GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 To what extent does vine balance actually drive fruit composition?

To what extent does vine balance actually drive fruit composition?

Abstract

Context and purpose of the study ‐ Vine balance is a concept describing the relationship between carbon assimilation (usually estimated using a measure of vine vigour, e.g. pruning weight) and its utilisation for fruit production (usually estimated using harvest yield). Manipulating vine balance through leaf area or crop load adjustments affects the proportion of the vine’s total carbohydrate production required to mature the fruit. It is commonly considered that composition of the berry, and resulting wine, is strongly affected by vine balance.

Material and methods – Field manipulations of vine balance were replicated in three contrasting viticultural regions of Australia, Hilltops, Murray Valley and Langhorne Creek, over three seasons. The manipulations were early defoliation (pre‐capfall), late defoliation (pre‐véraison) and 50% crop removal (pre‐véraison). Fruit were sampled prior to a treatment being applied and then at approximately two‐ week intervals until harvest, where small lot wines were made from each field replicate. The fruit samples were analysed for maturity, basic composition and the expression of key genes that regulate anthocyanin and tannin formation. In addition, the effect of defoliation was simulated, without changing bunch environment, by enclosing whole vines in chambers and supplying them with low CO2 air to reduce photosynthesis.

Results – Changing vine balance consistently altered the rate of ripening, but did not correlate with treatment effects on fruit composition, where they occurred. Late defoliation extended the maturation period, but reduced total anthocyanin content. Crop removal shortened the maturation period, but had little effect on the fruit. Interestingly, early defoliation had no clear effect on vine balance, but resulted in both increased anthocyanin and increased tannin content. The chamber experiment also extended the maturation period, but had no effect on the relationship between sugar and anthocyanins. Overall, there was no conclusive evidence that the changes in vine balance achieved had any significant effect on fruit or wine composition when fruit were harvested at the same sugar ripenesss. 

 

 

DOI:

Publication date: June 19, 2020

Issue: GIESCO 2019

Type: Article

Authors

Everard J. EDWARDS (1), Jason SMITH (2,5), Amanda WALKER (1), Celia BARRIL (2,3), Annette BETTS(1), David FOSTER (2), Julia GOUOT (2), and Bruno HOLZAPFEL (2,4)

(1) CSIRO Agriculture, Locked Bag 2, Glen Osmond, SA 5064, Australia
(2) National Wine and Grape Industry Centre, Wagga Wagga, Australia
(3) School of Agricultural and Wine Sciences, Charles Sturt University Wagga Wagga, Australia
(4) New South Wales Department of Primary Industries, Wagga Wagga, Australia
(5) Current address: Hochschule Geisenheim University, Germany

Contact the author

Keywords

maturation rate, vine balance, Vitis vinifera, wine composition

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Wine tourism as a catalyst for sustainable competitive advantage: unraveling the role of winery image and reputation

This study examines the impact of wine tourism development on the sustainable competitive advantage of Spanish wineries, while also exploring the mediating roles of winery image and winery reputation in this relationship.

The impact of Saccharomyces yeasts on wine varietal aroma, wine aging and wine longevity

The objective of the present work is to assess yeast effects on the development of wine varietal aroma throughout aging and on wine longevity.

Three independent experiments were carried out; two fermenting semi-synthetic musts fortified with polyphenols and aroma precursors extracted from Tempranillo (1) or Albariño (2) grapes and with synthetic precursors of polyfunctional mercaptans (PFMs), and a third in which a must, mixture of 6 different grape varieties was used. In all cases, fermentations were carried out by different Saccharomyces cerevisiae strains and one S. kudriavzevii, and the obtained wines were further submitted to anoxic accelerated aging to reproduce bottle aging. The volatile profile of the wines was analyzed using several chromatographic procedures, in order to provide a comprehensive evaluation of wine aroma. Aroma compounds analyzed included fermentation volatile metabolites, grape-derived aroma compounds including PFMs, and Strecker aldehydes (SA).

Results revealed that the effects of yeast on wine aroma throughout its self-life extend along three main axes:

1. A direct or indirect action on primary varietal aroma and on its evolution during wine
aging.

2. The direct production of SA during fermentation and/or their delayed formation by producing the required reagents (amino acids + dicarbonyls) for Strecker degradation
during anoxic aging.

3. Producing acids (leucidic, branched acids) precursors to fruity esters. More specifically, and leaving aside the infrequent de novo formation, the action of the different strains of yeast on primary varietal aroma takes four different forms:

1.- Speeding the hydrolysis of aroma precursors, which leads to early aroma formation without changing the amount of aroma formed. In the case of labile molecules, such as linalool, the enhancement of young wine aroma implies a short-living wine. 2.- Metabolizing the aroma precursor, reducing the amounts of aroma formed, which can be of advantage for negative aroma compounds, such as TDN or guaiacol; 3.- Transforming grape components into aroma precursors, increasing the amounts of aroma formed, as for ethyl cinnamate, leucidic acid or vinylphenols; 4.- Forming reactive species such as vinylphenols able to destroy varietal polyfunctional mercaptans.

Overall, it can be concluded that the yeast carrying alcoholic fermentation not only influences fermentative wine aroma but also affects to the wine varietal aroma, to its evolution during aging and to the development of oxidative off-odors

From vineyard to bottle. Rationalizing grape compositional drivers of the expression of “Amarone della Valpolicella” terroir

Valpolicella is a famous Italian wine-producing region. One of its main characteristic is the intensive use of grapes that are submitted to post-harvest withering. This is rather unique in the context of red wine, especially for the production of a dry red wine such as Amarone. Amarone wines produced in Valpolicella different geographic origin are anecdotally believed to be aromatically different, although there is no systematic study addressing the chemical bases of such diversity. Aroma is the product of a biochemical and technological series of steps, resulting from the contribution of different volatile molecules deriving from grapes, fermentations, and reactions linked to aging, as well as one of the most important features in the expression of the geographic identity and sensory uniqueness of a wine.

Non-invasive quantification of phenol content during red wine fermentations

Phenolic compounds are responsible for the most important red wine quality attributes. Anthocyanins and tannins play crucial roles in color and mouthfeel properties of red wines. Phenolic analysis in the winery is hindered by analytical constrains.

USING CHECK-ALL-THAT-APPLY (CATA) TO CATEGORIZE WINES: A DECISION-MAKING TOOL FOR WINE SELECTION

Bordeaux is the largest appellation vineyard in France. This contrasting vineyard with varied terroirs offers all styles of wine, resulting from the blending of several grape varieties. If these different profiles make the renown of Bordeaux wines, it can appear as a constraint when the aim is to study Bordeaux wines in their diversity. The selection of a representative sample can be performed by a sensory analysis carried out by trained panelists or by wine professionals, which can take several forms: consensus among experts, conventional descriptive analysis, typicality or quality evaluation. However, because of time, economic, and logistical constraints, these methods have limited applications. As an alternative to classical descriptive analysis, more intuitive methods that do not require training have been proposed recently to describe wines using an expert panel such as Napping, Free Choice or Flash Profiling, CATA or RATA.