Taste Of Wine Research Articles

Construction of self-cloning, indigenous wine strains of Saccharomyces cerevisiae with enhanced glycerol and glutathione production

To improve wine taste and flavor stability, a novel indigenous strain of Saccharomyces cerevisiae with enhanced glycerol and glutathione (GSH) production for winemaking was constructed. ALD6 encoding an aldehyde dehydrogenases of the indigenous yeast was replaced by a GPD1 and CUP1 gene cassette, which are responsible for NAD-dependent glycerol-3-phosphatase dehydrogenase and copper resistance, respectively. Furthermore, the α-acetohydroxyacid synthase gene ILV2 of the indigenous yeast was disrupted by integration of the GSH1 gene which encodes γ-glutamylcysteine synthetase and the CUP1 gene cassette. The fermentation capacity of the recombinant was similar to that of the wild-type strain, with an increase of 21 and 19 % in glycerol and GSH production. No heterologous DNA was harbored in the recombinant in this study.

Stephanie L. Normann, 1935–2011

Stephanie L. Normann, 1935–2011

Assessment of the Chain Dependence Relationships Between Geology, Soil Properties and Grape Composition Using a Metric Generalization of Partial Least Squares Regression

An investigation was carried out to assess the suitability of an approach based on a metric generalization of the Partial Least Square Regression to identify and discriminate chain dependence relationships between geology, soil properties and grape composition. The study area was Telesina Valley (Campania Region, southern Italy), a foremost vineyard district with the Falanghina grape cultivar. Five geopedological units, with different assemblages of geological substrates and pedotypes, were surveyed. Soil surface horizons were sampled from 85 sites, representing the widest variability of geological and pedological features. Our results allowed, for each geopedological unit, to categorise the specific variables influencing grape quality, and to quantify their individual contribution. In particular, geopedological units with volcanic (Andisols) and more or less developed (Inceptisols) soils on recent (Olocenic) colluvial debris, as well as with Andisols and organic matter-rich soils (Mollisols) on older Pleisto-Olocenic pyroclastites, express the best performance of the main components of wine taste and flavour, as tartaric acid, malic acid and titratable acidity of grape. Specifically, these last were significantly dependent on soil features as fine texture, neutral-alkaline pH, and appreciable content of soil organic matter and high CEC. Keywords: Geomorphology, Soil, Grape composition, Generalized Partial Least Square Regression

Chasing after minerality, relationship to yeasts nutritional stress and succinic acid production

Minerality is certainly one of the most mysterious and most valuable tones of wine taste and it is very often associated with the concept of terroir. The isotachophoresis was used for determination of cations – minerals in two wines from vineyards with different soil conditions, with and without exceptional “minerality”. However, it was found that it has nothing to do with minerals. More attention was paid to the relationship between the nutritional stress of yeasts and succinic acid production, which can result in a final difference in the taste of wine. In addition, sensory evaluation was used to reveal differences between wines with increasing levels of succinic acid.    

CLIMATE CHANGE EFFECTS ON RIPENING PROCESS AND WINE COMPOSITION IN OLTENIA'S VINEYARDS FROM ROMANIA

Climate change has a big impact on viticulture and vinification from many viticulture areas. For example, in Oltenia, a viticulture region in the south-west of Romania, the observed warming has influenced changes in viticulture and winemaking practices. In viticulture, these changes regard the precociousness of the vegetation cycle of the vine and, especially, the growing up and increase in the ripening process of grapes. The research made by the Department of Enology - Faculty of Horticulture, from Craiova University, have shown that in the 1st decade of the XXI century in the vineyards from Oltenia area, the grapes are reaching the absolute maturity 10-15 days earlier, than in the 1950s and 1960s. At the same time, important changes occurred in the main parameters of the grapes composition: sugars contents and total acidity with an overall increase of sugars content of the grapes at absolute maturity (over all vine cultivars, 12-20 g/L), while the total acidity of the grapes, at the same stage of maturity, decreased with 0.75-1.8 g/L tartaric acid. The increase in sugar content and the decrease of the total acidity have different effects in the different wines produced in the region. For red wines these changes have been favourable for quality. Another positive effect from a changing climate for red wines is an over 100 mg/kg increased content in grapes anthocyanins. For white grapes, the decrease in acidity has a negative influence upon the balance of the taste of white wines, and is one of the main factor that leads to the limitation of extension in the culture of some white cultivars.

