Macrowine 2021
IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Chemical diversity of 'special' wine styles: fortified wines, passito style, botrytized and ice wines, orange wines, sparkling wines 9 Comparison of two procedures to measure foamability from sparkling base wines supplemented with acacia gums

Comparison of two procedures to measure foamability from sparkling base wines supplemented with acacia gums

Abstract

In sparkling wines, foam is a relevant aspect whose measurement method could affect the results. The shaking test (ST) is a simple method measuring foamability1,2. But, unlike the most used and classical sparging-gas method (the so-called Mosalux; MOS)3, the amount of gas introduced is not controlled. MOS is, however, longer and needs more complex equipment. Our work compares both methods trying to demonstrate that ST can be an alternative and reliable method easily used by winemakers and enological laboratories.Eight base wines were elaborated by the traditional method, treated with bentonite, stirred and filtered. The origins of three base wines were three different regions from Spain (using Moscatel and Macabeo grapes). The other five were elaborated in the French region of Champagne (using Chardonnay and Pinot noir grapes). Four Acacia gums fractions were separately added to two selected wines (one French wine and one Spanish wine). These two (six modalities: control, bentonite-treated and gums fractions-treated wines; n=12) and the other six wines (two modalities: control and bentonite-treated wines; n’=12) were analyzed by MOS and ST. In this way the differences of wines were not only caused by the origin and by the cultivar but also by varying oenological techniques, ensuring a great variability of samples. Using MOS, wine was in a glass cylinder with a frit at the bottom injecting CO2. The Maximum Foam Height (HM-MOS) and the Foam Stability Height (HS-MOS) were measured. In ST, wine in tubes was strongly hand-shaken. The foam height was measured at 5 sec. (ST5) and every 10 sec. (ST10, ST20…) during 90 seconds (all in triplicate).ST required six times less amount of wine and gum fractions than MOS. The Maximum Foam Height by ST (HM-ST) was always reached at ST5 (closely followed by ST10). The foam stability period (when foam height was not statistically different to the last measure) always started before or just at ST70. In all modalities of both selected wines, HM-MOS and HM-ST presented similar ANOVA-statistical relationships. However, HS-MOS and ST90 were statistically related only in one selected wine. Multiple regression analyses were performed trying to know if some correlation could be established between (i) the foam height values at T5 and T10 by ST and (ii) the HM-MOS of 24 varying wines, as well as between (I) the foam height values at T70 and T90 by ST and (II) the HS-MOS. T5 and T10 were selected as the two moments presenting the two higher foam height values. T70 and T90 were selected as the two moments when the foam stability period began and finished. Multiple Regressions showed that HM-MOS correlated with ST5-ST10, and HS-MOS with ST70-ST90 (R2>70%; p

DOI:

Publication date: September 15, 2021

Issue: Macrowine 2021

Type: Article

Authors

Thierry Doco

UMR-1083/SPO, INRAE-Montpellier, France,Rafael Apolinar-Valiente, UMR-1208/IATE, Montpellier SupAgro, France. Thomas Salmon, LOCA, Université de Reims, France. Pascale Williams, UMR-1083/SPO, INRAE-Montpellier, France.  Michaël Nigen, UMR-1208/IATE, Université Montpellier, France. Christian Sanchez, UMR-1208/IATE, Université Montpellier, France. Richard Marchal, LVBE, Université de Haute-Alsace, Colmar, France.

Contact the author

Keywords

sparkling base wine; foamability; shaking test; gas-sparging method; maximum foam height; foam stability height

Citation

Related articles…

Impact of long term agroecological and conventional practices on subsurface soil microbiota in Macabeu and Xarel·lo vineyards

There is a growing trend on the transition from conventional to agroecological management of vineyards. However, the impact of practices, such as reduced-tillage, organic fertilization and cover crops, is not well-understood regarding the soil microbial diversity, and its relationship with the soil physicochemical properties in the subsurface depth near the rooting zone. Soil bacterial diversity is an important contributor towards plant health, productivity and response to environmental stresses. A field experiment was conducted by sampling subsurface soil bacterial community (NGS and qPCR) near to the root zone of Macabeu and Xarel·lo vineyards, located at the Penedes. 3 organic (ECO) and 3 conventional (CON) vineyards, with more than 10 years of respective management were sampled (n=5 each plot). ECO practices did not affect bacterial and fungal abundance but increased significantly the ammonium oxidizing bacteria and alpha-diversity (Inv.Simpson). Interestingly beta-diversity was significantly affected by the management strategy. ANOSIM-tests revealed a significative effect of the management (ecological vs conventional) and plot, on the soil microbial structure (ASV abundance). Main phyla depicted were Proteobacteria, Actinobacteria and Acidobacteria, whose relative abundances were not affected by the management. EdgeR assay revealed a significant increase of Cyanobacteria and decrease of Gemmatimonadetes and Firmicutes phyla in ECO. Interestingly, the grapevine variety was not correlated with the soil microbial community structure. Mantel-test revealed an important correlation (Spearman) of some physicochemical parameters with the soil microbiota structure, in order of importance: texture, EC, pH Ca/Mg, Mg/P, K+, Mg2+, Ca2+, SO42-, and OM. N-NH4 and NTK, which were higher in the ECO managed soils, did not correlated significantly with the soil microbiome population. The results revealed the importance of combining a deep physicochemical characterization of each replicate with the microbial diversity assessment to gain better insights on the relationship between soil microbiome and vineyard management.

