Review of smoke taint in wine: smoke-derived volatile phenols and their glycosidic metabolites in grapes and vines as biomarkers for smoke exposure and their role in the sensory perception of smoke taint

2015 ◽  
Vol 21 ◽  
pp. 537-553 ◽  
Author(s):  
M.P. Krstic ◽  
D.L. Johnson ◽  
M.J. Herderich
Keyword(s):  
Sensory Perception ◽  
Smoke Exposure ◽  
Volatile Phenols

scholarly journals Potential Mitigation of Smoke Taint in Wines by Post-Harvest Ozone Treatment of Grapes

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1798
Author(s):  
Margherita Modesti ◽  
Colleen Szeto ◽  
Renata Ristic ◽  
WenWen Jiang ◽  
Julie Culbert ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Sensory Perception ◽  
Smoke Exposure ◽  
Ozone Treatment ◽  
Volatile Phenols ◽  
Post Harvest ◽  
Gaseous Ozone ◽  
Volatile Phenol ◽  
Marker Compounds ◽  
Phenol Glycoside

When bushfires occur near grape growing regions, vineyards can be exposed to smoke, and depending on the timing and duration of grapevine smoke exposure, fruit can become tainted. Smoke-derived volatile compounds, including volatile phenols, can impart unpleasant smoky, ashy characters to wines made from smoke-affected grapes, leading to substantial revenue losses where wines are perceivably tainted. This study investigated the potential for post-harvest ozone treatment of smoke-affected grapes to mitigate the intensity of smoke taint in wine. Merlot grapevines were exposed to smoke at ~7 days post-veraison and at harvest grapes were treated with 1 or 3 ppm of gaseous ozone (for 24 or 12 h, respectively), prior to winemaking. The concentrations of smoke taint marker compounds (i.e., free and glycosylated volatile phenols) were measured in grapes and wines to determine to what extent ozonation could mitigate the effects of grapevine exposure to smoke. The 24 h 1 ppm ozone treatment not only gave significantly lower volatile phenol and volatile phenol glycoside concentrations but also diminished the sensory perception of smoke taint in wine. Post-harvest smoke and ozone treatment of grapes suggests that ozone works more effectively when smoke-derived volatile phenols are in their free (aglycone) form, rather than glycosylated forms. Nevertheless, the collective results demonstrate the efficacy of post-harvest ozone treatment as a strategy for mitigation of smoke taint in wine.

scholarly journals A review of the techniques for mitigating the effects of smoke taint in wine production

2021 ◽  
Author(s):  
Ysadora A. Mirabelli-Montan ◽  
Matteo Marangon ◽  
Antonio Graça ◽  
Christine M. Mayr Marangon ◽  
Kerry L. Wilkinson
Keyword(s):  
Climate Change ◽  
Fermentation Process ◽  
Smoke Exposure ◽  
Wine Industry ◽  
Negative Effects ◽  
Volatile Phenols ◽  
Wine Production ◽  
The World ◽  
Single Method ◽  
Negative Impacts

Smoke taint has become a prominent issue for the global wine industry as climate change continues to impact the length and extremity of fire seasons around the world. When grapevines are exposed to smoke, their leaves and fruit can adsorb volatile smoke compounds (for example, volatile phenols such as guaiacol, 4-methylguaiacol, o-, m- and p-cresol, and syringol), which can initially be detected in free (aglycone) forms but are rapidly converted to glycoconjugate forms due to glycosylation. During the fermentation process, these glycoconjugates can be broken down, releasing volatile phenols that contribute undesirable sensory characteristics to the resultant wine (i.e. smokey and ashy attributes). Several methods have been evaluated, both viticultural measures and winemaking techniques, for mitigating and/or remediating the negative effects of grapevine smoke exposure. While there is currently no single method that universally solves the problem of smoke taint, this paper outlines the tools available that can help to minimize the negative impacts of smoke taint (Figure 1).

scholarly journals Compositional Changes in Grapes and Leaves as a Consequence of Smoke Exposure of Vineyards from Multiple Bushfires across a Ripening Season

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3187
Author(s):  
WenWen Jiang ◽  
Mango Parker ◽  
Yoji Hayasaka ◽  
Con Simos ◽  
Markus Herderich
Keyword(s):  
Economic Impacts ◽  
Smoke Exposure ◽  
Phenolic Glycosides ◽  
Negative Effects ◽  
Volatile Phenols ◽  
Berry Ripening ◽  
Compositional Changes ◽  
The Impact

