ORCID Profile
0000-0002-6056-9325
Current Organisation
University of Adelaide
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Publisher: Hindawi Limited
Date: 04-2005
Publisher: Wiley
Date: 25-05-2016
DOI: 10.1002/JSFA.7769
Abstract: Clonal selection is one of the tools used for grapevine improvement and therefore is very important for obtaining clones with better characteristics than the variety population. The aim of this study was to select superior grapevines of Vitis vinifera L. cv. Muscat Hamburg grown for fresh consumption. The viticultural parameters and fruit composition of 35 selected vines were determined during a 5-year period. The evaluated parameters showed high variability among selected vines. The significant effect of vintage was observed for all descriptors with the exception of the number of seeds per berry and sugar concentration. Additionally, all vines were examined for their tolerance to low temperatures and the results showed 73% and 90% of primary bud injury at -20 and -25 °C, respectively. In relation to berry classification, the percentage of first-class grapes ranged from 60% to 69% for all selected grapevines. Multivariate statistical analysis was performed to classify grapevines based on their performance. Fourteen grapevines were identified as the most promising among the 35 vines initially planted, based on high yield, bunch and berry weight, sugar content and percentage of first-grade grapes. Those grapevines were selected for the next phase of the clonal selection. This study highlighted the importance of clonal selection for improvement of the variety population. © 2016 Society of Chemical Industry.
Publisher: MDPI AG
Date: 31-08-2021
DOI: 10.3390/MOLECULES26175277
Abstract: 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.
Publisher: MDPI AG
Date: 06-07-2019
DOI: 10.3390/MOLECULES24132485
Abstract: Grape brandy, known as ‘Lozovača’, is one of the most produced alcoholic beverages in the Republic of Serbia. Muscat cultivars are highly priced in grape brandy manufacturing. Among the numerous factors, cultivar-specific characteristics have a significant influence on its quality and aroma profile. Pectolytic enzymes play a part in increasing intensity of the prefermentative aroma by hydrolysis of terpenic glycosides, from which the compounds that contribute to the aroma of brandy are released. In this study, grape brandy s les were produced from five Muscat table grapevine cultivars (Vitis vinifera L.) namely, Early Muscat, Radmilovac Muscat, Banat Muscat, Italia Muscat, and Muscat Hamburg, with the addition of pectolytic enzyme in two different concentrations or without it (control). A total of 58 volatile aroma compounds were detected by means of combined gas chromatographic-mass spectrometric (GC/MS) method. Ethyl esters of C8–C18 fatty acids (21) and terpene (16) compounds were considerably more abundant in all grape brandy s les compared to the other volatile compounds identified. Pectolytic enzyme, positively affected terpenes content in the brandy of all studied cultivars. The similarities between brandy s les produced from Muscat Hamburg (MH) and other Muscat cultivars may be attributed to the parentage of MH to those cultivars.
Publisher: MDPI AG
Date: 03-03-2022
DOI: 10.3390/MOLECULES27051667
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.
Publisher: MDPI AG
Date: 08-05-2015
Publisher: Hindawi Limited
Date: 28-12-2018
DOI: 10.1111/AJGW.12320
Publisher: American Society for Enology and Viticulture
Date: 16-01-2015
Publisher: American Chemical Society (ACS)
Date: 06-01-2015
DOI: 10.1021/AC503883S
Abstract: Volatile sulfur compounds contribute characteristic aromas to foods and beverages and are widely studied, because of their impact on sensory properties. Certain thiols are particularly important to the aromas of roasted coffee, cooked meat, passion fruit, grapefruit, and guava. These same thiols enhance the aroma profiles of different wine styles, imparting pleasant aromas reminiscent of citrus and tropical fruits (due to 3-mercaptohexan-1-ol, 3-mercaptohexyl acetate, 4-mercapto-4-methylpentan-2-one), roasted coffee (2-furfurylthiol), and struck flint (benzyl mercaptan), at nanogram-per-liter levels. In contrast to the usual gas chromatography (GC) approaches, a simple and unique high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for routine analysis of five wine thiols, using 4,4'-dithiodipyridine (DTDP) as a derivatizing agent and polydeuterated internal standards for maximum accuracy and precision. DTDP reacted rapidly with thiols at wine pH and provided stable derivatives, which were enriched by solid-phase extraction (SPE) prior to analysis by HPLC-MS/MS. All steps were optimized and the method was validated in different wine matrices, with method performance being comparable to a well-optimized but more cumbersome gas chromatography-mass spectrometry (GC-MS) method. A range of commercial wines was analyzed with the new method, revealing the distribution of the five thiols in white, red, rosé, and sparkling wine styles.
