Aroma release of a model wine solution as influenced by the presence of non-volatile components. Effect of commercial tannin extracts, polysaccharides and artificial saliva

Assessment Wine Aroma Persistence by Using an in Vivo PTR-ToF-MS Approach and Its Relationship with Salivary Parameters

To better understand wine aroma persistence, the nasal cavity of nine volunteers was monitored by Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) after they rinsed their mouths with three rosé wines (one control and the same wine supplemented with two tannin extracts) during four minutes. Wines were aromatised with a mixture of five target aroma compounds. Results showed that wine aroma persistence was highly compound-dependent: while esters disappeared very fast, other compounds such as linalool remained in the oral cavity for longer times after wine expectoration. A low effect of tannins (at 50 mg/L) on nasal cavity parameters was observed, with the exception for the compound ethyl decanoate that was significantly higher released in the presence of tannins. Strong interindividual differences on aroma persistence were also found. Significant positive correlations with the salivary total protein content and negative with the salivary flow were observed for specific compounds. This work has studied for the first time in vivo wine aroma persistence in real time from an analytical perspective.

Impact of polyphenols on the headspace concentration of aroma compounds in apple cider

BACKGROUND

To study the effect of polyphenols on the release of aroma compounds in apple cider, the impact of (-)-epicatechin, hydrocaffeic acid and phloridzin on volatility of 12 typical aroma compounds was investigated by headspace solid phase microextraction and gas chromatography-mass spectrometry.

RESULTS

Analysis of variance results showed that increased concentrations of the phenolic compounds significantly affected the headspace concentration of most aroma compounds. The three polyphenols induced a volatility decrease for the majority of hydrophobic aroma compounds, while they exhibited an opposite behavior by salting out some hydrophilic alcohols. (-)-Epicatechin and hydrocaffeic acid showed a higher retention effect on most hydrophobic aroma compounds than phloridzin did.

CONCLUSION

This study showed that the polyphenols had varying effects on aroma compound volatility in apple cider. The physicochemical characteristics and spatial conformation of polyphenols and aroma compounds influenced the magnitude of aroma-polyphenol interaction in apple cider. Understanding the effects of polyphenols on aroma release can improve the prediction of aroma profiles through chemical analysis, which assists cidermakers in improving the aroma quality of apple cider. © 2018 Society of Chemical Industry.

Flavor Retention and Release from Beverages: A Kinetic and Thermodynamic Perspective

For the investigation of retention and release of flavor components, various methods are available, which are mostly used on a case-to-case basis depending on the raw material. These effects that originate from kinetics and thermodynamics could be put in a much wider perspective if these fields were taken as a starting point of investigation in combination with rigorous data analysis. In this Review, we give an overview of experimental techniques and data analysis methods, and predictive methods using mass transfer techniques are also discussed in detail. We use this as a foundation to discuss the interactions between volatile flavors and the matrix of liquid foods/beverages. Lipids present in the form of an emulsion are the strongest volatile retainers due to the lipophilic nature of most of the volatile flavors. Proteins also have flavor retention properties, whereas carbohydrates hardly have a retention effect in beverages. Smaller components, such as sugars and salts, can change the water activity, thereby facilitating flavor release. Alternatively, salts can also indirectly affect binding sites of proteins leading to release (e.g., NaCl and Na2SO4) or retention (NaCSN and Cl3CCOONa) of flavors. Furthermore, the effects of temperature and pH are discussed. The Review concludes with a critical section on determination of parameters relevant to flavor release. We highlight the importance of accurate determination of low concentrations when using linearization methods and also show that there is an intrinsic preference for nonlinear regression methods that are much less sensitive to measurement error.

Aroma release in the oral cavity after wine intake is influenced by wine matrix composition

The aim of this study has been to investigate if wine matrix composition might influence the interaction between odorants and oral mucosa in the oral cavity during a "wine intake-like" situation. Aroma released after exposing the oral cavity of three individuals to different wines (n=12) previously spiked with six target aromas was followed by an -in vivo intra-oral SPME approach. Results showed a significant effect of wine matrix composition on the intra-oral aroma release of certain odorants. Among the wine matrix parameters, phenolic compounds showed the largest impact. This effect was dependent on their chemical structure. Some phenolic acids (e.g. hippuric, caffeic) were associated to an increase in the intra-oral release of certain odorants (e.g. linalool, β-ionone), while flavonoids showed the opposite effect, decreasing the intra-oral release of aliphatic esters (ethyl hexanoate). This work shows for the first time, the impact of wine composition on oral-mucosa interactions under physiological conditions.

