1
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Hewitt S, Aragon M, Ashmore PL, Collins TS, Dhingra A. Transcriptome analysis reveals activation of detoxification and defense mechanisms in smoke-exposed Merlot grape (Vitis vinifera) berries. Sci Rep 2024; 14:21330. [PMID: 39266584 DOI: 10.1038/s41598-024-72079-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Accepted: 09/03/2024] [Indexed: 09/14/2024] Open
Abstract
A significant consequence of climate change is the rising incidence of wildfires. When wildfires occur close to wine grape (Vitis vinifera) production areas, smoke-derived volatile phenolic compounds can be taken up by the grape berries, negatively affecting the flavor and aroma profile of the resulting wine and compromising the production value of entire vineyards. Evidence for the permeation of smoke-associated compounds into grape berries has been provided through metabolomics; however, the basis for grapevines' response to smoke at the gene expression level has not been investigated in detail. To address this knowledge gap, we employed time-course RNA sequencing to observe gene expression-level changes in grape berries in response to smoke exposure. Significant increases in gene expression (and enrichment of gene ontologies) associated with detoxification of reactive compounds, maintenance of redox homeostasis, and cell wall fortification were observed in response to smoke. These findings suggest that the accumulation of volatile phenols from smoke exposure activates mechanisms that render smoke-derived compounds less reactive while simultaneously fortifying intracellular defense mechanisms. The results of this work lend a better understanding of the molecular basis for grapevines' response to smoke and provide insight into the origins of smoke-taint-associated flavor and aroma attributes in wine produced from smoke-exposed grapes.
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Affiliation(s)
- Seanna Hewitt
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, USA
| | - Mackenzie Aragon
- Department of Viticulture and Enology, Washington State University, Richland, WA, 99354, USA
| | - P Layton Ashmore
- Department of Viticulture and Enology, Washington State University, Richland, WA, 99354, USA
| | - Thomas S Collins
- Department of Viticulture and Enology, Washington State University, Richland, WA, 99354, USA
| | - Amit Dhingra
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, USA.
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2
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Huo Y, Ristic R, Puglisi C, Wang X, Muhlack R, Baars S, Herderich MJ, Wilkinson KL. Amelioration of Smoke Taint in Wine via Addition of Molecularly Imprinted Polymers during or after Fermentation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:18121-18131. [PMID: 39093022 DOI: 10.1021/acs.jafc.4c03912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
The adsorbents used to remove taint compounds from wine can also remove constituents that impart desirable color, aroma, and flavor attributes, whereas molecularly imprinted polymers (MIPs) are tailor-made to selectively bind one or more target compounds. This study evaluated the potential for MIPs to ameliorate smoke taint in wine via removal of volatile phenols during or after fermentation. The addition of MIPs to smoke-tainted Pinot Noir wine (for 24 h with stirring) achieved 35-57% removal of guaiacol, 4-methylguaiacol, cresols, and phenol, but <10% of volatile phenol glycoconjugates were removed and some wine color loss occurred. Of the MIP treatments that were subsequently applied to Semillon and Merlot fermentations or wine, MIP addition post-inoculation of yeast yielded the best outcomes, both in terms of volatile phenol removal and wine sensory profiles. Despite some impact on other aroma volatiles and red wine color, the findings demonstrate that MIPs can ameliorate smoke-tainted wine.