Publisher: Hindawi Limited
Date: 07-2007
Publisher: Hindawi Limited
Date: 24-08-2012
Publisher: American Society for Horticultural Science
Date: 06-2017
DOI: 10.21273/HORTSCI.43.3.957
Abstract: The response of grape berries at a cellular level to environmental change was explored with particular emphasis on physiological changes such as weight, sugar content, and the biosynthesis of organic acids. Three levels of light were used: highly exposed, moderately exposed, and light-excluding boxes (1% ambient with no change in temperature effect). Berry weight was significantly lower in light-excluding boxes than in exposed bunch treatments. Organic acid content and berry development were followed throughout the growing season. Light exclusion resulted in a significant reduction of both tartaric acid and oxalic acid compared with highly exposed fruit, suggesting that in this experiment, light irradiance influenced accumulation of these metabolites. In contrast, malic acid was broken down postveraison at a dramatically slower rate in light exclusion treatments. The sink properties of grape berries appear to change according to the light received by the bunch. These data imply that cluster shading significantly reduced berry size and suggest the role of organic acids as osmotica.
Publisher: Hindawi Limited
Date: 06-12-2021
DOI: 10.1111/AJGW.12469
Publisher: Hindawi Limited
Date: 27-02-2022
DOI: 10.1111/AJGW.12548
Publisher: MDPI AG
Date: 03-12-2020
DOI: 10.3390/FOODS9121798
Abstract: Wine consumer lifestyle segmentation has been widely studied however, most studies have solely utilised online surveys. This work investigated the impact of context on wine consumer segments’ liking and emotions while consuming wines in different environments. Two studies were conducted with regular wine consumers segmented based on their fine wine behaviour using the Fine Wine Instrument. Study 1 (n = 122) investigated the effects of wine variety and product information, and Study 2 (n = 346) the effects of wine quality and consumption context, on hedonic and emotional responses of the segments. Within both studies, three segments were identified and named: Wine Enthusiasts, Aspirants and No Frills. The Wine Enthusiast segment generally liked the wines more and perceived more intense positive emotions when consuming wine compared to the No Frills segment, with the Aspirant’s likes and emotion intensities ranging in between. Wine Enthusiasts were more discriminative of their preferred wines and reported stronger positive emotions when tasting higher quality (Study 1) and more complex (Study 2) wines. The consistent results across the two studies showed for the first time that consumer segments, based on lifestyle segmentation, differ in their hedonic and emotional responses towards wine when actually tasting wines, demonstrating that the Fine Wine Instrument has practical implications and can identify wine consumers displaying different wine consumption behaviours.