The negative effects of smoke exposure of grapes in vineyards that are close to harvest are well documented. Volatile phenols in smoke from forest and grass fires can contaminate berries and, upon uptake, are readily converted into a range of glycosylated grape metabolites. These phenolic glycosides and corresponding volatile phenols are extracted into the must and carried through the winemaking process, leading to wines with overtly smoky aromas and flavours. As a result, smoke exposure of grapes can cause significant quality defects in wine, and may render grapes and wine unfit for sale, with substantial negative economic impacts. Until now, however, very little has been known about the impact on grape composition of smoke exposure very early in the season, when grapes are small, hard and green, as occurred with many fires in the 2019–20 Australian grapegrowing season. This research summarises the compositional consequences of cumulative bushfire smoke exposure of grapes and leaves, it establishes detailed profiles of volatile phenols and phenolic glycosides in samples from six commercial Chardonnay and Shiraz blocks throughout berry ripening and examines the observed effects in the context of vineyard location and timing of smoke exposure. In addition, we demonstrate the potential of some phenolic glycosides in leaves to serve as additional biomarkers for smoke exposure of vineyards.

scholarly journals Evaluating the Potential for Smoke from Stubble Burning to Taint Grapes and Wine

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7540
Author(s):  
Kerry Wilkinson ◽  
Renata Ristic ◽  
Imogen McNamara ◽  
Beth Loveys ◽  
WenWen Jiang ◽  
...  
Keyword(s):  
Smoke Exposure ◽  
Barley Straw ◽  
Low Density ◽  
Chemical Markers ◽  
Sensory Panel ◽  
Volatile Phenols ◽  
Wildfire Smoke ◽  
Sensory Evidence ◽  
Low Levels ◽  
Stubble Burning

It has been well established that bushfire/wildfire smoke can taint grapes (and therefore wine), depending on the timing and duration of exposure, but the risk of smoke contamination from stubble burning (a practice employed by some grain growers to prepare farmland for sowing) has not yet been established. This study exposed excised bunches of grapes to smoke from combustion of barley straw and pea stubble windrows to investigate the potential for stubble burning to elicit smoke taint. Increased levels of volatile phenols (i.e., chemical markers of smoke taint) were detected in grapes exposed to barley straw smoke (relative to control grapes), with smoke density and the duration of smoke exposure influencing grape volatile phenols. However, the sensory panel did not perceive wine made from grapes exposed to low-density smoke to be tainted, despite the presence of low levels of syringol providing compositional evidence of smoke exposure. During the pea stubble burn, grapes positioned amongst the burning windrows or on the edge of the pea paddock were exposed to smoke for ~15–20 and 30–45 min, respectively, but this only resulted in 1 µg/kg differences in the cresol and/or syringol concentrations of smoke-affected grapes (and 1 µg/L differences for wine), relative to controls. A small, but significant increase in the intensity of smoke aroma and burnt rubber flavor of wine made from the grapes positioned amongst the burning pea stubble windrows provided the only sensory evidence of any smoke taint. As such, had vineyards been located immediately downwind from the pea stubble burn, it is unlikely that there would have been any smoke contamination of unharvested grapes.

scholarly journals Uptake and Glycosylation of Smoke-Derived Volatile Phenols by Cabernet Sauvignon Grapes and Their Subsequent Fate during Winemaking

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3720 ◽  
Author(s):  
Colleen Szeto ◽  
Renata Ristic ◽  
Dimitra Capone ◽  
Carolyn Puglisi ◽  
Vinay Pagay ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Compositional Analysis ◽  
Sprinkler System ◽  
Smoke Exposure ◽  
Cabernet Sauvignon ◽  
Significant Delay ◽  
Volatile Phenols ◽  
Volatile Phenol ◽  
Marker Compounds ◽  
Glycosylation Pathway

