Relationship between nonvolatile composition and sensory properties of premium Spanish red wines and their correlation to quality perception

Fast and Simple UPLC-Q-TOF MS Method for Determination of Bitter Flavan-3-ols and Oligomeric Proanthocyanidins: Impact of Vegetable Protein Fining Agents on Red Wine Composition

Wine phenolic compounds, particularly proanthocyanidins (PAs), play a significant role in wine sensory characteristics, specifically bitterness and astringency. Although not consensual, flavan-3-ols and oligomeric PAs are generally considered the primary contributors to wine bitterness. Patatin, a vegetable protein fining agent, has been explored as an alternative to animal and synthetic fining agents for reducing wine bitterness. However, contradictory results exist regarding its effectiveness in removing flavan-3-ols and oligomeric PAs in red wines. In this work, a UPLC-Q-TOF MS/MS method was optimized and validated for accurately measuring flavan-3-ols, as well as dimeric and trimeric PAs, in red wines. The MS/MS analysis of flavan-3-ols, in addition to the typical fragmentation described in the literature, revealed an intense mass fragment resulting from the loss of C3O2 and C3O2 + H2O from the parent ion. It was observed that flavan-3-ols and PAs undergo oxidation during sample preparation, which was reversed by the addition of 5 g/L of ascorbic acid. The method demonstrated good linearity range (2 mg/L to 20 mg/L), detection limit (0.3 mg/L to 0.7 mg/L), quantification limit (0.8 mg/L to 2.2 mg/L), precision (repeatability 2.2% to 7.3%), and accuracy (recovery 98.5% to 100.5%). The application of patatin at different doses (5 g/L to 30 g/L) in two different red wine matrices did not reduce the levels of monomeric, dimeric, and trimeric PAs in red wines. However, similar behaviors were observed for pea protein and gelatin. Therefore, wine fining trials and efficiency measurements of the treatments in each matrix are strongly advised.

Mouthfeel subqualities in wines: A current insight on sensory descriptors and physical-chemical markers

Astringency and more generally mouthfeel perception are relevant to the overall quality of the wine. However, their origin and description are still uncertain and are constantly updating. Additionally, the terminology related to mouthfeel properties is expansive and extremely diversified, characterized by common traditional terms as well as novel recently adopted descriptors. In this context, this review evaluated the mention frequency of astringent subqualities and other mouthfeel attributes in the scientific literature of the last decades (2000-August 17, 2022). One hundred and twenty-five scientific publications have been selected and classified based on wine typology, aim, and instrumental-sensorial methods adopted. Dry resulted as the most frequent astringent subquality (10% for red wines, 8.6% for white wines), while body-and related terms-is a common mouthfeel sensation for different wine types, although its concept is still vague. Alongside, promising analytical and instrumental techniques investigating and simulating the in-mouth properties are discussed in detail, such as rheology for the viscosity and tribology for the lubrication loss, as well as the different approaches for the quantitative and qualitative evaluation of the interaction between salivary proteins and astringency markers. A focus on the phenolic compounds involved in the tactile perception was conducted, with tannins being the compounds conventionally found responsible for astringency. Nevertheless, other non-tannic polyphenolic classes (i.e., flavonols, phenolic acids, anthocyanins, anthocyanin-derivative pigments) as well as chemical-physical factors and the wine matrix (i.e., polysaccharides, mannoproteins, ethanol, glycerol, and pH) can also contribute to the wine in-mouth sensory profile. An overview of mouthfeel perception, factors involved, and its vocabulary is useful for enologists and consumers.

Characterization of the color parameters and monomeric phenolic composition of 'Tempranillo' and 'Graciano' wines made by carbonic maceration

The current study aims to gather information about the color-related characteristics and the monomeric phenolic composition of carbonic maceration (CM) wines. The study was conducted over two vintages, with two different grape varieties. Color-related general parameters and wine monomeric phenolic composition were determined in both free-run and press CM fractions and were compared to conventional winemaking (CW). Overall, wines made by CM had lower phenolic content and color intensity. The analysis of wine detailed phenolic composition showed that CM wines were characterized by low contents of anthocyanins and flavonols. In contrast, free-run wine obtained by CM had the greatest concentration of flavanols and hydroxycinnamic acids, probably due to the presence of stems during the fermentation. In conclusion, vinification by CM leads to important differences in wine phenolic composition and, as consequence, on wine color properties. These differences could play an important role in wine sensorial properties and wine aging potential.

Developing novel oenological tannins from 44 plants sources by assessing astringency and color in model wine

BACKGROUND

Oenological tannins are commercial natural products extracted from different botanical sources, which were widely reported as prominent contributors to wine quality. Research on wine quality affected by tannins extracts promoted the development of new oenological products with low cost and high accessibility. In the present study, the structure and concentration of tannin in polyphenol extracts, as well as their correlation with astringency and the color of model wine, was investigated by UV spectrophotometer, HPLC, fluorescence quenching, sodium dodecylsulfate-polyacrylamide gel electrophoresis, colorimeter and sensory evaluation.

