Taste-aroma interaction in model wines: Effect of training and expertise

Olfactory perception complexity induced by key odorants perceptual interactions of alcoholic beverages: Wine as a focus case example

The odorants in alcoholic beverages are frequently experienced as complex mixtures, and there is a complex array of influence factors and interactions involved during consumption that deeply increase its olfactory perception complexity, especially the complexity induced by perceptual interactions between different odorants. In this review, the effect of olfactory perceptual interactions and other factors related to the complexity of olfactory perception of alcoholic beverages are discussed. The classification, influencing factors, and mechanisms of olfactory perceptual interactions are outlined. Recent research progress as well as the methodologies applied in these studies on perceptual interactions between odorants observed in representative alcoholic beverages, especially wine, are briefly summarized. In the future, unified theory or systematic research methodology need to be established, since up to now, the rules of perceptual interaction between multiple odorants, which is critical to the alcoholic beverage industry to improve the flavor of their products, are still not revealed.

Co-expression of metabolites and sensory attributes through weighted correlation network analysis to explore flavor-contributing factors in various Pyrus spp. Cultivars

Flavor profiles of various Pyrus spp. cultivars exhibit significant variations, yet the underlying flavor-contributing factors remain elusive. In this investigation, a comprehensive approach encompassing metabolomics analysis, volatile fingerprint analysis, and descriptive sensory analysis was employed to elucidate the flavor disparities among Nanguoli, Korla fragrant pear, and Qiuyueli cultivars and uncover potential flavor contributor. The study comprehensively characterized the categories and concentrations of nonvolatile and volatile metabolites, and 925 metabolites were identified. Flavonoids and esters dominated the highest cumulative response, respectively. Utilizing weighted correlation network analysis (WGCNA), seven highly correlated modules were identified, yielding 407 pivotal metabolites. Further correlation analysis of the differential substances provided potential flavor constituents strongly associated with various sensory attributes; taste factors had a certain association with olfactory characteristics. Our findings demonstrated the manifestation of flavor was a result of the synergistic effect of various compounds; evaluation olfactory flavor necessitated a comprehensive consideration of taste substances.

Tracing the origin of Argentine Malbec wines by sensometrics

The study of terroir, increasingly popular in scientific circles, remains a challenging field, particularly in terms of sensory analysis. This paper summarizes our own contribution to the field-an approach for tracing the typicity of wines by sensometrics, using the Malbec variety as a case study. This large-scale research fingerprinted 81 wines from 29 parcels from highly contrasting environments (varying climate, elevation, and soils), produced under standardized conditions in three consecutive vintages. Wines were evaluated through descriptive sensory analysis (DA) by a trained panel, and sensory descriptors were associated with different size geographic scales (zones, departments, and Geographic Indications (GIs)). The application of different sensometric tools allowed us to describe the typicity of wines and discriminate each region, proposing a novel methodology for the comprehensive evaluation of terroir from a sensory viewpoint. The vintage effect was very strong at the departmental and GI level, with aroma, taste and mouthfeel descriptors varying annually. However, certain origin descriptors remained consistent, providing insight into the typicity of Malbec. Considering the extension of the experimental study performed, this methodology provides a proof of concept for understanding both terroir and vintage effects from a sensorial perspective, offering wine producers and consumers a clear message backed by scientific evidence.

Advances in the Application of Direct Injection Mass Spectrometry Techniques to the Analysis of Grape, Wine and Other Alcoholic Beverages

Direct injection mass spectrometry (DIMS) entails the direct introduction of a gaseous sample into a mass analyser without prior treatment or separation. DIMS techniques offer the opportunity to monitor processes in time, with limits of detection as low as 0.5 parts per trillion in volume (for a 1 s measurement time) while providing results with high informational content. This review provides insight into current and promising future developments of DIMS in the analysis of grape, wine and other alcoholic beverages. Thanks to its unique characteristics, DIMS allows the online monitoring of volatile organic compounds (VOCs) released by grapes during fermentative bioprocesses or by wine directly from the glass headspace or during drinking. A DIMS-based approach can also be adopted to perform quality control and high-throughput analysis, allowing us to characterise the volatile profile of large sample sets rapidly and in a comprehensive fashion. Furthermore, DIMS presents several characteristic elements of green analytical chemistry approaches, catalysing an interest linked to the development of sustainable paths in research and development activities in the field of viticulture and oenology.