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Affiliation(s)
- Yiming Huo
- Discipline of Wine Science and Waite Research Institute, The University of Adelaide, Glen Osmond, South Australia 5064, Australia
| | - Renata Ristic
- Discipline of Wine Science and Waite Research Institute, The University of Adelaide, Glen Osmond, South Australia 5064, Australia
| | - Carolyn Puglisi
- Discipline of Wine Science and Waite Research Institute, The University of Adelaide, Glen Osmond, South Australia 5064, Australia
| | - Xingchen Wang
- Discipline of Wine Science and Waite Research Institute, The University of Adelaide, Glen Osmond, South Australia 5064, Australia
| | - Richard Muhlack
- Discipline of Wine Science and Waite Research Institute, The University of Adelaide, Glen Osmond, South Australia 5064, Australia
| | - Sylvia Baars
- amaea Limited, 10 Bisley Road, Hamilton 3214, New Zealand
| | - Markus J Herderich
- Discipline of Wine Science and Waite Research Institute, The University of Adelaide, Glen Osmond, South Australia 5064, Australia
- The Australian Wine Research Institute, Glen Osmond, South Australia 5064, Australia
| | - Kerry L Wilkinson
- Discipline of Wine Science and Waite Research Institute, The University of Adelaide, Glen Osmond, South Australia 5064, Australia
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3
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Parker M, Jiang W, Siebert TE, Herderich MJ. Smoky Characters in Wine: Distinctive Flavor or Taint? JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:9581-9586. [PMID: 38647217 DOI: 10.1021/acs.jafc.4c00811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
The frequency of wildfires has significantly increased in recent years, posing concerns for many grapegrowers and winemakers. Exposure of grapes to smoke can result in wines with notable smoky notes, which in severe cases are described as "smoke tainted". However, smoky aromas in wine are not a priori quality defects but may be considered desirable in some styles of wines, as also widely found and appreciated in many spirits. In this perspective, we summarize recent research on sources and assessment of smoky sensory attributes in wine and provide an outlook on opportunities for managing excessive smoky characters.
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Affiliation(s)
- Mango Parker
- The Australian Wine Research Institute, Hartley Grove cnr Paratoo Road, Urrbrae, South Australia 5064, Australia
| | - WenWen Jiang
- The Australian Wine Research Institute, Hartley Grove cnr Paratoo Road, Urrbrae, South Australia 5064, Australia
- School of Agriculture, Food and Wine, The University of Adelaide, Urrbrae, South Australia 5064, Australia
| | - Tracey E Siebert
- The Australian Wine Research Institute, Hartley Grove cnr Paratoo Road, Urrbrae, South Australia 5064, Australia
| | - Markus J Herderich
- The Australian Wine Research Institute, Hartley Grove cnr Paratoo Road, Urrbrae, South Australia 5064, Australia
- School of Agriculture, Food and Wine, The University of Adelaide, Urrbrae, South Australia 5064, Australia
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4
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Tan CE, Neupane BP, Wen Y, Lim LX, Medina Plaza C, Oberholster A, Tagkopoulos I. Volatile Organic Compound-Based Predictive Modeling of Smoke Taint in Wine. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:8060-8071. [PMID: 38533667 PMCID: PMC11010234 DOI: 10.1021/acs.jafc.3c07019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 03/11/2024] [Accepted: 03/12/2024] [Indexed: 03/28/2024]
Abstract
Smoke taint in wine has become a critical issue in the wine industry due to its significant negative impact on wine quality. Data-driven approaches including univariate analysis and predictive modeling are applied to a data set containing concentrations of 20 VOCs in 48 grape samples and 56 corresponding wine samples with a taster-evaluated smoke taint index. The resulting models for predicting the smoke taint index of wines are highly predictive when using as inputs VOC concentrations after log conversion in both grapes and wines (Pearson Correlation Coefficient PCC = 0.82; R2 = 0.68) and less so when only grape VOCs are used (Pearson Correlation Coefficient PCC = 0.76; R2 = 0.56), and the classification models also show the capacity for detecting smoke-tainted wines using both wine and grape VOC concentrations (Recall = 0.76; Precision = 0.92; F1 = 0.82) or using only grape VOC concentrations (Recall = 0.74; Precision = 0.92; F1 = 0.80). The performance of the predictive model shows the possibility of predicting the smoke taint index of the wine and grape samples before fermentation. The corresponding code of data analysis and predictive modeling of smoke taint in wine is available in the Github repository (https://github.com/IBPA/smoke_taint_prediction).
