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…

WHAT’S FUTURE FOR SANTORINI’S VITICULTURE IN THE CONTEXT OF CLIMATE CHANGE

The own-rooted vineyard of Santorini is a unique case of vineyard worldwide that is been cultivated for thousands of years. On the island’s volcanic soil, the vines are still cultivated with traditional techniques, which are adapted to the specific and extreme weather conditions that prevail on it. While climate change is a reality in the Mediterranean region, will Santorini vineyard endure its impact? The study of the traditional training systems, techniques and vine density, as well as the application of sustainable solutions (cover crops and use of kaolin etc.) revealed sustainable methods for the adaptation of the local viticulture to new climatic phenomena that tend to be more and more frequent in the region due to climate change.

Read More

EFFECT OF DIFFERENT VITICULTURAL AND ENOLOGICAL PRACTICES ON THE PHENOLIC COMPOSITION OF RED WINES

Global climate change is exerting a notable influence on viticulture sector and grape composition. The increase in temperature and the changes in rainfall pattern are causing a gap between phenolic and technological grape maturities [1]. As a result, the composition of grapes at harvest time and, consequently, that of wines are being affected, especially with regards to phenolic composition. Hence, wine quality is decreasing due to changes in the organoleptic properties, such as color and astringency, making necessary to implement new adaptive technologies in wineries to modulate these properties in order to improve wine quality.

Read More

UNRAVELING THE CHEMICAL MECHANISM OF MND FORMATION IN RED WINE DURING BOTTLE AGING : IDENTIFICATION OF A NEW GLUCOSYLATED HYDROXYKETONE PRO-PRECURSOR

During bottle aging, the development of wine aroma through low and gradual oxygen exposure is often positive in red wines, but can be unfavorable in many cases, resulting in a rapid loss of fresh, fruity flavors. Prematurely aged wines are marked by intense prune and fig aromatic nuances that dominate the desirable bouquet achieved through aging (Pons et al., 2013). This aromatic defect, in part, is caused by the presence of 3-methyl-2,4-nonanedione (MND). MND content was shown to be lower in nonoxidized red wines and higher in oxidized red wines, which systematically exceeds the odor detection threshold (62 ng/L).

Read More

INVESTIGATION OF FILM COATINGS AS A PROTECTIVE LAYER IN REDUCING THE ABSORPTION OF SMOKE PHENOLS INTO PINOT NOIR GRAPES

Wine grapes exposed to wildfire smoke have resulted in wines with burnt and ashy sensory characteristics¹, that are undesirable qualities in wine. In extreme wildfire events, this can lead to total loss of grape crop. Currently there are no effective solutions in the market to prevent the uptake of smoke compounds into grapes. In this study, previously developed innovative film coatings were tested to analyze their effectiveness in reducing smoke phenol absorption². Four different cellulose nanofiber-based film types were investigated.

Read More

INOCULATION OF THE SELECTED METSCHNIKOWIA PULCHERRIMA MP1 AS A BIOPROTECTIVE ALTERNATIVE TO SULFITES TO PREVENT BROWNING OF WHITE GRAPE MUST

Enzymatic browning (BE) of must is caused by polyphenol oxidases (PPOs), tyrosinase and laccase. Both PPOs can oxidize diphenols such as hydroxycinnamic acids (HA) to quinones, which can later polymerize to form melanins [1], which are responsible of BE in white wines and of oxidasic haze in red wines. SO₂ is the main tool used to protect must from BE thanks to its capacity to inhibit PPOs [2]. However, the current trend in winemaking is to reduce and even eliminate this unfriendly additive. Among the different possible alternatives for protecting must against BE, the inoculation with a selected Metschnikowia pulcherrima MP1 is without any doubt one of the most promising ones.

Read More