IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Effect of pre-fermentative strategies on the polysaccharide composition of must and white wines

Effect of pre-fermentative strategies on the polysaccharide composition of must and white wines

Abstract

Among the macromolecules of enological interest in white wines, much attention has been paid to polysaccharides. They have their origin in grape skin and pulp cell walls and includes polysaccharides rich in arabinose and galactose (PRAG), rhamnogalacturonans type II (RG-II) and homogalacturonans (HG); and cell walls from yeasts, constituted by mannoproteins (MP) and glucans. Polysaccharide content and composition change during fermentation and bottle aging.
Polysaccharide composition of white wines will depend, among other factors, on the pre-fermentative treatment applied to the grapes. Direct pressing or pre-fermentation maceration of crushed and destemmed grapes are usually applied. There are few studies analyzing the effect these treatments on the content of polysaccharides. Recently, the International Organization of Vine and Wine has approved the use of sonication of crushed grapes to promote the extraction of their compounds. However, there are no studies on the effect of sonication on crushed and white grapes on the content of polysaccharides in the musts and during the aging in bottle.
The aim of this study was to study the effect of direct pressing of white grapes, prefermentative maceration and prefermentative sonication of crushed and destemmed grapes on the polysaccharide composition in musts from Vitis vinifera L. cv. Airén. It was also studied the effect during the bottle aging.
Airén white grapes were destemmed and crushed. One batch was directly pressed into a pneumatic press; other was pressed after 4 hours of-fermentative maceration; and other was treated with power ultrasound at 30 kHz before pressing. Samples were taken of the raked musts, when bottling and after 6 months of bottle aging. Glycosyl residue composition was analyzed as previously described (Guadalupe et al., 2012; Ayestarán et al., 2004).
All the musts showed contents of glucosyl monosaccharides significantly higher than pectic monosaccharides. Sonication treatment improved the release of RG-II and mannans in musts and the pre-fermentative maceration favored the extraction of PRAG. Musts from direct pressing had the lowest content of total monosaccharides and RG-II. From the must to the time of bottling, there was an increase in the content of RG-II and MP and a decrease of PRAG in all wines evaluated. At the time of bottling, wines from sonicated grapes showed the highest content of pectic monosaccharides and RG-II, while wines from pre-fermentative maceration showed the highest content of glucosyl monosaccharides. After 6 months of bottle aging, all wines showed a decrease in the content of MP and PRAG. Wines made with pre-fermentative maceration showed the highest content of total polysaccharides families, PRAG and MP.
This research was funded by the Ministerio de Ciencia, Innovación y Universidades and Feder Funds, grant number RTI2018-093869-B-C21.

References

Ayestarán, B.; Guadalupe, Z.; León, D. Quantification of major grape polysaccharides (Tempranillo v.) released by maceration enzymes during the fermentation process. Anal. Chim. Acta. 2004, 513, 29–39.
Guadalupe, Z.; Martínez-Pinilla, O.; Garrido, A.; Carrillo, J. D.; Ayestarán, B. Quantitative determination of wine polysaccharides by gas chromatography–mass spectrometry (GC–MS) and size exclusion chromatography (SEC). Food Chem. 2012, 131, 367–374.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Poster

Authors

Canalejo Diego1, Zhao Feng1, Martínez-Lapuente Leticia1, Guadalupe Zenaida1, Ayestarán Belén1, Pérez-Porras Paula2, Bautista-Ortín Ana Belén2 and Gómez-Plaza Encarna2

1Institute of Vine and Wine Sciences, ICVV (University of La Rioja, Government of La Rioja and CSIC)
2Department of Food Science and Technology, Faculty of Veterinary Science, University of Murcia

Contact the author

Keywords

White wine; Monosaccharides; High-power ultrasounds; Direct pressing; Pre-fermentation maceration

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

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.

Late frost protection in Champagne

Probably one of the most counterintuitive impacts of climate change on vine is the increased frequency of late frost. Champagne, due to its septentrional position is historically and regularly affected by this meteorological hazard. Champagne has therefore developed a strong experience in frost protection with first experiments dating from the end of 19th century. Frost protection can be divided in two parts: passive and active. Passive protection includes all the methods that do not seek to modify the vine’s environment or resistance at the time of frost. The most iconic passive protection in Champagne is the establishment of the individual reserve. This reserve allows to stock a certain quantity of clear wine during a surplus year to compensate a meteorological hazard like frost during the following years. Other common passive methods are the control of planting area (walls, bushes, topography), the choice of grape variety, late pruning, or the impact of grass cover and tillage. Active frost protection is also divided in two parts. Most of the existing techniques tend to modify vine’s environment. Most of the time they provide warmth (candles, heaters, windmills, heating cables…), or stabilise bud’s temperature above a lethal threshold (water sprinkling). The other way to actively fight is to enhance the resistance of buds to frost (elicitors). The Comité Champagne evaluates frost protection methods following three main axes: the efficiency, the profitability, and the environmental impact through a lifecycle assessment. This study will present the results on both passive and active protection following these three axes.

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.

Terroir analysis and its complexity

Terroir is not only a geographical site, but it is a more complex concept able to express the “collective knowledge of the interactions” between the environment and the vines mediated through human action and “providing distinctive characteristics” to the final product (OIV 2010). It is often treated and accepted as a “black box”, in which the relationships between wine and its origin have not been clearly explained. Nevertheless, it is well known that terroir expression is strongly dependent on the physical environment, and in particular on the interaction between soil-plant and atmosphere system, which influences the grapevine responses, grapes composition and wine quality. The Terroir studying and mapping are based on viticultural zoning procedures, obtained with different levels of know-how, at different spatial and temporal scales, empiricism and complexity in the description of involved bio-physical processes, and integrating or not the multidisciplinary nature of the terroir. The scientific understanding of the mechanisms ruling both the vineyard variability and the quality of grapes is one of the most important scientific focuses of terroir research. In fact, this know-how is crucial for supporting the analysis of climate change impacts on terroir resilience, identifying new promised lands for viticulture, and driving vineyard management toward a target oenological goal. In this contribution, an overview of the last findings in terroir studies and approaches will be shown with special attention to the terroir resilience analysis to climate change, facing the use and abuse of terroir concept and new technology able to support it and identifying the terroir zones.

Influence of a spontaneous cover crop on the vineyard and soil erosion under Mediterranean climate

Sixty five % of the agricultural area of the Basque Country located in the DO Ca Rioja corresponds to vineyards. More than 40% of it has an average slope greater than 10%, which makes it sensitive to erosive processes. Furthermore, it is foreseeable that extreme weather events (storms, hail, extreme heat and cold, etc.) will be favored due to climate change. Cover cropping can mitigate this risk, and therefore the objective of this work is to evaluate the impact that a vegetable cover has on the agronomic behavior of the vineyard, the quality of the grape and soil erosion. For this, a trial has been carried out with a Graciano variety vineyard with a slope between 10% -20% during the years 2020 and 2021. Conventional tillage management in the area has been compared (4-6 passes per year of tillage machinery) versus spontaneous vegetation cover management in the vineyard. This implies not tilling and allowing the grass of the land to colonize the range between the lines of vines, controlling their height through 1-3 mowing passes per year, always trying to affect the surface of the land as little as possible. The vegetative growth, yield and quality of the grape and wine was measured. Furthermore, erosion has been measured using Gerlasch boxes. The yield was lower in the second year of the trial in the cover crop treatment, but erosion was significantly reduced.