Valentina2, Roda Barbara2, Zattoni Andrea2, Reschiglian Pierluigi2, Mattivi Fulvio3,4, Moio Luigi5, Parpinello Giuseppina Paola6, Piombino Paola5, Río Segade Susana7, Rolle Luca7, Slaghenaufi Davide8, Versari Andrea6, Vrhovsek Urska4, Ugliano Maurizio8 and Curioni Andrea1

1Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Italy
2Department of Chemistry “G. Ciamician”, University of Bologna, Italy
3Department of Cellular, Computational and Integrative Biology – CIBIO, University of Trento, Italy
4Department of Food Quality and Nutrition, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all’Adige, Italy
5Department of Agricultural Sciences, Division of Vine and Wine Sciences, University of Napoli Federico II, Italy
6Department of Agricultural and Food Sciences, University of Bologna, Italy
7Department of Agricultural, Forest and Food Sciences, University of Torino, Italy
8Department of Biotechnology, University of Verona, Italy

Contact the author

Keywords

red wine, colloids, proteins, polysaccharides, phenolics

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Sustainable fertilisation of the vineyard in Galicia (Spain)

Excessive fertilization of the vineyard leads to low quality grapes, increased costs and a negative impact on the environment. In order to establish an integrated management system aimed at a sustainable fertilization of the vineyards, nutritional reference levels were established. For this purpose, 30 representative vineyards of the Albariño variety were studied, in which soil and petiole analyses were carried out for two years and grape yield and quality at harvest were measured. In both years of study, soil pH, calcium, sodium and cation exchange capacity were positively correlated with calcium content and negatively correlated with manganese in grapes. Irrigated vineyards had higher levels of aluminium in soil and lower levels of calcium in petiole. Climatic conditions were very different in the years of the study. The year 2019 was colder than usual, in 2020 there was a marked water stress with high summer temperatures. This resulted in medium-high acidity in grapes in 2019 and low acidity in 2020, with sugar levels being similar both years. A very marked decrease in must amino nitrogen was observed in 2020, with ammonia nitrogen remaining stable. The correlation of acidity and sugar values in grapes with soil and petiole analysis data made it possible to establish reference levels for the nutritional diagnosis of the Albariño variety in this region. Based on these results, an easy-to-use TIC application is currently being created for grapegrowers, aimed at improving the sustainability of the vineyard through reasoned fertilization. This study has now been extended to other Galician vine varieties.

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)

Effect of regulated deficit irrigation regime on amino acids content of Monastrell (Vitis vinifera L.) grapes

Irrigation is an important practice to influence vine quality, especially in Mediterranean regions, characterized by hot summers and severe droughts during the growing season. This study focused on deficit irrigation regime influence on amino acids composition of Monastrell grapevines under semiarid conditions (Albacete, Southeastern of Spain). In 2019, two treatments were applied: non-irrigation (NI) and regulated deficit irrigation (RDI), watered at 30% of the estimated crop evapotranspiration from fruit set to onset of veraison. Grape amino acids content was analyzed by HPLC. Berries from non-irrigated vines showed higher concentration of several amino acids, such as tryptophan (73%), arginine (70%), lysine (36%), isoleucine (27%), and leucine (21%), compared to RDI grapes. Arginine is, together with ammonium ion, the principal nitrogen source for yeasts during the alcoholic fermentation; while isoleucine, tryptophan, and leucine are precursors of fermentative volatile compounds, key compounds for wine quality. Moreover, NI treatment increased in a 14% the total amino acids content in grapes compared to RDI treatment. The reported effects might be because yield was 70% higher in RDI vines than in the NI ones and, therefore, the sink demand was increased in the irrigated vines. In addition, NI vines suffered more severe water stress and it is known that the amino acids synthesis and accumulation can be influenced by the plant response to stress. According to the results, the irrigation regime showed effect on amino acids concentration in Monastrell grapes under semiarid conditions. Grapes from non-irrigated vines showed a higher content of several amino acids relevant to the fermentative process and to the wine aroma compounds formation. It is demonstrated that the final content of nitrogen-related components in grapes is influenced by the irrigation regime. The convenience of the irrigation strategy to suggest will depend on the desired wine style and the target yield levels.

The combined effects of climate, soils, and deficit irrigation on yield and quality of Touriga Nacional under high atmospheric demand in the Douro Region

Global warming is one of the biggest environmental, social and economic threats in several viticultural regions. In the Douro Valley, changes are expected in the coming years, namely an increase in temperature and a decrease in precipitation. These changes are likely to have consequences for the production and quality of wine.
The aim of this study was to explore the effects of different soil characteristics combined with several deficit irrigation strategies, managed throughout ETc references and predawn leaf water potentials thresholds, on physiology, yield, and qualitative attributes on the Touriga Nacional variety under years of mild to severe water and heat stress.
The studies were conducted over seven years (2015 to 2021) in two plots of a commercial vineyard located at Quinta do Ataíde (Symington Family Estates) planted in 2011 and 2014 at 170 meters elevation, growing under three water regimes: non-irrigated (NI) and two deficit irrigation strategies (30% and 60% ETc) assessed weekly by Ψpd. The site has an annual rainfall below 500 mm, with high atmospheric demand. Climate data was collected from a weather station, located on site. Berry ripening was followed weekly for fruit analysis. At harvest, yield, vigour and pruning weight per vine were determined from 90 vines by treatment. Each season at veraison the NDVI Index was accessed by a drone. The soils physic-chemistry in the experimental blocs were analysed and grouped by SWHC. Delta C-13 analyses were also performed per treatment in two years.Irrigation had a positive effect on yield per vine, mostly due to an increase in berry and cluster weight, and fertility index through the years. A significant increase in sugar content, colour and phenols was observed with deficit irrigation in some years, but vine vigour related to soil characteristics had by far the greatest impact on quality.

austrianvineyards.com: online viewer of all designations of Austrian wine

To digitally record and present all the origins of Austrian wines in the same perfect and clear way was the motivation for the Austrian Wine Marketing Board (Austrian Wine) to start with the project in 2018. In June 2021 the results were presented to the public in an online viewer showing all the designations of Austrian wine, available at https://austrianvineyards.com in a largely barrier-free manner. The online viewer provides tailored individual maps fitted to the respective zoom level. The smallest unit of wine-origins in Austria is called Ried and is displayed in a plot-specific manner highlighting areas under vine. Information on the Ried include administrative district, winegrowing municipality, cadastral municipality, large collective vineyard site, specific winegrowing region, generic winegrowing region, winegrowing area and, in many cases, an illustrative picture. Complementary data on the size, elevation (minimum-maximum), orientation (in 8 sectors plus flat) and gradient (minimum, maximum, average) are based on the area under vine according to the EU’s Integrated Administration and Control System. Additional information covers climate data. The diagrams are taken from the monthly breakdown of data in the annals of the Central Institute for Meteorology and Geodynamics, Austria provide a display of values for air temperature, precipitation, and sunshine hours for the reference year and the long-term average. Seasonal aggregated data on temperature, precipitation, and sunshine hours complete the display. Short descriptions with emphasis on geology and soil, field name in historical maps, etymology of the denomination, and main planted variety complements the available information for the main designations in the online viewer. These descriptions are compiled by winegrowers, geologists, historians, and journalists. All the information and data can be extracted to a pdf-file. Printed vineyard maps are also available. Missing content regarding wine origins in Styria will be completed in winter 2021/22.