Impact of tannins on intraoral aroma release and retronasal perception, including detection thresholds and temporal perception by taste, in model wines

Tannins, as an important wine nonvolatile matrix component, can cause astringency, which may affect aroma perception through cross-modal interactions during wine consumption. An aromatic model wine with tannin extracts was evaluated by intraoral aroma release and sensory analysis after wine spitting. Overall, tannin extracts could significantly decrease all initial aroma release, while they could not reduce most aroma release at 150 s after wine spitting. Regarding the sensory evaluation results, the retronasal detection threshold of most aromas increased. The temporal aroma intensity showed a significant decrease at early time points and was almost unaffected at later time points. In addition, temporal dominance of sensation (TDS) curves revealed that the presence of astringency could reduce the dominant time of most aromas. Therefore, although there was good consistency between instrumental analysis and sensory evaluation, the effect of astringency induced by tannins on retronasal perception cannot be ignored.

Characterization of sensory perceptions elicited by white wine spiked with different aroma, taste and mouth-feel active molecules

The present work was aimed at understanding the sensory responses induced by dry white wine modified with increasing concentrations of different sensory active molecules. The tasting panel was composed by 34 trained subjects characterized according to gender, smoking habits, 6-n-propylthiouracil (PROP) taster status, and sensitivity to tartaric acid, tannic acid and sucrose. Additional taste/mouthfeel responsiveness was evaluated in a basal white wine added of tartaric acid, tannic acid and sucrose. The addition of a fruity odorant mixture to the base white wine enabled the assessment of orthonasal aroma and taste intensities (sweetness, sourness, saltiness). The diversity of taste/mouthfeel responsiveness in water or wine enabled to group individuals as high or low sensitives. Likewise, the tasting panel showed two groups responding differently to aroma and flavor. Both high and low aroma sensitivity individuals showed equal (p>0.05) and congruent response to in-mouth sweet flavor perception. Moreover, the high smell sensitive group was less sensitive to sourness and saltiness than the low smell sensitives for the spiked wines across all flavor concentrations. Differences in PROP taster status and sensitivity to other tastants in water solutions were not correlated with the taste/mouthfeel perceptions in wine. The individuals most sensitive to sucrose in wine taste showed higher response to the fruity aroma. In conclusion, taste, mouthfeel and flavor perceptions showed a high variability among individuals evidencing the advantage of grouping tasters with different chemosensory sensitivities to understand cross-modal sensory interactions.

The Impact of Optical Berry Sorting on Red Wine Composition and Sensory Properties

The impact of optical berry sorting was investigated using Grenache, Barbera, and Cabernet Sauvignon grapes from Yolo County, California in 2016. Optical sorting parameters were adjusted to remove underripe berries and material other than grapes using color parameters. Wines were made from three treatments, control (no sorting), sort (accepted material), and reject (material rejected by the optical sorter). The rate of rejection was approximately 14.9%, 3.9%, and 1.5% (w/w) for Grenache, Barbera, and Cabernet Sauvignon, respectively. Chemical composition in the finished wines was analyzed by the Adams-Harbertson assay and reversed-phase high-performance liquid chromatography for phenolics, and head-space solid-phase microextraction gas chromatography mass spectrometry for aroma profiling. In general, optical sorting was successful in removing underripe berries and material other than grapes as evidenced by lower ethanol levels and higher concentrations of total phenolics and tannin (due to the inclusion of material other than grapes) in wine made from rejected material. Despite this, no difference in final ethanol content and minimal differences in phenolic composition were observed between control and sort treatment wines for the three varieties studied. Differences were observed in the aroma profiles of the reject treatments for all three varieties compared to sort and control; however, few compounds differed significantly between the sort and control treatments. Descriptive sensory analysis revealed that panelists had difficulty distinguishing aroma, taste, mouthfeel, and color parameters among wines made from different treatments for all three varieties. Thus, optical sorting had minimal impact on wine sensory properties using the varieties and vineyards studied. Optical sorting may be used to differentiate and sort for different ripeness levels using color as a primary criterion; however, the impact on the resulting wine is likely dependent on the initial variability in grape ripeness.