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Affiliation(s)
- Cheng-En Tan
- Department
of Computer Science, University of California,
Davis, Davis, California 95616, United States
- Genome
Center, University of California, Davis, Davis, California 95616, United States
- USDA/NSF
AI Institute for Next Generation Food Systems (AIFS), University of California, Davis, Davis, California 95616, United States
| | - Bishnu Prasad Neupane
- Department
of Viticulture and Enology, University of
California, Davis, Davis, California 95616, United States
| | - Yan Wen
- Department
of Viticulture and Enology, University of
California, Davis, Davis, California 95616, United States
| | - Lik Xian Lim
- Department
of Viticulture and Enology, University of
California, Davis, Davis, California 95616, United States
| | - Cristina Medina Plaza
- Department
of Viticulture and Enology, University of
California, Davis, Davis, California 95616, United States
| | - Anita Oberholster
- Department
of Viticulture and Enology, University of
California, Davis, Davis, California 95616, United States
| | - Ilias Tagkopoulos
- Department
of Computer Science, University of California,
Davis, Davis, California 95616, United States
- Genome
Center, University of California, Davis, Davis, California 95616, United States
- USDA/NSF
AI Institute for Next Generation Food Systems (AIFS), University of California, Davis, Davis, California 95616, United States
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5
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Tran TT, Jung J, Garcia L, Deshields J, Cerrato C, Penner MH, Tomasino E, Levin A, Zhao Y. Evaluation of Functional Spray Coatings for Mitigating the Uptake of Volatile Phenols by Pinot Noir Wine Grapes via Blocking, Absorption, and/or Adsorption. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:20222-20230. [PMID: 38054467 DOI: 10.1021/acs.jafc.3c05621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Spray coatings have shown promising potential in preventing the uptake of smoke phenols from wildfires into wine grapes. Three cellulose nanofiber-based coatings with low methoxyl pectin or varying concentrations of chitosan were made into films and their potential for blocking, absorption, or adsorption of phenols (guaiacol, m-cresol, and syringol) was evaluated using a custom-built smoke diffusion box. The coatings were also applied to Pinot noir grapes in a vineyard. GC-MS analysis for smoke phenols from headspace gases of diffusion study and extractions of films indicated that chitosan-based films can block guaiacol and syringol, and all films are able to capture m-cresol. The type of coating and application time in a vineyard did not affect (P < 0.05) physicochemical properties, size, and weight of the berries, whereas chitosan-based coatings resulted in a higher anthocyanin content of berries. This study provided new information about the key mechanisms (i.e., blocking phenols) of coatings to mitigate smoke phenol uptake in wine grapes.
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Affiliation(s)
- Trung T Tran
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon 97331, United States
| | - Jooyeoun Jung
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon 97331, United States
| | - Lindsay Garcia
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon 97331, United States
| | - Joseph Deshields
- Department of Horticulture, Oregon State University, Corvallis, Oregon 97331, United States
- Southern Oregon Research, Oregon State University, 569 Hanley Rd., Central Point, Oregon 97502, United States
| | - Cole Cerrato
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon 97331, United States
| | - Michael H Penner
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon 97331, United States
| | - Elizabeth Tomasino
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon 97331, United States
| | - Alexander Levin
- Department of Horticulture, Oregon State University, Corvallis, Oregon 97331, United States
- Southern Oregon Research, Oregon State University, 569 Hanley Rd., Central Point, Oregon 97502, United States
| | - Yanyun Zhao
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon 97331, United States
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6
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Oberholster, Lim LX, Plaza CM, Perez IA, Wen Y, Neupane B. Grape smoke exposure risk assessment: Wine matrix impact on smoke marker compound smoke expression. BIO WEB OF CONFERENCES 2023. [DOI: 10.1051/bioconf/20235602039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023] Open
Abstract
During wildfires large amounts of volatile phenols (VP’s) are released into the air from wood burning. These compounds absorb through the berry skin, where they are quickly glycosylated. Studies have shown that both the free and bound volatile phenols contribute to smoke taint perception. For grape smoke exposure risk assessment, both the natural amount of free and bound VP’s in grapes (baseline) as well as rejection threshold levels of these compounds in different wine matrixes need to be determined. In the current study the sensory attributes of different smoke impacted and non-smoke impacted wines from the same sites were determined by descriptive analysis. Multivariate statistics were used to relate smoke-related sensory attributes to smoke marker compounds. Subsequently, wines with different levels of smoke marker compounds were made by serial dilution of a smoke impacted wine with its respective non-impacted wine. A consumer study was conducted to determine the change in ‘liking’ for a wine depending on the percentage inclusion of smoke impacted wine. Rejection threshold levels of smoke marker compounds in red wine matrixes were determined by linking ‘liking’ scores to specific wine attributes. This is the first step in creating clear guidelines for wine smoke taint risk assessment.