Understanding the release and metabolism of aroma compounds using micro-volume saliva samples by ex vivo approaches

This study investigated the behaviour of key aroma compounds in the presence of human saliva (200μL) from different individuals (n=3) submitted or not to centrifugation (whole vs clarified saliva). HS-GC results showed that human saliva strongly decreased the release of carbonyl compounds (aldehydes and ketones). This effect was dependent on i) the structure of the aroma compounds and ii) the saliva composition. Whole saliva exerted a higher effect than clarified saliva on aroma compounds. Moreover, this effect was individual-dependent and related to the total protein content and the total antioxidant capacity of saliva. HS-SPME and LLE-GC/MS analyses revealed that metabolism of the compounds by salivary enzymes was involved. This observation indicates that some aroma compounds could be metabolized in the oral cavity in an individual manner, which could have implications for aroma perception (e.g., formation of new metabolites with different odor thresholds and qualities) and/or organisms' health status (e.g., compound detoxification).

Use of Winemaking Supplements To Modify the Composition and Sensory Properties of Shiraz Wine

Wine quality can be significantly affected by tannin and polysaccharide composition, which can in turn be influenced by grape maturity and winemaking practices. This study explored the impact of three commercial wine additives, a maceration enzyme, an enotannin, and a mannoprotein, on the composition and sensory properties of red wine, in particular, in mimicking the mouthfeel associated with wines made from riper grapes. Shiraz grapes were harvested at 24 and 28 °Brix and the former vinified with commercial additives introduced either individually or in combination. Compositional analyses of finished wines included tannin and polysaccharide concentration, composition and size distribution by high-performance liquid chromatography, whereas the sensory profiles of wines were assessed by descriptive analysis. As expected, wines made from riper grapes were naturally higher in tannin and mannoprotein than wines made from grapes harvested earlier. Enzyme addition resulted in a significantly higher concentration and average molecular mass of wine tannin, which increased wine astringency. Conversely, mannoprotein addition reduced tannin concentration and astringency. Addition of enotannin did not meaningfully influence wine composition or sensory properties.

Changes in volatile composition and sensory attributes of wines during alcohol content reduction

A desirable sensory profile is a major consumer driver for wine acceptability and should be considered during the production of reduced-alcohol wines. Although various viticultural practices and microbiological approaches show promising results, separation technologies such as membrane filtration, in particular reverse osmosis and evaporative perstraction, in addition to vacuum distillation, represent the most common commercial methods used to produce reduced-alcohol wine. However, ethanol removal from wine can result in a significant loss of volatile compounds such as esters (ethyl octanoate, ethyl acetate, isoamyl acetate) that contribute positively to the overall perceived aroma. These losses can potentially reduce the acceptability of the wine to consumers and decrease their willingness to purchase wines that have had their alcohol level reduced. The change in aroma as a result of the ethanol removal processes is influenced by a number of factors: the type of alcohol reduction process; the chemical-physical properties (volatility, hydrophobicity, steric hindrance) of the aroma compounds; the retention properties of the wine non-volatile matrix; and the ethanol level. This review identifies and summarises possible deleterious influences of the dealcoholisation process and describes best practice strategies to maintain the original wine composition. © 2016 Society of Chemical Industry.

Determination of rheological property and its effect on key aroma release of Shanxi aged vinegar

The rheological property of Shanxi aged vinegar (SAV) was determined by rheometer, and its effects on release in eight key aroma components of SAV was investigated by SPME-GC-MS. In order to simulate the change of rheological property of SAV, a modified SAV system was developed from a finished SAV using carboxymethylcellulose, pectin, glucose, fructose, sodium chloride and tannic acid at indicate levels. The consistency coefficients (K) of SAV ranged from 1.09e-5 to 0.0137, which was correlated to glucose, polyphenol, acids and oBx. SAV changed from shear-thickening to Newtonian fluid during long-time ageing. In the modified SAV system, the K values increased significantly, and two modified vinegar became quasi-Newtonian fluids too. Furthermore, release of the eight key aroma compounds decreased significantly and decreased was pronounced, for acetic acid, furfural and tetramethylpyrazine. The results demonstrated rheological property correlated to the concentrate of sugar, salt, polyphenol, acids and macromolecule, which significantly affected the release of major aroma compounds.