Evaluation of bitterness in white wine applying descriptive analysis, time-intensity analysis, and temporal dominance of sensations analysis

Bitterness in wine, especially in white wine, is a complex and sensitive topic as it is a persistent sensation with negative connotation by consumers. However, the molecular base for bitter taste in white wines is still widely unknown yet. At the same time studies dealing with bitterness have to cope with the temporal dynamics of bitter perception. The most common method to describe bitter taste is the static measurement amongst other attributes during a descriptive analysis. A less frequently applied method, the time-intensity analysis, evaluates the temporal gustatory changes focusing on bitterness alone. The most recently developed multidimensional approach of the temporal dominance of sensations method reveals the temporal dominance of bitter taste in relation to other attributes. In order to compare the results comprised with these different sensory methodologies, 13 commercial white wines were evaluated by the same panel. To facilitate a statistical comparison, parameters were extracted from bitterness curves obtained from time-intensity and temporal dominance of sensations analysis and were compared to bitter intensity as well as bitter persistency based on descriptive analysis. Analysis of variance differentiated significantly the wines regarding all measured bitterness parameters obtained from the three sensory techniques. Comparing the information of all sensory parameters by multiple factor analysis and correlation, each technique provided additional valuable information regarding the complex bitter perception in white wine.

Demarcation: a dynamic methodology for quality grading within the Australian wine industry

Formal wine quality ranking has largely been a European phenomenon. While various publications and critics within new world wine industries conduct regular ranking exercises for wine taste or winery processes, these exercises usually target specific quality or taste elements, are often not particularly transparent, and are not comprehensive. In Australia, the lack of a comprehensive ranking system is not simply an oversight. Wine associations have directed the industry along very different pathways from those laid out by their more traditional European peers. There has been a much greater emphasis on the role of the winemaker and technological experimentation, and a more egalitarian, generic branding regime. Until very recently, little value has been placed on factors such as terroir, heritage, regional characteristics, or appropriate and specialised vineyard management. The author believes that the lack of a formalised and comprehensive quality ranking system for Australian wine is a deficiency that is now undermining the industry’s reputation both at home and abroad. The following paper provides the context for, and justification of, what is proposed as a dynamic, transparent, and multi-category wine ranking matrix.

Diversity and frequencies of methoxypyrazines in hemolymph of Harmonia axyridis and Coccinella septempunctata and their influence on the taste of wine

The study focuses on the odor-active intensity and occurrence of three methoxypyrazines in ladybird beetles, Harmonia axyridis, invasive in Europe and the USA, and Coccinella septempunctata, native in Europe, but invasive in the USA. It is known from previous studies that H. axyridis has negatively influenced the taste of wine in the USA because of releasing their hemolymph in must during harvesting. In relation to C. septempunctata, H. axyridis had more nitrogen containing compounds in its hemolymph and 2-isopropyl-3-methoxypyrazine (IPMP) and mainly 2-sec-buthyl-3-methoxypyrazine (SBMP) in higher amounts. The compound IPMP was detected as the main odor-active compound in both ladybird beetle species. Wines infested with hemolymph of C. septempunctata were more readily detected as altered wine with a ‘ladybird taint’ than wines infested with H. axyridis. 2-isobuthyl-3-methoxypyrazine (IBMP) could be identified as second intensive odor-active compound of C. septempunctata, which occurred in a much lower frequency in H. axyridis. SBMP, the second highest measured N-compound of H. axyridis, had a lower olfactory active threshold in gas chromatography–olfactometry test. C. septempunctata contained less SBMP in its hemolymph than H. axyridis. This study objected that besides H. axyridis also C. septempunctata can influence the taste of wine in a detectable way.

