Publications by authors named "Gary J Pickering"

17 Publications

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Lifestyle decisions and climate mitigation: current action and behavioural intent of youth.

Mitig Adapt Strateg Glob Chang 2021 26;26(6):25. Epub 2021 Jul 26.

Sustainability Research Centre, University of the Sunshine Coast, 90 Sippy Downs, QLD 4556 Australia.

Youth carry the burden of a climate crisis not of their making, yet their accumulative lifestyle decisions will help determine the severity of future climate impacts. We surveyed 17-18 year old's ( = 487) to establish their action stages for nine behaviours that vary in efficacy of greenhouse gas emission (GGE) reduction and the explanatory role of climate change (CC) knowledge, sociodemographic and belief factors. Acceptance of CC and its anthropogenic origins was high. However, the behaviours with the greatest potential for GGE savings () have the lowest uptake. Descriptive normative beliefs predicted intent to adopt all high-impact actions, while environmental locus of control, CC scepticism, knowledge of the relative efficacy of actions, religiosity and age were predictive of action stage for several mitigation behaviours (multinomial logistic regression). These findings inform policy and communication interventions that seek to mobilise youth in the global climate crisis response.

Supplementary Information: The online version contains supplementary material available at 10.1007/s11027-021-09963-4.
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http://dx.doi.org/10.1007/s11027-021-09963-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8550525PMC
July 2021

Prevalence and Management of Alkyl-Methoxypyrazines in a Changing Climate: Viticultural and Oenological Considerations.

Biomolecules 2021 10 15;11(10). Epub 2021 Oct 15.

Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada.

Alkyl-methoxypyrazines are an important class of odor-active molecules that contribute green, 'unripe' characters to wine and are considered undesirable in most wine styles. They are naturally occurring grape metabolites in many cultivars, but can also be derived from some Coccinellidae species when these 'ladybugs' are inadvertently introduced into the must during harvesting operations. The projected impacts of climate change are discussed, and we conclude that these include an altered alkyl-methoxypyrazine composition in grapes and wines in many wine regions. Thus, a careful consideration of how to manage them in both the vineyard and winery is important and timely. This review brings together the relevant literatures on viticultural and oenological interventions aimed at mitigating alkyl-methoxypyrazine loads, and makes recommendations on their management with an aim to maintaining wine quality under a changing and challenging climate.
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http://dx.doi.org/10.3390/biom11101521DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8533812PMC
October 2021

A Review of Ladybug Taint in Wine: Origins, Prevention, and Remediation.

Molecules 2021 Jul 17;26(14). Epub 2021 Jul 17.

Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843-2133, USA.

Ladybug taint (also known as ladybird taint) is a relatively recently recognized fault that has been identified in wines from a wide range of terroirs. Alkyl-methoxypyrazines-particularly 2-isopropyl-3-methoxypyrazine-have been determined as the causal compounds, and these are introduced into grape must during processing, when specific species of vineyard-dwelling Coccinellidae are incorporated into the harvested fruit. , and especially the invasive , are the beetles implicated, and climate change is facilitating wider dispersal and survivability of in viticultural regions worldwide. Affected wines are typically characterized as possessing excessively green, bell pepper-, and peanut-like aroma and flavor. In this paper, we review a range of vineyard practices that seek to reduce Coccinellidae densities, as well as both "standard" and novel wine treatments aimed at reducing alkyl-methoxypyrazine load. We conclude that while prevention of ladybug taint is preferable, there are several winery interventions that can remediate the quality of wine affected by this taint, although they vary in their relative efficacy and specificity.
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http://dx.doi.org/10.3390/molecules26144341DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8306610PMC
July 2021

The role of taste in alcohol preference, consumption and risk behavior.

Crit Rev Food Sci Nutr 2019 13;59(4):676-692. Epub 2017 Nov 13.

a Department of Biological Sciences , Brock University , St. Catharines , ON L2S 3A1 , Canada.

