In wine, one method of limiting the addition of sulphites, a harmful and allergenic agent, is bio-protection. This practice consists of the early addition of microorganisms on grape must before ...fermentation. Non-Saccharomyces yeasts have been proposed as an interesting alternative to sulphite addition. However, scientific data proving the effectiveness of bio-protection remains sparse. This study provides the first analysis of the chemical and microbiological effects of a Metschnikowia pulcherrima strain inoculated at the beginning of the red winemaking process in three wineries as an alternative to sulphiting. Like sulphiting, bio-protection effectively limited the growth of spoilage microbiota and had no influence on the phenolic compounds protecting musts and wine from oxidation. The bio-protection had no effect on the volatile compounds and the sensory differences were dependent on the experimental sites. However, a non-targeted metabolomic analysis by FTICR-MS highlighted a bio-protection signature.
Wine chemical compositions, which result from a complex interplay between environmental factors, genetic factors, and viticultural practices, have mostly been studied using targeted analyses of ...selected families of metabolites. Detailed studies have particularly concerned volatile and polyphenolic compounds because of their acknowledged roles in the organoleptic and therapeutic properties. However, we show that an unprecedented chemical diversity of wine composition can be unraveled through a nontargeted approach by ultrahigh-resolution mass spectrometry, which provides an instantaneous image of complex interacting processes, not easily or possibly resolvable into their unambiguous individual contributions. In particular, the statistical analysis of a series of barrel-aged wines revealed that 10-year-old wines still express a metabologeographic signature of the forest location where oaks of the barrel in which they were aged have grown.
A new method for efficient ionization of sugars in the negative‐ion mode of electrospray mass spectrometry is presented. Instead of using strongly hydrophobic dopants such as dichloromethane or ...chloroform, efficient ionization of sugars has been achieved by using aqueous HCl solution for the first time. This methodology makes it possible to use hydrophilic dopants, which are more appropriate for chromatographic separation techniques with efficient sugar ionization and detection in mass spectrometry. The interaction between chloride anions and monosaccharides (glucose and galactose) was studied by DFT in the gas phase and by implementing the polarizable continuum model (PCM) for calculations in solution at the high B3LYP/6‐31+G(d,p)//B3LYP/6‐311+G(2d,p) level of theory. In all optimized geometries of identified M+Cl− anions, a non‐covalent interaction exists. Differences were revealed between monodentate and bidentate complex anions, with the latter having noticeably higher binding energies. The calculated affinity of glucose and galactose toward the chloride anion in the gas phase and their chloride anion binding energies in solution are in excellent agreement with glucose and galactose M+Cl− experimental intensity profiles that are represented as a function of the chloride ion concentration. Density functional calculations of gas‐phase affinities toward chloride anion were also performed for the studied disaccharides sucrose and gentiobiose. All calculations are in excellent agreement with the experimental data. An example is introduced wherein HCl was used to effectively ionize sugars and form chlorinated adduct anions to detect sugars and glycosylated metabolites (anthocyanins) in real biological systems (Vitis vinifera grape extracts and wines), whereas they would not have been easily detectable under standard infusion electrospray mass spectrometry conditions as deprotonated species.
A new efficient ionization method for ultrahigh‐resolution electrospray mass spectrometry of carbohydrates using aqueous HCl solutions has been developed. The formation of chlorinated anions M+Cl− significantly enhances the detection sensitivity of sugars and glycosylated compounds compared with their deprotonated ionic forms (see figure).
A non‐targeted, ultra‐high‐resolution mass spectrometric, direct analysis of oak‐wood extracts from two species (Quercus robur L. and Quercus petraea Liebl.) from three French forests, and of a wine ...aged in barrels derived therefrom has been performed to identify families of metabolites that could discriminate both the species and the geographical origin of woods. From 12 T ultra‐high‐resolution Fourier transform ion cyclotron resonance mass spectra of wood extracts, hundreds of mass signals were identified as possible significant biomarkers of the two species, with phenolic and carbohydrate moieties leading the differentiation between Q. robur and Q. petraea, respectively, as corroborated by both FTMS and NMR data. For the first time, it is shown that oak woods can also be discriminated on the basis of hundreds of forest‐related compounds, and particular emphasis is put on sessile oaks from the Tronçais forest, for which sugars are significantly discriminant. Despite the higher complexity and diversity of wine metabolites, forest‐related compounds can also be detected in wines aged in related barrels. It is only by using these non‐targeted analyses that such innovative results, which reveal specific chemodiversities of natural materials, can be obtained.
