Terroir 2004 banner
IVES 9 IVES Conference Series 9 Determination of the maturity status of white grape berries (Vitis vinifera L. cv Chenin) through physical measurements

Determination of the maturity status of white grape berries (Vitis vinifera L. cv Chenin) through physical measurements

Abstract

[English version below]

La véraison, stade intermédiaire du développement de la baie de raisin, correspond au début de la maturation. Aux modifications de coloration de la pellicule sont associées une perte de fermeté, une diminution de l’acidité et une augmentation des teneurs en sucres et pigments ainsi que du volume de la baie. Le stade de véraison des cépages blancs reste difficile à apprécier visuellement. Son évaluation par palpation est subjective et donc sujette à caution. Une méthode non destructive d’analyse de la fermeté des baies (Cabernet franc) a été mise au point dans une précédente étude, utilisant des tests de compression. Cette méthode, qui permet de relier la fermeté à la composition biochimique a été étendue au Chenin. Des baies issues de deux parcelles bien caractérisées au plan des facteurs naturels du milieu (géo-pédologie) et du comportement de la vigne, ont fait l’objet de tests de compression et d’analyses biochimiques au cours de 10 prélèvements successifs couvrant la période 2 semaines avant véraison jusqu’à 2 semaines après véraison. Les résultats montrent que, comme dans le cas du Cabernet franc, le taux de compression à 20% de la hauteur de la baie ainsi que les classes de pression utilisées sont pertinentes. La méthode permet de déterminer avec précision une date de mi-véraison physique, de mettre en évidence le niveau d’hétérogénéité des baies au sein de chaque lot et des différences de précocité entre parcelles. Par ailleurs, une bonne corrélation entre la perte de fermeté des baies et leurs teneurs en sucres et acide malique peut être obtenue dès que le processus de véraison est amorcé. Ces résultats permettent d’envisager le suivi « in situ » de l’évolution de la maturation des baies, de manière dynamique et non destructive.

Veraison represents an intermediate stage in development of grape berries, coinciding with the onset of the maturation process. The change in skin coloration is associated with a loss of firmness, a reduction of acidity and an increase in sugar and pigment contents, as well as berry size. For white berries, veraison is difficult to determine on a visual basis. Its evaluation through finger pressure is too subjective to be used as a routine technique. In a previous work, compression tests realized with Cabernet franc berries allowed to develop a non destructive method to analyse the firmness of the berries in relation with their chemical composition ; this method is now extended to the Chenin variety. Samples of berries were taken from two experimental plots for compression tests and chemical analyses, at ten picking dates, from two weeks before veraison until two weeks after. The plots were chosen according to their geo-pedological characterisation and its consequences on the behaviour of the vine. Results indicated that the compression ratio of 20% of the berry diameter and the pressure classes determined for Cabernet franc were also accurate for Chenin. The method allowed to determine with precision the physical mid-veraison stage (loss of firmness for 50% of the berries) and brought to the fore the level of heterogeneity of berries and the differences between plots in terms of earliness. High correlations between berry firmness and both sugar and malic acid contents were obtained as soon as the veraison process initiated. These results will enable to follow in situ the evolution of the grape berry maturation, on a dynamic non destructive way.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

G. Barbeau, Y. Cadot, F. Neau

INRA, Unité Expérimentale Vigne et Vin, 42, rue Georges Morel, BP 57, 49071 Beaucouzé cedex (France)

Contact the author

Keywords

Vitis vinifera, chenin, terroirs, firmness, heterogeneity, veraison, maturation

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

Assessing the climate change vulnerability of European winegrowing regions by combining exposure, sensitivity and adaptive capacity indicators