Development of a SPME-GC-MS method for the determination of volatile compounds in Shanxi aged vinegar and its analytical characterization by aroma wheel

A solid-phase microextraction followed by gas chromatography-mass spectrometry method was developed to determine the volatile compounds in Shanxi aged vinegar. The optimal extraction conditions were: 50 °C for 20 min with a PDMS/DVB fiber. This analytical method was validated and showed satisfactory repeatability (0.5 %<RSD<12 %), reproducibility (2.5 %<RSD<15.6 %), accuracy and linearity in analysis of volatile compounds. According to the calculation of odor activity value, 19 volatile compounds were identified as aroma-active compounds. Among them, propanoic acid, acetic acid, trimethyl-oxazole, butanoic acid, acetoin, 3-methylbutanoic acid and furfural were the most powerful odorants. The aroma wheel of Shanxi aged vinegar showed that the classes of sensory descriptors are first fatty and roasty, next woody and nutty and minor fruity and floral. Principal component analysis enabled us to investigate dissimilarity/similarity of Shanxi aged vinegar sample of different raw material and ageing time.

Study of combined effect of proteins and bentonite fining on the wine aroma loss

The wine aroma loss as a consequence of treatments with bentonite is due to the occurrence of multiple interaction mechanisms. In addition to a direct effect of bentonite, the removal of aroma compounds bound to protein components adsorbed by the clay has been hypothesized but never demonstrated. We studied the effect of bentonite addition on total wine aroma compounds (extracted from Moscato wine) in a model solution in the absence and presence of total and purified (thaumatin-like proteins and chitinase) wine proteins. The results showed that in general bentonite alone has a low effect on the loss of terpenes but removed ethyl esters and fatty acids. The presence of wine proteins in the solution treated with bentonite tended to increase the loss of esters with the longest carbon chains (from ethyl octanoate to ethyl decanoate), and this was significant when the purified proteins were used. The results here reported suggest that hydrophobicity can be one of the driving forces involved in the interaction of aromas with both bentonite and proteins.

Understanding the role of saliva in aroma release from wine by using static and dynamic headspace conditions

The aim of this work was to determine the role of saliva in wine aroma release by using static and dynamic headspace conditions. In the latter conditions, two different sampling points (t = 0 and t = 10 min) corresponding with oral (25.5 °C) and postoral phases (36 °C) were monitored. Both methodologies were applied to reconstituted dearomatized white and red wines with different nonvolatile wine matrix compositions and a synthetic wine (without matrix effect). All of the wines had the same ethanol concentration and were spiked with a mixture of 45 aroma compounds covering a wide range of physicochemical characteristics at typical wine concentrations. Two types of saliva (human and artificial) or control samples (water) were added to the wines. The adequacy of the two headspace methodologies for the purposes of the study (repeatability, linear ranges, determination coefficients, etc.) was previously determined. After application of different chemometric analysis (ANOVA, LSD, PCA), results showed a significant effect of saliva on aroma release dependent on saliva type (differences between artificial and human) and on wine matrix using static headspace conditions. Red wines were more affected than white and synthetic wines by saliva, specifically human saliva, which provoked a reduction in aroma release for most of the assayed aroma compounds independent of their chemical structure. The application of dynamic headspace conditions using a saliva bioreactor at the two different sampling points (t = 0 and t = 10 min) showed a lesser but significant effect of saliva than matrix composition and a high influence of temperature (oral and postoral phases) on aroma release.

Impact of the nonvolatile wine matrix composition on the in vivo aroma release from wines

The impact of the nonvolatile wine matrix composition on the retronasal aroma release of four volatile compounds added to different types of wines has been evaluated. For this purpose, a tailor-made retronasal aroma trapping device (RATD) was used to entrap the exhaled breath of six panelists previously trained in a specific consumption procedure. Five wines of different composition (white wine, sparkling white wine, young red wine, aged red wine, and a sweet wine) were evaluated. Prior to the evaluation, with the exception of the sweet wine, the wines were adjusted to the same ethanol content and aromatized with a mixture of four target volatile compounds. Aroma release data were submitted to multivariate statistical analysis in order to relate wine chemical composition and aroma release during wine drinking. Results showed interindividual differences and a clustering of panelists among lower and higher aroma releasers, which was in agreement to the differences in their breathing capacity. A significant influence of the matrix composition in the low aroma releasers group during wine consumption was observed. The consumption of red wines provoked a significantly higher aroma release than the consumption of white and sweet wines. From the chemical composition determined in the wine samples (pH, total acidity, total polyphenols, neutral polysaccharides, residual sugar, and nitrogenous compounds), the amount of total polyphenols was better correlated with the observed effect.

