terclim by ICS banner
IVES 9 IVES Conference Series 9 EFFECTIVENESS OF APPLIED MATERIALS IN REDUCING THE ABSORPTION OF SMOKE MARKER COMPOUNDS IN A SIMULATED WILDFIRE SCENARIO

EFFECTIVENESS OF APPLIED MATERIALS IN REDUCING THE ABSORPTION OF SMOKE MARKER COMPOUNDS IN A SIMULATED WILDFIRE SCENARIO

Abstract

Smoke taint (ST) is a grape-wine off-flavour that may occur when grapes absorb volatile phenols (VPs) originating from wildfire smoke (1). ST is associated with the negative sensory attributes such as smoky and ashy notes. VPs are glycosylated in the plant and thus present in both free and bound forms (2; 3). Wildfire smoke has resulted in a decline in grape and wine quality and financial losses which has become a prominent issue for the global wine industry. This fact has highlighted the need to develop mitigation strategies to manage the impact of smoke exposure on grapes and the resulting wines (4). Currently there are no recommended mitigation action for grape smoke exposure.
The objective of this experiment was to compare the relative effectiveness of applying different potential protective barrier sprays to grapes in a simulated wildfire scenario. Twelve different material combina-tions were applied close to harvest as potential barrier sprays on three bunches each using four Cabernet Sauvignon vines. The vines were exposed to smoke for two hours three days after the barrier application. Control samples prior to smoke exposure was taken and smoked control (no barrier applied) grapes were sampled at different time points after exposure. For the smoke application a rectangular tent structure was built. The smoke was generated by a wood pellet smoker. Air samples were taken, and atmospheric parameters were monitored during the experiment. Grapes were analysed for free and acid-labile forms of VPs using a GC-MS and for glycosylated forms using UHPLC-qTOF MS.
Results show the presence of smoke and smoke derived compounds, however there was a strong stratifi-cation in the distribution of VPs within the structure. The heterogeneous distribution of smoke is reflected in the different concentrations of uptake of VPs in the grapes. Results from non-treated grapes indicate that glycosylation of the free volatile phenols takes place within hours, with significant increases in almost all glycosylated compounds. However, variation in smoke exposure will affect the glycosylation kinetics of VPs. The study indicated that some sprays exhibited some efficacy in reducing VPs absorption under these conditions. However, other treatments seemed to exacerbate the adsorption of VPs in grapes. In a next step, these barrier sprays will be studied further under field conditions. Acknowledgements: This work has been funded by the USDA-ARS.

 

1. Kennison, K. R., Wilkinson, K. L., Williams, H. G., Smith, J. H., & Gibberd, M. R. (2007). Smoke-derived taint in wine: Effect of postharvest smoke exposure of grapes on the chemical composition and sensory characteristics of wine. Journal of Agricultural and Food Chemistry, 55(26), 10897–10901. https://doi.org/10.1021/jf072509k
2. Caffrey, A., Lerno, L., Rumbaugh, A., Girardello, R., Zweigenbaum, J., Oberholster, A., & Ebeler, S. E. (2019). Changes in Smoke-Taint Volatile-Phenol Glycosides in Wildfire Smoke-Exposed Cabernet Sauvignon Grapes throughout Winemaking. American Journal of Enology and Viticulture, 70(4), 373–381. https://doi.org/10.5344/ajev.2019.19001
3. Hayasaka, Y., Dungey, K. A., Baldock, G. A., Kennison, K. R., & Wilkinson, K. L. (2010). Identification of a beta-D-glucopyranoside precursor to guaiacol in grape juice following grapevine exposure to smoke. Analytica Chimica Acta, 660(1–2), 143–148. https://doi.org/10.1016/j.aca.2009.10.039
4. Mirabelli-Montan, Y. A., Marangon, M., Graça, A., Mayr Marangon, C. M., & Wilkinson, K. L. (2021). Techniques for mitigating the effects of smoke taint while maintaining quality in wine production: A review. Molecules, 26(6), 1–19. https://doi. org/10.3390/molecules26061672