Publisher: Hindawi Limited
Date: 13-05-2011
Publisher: American Chemical Society (ACS)
Date: 13-06-2018
Abstract: 3-Isobutyl-2-methoxypyrazine (IBMP) is a potent odorant present in grapes and wines that is reminiscent of green capsicum. Suprathreshold concentrations can lead to obvious vegetative characters and suppress desirable fruity aroma nuances in wines, but options to manage IBMP concentrations are limited. This work investigated pre- and postfermentation addition of a putative imprinted magnetic polymer (PIMP) as a remedial treatment for elevated concentrations of IBMP in Cabernet Sauvignon grape must in comparison to nonimprinted magnetic polymer (NIMP) and to a commercially available polylactic acid (PLA) based film added postfermentation. Chemical and sensory analyses of wines showed that PIMP treatments were more effective than PLA film for decreasing "fresh green" aroma nuances without negatively impacting overall aroma profiles and that postfermentation addition of a magnetic polymer removed up to 74% of the initial IBMP concentration compared to 18% for PLA. Prefermentation addition of magnetic polymers removed 20-30% less IBMP compared to that of postfermentation addition but also had less of an effect on other wine volatiles and color parameters.
Publisher: Elsevier BV
Date: 04-2016
Publisher: Hindawi Limited
Date: 16-04-2017
DOI: 10.1111/AJGW.12277
Publisher: MDPI AG
Date: 23-03-2021
DOI: 10.3390/MOLECULES26061798
Abstract: 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.
Publisher: Hindawi Limited
Date: 07-2003
Publisher: American Society for Enology and Viticulture
Date: 11-07-2016
Publisher: MDPI AG
Date: 14-08-2020
DOI: 10.3390/MOLECULES25163720
Abstract: 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.
Publisher: Elsevier BV
Date: 08-2013
DOI: 10.1016/J.FOODCHEM.2013.01.090
Abstract: In this study, two-dimensional correlation spectroscopy (2D-COS) combined with mid-infrared (MIR) spectroscopy was evaluated as a novel technique for the identification of spectral regions associated with smoke-affected wine, for the purpose of screening taint arising from grapevine exposure to smoke. Smoke-affected wines obtained from experimental and industry sources were analysed using MIR spectroscopy and chemometrics, and calibration models developed. 2D-COS analysis was used to generate synchronous data maps for red and white cask wines spiked with guaiacol, a marker of smoke taint. Correlations were observed at wavelengths that could be attributable to aromatic C-C stretching, i.e., between 1400 and 1500 cm(-1), indicative of volatile phenols. These results demonstrate the potential of 2D-COS as a rapid, high-throughput technique for the preliminary screening of smoke tainted wine.
Publisher: MDPI AG
Date: 07-2021
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.
Publisher: Springer Science and Business Media LLC
Date: 15-02-2016
Publisher: MDPI AG
Date: 26-07-2016
Publisher: Hindawi Limited
Date: 28-09-2010
Publisher: MDPI AG
Date: 03-2020
Abstract: This study investigated the perceptions and preferences of Australian wine consumers towards different styles of sparkling wine, including French Ch agne and Australian sparkling white, red and rosé wine, Moscato and Prosecco. An online survey of 1027 regular sparkling wine consumers captured demographic information, sparkling wine perceptions and preferences, and typical spending and consumption patterns. Consumers were segmented into three distinct clusters (‘No Frills’, ‘Aspirants’ and ‘Enthusiasts’) using the Fine Wine Instrument model. The majority of No Frills consumers were female and typically consumed sparkling wine once per month. Almost 55% of Aspirants were male with a household income of more than AU$75,000. Enthusiast consumers were also predominantly male and well educated, and 64% were under the age of 35 years. Sparkling white wine and Ch agne were generally the preferred styles for each consumer group, followed by Moscato and sparkling rosé wine. Interestingly, Moscato scored favorably with both No Frills and Enthusiast segments. Almost 25% of respondents indicated that they were not familiar with Prosecco, while sparkling red wine was perceived similarly by male and female consumers. The findings from this study can be used by sparkling wine producers to better target their products and marketing to the specific needs and expectations of consumers within different segments of the Australian domestic market.