Wine made from grapes exposed to bushfire smoke can exhibit unpleasant smoky, ashy characters, which have been attributed to the presence of smoke-derived volatile phenols, in free or glycosylated forms. Here we report the uptake and glycosylation of volatile phenols by grapes following exposure of Cabernet Sauvignon vines to smoke, and their fate during winemaking. A significant delay was observed in the conversion of volatile phenols to their corresponding glycoconjugates, which suggests sequestration, the presence of intermediates within the glycosylation pathway and/or other volatile phenol storage forms. This finding has implications for industry in terms of detecting smoke-affected grapes following vineyard smoke exposure. The potential for an in-canopy sprinkler system to mitigate the uptake of smoke-derived volatile phenols by grapes, by spraying grapevines with water during smoke exposure, was also evaluated. While “misting” appeared to partially mitigate the uptake of volatile phenols by grapes during grapevine exposure to smoke, it did not readily influence the concentration of volatile phenols or the sensory perception of smoke taint in wine. Commercial sensors were used to monitor the concentration of smoke particulate matter (PM) during grapevine exposure to low and high density smoke. Similar PM profiles were observed, irrespective of smoke density, such that PM concentrations did not reflect the extent of smoke exposure by grapes or risk of taint in wine. The sensors could nevertheless be used to monitor the presence of smoke in vineyards during bushfires, and hence, the need for compositional analysis of grapes to quantify smoke taint marker compounds.

scholarly journals Detection of smoke-derived compounds from bushfires in Cabernet-Sauvignon grapes, must, and wine using Near-Infrared spectroscopy and machine learning algorithms

OENO One ◽  
2020 ◽  
Vol 54 (4) ◽  
pp. 1105-1119
Author(s):  
Vasiliki Summerson ◽  
Claudia Gonzalez Viejo ◽  
Damir D. Torrico ◽  
Alexis Pang ◽  
Sigfredo Fuentes
Keyword(s):  
Near Infrared ◽  
Smoke Exposure ◽  
High Density ◽  
Machine Learning Algorithms ◽  
Exposure Model ◽  
Volatile Phenols ◽  
Ann Models ◽  
Artificial Neural Network Ann ◽  
Harvest Model ◽  
Absorbance Spectra

The number and intensity of wildfires are increasing worldwide, thereby raising the risk of smoke contamination of grapevine berries and the development of smoke taint in wine. This study aimed to develop five artificial neural network (ANN) models from berry, must, and wine samples obtained from grapevines exposed to different levels of smoke: (i) Control (C), i.e., no misting or smoke exposure; (ii) Control with misting (CM), i.e., in-canopy misting, but no smoke exposure; (iii) low-density smoke treatment (LS); (iv) high-density smoke treatment (HS) and (v) a high-density smoke treatment with misting (HSM). Models 1, 2, and 3 were developed using the absorbance values of near-infrared (NIR) berry spectra taken one day after smoke exposure to predict levels of 10 volatile phenols (VP) and 18 glycoconjugates in grapes at either one day after smoke exposure (Model 1: R = 0.98; R2 = 0.97; b = 1) or at harvest (Model 2: R = 0.98; R2 = 0.97; b = 0.97), as well as six VP and 17 glycoconjugates in the final wine (Model 3: R = 0.98; R2 = 0.95; b = 0.99). Models 4 and 5 were developed to predict the levels of six VP and 17 glycoconjugates in wine. Model 4 used must NIR absorbance spectra as inputs (R = 0.99; R2 = 0.99; b = 1.00), while Model 5 used wine NIR absorbance spectra (R = 0.99; R2 = 0.97; b = 0.97). All five models displayed high accuracies and could be used by grape growers and winemakers to non-destructively assess at near real-time the levels of smoke-related compounds in grapes and/or wine in order to make timely decisions about grape harvest and smoke taint mitigation techniques in the winemaking process.

scholarly journals Assessment of Smoke Contamination in Grapevine Berries and Taint in Wines Due to Bushfires Using a Low-Cost E-Nose and an Artificial Intelligence Approach

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5108 ◽  
Author(s):  
Sigfredo Fuentes ◽  
Vasiliki Summerson ◽  
Claudia Gonzalez Viejo ◽  
Eden Tongson ◽  
Nir Lipovetzky ◽  
...  
Keyword(s):  
Low Cost ◽  
Field Trials ◽  
Smoke Exposure ◽  
High Density ◽  
Machine Learning Algorithms ◽  
Classification Model ◽  
Test Model ◽  
Volatile Phenols ◽  
Experimental Treatments ◽  
Harvest Model