The effect of background music on the taste of wine

Research concerning cross-modal influences on perception has neglected auditory influences on perceptions of non-auditory objects, although a small number of studies indicate that auditory stimuli can influence perceptions of the freshness of foodstuffs. Consistent with this, the results reported here indicate that independent groups' ratings of the taste of the wine reflected the emotional connotations of the background music played while they drank it. These results indicate that the symbolic function of auditory stimuli (in this case music) may influence perception in other modalities (in this case gustation); and are discussed in terms of possible future research that might investigate those aspects of music that induce such effects in a particular manner, and how such effects might be influenced by participants' pre-existing knowledge and expertise with regard to the target object in question.

What's in a number?

the scientific publishing world is being influenced by the Impact Factor (IF) just as the wine industry has been, and continues to be, influenced by a certain Robert Parker. There is little doubt that, just as Parker's personal taste in wine has caused winemakers in droves to change their procedures

Analysis on the Application of Ceramic Materials in Package - The Application of Ceramic Bottle in the Package of Jinjiu

Jinjiu’s ceramic bottle has been in China’s wine market for a few years, and the choice of ceramics reflects traditional Chinese design idea of “combination of object and practicability, and manifestation of life with object”， which satisfies consumers’ requirements about national traits, style and taste of wine. This paper will analyze how Jiujin Group skillfully adopted China’s traditional ceramic technology to the design of package and explore a successful way of national package of wine through the example of Jiujin.

New strategies to study the chemical nature of wine oligomeric procyanidins

Tannins represent a key element in red wine flavors, so researchers have made a lot of effort to try to understand the role of their structure in wine taste in recent decades. We report some new routes to achieve a true structure-taste relationship for the major tannins found in wine, which are procyanidins in their monomeric or oligomeric state. All these routes use synthetic standards. New advances in their synthesis and their analyses using chromatographic methods, NMR spectroscopy, and mass spectrometry to obtain more precise information about their chemical structure, including their stereochemistry and their precise degree of polymerization and galloylation, are described.

Representation of complexity in wine: Influence of expertise

The aim of the present study was to investigate the concept of complexity in wine as a function of domain-specific expertise. Thirty-nine wine professionals and 30 wine consumers participated in interviews aimed at inducing verbal responses concerning their representations of (i) wine complexity in general, (ii) wine complexity in relation to white wine with perceived ageing ability, and (iii) wine complexity in relation to red wine with perceived ageing ability. The verbal data were analysed with the textual data analysis software ALCESTE ( Reinert, 1983, 1986, 2001, 2008). Results showed that wine professionals as a group tended to represent complexity in wine in terms of extrinsic factors such as oenological processes (e.g., lees stirring; use of oak) and terroir variables (e.g., soil; viticulture: see Moran, 2006). On the other hand, wine consumers’ representations of wine complexity were dominated by intrinsic factors relating to their experience of consuming wine (e.g., smell and taste of wines) and were personalised and subjective (e.g., about their own enjoyment and pleasure). Further, wine professionals’ representations clearly differentiated between characteristics of white wine with ageing potential and characteristics of red wine with ageing potential whereas those of wine consumers did not. The results are discussed in terms of the salient components of the concept of complexity in wine, including wine judged to have ageing ability, along with the cognitive processing associated with wine expertise.