Evaluation of the Effect of a Grape Seed Tannin Extract on Wine Ester Release and Perception Using In Vitro and In Vivo Instrumental and Sensory Approaches

This study aimed to systematically evaluate the effect of a commercial grape seed tannin extract (GSE) fully characterized (53% monomers, 47% procyanidins) on wine ester release and perception using a global approach. The behavior of two esters (ethyl hexanoate, ethyl decanoate) was studied in a control wine or in the same wine supplemented with the GSE in preconsumption (in vitro headspace-stir bar sorptive extraction-gas chromatography mass spectrometry (HS-SBSE-GC/MS) and orthonasal perception) and consumption (intraoral-HS-SBSE-GC/MS and dynamic retronasal perception) conditions. For the compound ethyl hexanoate, no significant differences (p > 0.05) among wines were observed in the in vitro analyses while they were observed in the three in vivo experiments (p < 0.05). Thus, the wine supplemented with the GSE showed lower (35%) in vivo release and ortho (36%) and retronasal (16%) perception scores than the control wine. Overall, this suggests that components of the GSE could interact with this compound, directly and/or through complexes with oral components, affecting its release and conditioning its perception. However, perceptual interactions and effects of polyphenols on oral esterases cannot be discarded. On the contrary, the compound ethyl decanoate was not significantly affected by the addition of GSE. In conclusion, the addition of tannin extracts to wines can modulate aroma perception in a compound-dependent manner.

Sweetness Enhancement by Aromas: Measured by Descriptive Sensory Analysis and Relative to Reference Scaling

Sweetness enhancement by aromas has been suggested as a strategy to mitigate sugar reduction in food products, but enhancement is dependent on type of aroma and sugar level. A careful screening of aromas across sugar levels is thus required. Screening results might, however, depend on the method employed. Both descriptive sensory analysis and relative to reference scaling were therefore used to screen 5 aromas across 3 sucrose concentrations for their sweetness-enhancing effects in aqueous solutions. In the descriptive analysis, samples with added vanilla, honey, and banana aroma were rated as significantly sweeter than samples with added elderflower or raspberry aroma at all sucrose concentrations. In relative to reference scaling, honey aroma significantly increased the sweet taste compared with samples with added elderflower or no aroma at low and medium sucrose concentrations. Banana and raspberry aromas also increased the sweet taste significantly compared with the sample with added elderflower aroma at medium sucrose concentration in the relative to reference scaling. This demonstrates that the cross-modal effects observed by the 2 methods were different. In terms of the methods applied, relative to reference scaling was generally found to result in a decrease in the measured sweetness enhancement by aromas. In the descriptive analysis, the cross-modal effect of aromas on sweet taste perception was found to be significantly higher at 2.5% and 5.0% w/w sucrose compared with 7.5% w/w sucrose. These results highlight the importance of considering how references are employed in sensory analysis and how they affect cross-modal interactions.

Effect of aroma perception on taste and mouthfeel dimensions of red wines: Correlation of sensory and chemical measurements

The present study was aimed at increasing the understanding of red wine mouthfeel by investigating the potential cross-modal effect of aroma and establishing relationships between sensory dimensions and chemical measurements. Investigations involved a set of 42 non-wooded red wines that were described with a novel application of a variant of the rate-all-that-apply sensory methodology ("rate-K attributes") by a group of Spanish wine experts under two conditions: (1) with no aroma perception (using nose clips) and (2) with aroma perception. In parallel, ethanol content, pH, titratable acidity, tannin activity, concentration of tannins, and spectroscopic measures of wines were determined. Results suggest that aroma does not play a main effect on taste or mouthfeel perception of red wines, except for oily mouthfeel, which was hypothesised to be masked by earthy aromas and enhanced by alcoholic nuances attributed to cognitive interactions. Independent and non-correlated mouthfeel dimensions such as dry/silky and sticky, grainy, prickly or oily were also identified. Tannin activity was shown to be highly positively correlated to dry on the palate, and tannin concentration with both overall dry and dry on the palate. A significant partial least squares regression model showed that tannin concentration and activity (positive contribution) as well as pH values (negative) were good predictors of the mouthfeel dimension mainly related to dry and sticky terms.