Alcohol consumption is widespread, and high levels of use are associated with increased risk of developing an alcohol use disorder. Thus, understanding the factors that influence alcohol intake is important for disease prevention and management. Additionally, elucidating the factors that associate with alcohol preference and intake in non-clinical populations allows for product development and optimisation opportunities for the alcoholic beverage industry. The literature on how taste (orosensation) influences alcohol behavior is critically appraised in this review. Ethanol, the compound common to all alcoholic beverages, is generally aversive as it primarily elicits bitterness and irritation when ingested. Individuals who experience orosensations (both taste and chemesthetic) more intensely tend to report lower liking and consumption of alcoholic beverages. Additionally, a preference for sweetness is likely associated with a paternal history of alcohol use disorders. However, conflicting findings in the literature are common and may be partially attributable to differences in the methods used to access orosensory responsiveness and taste phenotypes. We conclude that while taste is a key driver in alcohol preference, intake and use disorder, no single taste-related factor can adequately predict alcohol behaviour. Areas for further research and suggestions for improved methodological and analytical approaches are highlighted.
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http://dx.doi.org/10.1080/10408398.2017.1387759DOI Listing
August 2019

Influence of biological, experiential and psychological factors in wine preference segmentation.

Aust J Grape Wine Res 2017 Jun 31;23(2):154-161. Epub 2017 Jan 31.

Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, University Park, PA 16802, USA.

Background And Aims: We sought to determine the influence of selected biological, experiential and psychological variables on self-reported liking and consumption of wine in a sample of 329 Ontario wine consumers.

Methods And Results: Cluster analysis revealed three distinct groups, representing plausible market segments: wine lovers; dry table wine likers/sweet dislikers; and sweet wine likers/fortified dislikers. These groups differ in level of wine expertise, wine adventurousness, alcohol intake, bitterness from 6--propylthiouracil (PROP), and several demographic variables. PROP hypo-tasters (=113) and PROP hyper-tasters (=112) differed in liking scores for nine of the 11 wine styles [ANCOVA, (F)<0.05]. When wines were grouped according to their dominant sensory properties (dry, sweet, carbonation and heat), liking scores for PROP hyper-tasters were higher than those of PROP hypo-tasters for all classes. Scores also varied with age, expertise and gender for some products. Effect sizes (eta-squared) were generally greatest for age, and those for PROP responsiveness were of similar magnitude as those for gender. As expected, wine consumption frequency was higher for men and experts, and increased with age.

Conclusions: Age is the most robust and consistent driver of wine liking and intake of the variables examined. Taste phenotype also contributes significantly to variation in wine liking.

Significance Of The Study: Ontario wine consumers fall into one of three wine liking clusters, which differ in experiential, biological, psychological and demographic features that can be targeted through branding and marketing strategies.
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http://dx.doi.org/10.1111/ajgw.12266DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5451159PMC
June 2017

Chemical and Sensory Evaluation of Silicone and Polylactic Acid-Based Remedial Treatments for Elevated Methoxypyrazine Levels in Wine.

Molecules 2016 Sep 16;21(9). Epub 2016 Sep 16.

Cool Climate Oenology and Viticulture Institute, Brock University, St. Catharines, ON L2S 3A1, Canada.

Alkylmethoxypyrazines (MPs) are a class of compounds that can elicit undesirable aroma and flavor characteristics in wine, and resist remediation using traditional wine making approaches. MPs are grape-derived constituents as well as contaminants from Coccinellidae beetles present during wine processing; the latter eliciting an off-flavor referred to as 'ladybug taint'. In this study we investigated the capacity of two plastic polymers-one silicone-based, the other polylactic acid-based-applied with varying surface areas to reduce concentrations of isopropylmethoxypyrazine (IPMP), sec-butylmethoxypyrazine (SBMP) and isobutylmethoxypyrazine (IBMP) in a Merlot wine using multi-dimensional gas chromatography coupled with mass spectrometry and headspace solid phase microextraction (SPME-MDGCMS). The impact of treatments on the sensory characteristics of the wine (descriptive analysis) and volatile aroma compounds (VOCs) (SPME-MDGCMS) was also investigated. Results showed substantial reductions for all of the target odorants: up to 38%, 44% and 39% for IPMP, SBMP and IBMP, respectively, for the silicone polymer, and up to 75%, 78% and 77% for IPMP, SBMP and IBMP, respectively, for the polylactic acid polymer. These polymers had no or minimal effect on VOCs at applications of 200 cm²/L for silicone or for all polylactic acid treatments. Sensory impacts were less clear, but generally showed minimal effect from the treatments. Taken overall, the data confirm the utility of both polylactic acid and silicone polymers in reducing elevated levels of grape-derived MPs, as well as potentially improving wine contaminated by ladybug taint.
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http://dx.doi.org/10.3390/molecules21091238DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6273560PMC
September 2016

Application of plastic polymers in remediating wine with elevated alkyl-methoxypyrazine levels.

Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2015 20;32(7):1199-206. Epub 2015 Apr 20.

a Cool Climate Oenology and Viticulture Institute , Brock University , St. Catharines , Canada.

3-Alkyl-2-methoxypyrazines (MPs) are odour-active compounds that elicit atypical green aromas and flavours in some wines, and are resilient to removal using traditional wine-making approaches. They originate either as contaminants from Coccinellidae beetles inadvertently introduced during wine processing ("ladybug taint") or as grape-derived constituents that are undesirable at elevated levels. In this study we investigated the capacity of a selection of plastic polymers to reduce concentrations of three MPs: isopropyl methoxypyrazine (IPMP), secbutyl methoxypyrazine (SBMP) and isobutyl methoxypyrazine (IBMP). In Trial 1, red wine was spiked with IPMP (20 ng/l), SBMP (20 ng/l) and IBMP (20 ng/l), then separately treated with 13 plastic polymers (surface area 350 cm(2)/l). Three polymers were then identified for further testing based on the results from Trial 1: silicone, ethylene and vinyl acetate (EVA) and a poly-lactic acid-based biodegradable polymer. In Trial 2, the efficacy of these selected polymers to reduce MP levels in red wine was tested as a function of contact time. Solid-phase micro-extraction multi-dimensional GC-MS was used to measure MP levels before and after treatment with the polymers. Results showed significant reductions in all target odorants after 24 h treatment: silicone reduced IPMP and IBMP by 96% and 100%, respectively, while the biodegradable polymer decreased IPMP and IBMP concentrations by 52% and 36%, respectively. EVA was less effective in lowering MP levels (7% IPMP and 23% IBMP after 24 h). Taken overall, the data suggest the potential for the use of poly-lactic acid and silicone in treating wines contaminated by ladybug taint, as well as in reducing high levels of grape-derived MPs.
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http://dx.doi.org/10.1080/19440049.2015.1028106DOI Listing
March 2016

Development of a rapid method for the quantitative analysis of four methoxypyrazines in white and red wine using multi-dimensional Gas Chromatography-Mass Spectrometry.

Food Chem 2014 Oct 18;160:141-7. Epub 2014 Mar 18.

Department of Food Science & Technology, Agricultural University of Athens, 11855 Athens, Greece.

Alkyl-methoxypyrazines (MPs) are important odour-active constituents of many grape cultivars and their wines. Recently, a new MP - 2,5-dimethyl-3-methoxypyrazine (DMMP) - has been reported as a possible constituent of wine. This study sought to develop a rapid and reliable method for quantifying DMMP, isopropyl methoxypyrazine (IPMP), secbutyl methoxypyrazine (SBMP) and isobutyl methoxypyrazine (IBMP) in wine. The proposed method is able to rapidly and accurately resolve all 4 MPs in a range of wine styles, with limits of detection between 1 and 2 ng L(-1) for IPMP, SBMP and IBMP and 5 ng L(-1) for DMMP. Analysis of a set of 11 commercial wines agrees with previously published values for IPMP, SBMP and IBMP, and shows for the first time that DMMP may be an important and somewhat common odorant in red wines. To our knowledge, this is the first analytical method developed for the quantification of DMMP in wine.
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http://dx.doi.org/10.1016/j.foodchem.2014.03.044DOI Listing
October 2014

Modifying bitterness in functional food systems.

Crit Rev Food Sci Nutr 2013 ;53(5):464-81

Department of Biological Sciences, Brock University, 500 Glenridge Avenue, St. Catharines, Ontario L2S 3A1, Canada.

The functional foods sector represents a significant and growing portion of the food industry, yet formulation of these products often involves the use of ingredients that elicit less than desirable oral sensations, including bitterness. Promising new functional ingredients, including polyphenolics, may be more widely and readily employed in the creation of novel functional foods if their aversive bitter taste can be significantly reduced. A number of approaches are used by the industry to improve the taste properties and thus the acceptance of conventional foods that elicit excessive bitterness. This article reviews the most commonly employed techniques, including the use of bitter-modifying additives, which may prove useful for successfully introducing new functional ingredients into this rapidly growing sector.
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http://dx.doi.org/10.1080/10408398.2010.542511DOI Listing
July 2013

Occurrence and contribution of alkyl methoxypyrazines in wine tainted by Harmonia axyridis and Coccinella septempunctata.