Publisher: American Chemical Society (ACS)
Date: 16-12-2012
DOI: 10.1021/JF203849H
Abstract: In this study, the suitability of mid-infrared (MIR) spectroscopy, combined with principal component analysis (PCA) and linear discriminant analysis (LDA), was evaluated as a rapid analytical technique to identify smoke tainted wines. Control (i.e., unsmoked) and smoke-affected wines (260 in total) from experimental and commercial sources were analyzed by MIR spectroscopy and chemometrics. The concentrations of guaiacol and 4-methylguaiacol were also determined using gas chromatography-mass spectrometry (GC-MS), as markers of smoke taint. LDA models correctly classified 61% of control wines and 70% of smoke-affected wines. Classification rates were found to be influenced by the extent of smoke taint (based on GC-MS and informal sensory assessment), as well as qualitative differences in wine composition due to grape variety and oak maturation. Overall, the potential application of MIR spectroscopy combined with chemometrics as a rapid analytical technique for screening smoke-affected wines was demonstrated.
Publisher: MDPI AG
Date: 24-02-2021
Abstract: This study investigated consumer preferences for different styles of sparkling wine and the influence of wine style and occasion on sparkling wine purchasing and consumption behavior. Australian consumers (n = 203) completed an online survey and blind tasting of representative styles of commercial sparkling wines, including Ch agne. Wine sensory profiles were determined by descriptive analysis using a trained panel (n = 12) and consumers were segmented into ‘No Frills’, ‘Aspirant’ and ‘Enthusiast’ clusters using the Fine Wine Instrument. Consumer perceptions, preferences and liking were measured using 9-point hedonic scales and compared via statistical analysis. Consumers anticipated liking Ch agne and sparkling white wine the most, and Moscato and Prosecco the least, but on tasting, could only readily identify the Moscato and sparkling red wines, as the most contrasting wine styles. As such, liking scores for the Ch agne and sparkling white wine were significantly lower based on tasting (median scores were 6.0, compared with 9.0 and 8.0 for survey responses, respectively). Consumers’ preconceived expectations of different sparkling wine styles clearly influenced purchasing and consumption behavior. Aspirants and Enthusiasts were more likely to spend more per bottle for Ch agne and sparkling white wine, and consumption of these sparkling wines was most frequently associated with celebratory occasions, such as anniversaries, birthdays, Christmas, New Year and weddings.
Publisher: Hindawi Limited
Date: 12-03-2013
DOI: 10.1111/AJGW.12017
Publisher: Bentham Science Publishers Ltd.
Date: 05-05-2017
DOI: 10.2174/1389201018666170313100919
Abstract: Three clones of Cabernet Franc (Nos. 02, 010 and 012) were selected in the last phase of clonal selection in Serbia. Wines made from each clone were assessed for quality parameters and taste during five consecutive vintages (2008-2012) and compared to the standard. The wine quality was determined based on the following parameters: alcohol, total extract, anthocyanins, tannins, pH, titratable acidity, volatile acidity, aldehydes, esters and reducing sugars, relative density, ash, colour, tonality, and tasting score. In the last year of the study, grapes and wines of Cabernet Franc clones and a standard were subjected to a chemical analysis of their phenolic composition, resveratrol and radical scavenging activity. In the last year of the study, grapes and wines of Cabernet Franc clones and a standard were subjected to a chemical analysis of their phenolic composition, resveratrol and radical scavenging activity. Chemical analyses of grapes and wines along with sensory and radical scavenging activity evaluations were done according to the standard procedures. The wines of the clone No. 010 showed some superior properties compared to the other two clones and the standard in five-year period the average concentration of anthocyanins (179±3.8 mg/L) and polyphenolics (1.85±0.02 g/L) was significantly higher than in wines of clones and the standard, (168-173 mg/L and 1.63-1.74 g/L for anthocyanins and phenolics, respectively). Furthermore, the same clone had a higher alcohol content (13.97±0.03%) in each year of the study, which indicated that it ripened faster than other clones (13.06-13.08 %) and compared to the standard (13.04±0.07%). This finding suggested that the clone No. 010 could possibly have a significant economic impact and further increase popularity of Cabernet Franc in a cooler climate viticultural region. It was also found to have the highest contents of aldehydes (488±1.54 mg/L) and esters (322±0.71 mg/L) compared to aldehydes (452-467 mg/L) and esters (290-310 mg/L) measured in other wines. Finally, the highest amount of phenolic compounds (1220±40 mg/kg) and resveratrol (70±3.3 mg/kg) were found in the grapes of the clone No. 010. The present study revealed a strong correlation of total phenolic contents and anthocyanins with radical scavenging activities (0.936 and 0.929, P<0.001, respectively) indicating that this activity of wines was derived mainly from their phenolic compounds. The wine of the clone No. 010 contained the highest concentration of aldehydes, esters, anthocyanins, polyphenolics and resveratrol and consequently achieved the best tasting score. This clone may offer a new Cabernet Franc wine with geographical indication.
