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…

Climate ethnography and wine environmental futures

Globalisation and climate change have radically transformed world wine production upsetting the established order of wine ecologies. Ecological risks and the future of traditional agricultural systems are widely debated in anthropology, but very little is understood of the particular challenges posed by climate change to viticulture which is seen by many as the canary in the coalmine of global agriculture. Moreover, wine as a globalised embedded commodity provides a particularly telling example for the study of climate change having already attracted early scientific attention. Studies of climate change in viticulture have focused primarily on the production of systematic models of adaptation and vulnerability, while the human and cultural factors, which are key to adaptation and sustainable futures, are largely missing. Climate experts have been unanimous in recognising the urgent need for a better understanding of the complex dynamics that shape how climate change is experienced and responded to by human systems. Yet this call has not yet been addressed. Climate ethnography, coined by the anthropologist Susan Crate (2011), aims to bridge this growing disjuncture between climate science and everyday life through the exploration of the social meaning of climate change. It seeks to investigate the confrontation of its social salience in different locations and under different environmental guises (Goodman 2018: 340). By understanding how wine producers make sense of the world (and the environment) and act in it, it proposes to focus on the co-production of interdisciplinary knowledge by identifying and foreshadowing problems (Goodman 2018: 342; Goodman & Marshall 2018). It seeks to offer an original, transformative and contrasted perspective to climate change scenarios by investigating human agency -individual or collective- in all its social, political and cultural diversity. An anthropological approach founded on detailed ethnographies of wine production is ideally placed to address economic, social and cultural disruptions caused by the emergence of these new environmental challenges. Indeed, the community of experts in environmental change have recently called for research that will encompass the human dimension and for more broad-based, integrated through interdisciplinarity, useful knowledge (Castree & al 2014). My paper seeks to engage with climate ethnography and discuss what it brings to the study of wine environmental futures while exploring the limitations of the anthropological environmental approach.

Teasing apart terroir: the influence of management style on native yeast communities within Oregon wineries and vineyards

Newer sequencing technologies have allowed for the addition of microbes to the story of terroir. The same environmental factors that influence the phenotypic expression of a crop also shape the composition of the microbial communities found on that crop. For fermented goods, such as wine, that microbial community ultimately influences the organoleptic properties of the final product that is delivered to customers. Recent studies have begun to study the biogeography of wine-associated microbes within different growing regions, finding that communities are distinct across landscapes. Despite this new knowledge, there are still many questions about what factors drive these differences. Our goal was to quantify differences in yeast communities due to management style between seven pairs of conventional and biodynamic vineyards (14 in total) throughout Oregon, USA. We wanted to answer the following questions: 1) are yeast communities distinct between biodynamic vineyards and conventional vineyards? 2) are these differences consistent across a large geographic region? 3) can differences in yeast communities be tied to differences in metabolite profiles of the bottled wine? To collect our data we took soil, bark, leaf, and grape samples from within each vineyard from five different vines of pinot noir. We also collected must and a 10º brix sample from each winery. Using these samples, we performed 18S amplicon sequencing to identify the yeast present. We then used metabolomics to characterize the organoleptic compounds present in the bottled wine from the blocks the year that we sampled. We are actively in the process of analysing our data from this study.

Grape must quality and mesoclimatic variability in Fruška Gora wine-growing region, Serbia