RESULTS

Resource extracts from 16 of 44 plants were screened as wine oenological tannins, according to the total polyphenol and total flavanol, as well as the intensity of astringency and bitterness. Polyphenols extracted from grape seeds and green tea were more effective in increasing the wine astringency compared to other plant tannins.

CONCLUSION

Total flavanol content and tannin activity showed a strong correlation with wine astringency. Condensed tannins with mean degree of polymerization also exhibited strong color stability, and the concentrations of (-)-epigallocatechin were associated with the a* value, a negative qualitative factor for wine color. The present study provides new clues regarding the development of low-cost and highly accessible sources of polyphenol extracts and lays a theoretical foundation for the development of the oenological product. © 2022 Society of Chemical Industry.

Identification and quantification of key phytochemicals in peas - Linking compounds with sensory attributes

Pea protein isolates contain high-quality plant protein. However, they have sensory drawbacks, notably bitterness and astringency, that have limited their use in commercial foods. This study's aim was thus to identify the main phytochemicals in pea-based samples and to examine associations with sensory attributes. The phytochemical profiles of pea flour, pea protein isolates, and pea protein isolate fractions were characterized via UHPLC-DAD-MS. A total of 48 phytochemicals have been revealed: 6 phenolic acids, 5 flavonoids, and 1 saponin were identified and quantified, while another 9 phenolic acids, 10 flavonoids, and 6 saponins were tentatively identified. The impacts of protein extraction and fractionation were studied. These processes appear to have caused some compound degradation. It was found that 29 compounds were correlated with perceived bitterness and/or astringency. Therefore, these results show that certain phytochemicals can lead to negative sensory attributes in pea-protein-based products.

A novel strategy for discriminating different cultivation and screening odor and taste flavor compounds in Xinhui tangerine peel using E-nose, E-tongue, and chemometrics

A rapid strategy for discriminating Quanzhi (QZ) and Bozhi (BZ) of different cultivation of Xinhui tangerine peel was established by combining electronic nose, electronic tongue and chemometrics, which can be used as tool in the market to identify food fraud. 30 volatiles and 34 low molecular weight compounds of characteristic fingerprints of Xinhui tangerine peel of 108 samples were identified using GC-MS and UHPLC-Q-TOF-MS. Key compounds of BZ and QZ were screened and further compared by chemometrics. We discriminated odor and taste of BZ and QZ using electronic nose and electronic tongue, respectively. Our studies showed that β-myrcene, limonene, β-trans-Ocimene, γ-terpinene and terpinolene, etc, were screened the chief volatile flavor compounds by Spearman's rank correlation. Hydroxymethyl furfural, hesperitin, nobiletin and tangeretin, etc, were screened the key taste flavor compounds based gray relational analysis and partial least squares regression. Our study provides further insight for quality evaluation of Xinhui tangerine peel.

In-mouth attributes driving perceived quality of Pinot noir wines: Sensory and chemical characterisation

We investigated perception of mouthfeel in Pinot noir wines and its physicochemical determinants. Seventeen wine professionals judged 18 Pinot noir wines via two tasting tasks, Descriptive Rating and Directed Sorting, the latter based on perception of in-mouth attributes. Selected chemical measures of the same 18 wines were determined. Sensory results demonstrated that mouthfeel attributes driving high quality were smoothness/silky/velvety, volume/fullness/roundness, overall body, and viscosity/mouth-coating, while the taste of bitterness and perceived tannin harshness drove low quality judgments. Perceived astringency and expressions of tannin (e.g., soft; harsh; fine) drove sorting behaviour of participants. Partial least squares regression (PLSR) was used to associate perceived in-mouth phenomena and chemical composition. The phenolic profile, in particular tannin concentration and structure, was the most important predictor of astringency and its sub-components. These results have important implications for wine producers aiming to enhance perceived quality in their Pinot noir wines.

Commercial Mannoproteins Improve the Mouthfeel and Colour of Wines Obtained by Excessive Tannin Extraction

In the production of red wines, the pressing of marcs and extended maceration techniques can increase the extraction of phenolic compounds, often imparting high bitterness and astringency to finished wines. Among various oenological products, mannoproteins have been shown to improve the mouthfeel of red wines. In this work, extended maceration (E), marc-pressed (P), and free-run (F) Sangiovese wines were aged for six months in contact with three different commercial mannoprotein-rich yeast extracts (MP, MS, and MF) at a concentration of 20 g/hL. Phenolic compounds were measured in treated and control wines, and sensory characteristics related to the astringency, aroma, and colour of the wines were studied. A multivariate analysis revealed that mannoproteins had a different effect depending on the anthocyanin/tannin (A/T) ratio of the wine. When tannins are strongly present (extended maceration wines with A/T = 0.2), the MP conferred mouthcoating and soft and velvety sensations, as well as colour stability to the wine. At A/T = 0.3, as in marc-pressed wines, both MF and MP improved the mouthfeel and colour of Sangiovese. However, in free-run wine, where the A/T ratio is 0.5, the formation of polymeric pigments was allowed by all treatments and correlated with silk, velvet, and mouthcoat subqualities. A decrease in bitterness was also obtained. Commercial mannoproteins may represent a way to improve the mouthfeel and colour of very tannic wines.