J Sci Food Agric 2013 Mar 19;93(4):803-10. Epub 2012 Oct 19.

Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada.

Background: Ladybug taint (LBT) is a wine fault caused by the inadvertent incorporation of ladybeetles to the wine during the winemaking process. Harmonia axyridis, also known as the multicolored Asian lady-beetle (MALB), was the only species considered responsible for causing the taint. A second species, Coccinella septempunctata (7 Spot), has recently also been implicated. The main objectives of this study were to identify and quantify the compounds associated with ladybug taint of white and red wine from these two Coccinellidae species (Harmonia axyridis and Coccinella septempunctata), and determine the most odor-active compounds in LBT-affected wines.

Results: Results show that Coccinellidae can contribute dimethyl, isopropyl, secbutyl and isobutyl methoxypyrazine to wine when they are processed with grapes, and that the methoxypyrazine composition varies between MALB and 7 Spot. Isopropyl methoxypyrazine is the major contributor to LBT in wines produced with these ladybeetle species, although secbutyl and isobutyl methoxypyrazine may contribute in MALB- and 7 Spot-affected wines, respectively. Finally, dimethyl methoxypyrazine is reported for the first time in wines not affected by Coccinellidae; the global significance and prevalence of this compound in wine remains to be determined.

Conclusion: Both Harmonia axyridis and Coccinella septempunctata can contribute alkyl methoxypyrazines, and particularly isopropyl methoxypyrazine, to wine at concentrations that can have a negative impact on wine quality. These findings will allow grape growers and winemakers to be more aware of the risks posed by 7 Spot beetles, and to take the appropriate preventative and remedial actions. Furthermore, this is the first time dimethyl methoxypyrazine is reported in wine, either as an endogenous or Coccinellidae-derived odorant.
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http://dx.doi.org/10.1002/jsfa.5800DOI Listing
March 2013

A novel method for controlling multicolored Asian lady beetle (Coleoptera: Coccinellidae) in vineyards.

Environ Entomol 2012 Oct;41(5):1169-76

School of Environmental Sciences, University of Guelph, 50 Stone Rd. East, Guelph, Ontario, Canada N1G 2W1.

The introduced biological control agent Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) has attained pest status in North America as its presence in vineyards during harvest may compromise the quality of the resulting wine. Control of H. axyridis in vineyards is difficult as their populations may fluctuate daily, and there are few products registered to control this pest. Sulfur dioxide, in the form of potassium metabisulfite (KMS), is commonly used in wine as both an antimicrobial and an antioxidant. In this study, the effectiveness of KMS as a repellent against H. axyridis was measured. In a Y-tube olfactometer, H. axyridis spent significantly less time in the treatment arm (KMS 2.5, 5, and 10 g/liter) than in the control arm during a 10-min period. When sprayed in a vineyard, KMS significantly reduced the number of H. axyridis on grape vines. KMS is an effective repellent against H. axyridis and may be suitable for use in vineyards to control this pest. KMS (5 g/liter) applied to Riesling grapes at 2 wk, 1 wk, 3 d, or 1 d before harvest did not affect free sulfur dioxide in either freshly processed or settled juice. This study lays the foundation for the development of a pest management strategy incorporating repellents for H. axyridis in vineyards.
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http://dx.doi.org/10.1603/EN11151DOI Listing
October 2012

Determination of ortho- and retronasal detection thresholds and odor impact of 2,5-dimethyl-3-methoxypyrazine in wine.

J Food Sci 2012 Nov 11;77(11):S394-8. Epub 2012 Oct 11.

Department of Biological Sciences, Brock University, St. Catharines, Ontario L2S 3A1, Canada.

