 IVES 9 IVES Conference Series 9 The role and quantification of vitamins in wine: what do we know?

The role and quantification of vitamins in wine: what do we know?

Abstract

AIM: Vitamins are essential compounds to numerous organisms, including yeasts, and appear highly significant during winemaking processes. Acting as cofactors in major yeast metabolic pathways, such as those of alcohols, amino acids and fatty acids, it appears very likely that their involvement in fermentation courses, as well as in the development of aromatic compounds in wine is consequential.

METHODS: Numerous assays have been developed to determine and quantify vitaminic contents in grape musts and wines. Microbial assays, relying on the specific growth requirements of selected microorganisms, were the earliest methods used pursuing this goal, however poorly precise and accurate. Methods relying on vitamin properties, such as acid titrations and spectrophotometry have also been used to quantify vitamins in grape musts and wines, although they require specific physicochemical properties, and do not allow for simultaneous determination of several vitamin groups.

RESULTS: As a consequence, contemporary techniques, such as chromatography-based methods, stand as efficient means to quantify vitamins in grape musts. However, no method has recently been developed to assay vitamin contents in this specific matrix. Similarly, assays relying on spectroscopy and electrophoresis, proved efficient in simultaneously quantifying vitamins in several fruit matrixes, appear promising for extension towards the grape must and wine matrixes. In addition, winemaking processes, such as the addition of sulfites or clarifying agents, or vatting lengths have been shown to significantly impact vitamin contents.

CONCLUSION

The development of more methods to quantify vitamins in grape musts, relying on more sensitive and precise recent analytical techniques could offer ground for a broad range of prospects in the wine science field. Such developments could support better comprehensions of yeast requirements during winemaking, and allow for finer modulations of the processes, as well as elucidate the role of vitamins in the development of aroma in wines

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Marie Sarah Evers

University of Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, VAlMiS-Institut Universitaire de la Vigne et du Vin, 2 rue Claude Ladrey, 21000 Dijon, France SAS Sofralab, 79, Avenue A.A. Thévenet, BP 1031, Magenta, France,Chloé ROULLIER-GALL, University of Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, VAlMiS-Institut Universitaire de la Vigne et du Vin, 2 rue Claude Ladrey, 21000 Dijon, France Christophe MORGE, SAS Sofralab, 79, Avenue A.A. Thévenet, BP 1031, Magenta, France Celine SPARROW, SAS Sofralab, 79, Avenue A.A. Thévenet, BP 1031, Magenta, France Antoine GOBERT, SAS Sofralab, 79, Avenue A.A. Thévenet, BP 1031, Magenta, France Hervé ALEXANDRE, University of Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, VAlMiS-Institut Universitaire de la Vigne et du Vin, 2 rue Claude Ladrey, 21000 Dijon, France

Contact the author

Keywords

vitamins ; fermentation ; enology ; yeasts ; metabolism

Citation

Modulation of berry composition by different vineyard management practices

High concentration of sugars in grapes and alcohol in wines is one of the consequences of climate change on viticulture production in several wine-growing regions. In order to investigate the possibilities of adaptation of vineyard management practices aimed to reduce the accumulation of sugar during the maturation phase without reducing the accumulation of anthocyanins in grapes, a study with severe shoot trimming, shoot thinning, cluster thinning and date of harvest was conducted on Merlot variety in Istria region (Croatia), under the Mediterranean climate. Four factors which may affect grape maturation and its composition at harvest were investigated in a two-years experiment; severe shoot trimming applied at veraison when >80% of berries changed colour (in comparison to untreated control), shoot thinning (0 and 30%), cluster thinning (0 and 30%), and the date of harvest (early and standard harvest dates). Shoot thinning had no significant impact on berry composition, despite the obtained reduction in yield per vine. Lower Brix in grapes were obtained with earlier harvest date and if no cluster thinning was applied, although at the same time a reduction in the concentration of anthocyanins in berries was observed in these treatments. On the other hand, if severe shoot trimming was applied when >80% of berries changed colour, a reduction of Brix was obtained without a negative impact on berry anthocyanins concentration. We conclude that in cases when undesirably high sugar concentrations at harvest are expected, severe shoot trimming at 80% veraison may effectively be used in order to obtain moderate sugar concentration in berries together with the adequate phenolic composition.

A predictive model of spatial Eca variability in the vineyard to support the monitoring of plant status

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...

Soil quality in Beaujolais vineyard. Importance of pedology and cultural practices

A pedological study was carried out from 2009 to 2017 in Beaujolais vineyard, to improve physical and chemical knowledge of soils. It was completed in 2016 and 2017 by the current study, dealing with microbial aspects, in order to build a reference frame for improved advice in soil management. Microbial biomass was measured on representative plots of the six most common soil types identified in Beaujolais and, for each soil type, on plots with different levels of the main impacting parameters: total organic carbon, pH, cation exchange capacity, extractable copper. A total of 59 soil samples were collected. Confirming the results of various trials carried out in Beaujolais over the past 20 years, the results of the present study showed that the soils were still alive, but exhibited a large variability of biological parameters, which appeared dependant on both pedological and anthropic factors. Therefore, a good interpretation of biological parameters and advice for vine growers must rely on a pedologically-based referential with differentiated main driving factors. For example, the control of pH is of primary importance in granitic soils and in no way organic matter addition can improve soil quality if pH is too low. Conversely, in calcareous soils, biological parameters are more directly affected by direct or indirect (cover crops for example) inputs of organic matter. The use of biological parameters, such as microbial biomass, is of great potential value to improve advice on agro-viticultural practices (soil management, fertilization, liming, etc.), basis of a sustainable wine production on fragile soils.

Upscaling the integrated terroir zoning through digital soil mapping: a case study in the Designation of Origin Campo de Borja

homogeneous zones by intersecting several partial zonings of major factors that influence vineyard growth. Each of them follows specific process from their corresponding disciplines. Soil zoning specifically refers to a Soil Resource Inventory map that has traditionally been generated by conventional soil mapping methods. These methods have shortcomings in reaching fine cartographic and categorical details and involve significant expenses, which undermines their applicability. A new framework named Digital Soil Mapping has introduced quantitative models by statistical techniques to establish soil-landscape relationships and is able to provide intensive scale cartography.

In the present study, a microzoning at 1:10.000 scale is generated from an initial zoning, where the conventional soil map with polytaxic map units is replaced by a new one from digital techniques that disaggregates them. The comparison between the zonings considers a quantitative evaluation of capability for each Homogeneous Terroir Unit by means of the Viticultural Quality Index and its categorization based on its distribution by map. The spatial intersection of both maps gives rise to a confusion matrix in which the flows of class variations after the substitution are assessed.

The results show a five-fold increase in the number of Homogeneous Terroir Units identified and a larger differentiation among them, evidenced by a wider range in the capability index distribution. Both elements are accompanied by an increase in the detection of areas of higher potential within previously undervalued uniform zones.These features are a direct effect of the improvements brought by Digital Soil Mapping techniques and would verify the advantages of their implementation in the Integrated Terroir zoning. Eventually, such new highly detailed terroir units would benefit precision viticulture and sustainable management practices.