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.

HOW TO EVALUATE THE QUALITY OF NATURAL WINES?

The movement of Natural wines has clearly increased in the last few years, to reach a high demand from consumers nowadays. Switzerland has not been left out of this movement and has created a dedicated association in 2021. This association has the ambition to develop a specific tasting sheet for natural wines. The study of the tasting notes shows that the olfactory description of wines is recent but predominant today. But wine is a product makes to be drunk and not (just) to smell it. Based on these findings, a new 100-point tasting sheet has been developed. The main characteristics are 1) an evaluation in the mouth before the description of the olfaction, 2) to give 50% of the points on the judgment for the mouth characteristics, 3) to pejorate the visual aspects only if the wine is judged as “not drinkable” and 4) to express personal emotions.

DO MICROPLASTICS IN VINEYARD SOIL AFFECT THE BIOAVAILABILITY OF VINE NUTRITION?

Microplastics can alter physicochemical and biogeochemical processes in the soil, but whether these changes have further effects on soil fertility, and if so, whether these effects vary depending on the type of soil in the vineyard and the type of plastic used in the vineyard. Knowing what types of plastics are currently used in vineyards in Slovenian viticultural regions as strings to tie vines to the stake, the aim of our study was to assess the effects of microplastic particles from polypropylene (PP) and polyvinyl chloride (PVC) on the availability of macro (potassium (K), Potassium (K), calcium (Ca), magnesium (Mg) and phosphate (P)) and micronutrients (iron (Fe), copper (Cu), manganese (Mn) and zinc (Zn)) in two vineyard soils contrasting in pH and mineralogy. For this purpose, a short-term soil incubation experiment (120 days) was carried out in which the soil samples were enriched with micro-PP and micro-PVC particles. After the incubation period, macro- and micronutrient availability were measured.

RED WINE AGING WITHOUT SO₂: WHAT IMPACT ON MICROBIAL COMMUNITY?

Nowadays, the use of food preservatives is controversial, SO2 being no exception. Microbial communities have been particularly studied during the prefermentary and fermentation stages in a context of without added SO2. However, microbial risks associated with SO2 reduction or absence, particularly during the wine aging process, have so far been little studied. The microbiological control of wine aging is a key issue for winemakers wishing to produce wines without added SO2. The aim of the present study is to evaluate the impact of different wine aging strategies according to the addition or not of SO2 on the microbiological population levels and diversity.

PROFILING OF LIPIDS IN WINES FROM MONOCULTURE FERMENTATION WITH INDIGENOUS METSCHNIKOWIA YEAST SPECIES

Lipids are a diverse group of organic compounds essential for living systems. They are vital compounds for yeast which makes them an important modulator of yeast metabolism in alcoholic fermentation. This study presents a comprehensive lipidome analysis of wine samples from the Vitis vinifera L., Maraština. The fermentation trails were set up in monoculture with different indigenous yeast strains selected from a collection of native yeasts established at the Institute for Adriatic Crops and Karst Reclamation in 2021, previously isolated from Croatian Maraština grapes: Metschnikowia pulcherrima, Metshnikowia sinensis/shanxiensis , and Metschnikowia chyrsoperlae.