From wood biochemistry to metabologeography: Non‐targeted ultra‐high‐resolution Fourier transform ion cyclotron resonance mass spectroscopy (FTICR‐MS) and NMR spectroscopy analyses show that broad chemical spaces particular to a given oak species in a given forest can manifest themselves in the composition of barrels and related barrel‐aged wines (see graphic).
•We investigated influence of wine colour and wine professionals’ culture on judgments of perceived quality in Pinot noir.•We demonstrated that perceived wine balance was the most important predictor ...of perceived quality in the wines.•We report several minor effects of wine colour on wine chemosensory judgments.•We report subtle effects of wine glass type (opaque vs clear) on sensory judgments.
Despite anecdotal reports suggesting an influence of perceived wine colour on wine professionals’ judgments of wine intrinsic quality, there is a lack of empirical evidence on the phenomenon. The major aim of the present study was to investigate the importance of perceived colour as a driver of chemosensory judgments of Pinot noir wines including sensory evaluations of quality and typicality. Twenty-three French and 23 New Zealand (NZ) wine professionals judged Pinot noir wines from France and NZ on a range of attributes including perceived colour (hue, intensity, and brightness), varietal characteristics, and overall wine quality. The wines were evaluated in both standard clear glassware where colour could serve as a cue, and in opaque (black) glassware. Results demonstrated that colour was not a major factor in sensory assessment of the Pinot noir wines including in judgments of wine quality, although wine colour had several minor effects. On the other hand, the data show that perceived balance of a wine was the most important factor driving quality judgments of the wines for tasters of both cultures. The data are discussed in terms of the concept of perceived quality in wine as well as in terms of cultural differences in sensory evaluation of Pinot noir wines. Finally, an important methodological issue, namely usage of opaque (black) glassware as opposed to standard, clear glassware in wine sensory research, is discussed.
The present study aims at evaluating the effect of culture and level of expertise on the perception of wine intrinsic quality. Therefore, regular consumers (108) and experts (119) from La Rioja ...(RJ-Spain) and Côtes du Rhône (CdR-France) evaluated the intrinsic quality of 12 red wines from both regions. Participants had to categorise the wines according to four levels of quality going from very low to very high quality. Results show no significant correlation between the quality scores given by experts and regular consumers whereas judgments given by French and Spanish experts are significantly correlated as are consumers' quality judgments. This demonstrates that perceived intrinsic quality is dependent on consumers' level of expertise. Consumers associate quality exemplars to woody-related aromas and experts to red fruity aromas. Animal and vegetal attributes are negatively correlated to wine quality, regardless of consumer's culture and level of expertise, while astringency negatively influences quality evaluated by Spanish consumers. It is also observed that Spanish consumers (who report to drink mostly RJ wines) find domestic wines (RJ) of higher quality than foreign wines (CdR). However, French consumers (who drink RJ and CdR with the same frequency) do not differentiate foreign and domestic wines in terms of intrinsic quality. This suggests that intrinsic quality perceived by both groups of regular wine consumers is related to consumers' exposure to wine, and thus to wine familiarity.
There is a lack of studies focusing on the chemical compounds involved in quality perception. The present work combines both sensory and chemical approaches with the final goal of evaluating the ...sensory-active compounds influencing wine experts' and consumers' perception of red wine quality.
Perceived quality was categorised by 108 consumers and 119 experts according to four levels going from very low to very high quality. In parallel, samples were described by a descriptive trained panel and volatile and non-volatile chemicals with known sensory activity were quantified.
Wines with higher concentrations of eugenol, E− and Z-whiskylactones and 4-ethylphenol (discussed in terms of matrix effect) are perceived higher in quality by consumers, while fusel alcohols and astringent-related compounds such as PAs, cis-aconitic acid, certain flavonols and hydroxycinnamic acid derivatives are linked to lower quality samples. In contrast, experts perceived wines with lower levels of whiskylactones and volatile phenols while higher levels of norisoprenoids to be higher in quality.
These results increase the understanding of wine quality perception and can give the wine industry knowledge of the main sensory-active compounds driving quality for different wine consumers.