Bushfires are increasing in number and intensity due to climate change. A newly developed low-cost electronic nose (e-nose) was tested on wines made from grapevines exposed to smoke in field trials. E-nose readings were obtained from wines from five experimental treatments: (i) low-density smoke exposure (LS), (ii) high-density smoke exposure (HS), (iii) high-density smoke exposure with in-canopy misting (HSM), and two controls: (iv) control (C; no smoke treatment) and (v) control with in-canopy misting (CM; no smoke treatment). These e-nose readings were used as inputs for machine learning algorithms to obtain a classification model, with treatments as targets and seven neurons, with 97% accuracy in the classification of 300 samples into treatments as targets (Model 1). Models 2 to 4 used 10 neurons, with 20 glycoconjugates and 10 volatile phenols as targets, measured: in berries one hour after smoke (Model 2; R = 0.98; R2 = 0.95; b = 0.97); in berries at harvest (Model 3; R = 0.99; R2 = 0.97; b = 0.96); in wines (Model 4; R = 0.99; R2 = 0.98; b = 0.98). Model 5 was based on the intensity of 12 wine descriptors determined via a consumer sensory test (Model 5; R = 0.98; R2 = 0.96; b = 0.97). These models could be used by winemakers to assess near real-time smoke contamination levels and to implement amelioration strategies to minimize smoke taint in wines following bushfires.

scholarly journals Altering social cue perception impacts honey bee aggression with minimal impacts on aggression-related brain gene expression

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
James W. Harrison ◽  
Joseph H. Palmer ◽  
Clare C. Rittschof
Keyword(s):  
Gene Expression ◽  
Sensory Perception ◽  
Smoke Exposure ◽  
Social Cues ◽  
Molecular Response ◽  
Brain Gene Expression ◽  
Social Cue ◽  
Behavioral Expression ◽  
Induced Changes

Abstract Gene expression changes resulting from social interactions may give rise to long term behavioral change, or simply reflect the activity of neural circuitry associated with behavioral expression. In honey bees, social cues broadly modulate aggressive behavior and brain gene expression. Previous studies suggest that expression changes are limited to contexts in which social cues give rise to stable, relatively long-term changes in behavior. Here we use a traditional beekeeping approach that inhibits aggression, smoke exposure, to deprive individuals of aggression-inducing olfactory cues and evaluate whether behavioral changes occur in absence of expression variation in a set of four biomarker genes (drat, cyp6g1/2, GB53860, inos) associated with aggression in previous studies. We also evaluate two markers of a brain hypoxic response (hif1α, hsf) to determine whether smoke induces molecular changes at all. We find that bees with blocked sensory perception as a result of smoke exposure show a strong, temporary inhibition of aggression relative to bees allowed to perceive normal social cues. However, blocking sensory perception had minimal impacts on aggression-relevant gene expression, althought it did induce a hypoxic molecular response in the brain. Results suggest that certain genes differentiate social cue-induced changes in aggression from long-term modulation of this phenotype.

scholarly journals Glycosylation of Volatile Phenols in Grapes Following Pre-Harvest (On-Vine) vs. Post-Harvest (Off-Vine) Exposure to Smoke

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5277
Author(s):  
Julie A. Culbert ◽  
WenWen Jiang ◽  
Renata Ristic ◽  
Carolyn J. Puglisi ◽  
Elizabeth C. Nixon ◽  
...  
Keyword(s):  
Sensory Analysis ◽  
Field Trials ◽  
Smoke Exposure ◽  
Cabernet Sauvignon ◽  
Financial Viability ◽  
Volatile Phenols ◽  
Post Harvest ◽  
Volatile Phenol ◽  
Phenol Glycosides

Taint in grapes and wine following vineyard exposure to bushfire smoke continues to challenge the financial viability of grape and wine producers worldwide. In response, researchers are studying the chemical, sensory and physiological consequences of grapevine smoke exposure. However, studies involving winemaking trials are often limited by the availability of suitable quantities of smoke-affected grapes, either from vineyards exposed to smoke or from field trials involving the application of smoke to grapevines. This study compared the accumulation of volatile phenol glycosides (as compositional markers of smoke taint) in Viognier and Cabernet Sauvignon grapes exposed to smoke pre- vs. post-harvest, and found post-harvest smoke exposure of fruit gave similar levels of volatile phenol glycosides to fruit exposed to smoke pre-harvest. Furthermore, wines made from smoke-affected fruit contained similar levels of smoke-derived volatile phenols and their glycosides, irrespective of whether smoke exposure occurred pre- vs. post-harvest. Post-harvest smoke exposure therefore provides a valid approach to generating smoke-affected grapes in the quantities needed for winemaking trials and/or trials that employ both chemical and sensory analysis of wine.

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