Label design: impact on millennials' perceptions of wine

PurposeThe purpose of this paper is to determine specific label attributes impacting both the taste and quality perceptions of millennial wine consumers.Design/methodology/approachA single‐blind study was developed to evaluate the direct implications labels have on millennial informants' taste and quality perceptions. A four‐stage research study tested the informants' reactions to the products both before and after evaluating the label and product packaging.FindingsPerceptions differed significantly from the blind tasting to the second tasting after evaluating the product packaging and label information. When the producer provided specific fruit characteristics, the informant perceived they tasted those fruits much more than without this information in the blind tasting.Research limitations/implicationsThe generalizability of this study was limited by the small population size (97 informants), the subject recruitment site, lack of ethnic diversity, and the high‐educational level of the respondents.Practical implicationsThe informants in this study indicated several factors such as closure, font style, eye‐catching front label, color of the bottle, food pairings, and wine producer information, as affecting their purchase intention.Originality/valueThere have been previous studies involving wine tourism and segmentation of wine consumers but a sensory label study on millennials presents a different approach.

The harlequin ladybird Harmonia axyridis – Sensory thresholds of the “ladybird taint” in wine under different processing conditions

Introduced as a biological control agent in North America and middle Europe the Harlequin Ladybird Harmonia axyridis has spread all over the countries and are capable to become an increasing problem for winegrowers and also households. Due to its preference to overwinter indoors H. axyridis enters private homes and people may have allergic reactions to its odor or bites. During harvests, the beetles feed on grapes and may get crushed with them during processing causing release of hemolymph into the must. The hemolymph of ladybirds contains specific substances which consist mainly of pyrazines like the 3-isopropyl-2-methoxypyrazine. These chemical compounds are responsible for a specific alteration of the smell and taste of wine called “ladybird taint”.According to the results of a survey (n = 50), 80 % of winegrowers in the Palatinate region, 65 % in Frankia and 55 % in the Mosel region have already spotted H. axyridis in their vineyards. More than 50 % of the Palatinate winegrowers, 40 % in Frankia and 30 % at the Mosel, respectively, have even found the beetles in wine presses and harvest crop. It did not matter whether the beetles were harvested by hand or with a harvester as H. axyridis could be detected in the press in both cases.Sensory trials on Riesling and Pinot Noir wines produced in 2009 with added live beetles of H. axyridis showed that the ladybird taint is detectable at a threshold of 4 beetles per kilogram of grapes. But the sensory detection depends on the winemaking practices and the cultivar. In red wine the sensory threshold of pyrazines is lower (1 ng/l) than in white wine (2 ng/l). In addition fermentation technique affects pyrazine contents in wine: Fermentation after must heating also increased the detection limit of the ladybird taint compared to crushed must fermentation.Further aspects of winemaking are represented by the power and duration of pressing and if the grapes were de-stemmed before. The mortality rate of the beetles in the mash and therefore the amount of pyrazine in the must rises clearly with higher pressing power (3 bar), meaning that a lower presspower should be applied at high beetle loads. In addition, pressing of grapes which are not de-stemmed can lower the mortality rate as the beetles can find more holes in which they can survive the pressing. The duration of pressing can be seen as another factor for the reduction of ladybug taint in wine. The longer the grapes are pressed, the more pyrazines can be dissolved in the wine. A risk assessment should be carried out in order to deliberate about the surplus of must and the contamination of the wine by beetles.In the nineteen seventies and eighties the wine quality in German wine growing regions suffered from a contamination with chemical compounds of Coccinella septempunctata (7-point-ladybeetle) which at this time was not yet considered a possible hazard. Cudjoe et al. (2005) found that H. axyridis has a hundred-fold higher quantity of pyrazine in their hemolymph than C. septempunctata. Up to now it is unknown whether there is a difference in the quantity of beetles of the two species necessary to deteriorate wine quality. However further studies are in progress.

The harlequin ladybird Harmonia axyridis – Sensory thresholds of the “ladybird taint” in wine under different processing conditions

