terclim by ICS banner
IVES 9 IVES Conference Series 9 ANTI-TRANSPIRANT MODULATION OF GRAPE RIPENING: EFFECTS ON MERLOT VINE DEVELOPMENT AND ROSÉ WINE PHENOLIC AND AROMATIC PROFILES

ANTI-TRANSPIRANT MODULATION OF GRAPE RIPENING: EFFECTS ON MERLOT VINE DEVELOPMENT AND ROSÉ WINE PHENOLIC AND AROMATIC PROFILES

Abstract

Climate changes are impacting viticultural regions throughout the world with temperature increases being most prevalent.1 These changes will not only impact the regions capable of growing grapes, but also the grapes that can be grown.2 As temperatures rise the growing degree days increase and with it the sugar accumulation within the berries and subsequent alcohol levels in wine. Consequently, viticultural practices need to be examined to decrease the levels of sugars. Anti-transpirants have been used to some degree of success, however their benefits may be linked to the varietal and style of wine produced.3 With this in mind we undertook a study of anti-transpirant application to merlot grapes to determine its effectiveness for reducing alcohol in Rosé wines.

The trial was performed in a commercial vineyard in the Hawke’s Bay region of New Zealand. The vines were two cane pruned and the vineyard was managed under conventional practices. The trial was setup as a randomized block design with five vines per block. Anti-transpirant was applied using a backpack sprayer to upper portion of the canopy to the point of run off at véraison. The berries were then harvested by hand at 18 °Brix and wine making using a standardized wine making protocol at the research winery.

The harvest dates were delayed between the treated and untreated vines. The treated wines were found to have a higher pH, lower titratable acidity, and increased total phenolics. The aroma compound analysis resulted in several significant differences that were noted in the sensory evaluation. In both vintages the control wines were found to be influenced by green, vegetal, and earthy notes while the treated wines were found to be influenced by fruit aromas. These sensory attributes were confirmed by examining the aromatic compounds by PCA. This resulted in the controls being influenced by methoxypyrazines and alcohols and a few esters, compared to treated wines which were influenced by esters and terpenoids.

In conclusion, we were able to show that the application of anti-transpirant was able to dissociate the ripening process of Merlot grapes. Its application decreased sugar production but allowed for aromatic compound production. This demonstrates the potential effectiveness for anti-transpirants to control sugar in grape production to mitigate increased temperatures. These results indicate that further research is necessary to optimize the application timing of the anti-transpirant.

 

1. Van Leeuwen, C. D.-I., A.; Dubernet, M.; Duchêne, E.; Gowdy, M.; Marguerit, E.; Pieri, P.; Parker, A.; de Rességuier, L.; Ollat, N. (2019). An Update on the Impact of Climate Change in Viticulture and Potential Adaptations. Agronomy, 9, 514
2. Parker, A. K., García de Cortázar-Atauri, I., Gény, L., Spring, J.-L., Destrac, A., Schultz, H., Molitor, D., Lacombe, T., Graça, A., Monamy, C., Stoll, M., Storchi, P., Trought, M. C. T., Hofmann, R. W., & van Leeuwen, C. (2020). Temperature-based grape-vine sugar ripeness modelling for a wide range of Vitis vinifera L. cultivars. Agricultural and Forest Meteorology, 285-286, 107902.
3. Di Vaio, C., Marallo, N., Di Lorenzo, R., & Pisciotta, A. (2019). Anti-Transpirant Effects on Vine Physiology, Berry and Wine Composition of cv. Aglianico (Vitis vinifera L.) Grown in South Italy. Agronomy, 9(5), 244.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Article

Authors

Kenneth Olejar1, Petra King2, Carmo Vasconcelos3, Elise Montgomery4, Karen Ball5, Stewart Field6