The Fruška Gora mountain is a traditional wine-growing region in Serbia situated in the Pannonian Basin. Due to such a position, the vicinity of the Danube River and the presence of concave configuration, it is suitable for grape production. This paper provides analyses of spatial variations in meteorological parameters and grape juice quality within Fruška Gora wine region over three consecutive vintages (2018-2020). The examined period can be defined as warm with cool nights during September (AVG 18,9°C; GDD 1918°C; CI 12°CF) and with the presence of mesoclimatic variability. The East part of the study area was somewhat drier and hotter compared to other parts of the region. The analyses of grape must samples (190 in total) of five cultivars (Cabernet-Sauvignon, Merlot, Chardonnay, Sauvignon blanc and Grašac (Welschriesling)) commonly grown across the region (19 sites), were performed using Fourier Transform Infrared Technology (FTIR). Among all cultivars, Sauvignon blanc was harvested first in the East area (DOY=246±5, GDD at harvest=1552±74, 22.2±0.7 °Brix), while the latest harvest was recorded for Cabernet-Sauvignon in the West (DOY=283±5, GDD at harvest=1936±187, 23.4±1.0 °Brix ). Both the red and white cultivars had higher acidity and YAN in the grape must if the vines were grown in the North and East compared to South and West areas. According to PCA analysis, Grašac showed the lowest variation in grape must chemical composition. Thus, the results confirm that Grašac is the most stable cultivar in Fruška Gora. All monitored cultivars reached technological fruit ripeness by the end of the growing season. However, it was difficult to reach full ripeness of red cultivars, mostly beacuse of uncoupling of technolocical and phenolic ripeness. Thus, Cabernet-Sauvignon had higher variations in GDD sums at harvest compared to other cultivars, which probably increased variations in grape must quality.

Adapting the vineyard to climate change in warm climate regions with cultural practices

Since the 1980s global regime shift, grape growers have been steadily adapting to a changing climate. These adaptations have preserved the region-climate-cultivar rapports that have established the global trade of wine with lucrative economic benefits since the middle of 17th century. The advent of using fractions of crop and actual evapotranspiration replacement in vineyards with the use of supplemental irrigation has furthered the adaptation of wine grape cultivation. The shift in trellis systems, as well as pruning methods from positioned shoot systems to sprawling canopies, as well as adapting the bearing surface from head-trained, cane-pruned to cordon-trained, spur-pruned systems have also aided in the adaptation of grapevine to warmer temperatures. In warm climates, the use of shade cloth or over-head shade films not only have aided in arresting the damage of heat waves, but also identified opportunities to reduce the evapotranspiration from vineyards, reducing environmental footprint of vineyard. Our increase in knowledge on how best to understand the response of grapevine to climate change was aided with the identification of solar radiation exposure biomarker that is now used for phenotyping cultivars in their adaptability to harsh environments. Using fruit-based metrics such as sugar-flavonoid relationships were shown to be better indicators of losses in berry integrity associated with a warming climate, rather than solely focusing on region-climate-cultivar rapports. The resilience of wine grape was further enhanced by exploitation of rootstock × scion combinations that can resist untoward droughts and warm temperatures by making more resilient grapevine combinations. Our understanding of soil-plant-atmosphere continuum in the vineyard has increased within the last 50 years in such a manner that growers are able to use no-till systems with the aid of arbuscular mycorrhiza fungi inoculation with permanent cover cropping making the vineyard more resilient to droughts and heat waves. In premium wine grape regions viticulture has successfully adapted to a rapidly changing climate thus far, but berry based metrics are raising a concern that we may be approaching a tipping point.

Modeling the suitability of Pinot Noir in Oregon’s Willamette Valley in a changing climate

Air temperature is the key driver of grapevine phenology and a significant environmental factor impacting yield and quality for a winegrape growing region. In this study the optimal downscaled CMIP5 ensemble for computing thegrowing season average temperature (GST) viticulture climate classification index was determined to spatially compute on a decadal basis predictions of the GST climate index and the grapevine sugar ripeness (GSR) model for Pinot Noir throughout the Willamette Valley (WV) American Viticultural Area (AVA). Forecasts for average temperature and a 220 g/L target sugar concentration level were computed using daily Localized Constructed Analogs (LOCA) downscaled CMIP5 historic and Representative Concentration Pathways (RCP) future climate projections of minimum and maximum daily temperature. We explore spatiotemporal trends of the GST climate classification index and Pinot Noir specific applications of the GSR phenology model for the WV AVA. Spatiotemporal computations of the GST climate index and Pinot Noir specific applications of the GSR model enable the opportunity to explore relationships between their computed values with one intent being to provide updated GST ranges that better align with current temperature-based modeling understanding of Pinot Noir grapevine phenology and the viticultural application of LOCA CMIP5 climate projections for the WV AVA. The Pinot Noir specific applications of the GSR model or the GST index with updated bounds indicate that the percent of the WV AVA area suitable for Pinot Noir production is currently at or near its peak value in the upper 80s to lower 90s of this century.