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.FOODRES.2017.05.019
Abstract: This study investigated how information, typically presented on wine back-labels or wine company websites, influences consumers' expected liking, informed liking, wine-evoked emotions and willingness to pay for Australian white wines. Regular white wine consumers (n=126) evaluated the same set of three commercially available white wines (mono-varietal Chardonnay, Riesling, Sauvignon Blanc) under three information levels. Session 1, blind tasting (no information provided) and Session 2, informed tasting (held at least 1week later) with both basic (sensory description of the wines) and elaborate (sensory plus high wine quality and favourable winery information) descriptions followed by liking, wine-evoked emotions (measured with the Australian Wine Evoked Emotions Lexicon (AWEEL)) and willingness to pay evaluations. Before tasting the wine in session 2, consumers also rated expected liking. Results showed that information level had a significant effect on all investigated variables. The elaborate information level evoked higher expectations before tasting the wines, plus resulted in higher liking ratings, elicitation of more intense positive (e.g. contented, happy and warm-hearted) and less intense negative emotions (e.g. embarrassed and unfulfilled), and a substantial increase in willingness to pay after tasting the wines compared to the blind condition, with the basic condition ranging in-between. These results were consistent across the three wine s les. Furthermore, if the liking rating after tasting the wines matched the expected liking or exceeded the expectations by 1 point on a 9-point hedonic scale, participants felt the most intense positive emotions and the least intense negative emotions. Whereas, if the expectations were not met or the actual liking exceeded the expectations by >2 points, participants felt less intense positive and more intense negative emotions. This highlights not only the importance of well written and accurate wine descriptions, but also that information can influence consumers' wine drinking experience and behaviour.
Publisher: MDPI AG
Date: 13-12-2021
DOI: 10.3390/MOLECULES26247540
Abstract: 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.
Publisher: MDPI AG
Date: 30-07-2019
DOI: 10.3390/S19153335
Abstract: Bushfires are becoming more frequent and intensive due to changing climate. Those that occur close to vineyards can cause smoke contamination of grapevines and grapes, which can affect wines, producing smoke-taint. At present, there are no available practical in-field tools available for detection of smoke contamination or taint in berries. This research proposes a non-invasive/in-field detection system for smoke contamination in grapevine canopies based on predictable changes in stomatal conductance patterns based on infrared thermal image analysis and machine learning modeling based on pattern recognition. A second model was also proposed to quantify levels of smoke-taint related compounds as targets in berries and wines using near-infrared spectroscopy (NIR) as inputs for machine learning fitting modeling. Results showed that the pattern recognition model to detect smoke contamination from canopies had 96% accuracy. The second model to predict smoke taint compounds in berries and wine fit the NIR data with a correlation coefficient (R) of 0.97 and with no indication of overfitting. These methods can offer grape growers quick, affordable, accurate, non-destructive in-field screening tools to assist in vineyard management practices to minimize smoke taint in wines with in-field applications using smartphones and unmanned aerial systems (UAS).