Attending to the Chemical Senses

Theorizing around the topic of attention and its role in human information processing largely emerged out of research on the so-called spatial senses: vision, audition, and to a lesser extent, touch. Thus far, the chemical senses have received far less research interest (or should that be attention) from those experimental psychologists and cognitive neuroscientists interested in the topic. Nevertheless, this review highlights the key role that attentional selection also plays in chemosensory information processing and awareness. Indeed, many of the same theoretical approaches/experimental paradigms that were originally developed in the context of the spatial senses, can be (and in some cases already have been) extended to provide a useful framework for thinking about the perception of taste/flavour. Furthermore, a number of those creative individuals interested in modifying the perception of taste/flavour by manipulating product-extrinsic cues (such as, for example, music in the case of sonic seasoning) are increasingly looking to attentional accounts in order to help explain the empirical phenomena that they are starting to uncover. However, separate from its role in explaining sonic seasoning, gaining a better understanding of the role of attentional distraction in modulating our eating/drinking behaviours really ought to be a topic of growing societal concern. This is because distracted diners (e.g., those who eat while watching TV, fiddling with a mobile device or smartphone, or even while driving) consume significantly more than those who mindfully pay attention to the sensations associated with eating and drinking.

Basic In-Mouth Attribute Evaluation: A Comparison of Two Panels

Astringency is often difficult to evaluate accurately in wine because of its complexity. This accuracy can improve through training sessions, but it can be time-consuming and expensive. A way to reduce these costs can be the use of wine experts, who are known to be reliable evaluators. Therefore, the aim of this work was to compare the sensory results and the panel performance obtained using trained panelists versus wine experts (winemakers). Judges evaluated twelve red wines for in-mouth basic perception (sweet, sour, bitter, astringent, and burning sensation) following the same tasting protocol and with the samples being presented in two different tasting modalities. Panels’ performance and relationship between the chemical composition and the sensory perception were investigated. Both panels showed similar consistency and repeatability, and they were able to accurately measure the astringency of the wines. However, the significant correlations between sensory scores and chemical composition varied with the panel and the tasting modality. From our results, we could see that winemakers tended to discriminate better between the samples when the differences were very small.

Dose-Response Relationships for Vanilla Flavor and Sucrose in Skim Milk: Evidence of Synergy

Regarding cross-modality research, taste-aroma interaction is one of the most studied areas of research. Some studies have reported enhancement of sweetness by aroma, although it is unclear as to whether these effects actually occur: depending on the cognitive strategy employed by panelists, the effects may disappear, e.g., forcing panelists into an analytical strategy to control for dumping may not be able to reveal perceptual interactions. Previous studies have largely focused on solutions and model foods, and did not test stimuli or concentrations relevant to real food applications. This study addresses these gaps: 18 vanilla flavored sucrose milks, varying between 0–0.75% (w/w) two-fold vanilla, and 0–5% (w/w) sucrose, were rated by 108 panelists for liking and perceived sweetness, vanilla flavor, milk flavor, and thickness. Interactions between vanilla and sucrose were measured using deviations of real mixtures from additive models (via the isobole method), indicating vanilla aroma does enhance perceived sweetness. However, the sweetness enhancing effect of vanilla aroma was not as pronounced as that of sucrose on vanilla flavor. Measurable cross-modal interactions occur despite using an analytical cognitive strategy. More work is needed to investigate the influence of perceptual strategy on the degree of taste-aroma interactions in real foods.

Towards a whole brain model of Perceptual Learning

A hallmark of modern Perceptual Learning (PL) is the extent to which learning is specific to the trained stimuli. Such specificity to orientation, spatial location and even eye of training has been used as psychophysical evidence of the neural basis of learning. This argument that specificity of PL implies regionalization of brain plasticity implicitly assumes that examination of a singular locus of PL is an appropriate approach to understand learning. However, recent research shows that learning effects once thought to be specific depend on subtleties of the training paradigm and that within even a simple training procedure there are multiple aspects of the task and stimuli that are learned simultaneously. Here, we suggest that learning on any task involves a broad network of brain regions undergoing changes in representations, read-out weights, decision rules, attention and feedback processes as well as oculomotor changes. However, importantly, the distribution of learning across the neural system depends upon the details of the training procedure and the characterstics of the individual being trained. We propose that to advance our understanding of PL, the field must move towards understanding how distributed brain processes jointly contribute to behavioral learning effects.