Wine, Food and Health

Wine has historically been associated with religious rights, used as a salubrious beverage, employed as a medication as well as a medicinal solvent, and consumed as a food accompaniment. It is the latter that is most intimately associated in the minds of most modern consumers. Despite this, there is little flavor commonality on which pairing could be based. The first section of the chapter examines this feature, and wine’s primary role as a palate cleanser and food condiment. The synergistic role of food and wine in suppressing each other’s least pleasant attributes is also explained. The final section deals with the latest evidence relating to the many beneficial health effects of moderate wine consumption, shortfalls in the data, headache induction, dental erosion, and conditions under which wine intake is contraindicated.

A comparative analysis of the influence of human salivary enzymes on odorant concentration in three palm wines

The influence of human salivary enzymes on palm wines' odorant concentrations were investigated by the application of aroma extracts dilution analysis (AEDA) and by the calculation of odour activity values (OAVs), respectively. The odorants were quantified by means of stable isotope dilution assays (SIDA), and the degradation profiles of odorants by human saliva were also studied. Results revealed 46 odour-active compounds in the flavour dilution (FD) factor range of 4-256, and all were subsequently identified. Of the 46 odorants, 41 were identified in the Elaeis guineensis wine, 36 in Raphia hookeri wine and 29 in Borassus flabellifer wine. Among the odorants, the highest FD-factors were obtained from acetoin, 2-acetyl-1-pyrroline and 3-isobutyl-2-methoxypyrazine. Among the 13 potent odorants identified, five aroma compounds are reported here as important contributors to palm wine aroma, namely 3-isobutyl-2-methoxy-pyrazine, acetoin, 2-acetyl-1-pyrroline, 3-methylbutylacetate and ethyl hexanoate. Meanwhile, salivary enzymic degradation of odorants was more pronounced among the aldehydes, esters and thiols.

Wine matrix compounds affect perception of wine aromas

Wine is a complex alcoholic beverage. The wine matrix or the components that are present in the wine play an important role in the perceived aroma and flavor of the wine. The wine matrix is composed of two fractions, the nonvolatile fraction, which includes ethanol (in liquid phase), polyphenolic compounds, proteins, and carbohydrates, and the volatile fraction, which incorporates flavor and aroma compounds. Interactions among these compounds may arise through various mechanisms, thus affecting the sensory and chemical properties of the wine. The main focus of this review is to highlight recent research on wine component interactions and their effects on perceived aroma in the wine. An overview of the wine impact odorants and their determination using sensory and chemical methods is also provided in this paper.

Chemometrical development and comprehensive validation of a solid phase microextraction/gas chromatography-mass spectrometry methodology for the determination of important free and bound primary aromatics in Greek wines

In this work, a solid-phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS) methodology was developed for the determination of 21 free and glycosidically-bound volatile varietal aroma compounds in wines. Initially, a comparison was made of 5 commercially available SPME fibers for the isolation/preconcentration of the target compounds in the headspace (HS) and direct immersion (DI) modes. The statistical significance of the microextraction variables was evaluated using a 2-level Plackett-Burman experimental design; the most significant variables were further optimized using a modified Simplex procedure. Using the selected conditions, a GC-MS method was fully validated for the quantitative determination of the 21 free primary aroma compounds. The hydrophilic bound precursors were isolated by solid-phase extraction (SPE), enzymatically hydrolyzed to liberate them as the free compounds and further detected by SPME/GC-MS. The method has been successfully applied to the analysis of 20 Greek white wine samples.

Changes in total and individual crocetin esters upon in vitro gastrointestinal digestion of saffron aqueous extracts

Changes that may be expected in crocetin esters (crocins) upon digestion were examined in saffron aqueous extracts for the first time. Chemical characterization of total and individual crocins and other bioactive compounds was achieved by UV-vis spectrophotometry, RP-HPLC-DAD, and LC-ESI-MS. Antioxidant activity was evaluated using in vitro assays and the comet assay. The observed loss for both total and trans-crocins was higher in saffron (∼50%) than in gardenia extracts (∼30%), which were also examined for comparison. Loss was lower than that reported for hydrophobic carotenoids. cis-Isomers were less affected, leading to the hypothesis that trans/cis isomerization may occur in parallel to degradation reactions. Monitoring changes in the extracts at oral, gastric, or intestinal phases, separately, verified this view pointing out the critical effect of pH, temperature, and duration of process but not of digestive enzymes. No isomerization and less degradation (<20% loss) was evidenced when pure trans-crocetin (di-β-D-gentiobiosyl) ester was subjected to gastric or intestinal conditions.