Extreme canopy management for vineyard adaptation to climate change: is it a good idea?

Climate change constitutes an enormous challenge for humankind and for all human activities, viticulture not being an exception. Long-term strategic changes are probably needed the most, but growers also need to deal with short-term changes: summers that are getting progressively warmer, earlier harvest dates and higher pH in musts and wines. In the last 10-15 years, a relevant corpus of research is being developed worldwide in order to evaluate to which extent extreme canopy management operations, aimed at reducing leaf area and, thus, limiting the source to sink ratio, could be useful to delay ripening. Although extreme canopy management can result in relevant delays in harvest dates, longer term studies, as well as detailed analysis of their implications on carbohydrate reserves, bud fertility and future yield are desirable before these practices can be recommended.

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.

1H-NMR-based Metabolomics to assess the impact of soil type on the chemical composition of Mediterranean red wines

The aim of this study was to evaluate the effects of different soil types on the chemical composition of Mediterranean red wines, through untargeted and targeted 1H-NMR metabolomics. One milliliter of raw wine was analyzed by means of a Bruker Avance II 400 spectrometer operating at 400.15 MHz. The spectra were recorded by applying the NOESYGPPS1D pulse sequency, to achieve water and ethanol signals suppression. No modification of the pH was performed to avoid any chemical alteration of the matrix. The generation of input variables for untargeted analysis was done via bucketing the spectra. The resulting dataset was preprocessed prior to perform unsupervised PCA, by means of MetaboAnalyst web-based tool suite. The identification of compounds for the targeted analysis was performed by comparison to pure compounds spectra by means of SMA plug-in of MNova 14.2.3 software. The dataset containing the concentrations (%) of identified compounds was subjected to one-way analysis of variance (ANOVA) to highlight significant differences among the wines. The untargeted analysis, carried out through the PCA, revealed a clear differentiation among the wines. The fragments of the spectra contributing mostly to the separation were attributed to flavonoids, aroma compounds and amino acids. The targeted analysis leaded to the identification of 68 compounds, whose concentrations were significant different among the wines. The results were related to soils physical-chemical analysis and showed that: 1) high concentrations of flavan-3-ols and flavonols are correlated with high clay content in soils; 2) high concentrations of anthocyanins, amino acids, and aroma compounds are correlated with neutral and moderately alkaline soil pH; 3) low concentrations of flavonoids and aroma compounds are correlated with high soil organic matter content and acidic pH. The 1H-NMR metabolomic analysis proved to be an excellent tool to discriminate between wines originating from grapes grown on different soil types and revealed that soils in the Mediterranean area exert a strong impact on the chemical composition of the wines.

Spatial variability of temperature is linked to grape composition variability in the Saint-Emilion winegrowing area

Elevated temperature during the grape maturation period is a major threat for grape quality and thus wine quality. Therefore, characterizing the grape composition response to temperature at a larger scale would represent a crucial step towards adaptation to climate change. In response to changes in temperature, various physiological mechanisms regulate grape composition. Primary and secondary metabolisms are both involved in this response, with well-known effects, for example on anthocyanins, and lesser known effects, for example on aromas or aroma precursors. At the field scale or at the regional scale, however, numerous environmental or plant-specific factors intervene to make the effects of temperature difficult to distinguish from overall variability. In this study, it was attempted to overcome this difficulty by selecting well-characterized situations with differing temperatures.
A long-term study of air temperature variability across several Merlot vineyards in the Saint-Emilion and Pomerol wine producing area found significant temperature differences and gradients at various time scales linked to environmental factors. From this study area, a few sites were selected with similar age, soil and training system conditions, and with repeated and contrasted temperature differences during the maturation period. The average temperature difference during the maturation period was about 2°C between cooler and warmer sites, a difference similar to that expected under future climate change scenarios. In close vicinity to the temperature sensors at each site, grape berries were sampled at different times until full maturity during 2019 and 2020. Also, berries from bunches on either side of the row were analyzed separately, allowing an investigation of bunch exposure effect associated with the coupling of berry temperature and solar radiation. Four replicates of pooled berries for each time – site – bunch exposure combination were obtained and analyzed for biochemical composition. Analyses of variance of the biochemical composition data collected at different sampling times reveal significant effects associated with temperature, site, and bunch azimuth. For instance, anthocyanins in grape skins are clearly influenced by temperature and solar radiation exposure, with up to 30% reduction in warmer conditions.