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…

First step in the preparation of a soil map of the Protected Designation of Origin Valdepeñas (Central, Spain)

This work is a first step to make a map of vineyard soils. The characterization of the soils of the Protected Designation of Origin (D.P.O.) Valdepeñas will allow to group the studied profiles according to their physico-chemical characteristics and the concentrations of most relevant chemical elements. 90 soil profiles were analysed throughout the territory and the soils were sampled and described according to FAO (2006) and classified according to and Soil Taxonomy (2014). All samples were air dried, sieved and some physico-chemical parameters were determined following standard protocols. Also, major and trace elements were analysed by X-ray fluorescence. The statistically study was made using the SPSS program. Trend maps were made using the ArcGIS program. The studied soils have the following average properties: pH, 8.3; electrical conductivity, 0,20 dS/m (low); clay, 18.8% (medium) and CaCO3, 17.1% (high). In the study for the major elements. The major elements of these soils are Si, followed by Ca and Al, with an average content of 203.7 g/kg, 105.5 g/kg and 74.0 g/kg respectively. On the other hand, 27 trace elements have been studied. Of all of them, it can be highlighted the average values of Ba (361.8 mg/kg), Sr (129.3 mg/kg), Rb (83.4 mg/kg), V (74.2 mg/kg) and Ce (70.6 mg/kg). Ba, V and Ce values are higher and the values of Sr and Rb are lower to those found in the literature. The discriminant analysis shows a percentage of grouping of 91%. The content of chemical elements together with the physico-chemical characteristics allows grouping the soils in 4 group according to their order in the classification to Soil Taxonomy; due to the importance of the Calcisols in Castilla-La Mancha, it has been decided to establish them as their own group even if they do not appear in Soil Taxonomy classification.

Making sense of available information for climate change adaptation and building resilience into wine production systems across the world

Effects of climate change on viticulture systems and winemaking processes are being felt across the world. The IPCC 6thAssessment Report concluded widespread and rapid changes have occurred, the scale of recent changes being unprecedented over many centuries to many thousands of years. These changes will continue under all emission scenarios considered, including increases in frequency and intensity of hot extremes, heatwaves, heavy precipitation and droughts. Wine companies need tools and models allowing to peer into the future and identify the moment for intervention and measures for mitigation and/or avoidance. Previously, we presented conceptual guidelines for a 5-stage framework for defining adaptation strategies for wine businesses. That framework allows for direct comparison of different solutions to mitigate perceived climate change risks. Recent global climatic evolution and multiple reports of severe events since then (smoke taint, heatwave and droughts, frost, hail and floods, rising sea levels) imply urgency in providing effective tools to tackle the multiple perceived risks. A coordinated drive towards a higher level of resilience is therefore required. Recent publications such as the Australian Wine Future Climate Atlas and results from projects such as H2020 MED-GOLD inform on expected climate change impacts to the wine sector, foreseeing the climate to expect at regional and vineyard scale in coming decades. We present examples of practical application of the Climate Change Adaptation Framework (CCAF) to impacts affecting wine production in two wine regions: Barossa (Australia) and Douro (Portugal). We demonstrate feasibility of the framework for climate adaptation from available data and tools to estimate historical climate-induced profitability loss, to project it in the future and to identify critical moments when disruptions may occur if timely measures are not implemented. Finally, we discuss adaptation measures and respective timeframes for successful mitigation of disruptive risk while enhancing resilience of wine systems.

Geospatial trends of bioclimatic indexes in the topographically complex region of Barolo DOCG

Barolo DOCG is an economically important wine producing region in Northwest Italy. It is a small region of approximately 70 km2 gross area. The topography is very complex with steep sloped hills ranging in elevation from below 200 m to 550 m. Barolo DOCG wine is made exclusively from the Nebbiolo grape. Bioclimatic indexes are often used in viticulture to gain a better understanding of broader climate trends which can be compared temporally and geographically. These indexes are also used for identifying potential phenological timing, growing region suitability, and potential risks associated with expected climatic changes. Understanding how topography influences bioclimatic indexes can help with understanding of mesoscale climate behaviour leading to improved decision making and risk management strategies. The average monthly maximum and minimum temperatures, the Cool Night Index, the Huglin Index, and the monthly diurnal range (from July to October) were calculated using data from 45 weather stations within a 40 km radius of the Barolo DOCG growing area between the years 1996 and 2019. Linear and multiple regression models were developed using independent variables (elevation, aspect, slope) extracted from a digital elevation model to identify significant relationships. Bioclimatic indexes were then kriged with external drift using independent variables that showed significant relationships with the bioclimatic index using a 100 m resolution grid. The maximum monthly temperatures and the Huglin Index showed consistent significant negative relationships with elevation in all years. The minimum monthly temperatures showed no relationship with elevation but in some months a small but significant relationship was observed with aspect. Due to the lack of a relationship between minimum monthly temperatures and elevation compared to the significant relationship between maximum monthly temperatures and elevation, monthly diurnal range had a negative relationship with elevation.

Climate, Viticulture, and Wine … my how things have changed!

The planet is warmer than at any time in our recorded past and increasing greenhouse emissions and persistence in the climate system means that continued warming is highly likely. Climate change has already altered the basic framework of growing grapes for wine production worldwide and will likely continue to do so for years to come. The wine sector can continue to play an important role in leading the agricultural sector in addressing climate change. From developing on…

Delaying irrigation initiation linearly reduces yield with little impact on maturity in Pinot noir

When to initiate irrigation is a critical annual management decision that has cascading effects on grapevine productivity and wine quality in the context of climate change. A multi-site trial was begun in 2021 to optimize irrigation initiation timing using midday stem water potential (ψstem) thresholds characterized as departures from non-stressed baseline ψstemvalues (Δψstem). Plant material, vine and row spacing, and trellising systems were concomitant among sites, while vine age, soil type, and pruning systems varied. Five target Δψstem thresholds were arranged in an RCBD and replicated eight times at each site: 0.2, 0.4, 0.6, 0.8, and 1.0 MPa (T1, T2, T3, T4, and T5, respectively). When thresholds were reached, plots were irrigated weekly at 70% ETc. Yield components and berry composition were quantified at harvest. To better generalize inferences across sites, data were analyzed by ANOVA using a mixed model including site as a random factor. Across sites, irrigation was initiated at Δψstem = 0.24, 0.50, 0.65, 0.93, and 0.98 MPa for T1, T2, T3, T4, and T5, respectively. Consistent significant negative linear trends were found for several key yield and berry composition variables. Yield decreased by 12.9, 15.9, 19.5, and 27.4% for T2, T3, T4, and T5, respectively, compared to T1 (p < 0.0001) across sites that were driven by similarly linear reductions in berry weight (p < 0.0001). Comparatively, berry composition varied little among treatments. Juice total soluble solids decreased linearly from T1 to T5 – though only ranged 0.9 Brix (p = 0.012). Because producers are paid by the ton, and contracts simply stipulate a target maturity level, first-year results suggest that there is no economic incentive to induce moderate water deficits before irrigation initiation, regardless of vineyard site. Subsequent years will further elucidate the carryover effects of delaying irrigation initiation on productivity over the long term.