Publisher: Elsevier BV
Date: 09-0100
Publisher: Hindawi Limited
Date: 16-08-2018
DOI: 10.1111/AJGW.12300
Publisher: American Chemical Society
Date: 2012
Publisher: Hindawi Limited
Date: 10-2000
Publisher: MDPI AG
Date: 18-05-2015
Publisher: MDPI AG
Date: 21-11-2022
DOI: 10.3390/MOLECULES27228096
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.
Publisher: American Society for Enology and Viticulture
Date: 05-01-2017
Publisher: Emerald
Date: 13-03-2017
DOI: 10.1108/IJWBR-10-2015-0048
Abstract: This paper aims to provide further insight into factors influencing Australian consumers’ purchasing preferences for sparkling wine, including ch agne. Focus groups were conducted and thematic analysis was undertaken to identify factors influencing sparkling wine consumers’ purchasing preferences. Personal taste was found to influence choice of a sparkling wine rather than another type of beverage, and selection of a particular style and brand of sparkling wine. Country or region of origin was found to be important, often linked to the product being ch agne. Brand image, reputation and symbolism were found to influence purchase decisions (sometimes linked to consumption occasion), especially for purchases of gifts. Advice, recommendations and expert reviews, and consumption occasion also were found to influence purchase decisions. Price was found to influence style and brand of sparkling wine purchased. A high price was found to be a barrier for some participants, while other participants were found to avoid sparkling wines priced below some particular level. Thematic analysis enabled development of a preliminary model of purchasing preferences. Being exploratory in nature, findings cannot be generalised. Further studies are required to confirm the preliminary model and to evaluate the validity and significance of proposed relationships. Findings suggest a producer could benefit from marketing a range of sparkling wines to cater to different tastes, occasions and gift purchases. Findings also confirm the importance of marketers pursuing opportunities to obtain and promote favourable expert reviews for their sparkling wines, and of identifying and promoting regional distinctiveness. The first comprehensive model of sparkling wine consumers’ purchasing preferences has been developed. Empirical testing would enable refinement and enhance understanding.
Publisher: American Society for Enology and Viticulture
Date: 07-09-2017
Publisher: Elsevier
Date: 2019
Publisher: Elsevier BV
Date: 2019
Publisher: American Society for Enology and Viticulture
Date: 17-08-2016
Publisher: Hindawi Limited
Date: 26-09-2023
DOI: 10.1155/2023/6693220
Publisher: Elsevier BV
Date: 09-2013
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.FOODRES.2016.08.006
Abstract: This study investigated the effect of different contexts on consumers' mood, product-evoked emotions, liking and willingness to pay for wine. Three consumer trials (n=114, 115, and 120) examined 3 different s le sets of 4 Australian commercial Shiraz wines. Each s le set was comprised of a high, medium-high, medium-low and low quality wine as designated by an expert panel. Wine consumers evaluated the same set of wines in the three different contexts, ranging from a highly-controlled laboratory setting to more realistic restaurant and at-home settings. Results showed that high quality wines were liked more and elicited more intense emotions of positive valence compared to wines of lower quality. Context effects were observed on emotions, but not on liking, indicating that although emotions and liking are correlated, the measurement of emotions can deliver additional information over liking. Tasting wine in the restaurant context evoked more intense positive emotions compared to the home and laboratory contexts. Participants' mood before tasting the wines had a strong influence on consecutive product-evoked emotion ratings, but only weak influence on liking ratings. Furthermore, a strong relationship between wine-evoked emotions and willingness to pay was observed, showing that if a wine-evoked more intense emotion of positive valence e.g., contented, enthusiastic, happy, optimistic and passionate participants were willing to pay significantly more for a bottle. Additionally, the absence of negative emotions, even if typically evoked to a very weak extent, is a requirement for an increased willingness to pay. This study indicates it is worthwhile to consider context and emotions in wine testing and marketing.