2,5-Dimethyl-3-methoxypyrazine (DMMP) has been recently identified in both Coccinellidae-tainted (by either Coccinella septempunctata or Harmonia axyridis beetles) and untainted wines; however, little is known regarding its impact on wine aroma and flavor. The aims of this study were to obtain an accurate estimate of both the ortho- and retronasal detection thresholds of DMMP in red wine and to understand how DMMP contributes to the aroma profile of red wine. In the first study, thresholds were determined for 21 individuals using the ASTM E679 ascending forced choice method of limits. The orthonasal group best estimate threshold (BET) was 31 ng/L and the retronasal group BET was 70 ng/L. A moderate variation in individual thresholds was observed for the orthonasal modality (standard deviation (SD) = 19.8) and a larger variation was noted for retronasal thresholds (SD = 111.8). In the second study, a panel of 8 assessors performed descriptive sensory analysis on 3 red wines containing various concentrations of added DMMP (0, 50, and 120 ng/L). Results show significant changes in aroma characteristics in the 120 ng/L wine and smaller effects at the 50 ng/L level. Overall, wines spiked with DMMP generated lower intensity ratings for cherry and red berry descriptors and higher ratings for earthy/musty and green/vegetal descriptors. When considered with other recent results on DMMP concentrations found in wine, DMMP can be considered a hitherto undescribed impact odorant in some wine styles.
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http://dx.doi.org/10.1111/j.1750-3841.2012.02942.xDOI Listing
November 2012

Wine Expertise Predicts Taste Phenotype.

Am J Enol Vitic 2012 Mar;63(1):80-84

Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA.

Taste phenotypes have long been studied in relation to alcohol intake, dependence, and family history, with contradictory findings. However, on balance - with appropriate caveats about populations tested, outcomes measured and psychophysical methods used - an association between variation in taste responsiveness and some alcohol behaviors is supported. Recent work suggests super-tasting (operationalized via propylthiouracil (PROP) bitterness) not only associates with heightened response but also with more acute discrimination between stimuli. Here, we explore relationships between food and beverage adventurousness and taste phenotype. A convenience sample of wine drinkers (n=330) were recruited in Ontario and phenotyped for PROP bitterness via filter paper disk. They also filled out a short questionnaire regarding willingness to try new foods, alcoholic beverages and wines as well as level of wine involvement, which was used to classify them as a wine expert (n=110) or wine consumer (n=220). In univariate logisitic models, food adventurousness predicted trying new wines and beverages but not expertise. Likewise, wine expertise predicted willingness to try new wines and beverages but not foods. In separate multivariate logistic models, willingness to try new wines and beverages was predicted by expertise and food adventurousness but not PROP. However, mean PROP bitterness was higher among wine experts than wine consumers, and the conditional distribution functions differed between experts and consumers. In contrast, PROP means and distributions did not differ with food adventurousness. These data suggest individuals may self-select for specific professions based on sensory ability (i.e., an active gene-environment correlation) but phenotype does not explain willingness to try new stimuli.
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http://dx.doi.org/10.5344/ajev.2011.11050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3415240PMC
March 2012

Optimizing the orosensory properties of model functional beverages: the influence of novel sweeteners, odorants, bitter blockers, and their mixtures on (+)-catechin.

J Food Sci 2012 Jun 14;77(6):S226-32. Epub 2012 May 14.

Dept of Biological Sciences, Brock Univ, St Catharines, Ontario L2S 3A1, Canada.

Unlabelled: The use of flavor-modifying strategies are important to improving the sensory profile of some excessively bitter and astringent functional ingredients, such as (+)-catechin (CAT). Two bitter blockers (ß-cyclodextrin [CYCLO], homoeriodictyol sodium salt [HED]), two sweeteners (sucrose [SUC], rebaudioside A [REB]), and two odorants (vanillin [VAN], black tea aroma [TEA]) were assessed for their efficacy at modifying the bitterness and astringency of CAT in model aqueous solutions. The intensity of oral sensations elicited by CAT was determined in duplicate in binary, ternary, and quaternary mixtures of these stimuli by a trained panel (n = 15) using a 15 cm visual analogue scale. Overall, bitterness and astringency were most effectively reduced by ternary solutions containing CYCLO + REB or CYCLO + SUC (68%, 60%, and 45%, 43% for bitterness and astringency, respectively). Odorants were not effective at modifying the bitterness or astringency of CAT. We conclude that the use of select bitter blockers and sweeteners may be of value in optimizing the flavor and acceptance of functional food and beverages fortified with phenolic compounds.

