OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 Foamability of bentonite treated wines: impact of new acacia gum fractions obtained by ionic exchange chromatography (IEC)

Foamability of bentonite treated wines: impact of new acacia gum fractions obtained by ionic exchange chromatography (IEC)

Abstract

Foam is a key aspect of quality of sparkling wines. Bentonite is usually added to the wine to prevent protein haze, but reducing its foamability [1]. New skills are searching to avoid this undesirable event [2]. Acacia senegal gum (Asen) is an exudate from Acacia trees, which can be used to stabilize red wine color. Asen can be fractionated, and the most widely used method is Hydrophobic Interaction Chromatography (HIC) to obtain low (HIC-F1), medium (HIC-F2) and high (HIC-F3) molar mass fractions. The effect of these fractions on the foamability of bentonite-treated wines was studied, showing positive or negative effects depending on the fraction and the wine [3].

Asen can also be fractionated by Ion Exchange Chromatography (IEC) giving a high (IEC-F1) and low (IEC-F2) molar mass fractions [4]. A synthetic wine (SYWI) was prepared (12 % v/v ethanol, 3 g·L-1 of tartaric acid). 8 base wines from Spain (3) and France (5) were made by the traditional white winemaking method. They were treated with bentonite (20 g·hL-1), stirred gently for a few hours, kept in cold storage (10 days, 4 °C), racked and filtered (1 μm). IEC-fractions were added to SYWI (60 g·hL-1) and to wines (30 and 10 g·hL-1). The foaming parameters were compared by shake test and by a classical gas-sparging method (Mosalux), being the qualitative aspect of foam also observed.

In SYWI, IEC-F1 improves the foamability during the total shake test. Both fractions enhance its Maximum Foam Height (HM) and the Foam Stability Height at 5 minutes (HS) measured by Mosalux. IEC-F1 provides less compact foam with larger bubble. In Spanish wines, IEC-F1 increases the foamability during the total shake test. IEC-F1 also improves it in French wines, but weaker and differently depending on the wine. The foamability is punctually enhanced by IEC-F2 in some wines, but it is greatly decreased in 1 French wine. The dose reduction decreases the improving impact of IEC-F1 on the foamability of the French selected wine but not in the Spanish selected wine. IEC-F1 increases HM and HS in both selected wines, whereas IEC-F2 improves HS only in the Spanish selected wine.

Concluding, the addition of IEC-F1 increases foamability for all the studied wines, but very differently depending on the wine. IEC-F2 addition shows positive, neutral or even negative effects depending on the wine. Dose of IEC-F1 may also play a key role depending on the wine.

References:

[1] Marchal et al. J. Agric. Food Chem., 2002, 50, 1420
[2] Martí-Raga et al. J. Agric. Food Chem., 2016, 96, 4962
[3] Apolinar-Valiente et al. J. Agric. Food Chem., Under Review
[4] Apolinar-Valiente et al. Food Hydrocoll., 2019, 89, 864

 

DOI:

Publication date: June 10, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Rafael Apolinar-Valiente (1), Pascale Williams (2), Thomas Salmon (3), Michaël Nigen (1), Christian Sanchez (1), Richard Marchal (3), Thierry Doco (2)

(1) UMR 1208 Ingénierie des Agropolymères et Technologies Emergentes, Université de Montpellier2, CIRAD, Montpellier SupAgro, INRA, Montpellier
(2) UMR 1083 Sciences Pour l’OEnologie, Montpellier SupAgro, INRA, Université de Montpellier2, Montpellier, France
(3) Laboratoire d’Oenologie et Chimie Appliquée, Université de Reims, Reims, France

Contact the author

Keywords

Acacia senegal gum, sparkling wine, Ionic Exchange Chromatography , foamability

Tags

IVES Conference Series | OENO IVAS 2019

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.