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7
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Tran TT, Jung J, Garcia L, DeShields JB, Cerrato DC, Penner MH, Tomasino E, Levin AD, Zhao Y. Impact of functional spray coatings on smoke volatile phenol compounds and Pinot noir grape growth. J Food Sci 2023; 88:367-380. [PMID: 36533941 DOI: 10.1111/1750-3841.16435] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/18/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022]
Abstract
The frequency and intensity of wildfires have been increasing over the last 50 years and negatively impacted the wine industry. Previous methods of smoke mitigation during grape processing have shown little impact in reducing smoke taint in wines. Therefore, a novel method of using edible spray coatings for vineyard application was developed to help prevent volatile smoke phenol uptake in wine grapes. Four cellulose nanofiber-based coating suspensions incorporated with chitosan and/or β-cyclodextrin were evaluated. Films derived from the coating suspensions were exposed to volatile phenols found in wildfire smoke (guaiacol, 4-methyl guaiacol, m-cresol, o-cresol, p-cresol, syringol, and 4-methyl syringol) and evaluated with ultraviolet-visible spectroscopy where the results indicated that the coatings could uptake smoke phenols in varying degrees. The coatings were also applied in a vineyard at three different application times during grape growth: pea-sized, pre-bunch closure, and both at pea-sized and pre-bunch closure. The results showed that the application time did not have a significant (p < 0.05) effect on berry size, weight, °Brix, pH, or titratable acidity. The type of coating, time of application and washing were found to impact the number of volatile phenols in the grapes after a smoke event. Results from this study indicated that edible coatings could help mitigate smoke uptake in wine grapes without sacrificing the growth and key composition parameters of wine grapes. PRACTICAL APPLICATION: This research provides a novel spray coating that can be applied to wine grapes in the vineyard to potentially mitigate volatile smoke compounds in wine grapes without impacting fruit growth and key compositional parameters of wine grapes, thus maintaining high quality of wines for consumers. Results from this study can also be potentially applied to other agricultural commodities to solve the issues caused by the wildfire smoke.
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Affiliation(s)
- Trung T Tran
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Jooyeoun Jung
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Lindsay Garcia
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Joseph B DeShields
- Department of Horticulture, Oregon State University, Corvallis, Oregon, USA.,Southern Oregon Research and Extension Center, Oregon State University, Central Point, Oregon, USA
| | - D Cole Cerrato
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Michael H Penner
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Elizabeth Tomasino
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
| | - Alexander D Levin
- Department of Horticulture, Oregon State University, Corvallis, Oregon, USA.,Southern Oregon Research and Extension Center, Oregon State University, Central Point, Oregon, USA
| | - Yanyun Zhao
- Department of Food Science & Technology, Oregon State University, Corvallis, Oregon, USA
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Evaluation of Spinning Cone Column Distillation as a Strategy for Remediation of Smoke Taint in Juice and Wine. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27228096. [PMID: 36432197 PMCID: PMC9697475 DOI: 10.3390/molecules27228096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/04/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022]
Abstract
Where vineyard exposure to bushfire smoke cannot be avoided or prevented, grape and wine producers need strategies to transform smoke-affected juice and wine into saleable product. This study evaluated the potential for spinning cone column (SCC) distillation to be used for the remediation of 'smoke taint'. Compositional analysis of 'stripped wine' and condensate collected during SCC treatment of two smoke-tainted red wines indicated limited, if any, removal of volatile phenols, while their non-volatile glycoconjugates were concentrated due to water and ethanol removal. Together with the removal of desirable volatile aroma compounds, this enhanced the perception of smoke-related sensory attributes; i.e., smoke taint intensified. Stripped wines also became increasingly sour and salty as ethanol (and water) were progressively removed. A preliminary juice remediation trial yielded more promising results. While clarification, heating, evaporation, deionization and fermentation processes applied to smoke-tainted white juice gave ≤3 µg/L changes in volatile phenol concentrations, SCC distillation of smoke-tainted red juice increased the volatile phenol content of condensate (in some cases by 3- to 4-fold). Deionization of the resulting condensate removed 75 µg/L of volatile phenols, but fermentation of reconstituted juice increased volatile phenol concentrations again, presumably due to yeast metabolism of glycoconjugate precursors. Research findings suggest SCC distillation alone cannot remediate smoke taint, but used in combination with adsorbents, SCC may offer a novel remediation strategy, especially for tainted juice.