Practical Application: (+)-Catechin is a bitter-tasting plant-derived health-promoting phenolic compound of interest to functional food and beverage manufacturers. We investigated the efficacy of bitter blockers, plant-based sweeteners, and odorants in decreasing the bitterness and astringency elicited by (+)-catechin. Some of these additives, both alone and in combination, reduced bitterness and astringency, and may therefore assist in optimizing the flavor and consumer acceptance of some phenolic-based functional foods and beverages.
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http://dx.doi.org/10.1111/j.1750-3841.2012.02707.xDOI Listing
June 2012

Effect of closure and packaging type on 3-alkyl-2-methoxypyrazines and other impact odorants of Riesling and Cabernet Franc wines.

J Agric Food Chem 2009 Jun;57(11):4680-90

Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada.

3-Alkyl-2-methoxypyrazines (MPs) represent an important and potent class of grape- and insect-derived odor-active compounds associated with wine quality. Thirty nanograms per liter each of 3-isobutyl-2-methoxypyrazine (IBMP), 3-isopropyl-2-methoxypyrazine (IPMP), and 3-sec-butyl-2-methoxypyrazine (SBMP) was added to Riesling and Cabernet Franc wines and monitored with headspace solid-phase microextraction and gas chromatography-mass spectrometry over 18 months to investigate the effects of various closure and packaging options on MPs. Changes in MP concentrations during bottle aging varied with closure/packaging option, with the greatest decrease evident in Tetrapak cartons. After 18 months, IBMP, IPMP, and SBMP in both Tetrapak-stored wines decreased by approximately 45, 32, and 26%, respectively. Similar changes were observed in other impact odorants to previous studies, including a greater decrease in odorant concentrations in wines closed with synthetic corks compared to natural corks and screw caps. These differences are thought to be due to the differential sorptive capacities of the various closure types. Overall, the data suggest that differences in gas permeability/contribution from the different closure and packaging options strongly associate with changes in wine composition during aging.
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http://dx.doi.org/10.1021/jf803720kDOI Listing
June 2009

Astringency: mechanisms and perception.

Crit Rev Food Sci Nutr 2008 Oct;48(9):858-75

Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada.

Astringency plays an important role in the sensory experience of many foods and beverages, ranging from wine to nuts. Given the recent trend toward fortifying consumables with astringent compounds and the evidence regarding the health benefits of some astringents, the mechanisms and perceptual characteristics of astringency warrant further discussion and investigation. This paper reviews the current state of the literature, including consideration of new methods for describing and measuring astringency, and provides an overview of research concerned with elucidating the physical, physiological, and psychological factors that underlie and mediate perception of this sensation.
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http://dx.doi.org/10.1080/10408390701724223DOI Listing
October 2008

Thermal taste, PROP responsiveness, and perception of oral sensations.

Physiol Behav 2008 Nov 22;95(4):581-90. Epub 2008 Aug 22.

Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada L2S 3A1.

Differences between 6-n-propylthiouracil (PROP) taster groups have long been the focus of studies on individual variation in perception of oral sensation. Recently, "thermal taste" was described, the phenomenon whereby some individuals perceive "phantom" taste sensations after thermal stimulation of small areas of the tongue. As with PROP taster status (PTS), thermal taster status (TTS) has been proposed as a proxy for general responsiveness to oral stimuli. Here we examined the influence of PTS and TTS, independently, on the perceived intensity of sweet, sour, salty, bitter, astringent, and metallic stimuli, and temperature on heating or cooling the tongue. Interactions between PTS and TTS were also examined, and fungiform papillae (FP) density and salivary flow rate (SFR) were determined. Both PTS and TTS were associated with perceived stimulus intensities. PROP super-tasters (pSTs) rated all oral stimuli as more intense than PROP non-tasters (pNTs). Thermal tasters (TTs) gave higher logged ratings than thermal non-tasters (TnTs) for all oral sensations including temperature, with the exception of metallic flavour (at low concentration) and PROP. Examination of ETA-squared values showed that PTS had a greater effect on perceived intensities than did TTS for most sensations. No PTSTTS interaction was found for any oral stimuli. In contrast with PTS, TTS was not associated with FP density, and neither PTS nor TTS were associated with SFR. We conclude that pSTs and TTs possess greater responsiveness across a range of taste and trigeminal stimuli and concentrations.
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http://dx.doi.org/10.1016/j.physbeh.2008.08.009DOI Listing
November 2008
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