AbstractIntroduced as a biological control agent in North America and middle Europe the Harlequin Ladybird Harmonia axyridis has spread all over the countries and are capable to become an increasing problem for winegrowers and also households. Due to its preference to overwinter indoors H. axyridis enters private homes and people may have allergic reactions to its odor or bites. During harvests, the beetles feed on grapes and may get crushed with them during processing causing release of hemolymph into the must. The hemolymph of ladybirds contains specific substances which consist mainly of pyrazines like the 3-isopropyl-2-methoxypyrazine. These chemical compounds are responsible for a specific alteration of the smell and taste of wine called “ladybird taint”.According to the results of a survey (n = 50), 80 % of winegrowers in the Palatinate region, 65 % in Frankia and 55 % in the Mosel region have already spotted H. axyridis in their vineyards. More than 50 % of the Palatinate winegrowers, 40 % in Frankia and 30 % at the Mosel, respectively, have even found the beetles in wine presses and harvest crop. It did not matter whether the beetles were harvested by hand or with a harvester as H. axyridis could be detected in the press in both cases.Sensory trials on Riesling and Pinot Noir wines produced in 2009 with added live beetles of H. axyridis showed that the ladybird taint is detectable at a threshold of 4 beetles per kilogram of grapes. But the sensory detection depends on the winemaking practices and the cultivar. In red wine the sensory threshold of pyrazines is lower (1 ng/l) than in white wine (2 ng/l). In addition fermentation technique affects pyrazine contents in wine: Fermentation after must heating also increased the detection limit of the ladybird taint compared to crushed must fermentation.Further aspects of winemaking are represented by the power and duration of pressing and if the grapes were de-stemmed before. The mortality rate of the beetles in the mash and therefore the amount of pyrazine in the must rises clearly with higher pressing power (3 bar), meaning that a lower presspower should be applied at high beetle loads. In addition, pressing of grapes which are not de-stemmed can lower the mortality rate as the beetles can find more holes in which they can survive the pressing. The duration of pressing can be seen as another factor for the reduction of ladybug taint in wine. The longer the grapes are pressed, the more pyrazines can be dissolved in the wine. A risk assessment should be carried out in order to deliberate about the surplus of must and the contamination of the wine by beetles.In the nineteen seventies and eighties the wine quality in German wine growing regions suffered from a contamination with chemical compounds of Coccinella septempunctata (7-point-ladybeetle) which at this time was not yet considered a possible hazard. Cudjoe et al. (2005) found that H. axyridis has a hundred-fold higher quantity of pyrazine in their hemolymph than C. septempunctata. Up to now it is unknown whether there is a difference in the quantity of beetles of the two species necessary to deteriorate wine quality. However further studies are in progress.

Metabolic characterization of Palatinate German white wines according to sensory attributes, varieties, and vintages using NMR spectroscopy and multivariate data analyses

1H NMR (nuclear magnetic resonance spectroscopy) has been used for metabolomic analysis of ‘Riesling’ and ‘Mueller-Thurgau’ white wines from the German Palatinate region. Diverse two-dimensional NMR techniques have been applied for the identification of metabolites, including phenolics. It is shown that sensory analysis correlates with NMR-based metabolic profiles of wine. 1H NMR data in combination with multivariate data analysis methods, like principal component analysis (PCA), partial least squares projections to latent structures (PLS), and bidirectional orthogonal projections to latent structures (O2PLS) analysis, were employed in an attempt to identify the metabolites responsible for the taste of wine, using a non-targeted approach. The high quality wines were characterized by elevated levels of compounds like proline, 2,3-butanediol, malate, quercetin, and catechin. Characterization of wine based on type and vintage was also done using orthogonal projections to latent structures (OPLS) analysis. ‘Riesling’ wines were characterized by higher levels of catechin, caftarate, valine, proline, malate, and citrate whereas compounds like quercetin, resveratrol, gallate, leucine, threonine, succinate, and lactate, were found discriminating for ‘Mueller-Thurgau’. The wines from 2006 vintage were dominated by leucine, phenylalanine, citrate, malate, and phenolics, while valine, proline, alanine, and succinate were predominantly present in the 2007 vintage. Based on these results, it can be postulated the NMR-based metabolomics offers an easy and comprehensive analysis of wine and in combination with multivariate data analyses can be used to investigate the source of the wines and to predict certain sensory aspects of wine.Electronic supplementary materialThe online version of this article (doi:10.1007/s10858-011-9487-3) contains supplementary material, which is available to authorized users.