Winegrowing regions recognized as protected designations of origin (PDOs) are closely tied to well defined geographic locations with a specific set of pedoclimatic attributes and strictly regulated by legal specifications. However, climate change is increasingly threatening these regions by changing local conditions and altering winegrowing processes. The vulnerability to these changes is largely heterogenous across different winegrowing regions because it is determined by individual characteristics of each region, including the capacity to adapt to new climatic conditions and the sensitivity to climate change, which depend not only on natural, but also socioeconomic and legal factors. Accurate vulnerability assessments therefore need to combine information about adaptive capacity and climate change sensitivity with projected exposure to new climatic conditions. However, most existing studies focus on specific impacts neglecting important interactions between the different factors that determine climate change vulnerability. Here, we present the first comprehensive vulnerability assessment of European wine PDOs that spatially combines multiple indicators of adaptive capacity and climate change sensitivity with high-resolution climate projections. We found that the climate change vulnerability of PDO areas largely depends on the complex interactions between physical and socioeconomic factors. Homogenous topographic conditions and a narrow varietal spectrum increase climate change vulnerability, while the skills and education of farmers, together with a good economic situation, decrease their vulnerability. Assessments of climate change consequences therefore need to consider multiple variables as well as their interrelations to provide a comprehensive understanding of the expected impacts of climate change on European PDOs. Our results provide the first vulnerability assessment for European winegrowing regions at high spatiotemporal resolution that includes multiple factors related to climate exposure, sensitivity, and adaptive capacity on the level of single winegrowing regions. They will therefore help to identify hot spots of climate change vulnerability among European PDOs and efficiently direct adaptation strategies.

INFLUENCE OF CHITOSAN, ABSCISIC ACID AND BENZOTHIADIAZOLE TREATMENTS ON SAVVATIANO (VITIS VINIFERA L.) WINES VOLATILE COMPOSITION PROFILE

In the last decades the use of bioestimulants in viticulture have been promoted as alternative to conven- tional pesticides. Moreover, as bioestimulants promote the biosynthesis of secondary metabolites in grape berries, several studies had investigated their influence on the accumulation of phenolic com- pounds (Monteiro et al., 2022). However, few studies, so far, are focused on the accumulation of the vo- latile compounds and their impact on the produced wines (Giménez-Bañón et al., 2022; Gomez- Plaza et al., 2012; Ruiz Garcia et al., 2014).
This study was conducted in a single vineyard of white autochthonous grapevine variety Savvatia- no (Vitis vinifera L.) in Muses Valley (Askri, Viotia, Greece). Chitosan (CHT), Abscisic Acid (ABA) and Benzothiadiazole (BTH) were applied.

The use of Hanseniaspora vineae on the production of base sparkling wine

Non-Saccharomyces yeasts have been associated, for many years, with challenging alcoholic fermentation processes. However, during the last decade the use of non-Saccharomyces yeasts in wine production has become increasingly widespread due to the advantages they can offer in mixed inoculations with Saccharomyces cerevisiae (Sc). In this respect, Hanseniaspora vineae (Hv), in synergy with Saccharomyces spp, represents an interesting opportunity to impart a positive contribution to the aroma complexity of wines. In fact, it is a well-known producer of pleasant esters, such as 2-phenylethyl acetate. This study compares the performances of Hv (strain Hv-205) in sequential inoculation modality to Sc in three Chardonnay musts for base sparkling wine production. No significant differences were observed in basic chemical parameters between wines except for titratable acidity, with a significantly decrease (up to 1.5 g/L) in Hv processes due to malic acid degradation. The analysis of the aroma compounds revealed remarkable differences in concentration of volatile metabolites, among others up to 37-fold increase of 2-phenylethyl acetate. In contrast, lower concentration of its alcohol were detected, suggesting higher acetylation activity by Hv.

Barrel-to-Barrel Variation of Color and Phenolic Composition in Barrel-Aged Red Wine

Tangible variation of sensory characteristics is often perceived in wine aged in similar barrels. This variation is mostly explained by differences in the wood chemical composition, and in the production of the barrels. Despite these facts, the literature concerning barrel-to-barrel variation and its effect on wine sensory and chemical characteristics is very scarce [1]. In this study, the barrel-to-barrel variation in barrel-aged wines was examined in respect of the most important phenolic compounds of oenological interest and chromatic characteristics, considering both the effects of the (individual) barrel and cooperage. A red wine was aged in 49 new medium-toasted oak (Quercus petraea) barrels, from four cooperages, for 12 months

The colour pattern of flower arrangements influence wine tasters’ sensory description

The arrangements of flowers and wine counterparts are inextricably linked. Whether a fundamental aspect of tablescaping or acolytes to broader entertainment rituals, they have an entangled history since ancient times. The aim of this contribution is to verify the influence of visually delicate and robust flower arrangements on individual description of wines. Changes in the sensory description of wines were investigated during subjects’ (thirty-two participants) exposure to three different conditions: the presence of delicate, robust, or totally absent flower arrangements. In each condition, the same two wines were blind tasted: a wine previously defined as delicate – a Pinot Noir from Australia, and a wine known for its robust character – a Tannat from Uruguay.