Biodiversity in the vineyard agroecosystem: exploring systemic approaches

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

Assessment of climate change impacts on water needs and growing cycle on grapevine in three DOs of NE Spain

This study assessed the suitability of grapevine growing in three DOs (Empordà, Pla de Bages and Penedès) of Catalonia (NE Spain) over the 21st century. For this purpose, an estimation of water needs and agroclimatic and phenological indicators was made. Climate change impacts were estimated at 1 km pixel resolution using temperature and precipitation projections from several general circulation models (GCM) and two climate change scenarios: RCP 4.5 (stabilization scenario) and RCP 8.5 (worst-case scenario). Potential crop evapotranspiration (following FAO procedure) and a daily water balance considering soil water holding capacity were used to estimate actual evapotranspiration of vines and, finally, water needs. Dynamics would be similar in the three DOs studied although the magnitude of impact differs. Water needs would be 2 and 3 times greater (ranging from 0 to more than 1500 m3/ha) than current water needs at both climate change scenarios. Moreover, blooming date would advance from 3 to 6 weeks, harvest date from 1 to 2.5 months, resulting in growing cycles from 10 to 80 days shorter. It should also be noted that frost risk would decrease from 6 to 76%, the number of days with temperatures above 30ºC during ripening would rise from 48 to 500% and tropical nights (minimum temperature >20ºC) at ripening would increase from 28 to 150%, depending on the scenario and the DOs. The impacts of climate change in the three DOs could result in significant limitations for grapevine cultivation and wine production if adaptive strategies are not applied. This result could serve as a basis for the design of specific and particular adaptation strategies to improve and maintain vineyards in the DOs studied and could be extrapolated to similar DOs and regions.

Adaptation to soil and climate through the choice of plant material

Choosing the rootstock, the scion variety and the training system best suited to the local soil and climate are the key elements for an economically sustainable production of wine. The choice of the rootstock/scion variety best adapted to the characteristics of the soil is essential but, by changing climatic conditions, ongoing climate change disrupts the fine-tuned local equilibrium. Higher temperatures induce shifts in developmental stages, with on the one hand increasing fears of spring frost damages and, on the other hand, ripening during the warmest periods in summer. Expected higher water demand and longer and more frequent drought events are also major concerns. The genetic control of the phenotypes, by genomic information but also by the epigenetic control of gene expression, offers a lot of opportunities for adapting the plant material to the future. For complex traits, genomic selection is also a promising method for predicting phenotypes. However, ecophysiological modelling is necessary to better anticipate the phenotypes in unexplored climatic conditions Genetic approaches applied on parameters of ecophysiological models rather than raw observed data are more than ever the basis for finding, or building, the ideal varieties of the future.

Soil, vine, climate change – what is observed – what is expected

To evaluate the current and future impact of climate change on Viticulture requires an integrated view on a complex interacting system within the soil-plant-atmospheric continuum under continuous change. Aside of the globally observed increase in temperature in basically all viticulture regions for at least four decades, we observe several clear trends at the regional level in the ratio of precipitation to potential evapotranspiration. Additionally the recently published 6th assessment report of the IPCC (The physical science basis) shows case-dependent further expected shifts in climate patterns which will have substantial impacts on the way we will conduct viticulture in the decades to come.
Looking beyond climate developments, we observe rising temperatures in the upper soil layers which will have an impact on the distribution of microbial populations, the decay rate of organic matter or the storage capacity for carbon, thus affecting the emission of greenhouse gases (GHGs) and the viscosity of water in the soil-plant pathway, altering the transport of water. If the upper soil layers dry out faster due to less rainfall and/or increased evapotranspiration driven by higher temperatures, the spectral reflection properties of bare soil change and the transport of latent heat into the fruiting zone is increased putting a higher temperature load on the fruit. Interactions between micro-organisms in the rhizosphere and the grapevine root system are poorly understood but respond to environmental factors (such as increased soil temperatures) and the plant material (rootstock for instance), respectively the cultivation system (for example bio-organic versus conventional). This adds to an extremely complex system to manage in terms of increased resilience, adaptation to and even mitigation of climate change. Nevertheless, taken as a whole, effects on the individual expressions of wines with a given origin, seem highly likely to become more apparent.