Potential spoilage non-Saccharomyces yeasts in mixed cultures with Saccharomyces cerevisiae

With the aim of exploring the possibility to improve wine quality through the utilization of wine-related yeasts generally considered as spoilage, mixed cultures of Saccharomyces cerevisiae with Hanseniaspora osmophila, Pichia fermentans, Saccharomycodes ludwigii and Zygosaccharomyces bailii were inoculated in grape juice. All the fermentations got to completion and most of the compounds normally produced at high concentrations by pure cultures of non-Saccharomyces yeasts, and considered detrimental for wine quality, did not reach the threshold taste level in mixed fermentations with S. cerevisiae. Interestingly, the association of S. cerevisiae with P. fermentans, S. ludwigii and Z. bailii produced significant increases in the production of polysaccharides as compared to pure cultures of S. cerevisiae. Since polysaccharides improve wine taste and body, and exert positive effects on aroma persistence and protein and tartrate stability, a possible use for these yeasts can be envisaged in mixed starter cultures with S. cerevisiae for the enhancement of the final quality of wine.

Instrumental measurement of bitter taste in red wine using an electronic tongue

An electronic tongue (ET) based on potentiometric chemical sensors was assessed as a rapid tool for the quantification of bitterness in red wines. A set of 39 single cultivar Pinotage wines comprising 13 samples with medium to high bitterness was obtained from the producers in West Cape, South Africa. Samples were analysed with respect to a set of routine wine parameters and major phenolic compounds using Fourier transform infrared-multiple internal reflection spectroscopy (WineScan) and high-performance liquid chromatography, respectively. A trained sensory panel assessed the bitterness intensity of 15 wines, 13 of which had a bitter taste of medium to high intensity. Thirty-one wine samples including seven bitter-tasting ones were measured by the ET. Influence of the chemical composition of wine on the occurrence of the bitter taste was evaluated using one-way analysis of variance. It was found that bitter-tasting wines had higher concentrations of phenolic compounds (catechin, epicatechin, gallic and caffeic acids and quercetin) than non-bitter wines. Sensitivity of the sensors of the array to the phenolic compounds related to the bitterness was studied at different pH levels. Sensors displayed sensitivity to all studied compounds at pH 7, but only to quercetin at pH 3.5. Based on these findings, the pH of wine was adjusted to 7 prior to measurements. Calibration models for classification of wine samples according to the presence of the bitter taste and quantification of the bitterness intensity were calculated by partial least squares-discriminant analysis (PLS-DA) regression. Statistical significance of the classification results was confirmed by the permutation test. Both ET and chemical analysis data could discriminate between bitter and control wines with the correct classification rates of 94% and 91%, respectively. Prediction of the bitterness intensity with good accuracy (root mean square error of 2 and mean relative error of 6% in validation) was possible only using ET data.

Effects of Sulfur Dioxide on Formation of Fishy Off-Odor and Undesirable Taste in Wine Consumed with Seafood

In order to evaluate sensory compatibility of alcoholic beverages with food, beverages and dried squid, namely, "surume", a common Japanese accompaniment, were consumed together. White wine and dried squid pairings had a more undesirable taste and more fishy off-odor than sake and dried squid pairings. The undesirable taste and fishy off-odor appeared to be caused by degradation of unsaturated fatty acids (e.g., docosahexaenoic acid (DHA)), which are found in fish and squid. Upon addition of DHA to the beverage, bitterness intensity, measured by instrumental taste sensor analysis, and the concentration of certain aldehydes reported to contribute to fishy flavors, increased in white wines, whereas they remained largely the same in sake. Among the major chemical constituents that distinguish wine from sake, only wine-specific sulfite markedly increased bitterness intensity and aldehyde levels upon addition of DHA. These results suggest that sulfur dioxide in wine participated in degradation of unsaturated fatty acids, causing an increase in undesirable taste and fishy off-odor in wine and seafood pairings.