1 Appalchian State University, Department of Chemistry and Fermentation Sciences, Boone, NC, USA
2 Easten Institute of Technology, Department of Viticulture and Wine, Taradale, New Zealand
3 Bragato Research Institute, Blenheim, New Zealand
4 New Zealand Institute of Skills and Technology, Department of Viticulture and Wine, Taradale, New Zealand
5 Easten Institute of Technology, Department of Viticulture and Wine, Taradale, New Zealand
6 New Zealand Institute of Skills and Technology, Department of Viticulture and Wine, Blenheim, New Zealand

Contact the author*

Keywords

dissociatedripenin, glow-alcohol wine, wine sensory, wine aroma

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

WINE SWIRLING: A FIRST STEP TOWARDS THE UNLOCKING OF THE WINE’STASTER GESTURE

Right after the pouring of wine in a glass, a myriad of volatile organic compounds, including ethanol, overwhelm the glass headspace, thus causing the so-called wine’s bouquet [1]. Otherwise, it is worth noting that during wine tasting, most people automatically swirl their glass to enhance the release of aromas in the glass headspace [1]. About a decade ago, Swiss researchers revealed the complex fluid mechanics underlying wine swirling [2]. However, despite mechanically repeated throughout wine tasting, the consequences of glass swirling on the chemical space found in the headspace of wine glasses are still barely known.
Read More

THE IMPACT OF NON-SACCHAROMYCES YEASTS ON THE WHITE WINE QUALITY

Selected strains of non-Saccharomyces yeasts showed a positive effect on sensory characteristics and aromatic complexity of wine. A sequential microbial culture of non-Saccharomyces and S. cerevisiae species is usually inoculated due to poorer fermentability of non-Saccharomyces species. The aim of the study was to investigate the role of non-Saccharomyces yeasts in the production of white wines. We evaluated how individual combinations of sequential inoculations of non-Saccharomyces and S. cerevisiae species affect the aromatic compounds (volatile thiols and esters) and sensory characteristics of the wines.

Read More

PHENOTYPIC DIVERSITY AND BIO-PROTECTION CAPABILITY OF METSCHNIKOWIA SP. IN OENOLOGY

Nowadays, the trend is to reduce the use of chemical inputs in the food sector, including in oenology. One of the inputs widely used in the wine making process are sulfites, for its several properties: antimicrobial and antioxidiant. This use isn’t without consequences on consumer’s health and environment, it can lead for example to allergic reactions and pollution. To limit the addition of chemical inputs, microbial alternatives are used. It consists to inoculate in grape must, a micro-organism able to inhibit the growth of the negative indigenous flora during the phase before the fermentation and to guarantee the sensory qualities of wines.

Read More

WHICH IMPACT FOR PROANTHOCYANIDIC TANNINS ON RED WINE FRUITY AROMA? SENSORY AND PHYSICOCHEMICAL APPROACHES

Previous research on the fruity character of red wines highlighted the role of esters. Literature provides evidence that, besides these esters, other compounds that are not necessarily volatiles may have an important impact on the overall aroma of wine, contributing to a modulation of its global aromatic expression. The goal of this work was to assess the olfactory consequences of a mixture between esters and proanthocyanidic tannins, through sensory and physico-chemical approaches.
Sensory analysis of numerous aromatic reconstitutions, including triangular tests, detection thresholds, and sensory profiles, were conducted in order to evaluate the sensory impact of tannins on red wine esters perception.

Read More

WINE FERMENTATION METABOLITES PRODUCED BY TWO TORULASPORA DELBRUECKII STRAINS ISOLATED FROM OKANAGAN VALLEY, BC, CANADA VINEYARDS

Wine aroma is influenced by various factors, from agricultural practices in the vineyard to the enological choices made by winemakers throughout the vinification process. Spontaneous fermentations have a characteristically deeper complexity of aromas when compared to fermentations that have been inoculated with Saccharomyces (S.) cerevisiae because of the diversity of microflora naturally present on grape skins. Non-Saccharomyces yeast are being extensively studied for their ability to positively contribute to wine aroma and flavour. These yeasts are known to liberate more bound volatile compounds present in grape must than S. cerevisiae through the enzymatic action of β-glucosidases and β-lyases1.

Read More