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9
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Oberholster A, Wen Y, Dominguez Suarez S, Erdmann J, Cauduro Girardello R, Rumbaugh A, Neupane B, Brenneman C, Cantu A, Heymann H. Investigation of Different Winemaking Protocols to Mitigate Smoke Taint Character in Wine. Molecules 2022; 27:1732. [PMID: 35268834 PMCID: PMC8911878 DOI: 10.3390/molecules27051732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 02/26/2022] [Accepted: 02/27/2022] [Indexed: 11/17/2022] Open
Abstract
There is an increase in the levels of volatile phenols in wine made with smoke-impacted grapes. These compounds are present in wood smoke resulting from the pyrolysis (thermal decomposition) of lignin and at high levels give overpowering smoky and ashy characters to a wine. This research aimed to compare all the suggested wine mitigation strategies that evolved from prior research using smoke-impacted grapes under identical winemaking conditions except for the parameter under investigation. Cabernet Sauvignon grapes were received from three areas with varying amounts of smoke exposure in Northern California. Gas chromatography combined with mass spectrometry (GC-MS) and descriptive analyses were performed to correlate the volatile phenol composition to smoke taint characteristics. The winemaking variables investigated were the use of different fermentation yeasts, oak additions, and fermentation temperatures. Among other attributes, smokiness and ashy aftertaste were significantly different among the wines, showing a clear difference between the wines made from smoke-impacted fruit and the control wines made from non-impacted fruit. Findings indicate that mitigation strategies during red wine fermentation have a limited impact on the extraction of smoke-taint markers and the expression of smoke-taint sensory characteristics.
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Affiliation(s)
- Anita Oberholster
- Department of Viticulture & Enology, University of California Davis, One Shields Avenue, Davis, CA 95616, USA; (Y.W.); (S.D.S.); (J.E.); (R.C.G.); (A.R.); (B.N.); (C.B.); (A.C.); (H.H.)
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10
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Szeto C, Ristic R, Wilkinson K. Thinking Inside the Box: A Novel Approach to Smoke Taint Mitigation Trials. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27051667. [PMID: 35268767 PMCID: PMC8911903 DOI: 10.3390/molecules27051667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 02/21/2022] [Accepted: 03/01/2022] [Indexed: 11/16/2022]
Abstract
When bushfires occur near wine regions, grapevine exposure to smoke can taint grapes due to the uptake of smoke-derived volatile compounds that can subsequently impart unpleasant smoky, medicinal, burnt rubber and ashy characters to wine. Whereas early research sought to understand the effects of smoke on grapevine physiology, and grape and wine chemistry, research efforts have shifted towards the strategic imperative for effective mitigation strategies. This study evaluated the extent to which excised grape bunches could be reproducibly tainted during smoke exposure in a purpose-built ‘smoke box’. The volatile phenol composition of grapes exposed to smoke for 30 min was similar to that of smoke-affected grapes from field trials involving grapevine exposure to smoke. Some variation was observed between replicate smoke treatments, but implementing appropriate controls and experimental replication enabled the smoke box to be used to successfully evaluate the efficacy of several agrochemical sprays and protective coverings as methods for mitigating the smoke exposure of grapes. Whereas the agrochemical sprays did not provide effective protection from smoke, enclosing grape bunches in activated carbon fabric prevented the uptake of up to 98% of the smoke-derived volatile phenols observed in smoke-affected grapes. As such, the study demonstrated not only a convenient, efficient approach to smoke taint research that overcomes the constraints associated with vineyard-based field trials, but also a promising new strategy for preventing smoke taint.
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Affiliation(s)
- Colleen Szeto
- Department of Wine Science, Waite Research Institute, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia; (C.S.); (R.R.)