Publisher: Hindawi Limited
Date: 13-05-2011
Publisher: Hindawi Limited
Date: 13-05-2011
Publisher: MDPI AG
Date: 09-2020
DOI: 10.3390/FOODS9091208
Abstract: Natural flavorings could potentially be used to enhance the intensity of wine aroma and flavor albeit since flavor additives are not legally permitted winemaking aids, flavored wines would need to be labeled as wine products. In this study, changes in the composition and sensory profiles of flavored Chardonnay (n = 2) and Shiraz (n = 2) wines were compared at bottling, and then again after 12 months of bottle aging. Flavorings and flavored wines were also analyzed by gas chromatography-mass spectrometry (GC-MS) to determine the key constituents responsible for changes to aroma and flavor profiles. However, many of the volatile compounds identified in flavor additives were not detected at appreciably higher concentrations in flavored wines, which was attributed to the very small quantities of flavorings that were added to base wines. The sensory profiles of control and flavored wines were determined by descriptive analysis, and the addition of flavorings to base wines significantly influenced the perception of some sensory attributes. Flavored Chardonnay wines exhibited enhanced fruit aromas and flavors, while fruit and developed attributes were enhanced in flavored Shiraz wines. Differences in sensory profiles were less apparent in Chardonnay wines following bottle aging, but depending on the flavorings added, flavored Shiraz wines could still be discriminated from their corresponding control wines after bottle aging. Results from this study demonstrate the potential for flavor additives to be used to enhance desirable attributes and/or mitigate wine sensory deficiencies.
Publisher: American Chemical Society (ACS)
Date: 16-05-2017
Abstract: Smoke taint is the term given to the objectionable smoky, medicinal, and ashy characters that can be exhibited in wines following vineyard exposure to bushfire smoke. This study sought to investigate the stability of smoke taint by determining changes in the composition and sensory properties of wines following 5 to 6 years of bottle aging. Small increases in guaiacol and 4-methylguaiacol (of up to 6 μg/L) were observed after bottle aging of smoke-affected red and white wines, while syringol increased by as much as 29 μg/L. However, increased volatile phenol levels were also observed in control red wines, which indicated that changes in the composition of smoke-affected wines were due to acid hydrolysis of conjugate forms of both naturally occurring and smoke-derived volatile phenols. Acid hydrolysis of smoke-affected wines (post-bottle aging) released additional quantities of volatile phenols, which demonstrated the relative stability of glycoconjugate precursors to the mildly acidic conditions of wine. Bottle aging affected the sensory profiles of smoke-affected wines in different ways. Diminished fruit aroma and flavor led to the intensification of smoke taint in some wines, but smoke-related sensory attributes became less apparent in smoke-affected Shiraz wines, post-bottle aging.
Publisher: MDPI AG
Date: 30-07-2022
DOI: 10.3390/MOLECULES27154892
Abstract: Vineyard exposure to wildfire smoke can taint grapes and wine. To understand the impact of this taint, it is imperative that the analytical methods used are accurate and precise. This study compared the variance across nine commercial and research laboratories following quantitative analysis of the same set of smoke-tainted wines. In parallel, correlations between the interlaboratory consensus values for smoke-taint markers and sensory analyses of the same smoke-tainted wines were evaluated. For free guaiacol, the mean accuracy was 94 ± 11% in model wine, while the free cresols and 4-methylguaiacol showed a negative bias and/or decreased precision relative to guaiacol. Similar trends were observed in smoke-tainted wines, with the cresols and glycosidically bound markers demonstrating high variance. Collectively, the interlaboratory results show that data from a single laboratory can be used quantitatively to understand smoke-taint. Results from different laboratories, however, should not be directly compared due to the high variance between study participants. Correlations between consensus compositional data and sensory evaluations suggest the risk of perceivable smoke-taint can be predicted from free cresol concentrations, overcoming limitations associated with the occurrence of some volatile phenols, guaiacol in particular, as natural constituents of some grape cultivars and of the oak used for barrel maturation.
No related grants have been discovered for Renata Ristic.