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Article

Authors

Ignacio Arias-Pérez¹, Yan Wen1 and Anita Oberholster¹

1. Department of Viticulture and Enology, University of California Davis, 95616, CA, USA

Contact the author*

Keywords

Smoke taint, Barrier spray, Volatile phenols, Glycosylation

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

NEW TOOL FOR SIMULTANEOUS MEASUREMENT OF OXYGEN CONSUMPTION AND COLOUR MODIFICATIONS IN WINES

Measuring the effect of oxygen consumption on the colour of wines as the level of dissolved oxygen decreases over time is very useful to know how much oxygen a wine is able to consume without significantly altering its colour. The changes produced in wine after being exposed to high oxygen concen-trations have been studied by different authors, but in all cases the wine has been analysed once the oxygen consumption process has been completed. This work presents the results obtained with the use of an equipment designed and made to measure simultaneously the level of dissolved oxygen and the spectrum of the wine, during the oxygen consumption process from saturation levels with air to very low levels, which indicate the total consumption of the dosed oxygen.

THE EFFECT OF PRE-FERMENTATIVE GLYPHOSATE ADDITION ON THE METABOLITE PROFILE OF WINE

The synthetic herbicide glyphosate has been used extensively in viticulture over many decades to combat weeds. Despite this, the possible influence of residual glyphosate on both the alcoholic fermentation of grape juice and the subsequent metabolite profile of wines has not been investigated. In this study, Pinot noir juice supplemented with different concentrations of glyphosate (0 µg L-1, 10 µg L-1 and 1000 µg L-1) was fermented with commercial Saccharomyces cerevisiae yeast strains. Using a combination of analytical methods, 80 metabolites were quantified in the resulting wines.

PINKING PHENOMENA ON WHITE WINES: RELATION BETWEEN PINKING SUSCEPTIBILITY INDEX (PSI) AND WINE ANTHOCYANINS CONTENT

Pinking is the emergence of pink tones in white wines exclusively produced from white grape varieties, known as pinking phenomena for many years. Pinking is essentially appeared when white wines are produced under reducing conditions [1,2,3]. Pinking usually occurs after bottling and storage of white wines, but its appearance has also been described after alcoholic fermentation or even as soon as the grape must is extracted [4]. Therefore, the purpose of this work was to investigate the existence of an-thocyanins in white wines made from different white grape varieties and grown locations and critically evaluate the most common method used for predicting pinking appearance in white wines: the Pinking Susceptibility Index (PSI).

NEW INSIGHTS INTO VOLATILE SULPHUR COMPOUNDS SCALPING ON MICROAGGLOMERATED WINE CLOSURES

The evolution of wine during bottle ageing has been of great interest to ensure consistent quality over time. While the role of wine closures on the amount of oxygen is well-known [1], closures could also play other roles such as the scalping phenomenon of flavour compounds. Flavour scalping has been described as the sorption of flavour compounds by the packaging material, which could result in losses of flavour intensity. It has been reported in the literature that volatile sulphur compounds (VSC) can be scalped on wine closures depending on the type of closure (traditional and agglomerated cork, screw-cap, synthetic [2]).

CONSENSUS AND SENSORY DOMINANCE ARE DEPENDENT ON QUALITY CONCEPT DEFINITIONS

The definition of the term “quality” in sensory evaluation of food products does not seem to be consensual. Descriptive or liking methods are generally used to differentiate between wines (Lawless et al., 1997). Nevertheless, quality evaluation of a product such as wine can also relate to emotional aspects. As exposed by Costell (2002), product quality is defined as an integrated impression, like acceptability, pleasure, or emotional experiences during tasting. According to the ‘modality appropriateness’ hypothesis which predicts that wine tasters weigh the most suitable sensory inputs for a specific assess- ment (Freides, 1974; Welch & Warren, 1980), the nature of the quality definitions may modulate sensory influences.