- The Australian Research Council Training Centre for Innovative Wine Production, PMB 1, Glen Osmond, SA 5064, Australia
| | - Renata Ristic
- Department of Wine Science, Waite Research Institute, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia; (C.S.); (R.R.)
| | - Kerry Wilkinson
- Department of Wine Science, Waite Research Institute, The University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia; (C.S.); (R.R.)
- The Australian Research Council Training Centre for Innovative Wine Production, PMB 1, Glen Osmond, SA 5064, Australia
- Correspondence: ; Tel.: +61-8-8313-7360
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11
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Impact of Yeast Selection on Volatile Phenol Levels of Wines Produced from Smoked-Exposed Juice. FERMENTATION 2021. [DOI: 10.3390/fermentation7040240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Grapes exposed to smoke can result in wines that have unacceptable high levels of volatile phenols. High volatile phenols levels have a negative impact on wine quality. This study aimed to determine the levels of volatile phenols in wines produced from smoke-exposed juice by a selection of commercial wine yeasts and to determine if yeast selection affected the perception of smokiness in wine. Commercial white and red wine yeasts were screened for the production of volatile phenols in smoke-exposed Chenin Blanc and Merlot juice. Volatile phenol levels were determined by GC-MS/MS and wines were also subjected to sensory evaluation. Volatile phenol levels in smoked wines varied and was affected by yeast strain. The highest guaiacol levels in Chenin Blanc were found in wines fermented with QA23, while Merlot wines that underwent spontaneous alcoholic fermentation contained the highest levels. The levels of volatile phenols differed significantly between the smoked and unsmoked wines, and the sensory results supported the chemical data. Volatile phenols had a negative effect on Chenin Blanc flavor profiles even when the levels were below odor detection thresholds. Yeast selection is important and can affect the volatile phenol levels and flavor profiles of wines.
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12
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Culbert JA, Jiang W, Bilogrevic E, Likos D, Francis IL, Krstic MP, Herderich MJ. Compositional Changes in Smoke-Affected Grape Juice as a Consequence of Activated Carbon Treatment and the Impact on Phenolic Compounds and Smoke Flavor in Wine. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:10246-10259. [PMID: 34428045 DOI: 10.1021/acs.jafc.1c02642] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
An increase in bushfires and wildfires globally and consequent smoke exposure of grapevines has seen an elevated need for remediation options to manage the impact of smoke taint in the wine industry. Two commercially available activated carbons (PS1300 and CASPF) were evaluated at 1, 2, and 4 g/L with juice from smoke-affected Pinot Noir and Chardonnay grapes. PS1300 and CASPF treatments removed up to 75 and 92% of the phenolic glycosides in the smoke-affected Pinot Noir rosé juice, respectively, and both carbons removed virtually all (i.e., 98-99%) of the phenolic glycosides in the smoke-affected Chardonnay juice at the highest dose rate (4 g/L). The free volatile phenols in the wines were similarly lower in concentration following treatment. Sensory analysis confirmed that the wines made from carbon fined juice had reduced smoke aroma and flavor compared to those from the nontreated controls. However, desirable sensory properties such as color and fruity attributes were also negatively affected by the treatment. The dose rate should be optimized in industry practice to find a balance between reducing the intensity of smoke-related sensory attributes while maintaining or enhancing positive attributes.