Modified proton transfer reaction mass spectrometry (PTR-MS) operating conditions for in vitro and in vivo analysis of wine aroma

With proton transfer reaction-mass spectrometry standard operating conditions, analysis of alcoholic beverages is an analytical challenge. Ethanol reacts with the primary ion H₃ O⁺ leading to its depletion and to formation of ethanol-related ions and clusters, resulting in unstable ionization and in significant fragmentation of analytes. Different methods were proposed but generally resulted in lowering the sensitivity and/or complicating the mass spectra. The aim of the present study was to propose a simple, sensitive, and reliable method with fragmentation as low as possible, linearity within a realistic range of volatile organic compounds concentrations, and applicability to in vivo dynamic aroma release (nosespace) studies of wines. For in vitro analyses, a reference flask containing a hydro-alcoholic solution (10% ethanol) was permanently connected to the PTR-MS inlet in order to establish ethanol chemical ionization conditions. A low electric field strength to number density ratio E/N (80 Td) was used in the drift-tube. A stable reagent ion distribution was obtained with the primary protonated ethanol ion C₂ H₅ OH₂⁺ accounting for more than 80% of the ionized species. The ethanol dimer (C₂ H₅ OH)₂ H⁺ accounted for only 10%. Fragmentation of some aroma molecules important for white wine flavor (various esters, linalool, cis-rose oxide, 2-methylpropan-1-ol, 3-methylbutan-1-ol, and 2-phenylethanol) was studied from same ethanol content solutions connected alternatively with the reference solution to the instrument inlet. Linear dynamic range and limit of detection (LOD) were determined for ethyl hexanoate. Fragmentation of the protonated analytes was limited to a few ions of low intensity, or to specific fragment ions with no further fragmentation. Association and/or ligand switching reactions from ethanol clusters were only significant for the primary alcohols. Interpretation of the mass spectra was straightforward with easy detection of diagnostic ions. These results made this ethanol ionization method suitable for direct headspace analyses of model wines and to their nosespace analyses.

Assessing the influence of music on wine perception among wine professionals

Several recent studies have demonstrated that music can significantly influence the eating/drinking experience. It is not clear, however, whether this influence would be moderated by the expertise of the taster. In the experiments reported here, we tested a large group (N = 154) of very experienced wine tasters—the majority of whom were professionals working in the wine business—at a winemaking conference. The first study assessed the impact of putatively “sweet” and “sour” soundtracks on taste evaluation, whereas the second study assessed more subtle wine‐specific terminology such as length, balance, and body. The results revealed that the effect of music on wine perception can indeed be demonstrated in wine experts. Moreover, the amount of wine tasting experience, as measured in years, did not moderate the influence of music on sensory and hedonic wine evaluation. This result suggests that the aforementioned auditory modulation of drinking experience is not influenced by the increased analytical abilities afforded by traditional wine tasting expertise.

Characterization of the Key Aroma Compounds in Chinese Syrah Wine by Gas Chromatography-Olfactometry-Mass Spectrometry and Aroma Reconstitution Studies

The key aroma compounds and the organoleptic quality of two Chinese Syrah wines from the Yunnan Shangri-La region and Ningxia Helan mountain region were characterized. The most important eighty aroma-active compounds were identified by Gas Chromatography-Olfactometry. In both Syrah samples, ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, 3-methylbutyl acetate, 2- and 3-methyl-1-butanol, ethyl hexanoate, ethyl octanoate, 2-phenethyl acetate, methional, 3-methylbutanoic acid, hexanoic acid, octanoic acid, β-damascenone, guaiacol, 2-phenylethanol, trans-whiskylactone, 4-ethylguaiacol, eugenol, 4-ethylphenol, and sotolon were detected to have the highest odor intensities. In the chemical analysis, 72 compounds were quantitated by Stir Bar Sorptive Extraction combined with Gas Chromatography Mass Spectrometry. Based on the Odor Activity Value (OAV), the aromas were reconstituted by combining aroma compounds in the synthetic wine, and sensory descriptive analysis was used to verify the chemical data. Fatty acid ethyl esters, acetate esters, and β-damascenone were found with higher OAVs in the more fruity-smelling sample of Helan Mountain rather than Shangri-La.