•Experts' and consumers' quality perception is linked to chemical composition.•For experts, wine quality is linked to low contents of whiskylactones and volatile phenols.•For experts, wine quality is linked to high contents of norisoprenoids.•For consumers, wine quality is linked to high contents of oak-related volatiles.•For consumers, wine quality is linked to higher contents of 4-ethylphenol.
•Extrinsic wine quality representation for Spanish and French consumers is studied.•Extrinsic quality drivers of wines are studied by a cross-cultural study.•Country-of-origin of wine is the most ...important cue for less-involved consumers.•Consumers’ knowledge, involvement and nationality can predict quality perception.
Understanding quality perception requires focusing both on product proprieties and consumers’ representations. The goal of this study was to access the representations of perceived extrinsic wine quality of consumers from two different wine regions in two European countries with an important wine tradition: La Rioja-RJ-(Spain) and Côtes du Rhône-CdR-(France).
Twenty commercial red wines (ten from RJ and ten from CdR) were evaluated in terms of quality by means of a categorization task. Ninety-five French and 93 Spanish consumers had to categorize the 20 wines according to four levels of quality going from very low to very high quality.
Three clusters of French and two of Spanish consumers have been identified. Country-of-origin of wine arises as the most important extrinsic cue for less-involved French and Spanish consumers, while more-involved consumers with higher knowledge in wine are able to interpret and use a wider range of cues. Consumers’ knowledge, involvement and nationality appear to be good predictors of quality perception.
These results are relevant for the field of sensory analysis in that they help understanding the construction of quality perception. The wine industry can benefit also from these results, especially when exporting wines. This cross-cultural study may help them to develop marketing strategies able to enhance the quality perception of wines and to make use of different extrinsic factors.
•The vague but frequently employed wine descriptor ‘mineral’ was investigated.•New Zealand and French wine professionals judged perceived minerality in Sauvignon wines.•Perception of mineral ...character was demonstrated in three perception mode conditions.•Cross-cultural similarities and differences were demonstrated.•Specific wine attributes associated statistically with judgments of minerality.
Description of wine in terms of perceived mineral character has become common practice in recent decades. The major aim of our study was to investigate cultural differences in perception of minerality in wines from France and New Zealand, these countries having very different wine-production histories. A second aim was to investigate influence of perception mode on perceived mineral character in wine to gain increased understanding of the metaphorical descriptor “mineral” as applied to wine chemosensory attributes. Thirty-two French and 31 New Zealand wine professionals evaluated 16 wines (8 French; 8 New Zealand) under three conditions: orthonasal olfaction; global (orthonasal and retronasal olfaction; taste; other palate sensations); and nose-clip (taste and palate sensations only). Results demonstrated that both French and New Zealand participants reported minerality to be perceived via all three perception modes. In terms of culture, similarities and differences were both observed in terms of quantitative judgments of minerality, and in terms of the wine attributes perceived as related to minerality. Cross-cultural differences were particularly evident in the global condition. Results are described in terms of cognitive processing of metaphorical terms employed to label perceived wine attributes.
BACKGROUND AND AIMS: The use of minerality as a wine descriptor has increased in the last few years. Minerality always suggests high quality and evokes a link between wine and the soil. The sensory ...meaning of minerality, however, is not yet clearly understood. The present study was designed to understand how wine experts conceptualise minerality and to explore whether they can judge wine minerality in a consensual way. METHODS AND RESULTS: Experts carried out an orthonasal free sorting task on 16 Chardonnay wines. Afterwards, they rated their mineral character according to two conditions: orthonasally and on the palate while wearing a nose‐clip. The experts also answered a questionnaire in which they defined minerality. A trained panel independently performed a sensory description of the samples. The wine experts showed strong disagreement in their minerality judgements under both conditions. Three groups of experts emerged for each condition. Each group considered as mineral wines with quite different sensory characteristics which prevents any generalisation concerning the sensory meaning of minerality. Surprisingly, definitions of minerality by the experts showed some commonality despite the use of idiosyncratic terms. CONCLUSIONS: Minerality is an ill‐defined sensory concept, despite the apparent consistency emerging from verbal definitions by the experts. SIGNIFICANCE OF THE STUDY: Minerality is nowadays a popular term in wine marketing. Some attempts to understand its chemical origin have been made; however, this study has shown that a sensory definition of minerality should first be developed.
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