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Affiliation(s)
- Julie A Culbert
- The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia
| | - WenWen Jiang
- The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia
| | - Eleanor Bilogrevic
- The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia
| | - Desireé Likos
- The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia
| | - I Leigh Francis
- The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia
| | - Mark P Krstic
- The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia
| | - Markus J Herderich
- The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia
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13
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Culbert JA, Krstic MP, Herderich MJ. Development and Utilization of a Model System to Evaluate the Potential of Surface Coatings for Protecting Grapes from Volatile Phenols Implicated in Smoke Taint. Molecules 2021; 26:molecules26175197. [PMID: 34500628 PMCID: PMC8434455 DOI: 10.3390/molecules26175197] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 01/16/2023] Open
Abstract
Due to the increasing frequency of wildfires in recent years, there is a strong need for developing mitigation strategies to manage the impact of smoke exposure of vines and occurrence of ‘smoke taint’ in wine. One plausible approach would be to prevent or inhibit the uptake of volatile phenols from smoke into grape berries in the vineyard. In this study we describe a model system we developed for evaluating under controlled conditions the effectiveness of a range of surface coatings (including existing horticultural sprays) for reducing/preventing the uptake of volatile phenols and their subsequent conversion to phenolic glycosides. Grapes were coated with the materials to be tested and then exposed to gaseous phenols, via evaporation from an aqueous solution, in a semi-closed glass container. Analysis of volatile phenols and their glycosidic grape metabolites demonstrated that the treatments typically did not provide any significant protection; in fact, some resulted in higher concentrations of these compounds in the grapes. The highest concentrations of volatile phenols and their glycosides were observed after application of oily, hydrophobic materials, suggesting that these materials may enhance the adsorption or transfer of volatile phenols into grape berries. Therefore, it is important to consider the types of sprays that are being applied in the vineyard before and during smoke events to prevent the potential of exacerbating the uptake of smoke compounds by grape berries.
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Affiliation(s)
- Julie A Culbert
- The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia
| | - Mark P Krstic
- The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia
| | - Markus J Herderich
- The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia
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Digital Smoke Taint Detection in Pinot Grigio Wines Using an E-Nose and Machine Learning Algorithms Following Treatment with Activated Carbon and a Cleaving Enzyme. FERMENTATION-BASEL 2021. [DOI: 10.3390/fermentation7030119] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The incidence and intensity of bushfires is increasing due to climate change, resulting in a greater risk of smoke taint development in wine. In this study, smoke-tainted and non-smoke-tainted wines were subjected to treatments using activated carbon with/without the addition of a cleaving enzyme treatment to hydrolyze glycoconjugates. Chemical measurements and volatile aroma compounds were assessed for each treatment, with the two smoke taint amelioration treatments exhibiting lower mean values for volatile aroma compounds exhibiting positive ‘fruit’ aromas. Furthermore, a low-cost electronic nose (e-nose) was used to assess the wines. A machine learning model based on artificial neural networks (ANN) was developed using the e-nose outputs from the unsmoked control wine, unsmoked wine with activated carbon treatment, unsmoked wine with a cleaving enzyme plus activated carbon treatment, and smoke-tainted control wine samples as inputs to classify the wines according to the smoke taint amelioration treatment. The model displayed a high overall accuracy of 98% in classifying the e-nose readings, illustrating it may be a rapid, cost-effective tool for winemakers to assess the effectiveness of smoke taint amelioration treatment by activated carbon with/without the use of a cleaving enzyme. Furthermore, the use of a cleaving enzyme coupled with activated carbon was found to be effective in ameliorating smoke taint in wine and may help delay the resurgence of smoke aromas in wine following the aging and hydrolysis of glycoconjugates.
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15
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Amelioration of Smoke Taint in Cabernet Sauvignon Wine via Post-Harvest Ozonation of Grapes. BEVERAGES 2021. [DOI: 10.3390/beverages7030044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Strategies that mitigate the negative effects of vineyard exposure to smoke on wine composition and sensory properties are needed to address the recurring incidence of bushfires in or near wine regions. Recent research demonstrated the potential for post-harvest ozonation of moderately smoke-exposed grapes to reduce both the concentration of smoke taint marker compounds (i.e., volatile phenols and their glycosides) and the perceived intensity of smoke taint in wine, depending on the dose and duration of ozone treatment. The current study further evaluated the efficacy of ozonation as a method for the amelioration of smoke taint in wine by comparing the chemical and sensory consequences of post-harvest ozonation (at 1 ppm for 24 h) of Cabernet Sauvignon grapes following grapevine exposure to dense smoke, i.e., ozone treatment of more heavily tainted grapes. Ozonation again yielded significant reductions in the concentration of free and glycosylated volatile phenols—up to 25% and 30%, respectively. However, although the intensities of smoke-related sensory attributes were generally lower in wines made with smoke-exposed grapes that were ozonated (compared to wines made with smoke-exposed grapes that were not ozonated), the results were not statistically significant. This suggests that the efficacy of ozone treatment depends on the extent to which grapes have been tainted by smoke.
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