 IVES 9 IVES Conference Series 9 Impact of the pre-fermentative addition of enological adjuvants on the development of UTA in wines

Impact of the pre-fermentative addition of enological adjuvants on the development of UTA in wines

Abstract

AIM: During alcoholic fermentation and wine aging, indole-3-acetic acid (IAA) can degrade into 2-aminoacetophenone (AAP). The presence of reasonable amount of AAP in wines is regarded as the main cause of untypical ageing defect (UTA) described by aroma descriptors such as “acacia blossom”, “furniture polish”, “wet wool”, “mothball”, or “fusel alcohol” [1, 2]. This study aims to evaluate the effectiveness of different oenological adjuvants (ascorbic acid, glutathione, ellagic tannin, gallotannin and grape tannin) added to must in pre-fermentation for preventing the possible development of UTA. In addition, a high-resolution suspect-screening approach was performed to evaluate the kinetics of formation and consumption of metabolites formed during the oxidative degradation of IAA into AAP.

METHODS: Johannitter, Pinot Blank, Pinot Gris and Riesling musts were separately added with each of the 5 adjuvants (GrT, EgT, GaT, ASC and GSH), fermented and finally added of sulfur dioxide. The free and conjugated IAA forms were qualified or quantified in wine at the end of the fermentation and the AAP was finally quantified after a period of forced ageing (6 days at 40 °C). Quantification was performed using a HPLC coupled with a high-resolution mass spectrometer (UHPLC-HQOMS) using a biphenyl column (3×150 mm, 2.7 µm) with formic acid 2% and acetonitrile as eluents [3]. The quantification limits ranged from 0.25 to 2 μg/L, excepted for AAP that had a quantification limit of 0.02 μg/L. For qualitative analyses, homemade standards of indole-acetic acid-2-sulfonate (IAA-SO3H) and of metabolites produced by oxidative chemical reaction of IAA to AAP (radical cation, FAP, FAPOP and Ox-IAA) were prepared. The IAA-hexoside RT was studied with a full mass/all ion fragmentation/NL data dependent-MS2 (Full MS/AIF/NL dd-MS2) experiment in positive ion mode [4].

RESULTS: Ascorbic acid has been confirmed as the most appropriate antioxidant adjuvant which can be used for UTA defect prevention. With an almost comparable effect, gallotannin also did not show AAP productions greater than 1 µg/L. Over 80% of the variability of potential AAP formation in wines was explained by an ANCOVA model, which was used to predict the possible AAP production considering the varieties, treatments and IAA content in young wine as known variables.

CONCLUSIONS

Thanks to high resolution mass spectrometry, we were able to qualify and quantify different precursors and metabolites that take part in the development of UTA, allowing a better understanding of the mechanisms of AAP formation and the adjuvants actions involved in the wine protection.

DOI:

Publication date: September 14, 2021

Issue: Macrowine 2021

Type: Article

Authors

Tiziana Nardin

Technology Transfer Centre, Fondazione Edmund Mach, San Michele all’Adige, Italy,Tomas Roman, Susanne Dekker, Roberto Larcher Technology Transfer Centre, Fondazione Edmund Mach, San Michele all’Adige, Italy

Contact the author

Keywords

uta, AAP, HRMS

Citation

Great highlands wine growing terroir: conditions and expressions

During 1982 started our wine growing project at the Puntalarga Hill, between 2500 and 2600 meters a.s.l.: 5.78 ºN, 72.98 ºW. Pinot noir, white Riesling and Riesling x Silvaner crossings are the most planted grapevines. Since 1984 research and development activities are carried out on pertinent subjects.

Aromatic maturity is a cornerstone of terroir expression in red wine

In this video recording of the IVES science meeting 2023, Stéphanie Marchand (University of Bordeaux, ISVV, INRAE, UMR 1366 OENOLOGIE, Villenave d’Ornon, France) speaks about the aromatic maturity as a cornerstone of terroir expression in red wine. This presentation is based on an original article accessible for free on OENO One.

From vine to wine : a multi-trait experiment for increasing the varietal diversity in the bordeaux wine region. How to adapt to climate change without damaging terroir expression?

Context and purpose of the study climate change is impacting wine typicity across the globe, raising concerns in wine regions historically renowned for the quality of their terroir. Replacing some of the plant material can be an efficient lever for adapting to climate change. However, the change of cultivars also raises questions about the region’s wine typicity. This study, based on seven years of data, investigates the potential adaptability of over 50 different varieties in the bordeaux wine region.

Evolution of the metabolic profile of grapes in a context of climate change

In the current context of global climate change, anticipating the evolution of the oenological potential of emblematic grape varieties of regions such as Burgundy and Champagne is a guarantee of the sustainability of a sector which has considerable economic weight. however, if various models of climate change cast doubt on the sustainability of these grape varieties in these regions, appellation decrees, as well as consumer expectations, do not allow or consider the use of alternative grape varieties. In addition, control/compensation methods such as irrigation are also not permitted.

On the losses of dissolved CO2 during champagne aging

A misconception lingers in the minds of some wine consumers that Champagne wines don’t age. It’s largely a myth, certainly as far as the best cuvees are concerned. Actually, during the so-called autolysis period of time (in the closed bottle, after the “prise de mousse”), complex chemical reactions take place when the wine remains in contact with the dead yeast cells, which progressively bring complex and very much sought-after aromas to champagne. Nevertheless, despite their remarkable impermeability to liquid and air, caps or natural cork stoppers used to cork the bottles are not 100% hermetic with regard to gas transfers. Gas species therefore very slowly diffuse through the cap or cork stopper, along their respective inverse partial pressure. After the “prise de mousse”, because the partial pressure of CO2 in the bottleneck reaches up to 6 bars (at 12 °C), gaseous CO2 progressively diffuse from the bottle to the ambient air
(where the partial pressure of gaseous CO2 is only of order of 0,0004 bar).