Analysis of chemical compounds in beverages - Guidance for establishing a compositional analysis

In recent years, much analysis has been carried out regarding the chemical compositions of nonalcoholic and alcoholic beverages. However, no study has ever considered the compositional pitfalls inherent in such studies, which may lead to arbitrary results. Two approaches were compared in this paper, compositional data analysis (CoDa) and classical statistical analyses, to demonstrate (1) how aging affects beer and (2) how the results vary depending on the applied approach. Exemplarily, chemical compounds of 43 beer samples were analyzed. Our work has led us to obtain different results when the correlation analysis and principal component analysis were conducted on the unmodified-, log-transformed-, or closed-data in contrary to the analyses of log-ratio coordinates. The outcome of the latter provided better separation between aged and fresh beer samples and also easier interpretability. These results lead us to advise the usage of CoDa methods for the analyses of chemical compositions of beverages.

The Role of Soluble Polysaccharides in Tannin-Cell Wall Interactions in Model Solutions and in Wines

The interactions between tannins and soluble and insoluble cell wall components are, in part, responsible for the low quantities of tannins found in wines compared with the quantities in grapes. The use of polysaccharides to compete with cell wall components could be an interesting approach for improving the chromatic and sensory characteristics of wines. The effect of two commercial polysaccharides, pectin and mannan, on limiting tannin-cell wall interactions was studied in a model solution, measuring the concentration of tannins and polysaccharides remaining in solution after the different interactions by chromatography. The treatment was also tested in a small-scale vinification. Soluble polysaccharides were added to the must and the wines were evaluated at the end of alcoholic fermentation and after six months in the bottle. In the model solution, the commercial polysaccharides formed soluble complexes with the tannins and limited the interactions with cell wall components, with some differences between skin and seed tannins. In the case of the wines, the treatments resulted in wines with a higher color intensity and phenolic content. Sensory analysis resulted in higher scores for the wines with added polysaccharides, since the complexation of tannins with the polysaccharides increased the roundness and body of the resulting wines.

Rootstock effects on grape anthocyanins, skin and seed proanthocyanidins and wine color and phenolic compounds from Vitis vinifera L. Merlot grapevines

BACKGROUND

Rootstocks affect vegetative and reproductive parameters of the scion. However, limited knowledge exists on the effects of the adoption of a specific rootstock on grape and wine phenolic composition, which contribute to certain sensory attributes such as color, body and astringency of wine. These compounds are mainly affected by the variety, viticultural management and rootstock. The aim of this work was to study the influence of eight rootstocks on grape anthocyanin content, skin and seed proanthocyanidins and wine chromatic characteristics obtained from Merlot vines.

RESULTS

Grapevines grafted onto SO4 rootstock, in general, presented a higher concentration of total proanthocyanidins in skins and seeds compared to the rest of the rootstocks, whereas grapevines grafted onto Gravesac presented a lower concentration of proanthocyanidins in skins and seeds. These differences were found in the wines developed from grapevines grafted onto SO4. Wines from grapevines grafted onto SO4, 140 Ruggeri, Gravesac and 4453 M rootstocks presented, in general, better chromatic characteristics and a higher anthocyanin and tannin content than the rest of the samples.

CONCLUSION

This work gives additional information concerning the influence of rootstock on grape and wine phenolic composition. © 2018 Society of Chemical Industry.

Malvidin-3- O-glucoside Chemical Behavior in the Wine pH Range

Anthocyanins are natural pigments responsible for the typical color of red wines and are critically associated with the wine commercial value and longevity. Thus, understanding the molecular bases of the anthocyanin chemical behavior in the complex wine environment is a central issue to the enological sector. By setting up a nuclear-magnetic-resonance-based experimental protocol, new important insights into the chemistry of malvidin-3- O-glucoside, a major wine anthocyanin, in model solution have been provided. Two new equilibrating isomers of the anthocyanin have been identified and quantified at typical wine pH values. More importantly, the key role of pH in determining the solubility and co-pigmentation process of malvidin-3- O-glucoside has been clarified. Consequently, a value of pH of about 3.3 or lower favors co-pigmentation while inhibiting the precipitation of significant quantities of anthocyanins during the maceration-extraction phase of the winemaking.

Effect of sodium sulfite, tartaric acid, tannin, and glucose on rheological properties, release of aroma compounds, and color characteristics of red wine

In this study, we evaluated the effect of addition of non-volatile compounds (sodium sulfite, tartaric acid, tannin, and glucose) on the rheological properties, release of aroma compounds, and color of the red wine. While determining the rheological properties of the supplemented samples, non-Newtonian fluidic and shear-thinning behavior of samples was noticed. The viscosity of these samples was found in negative correlation with the dose of addition of various non-volatile substances. The aroma profile of red wine after additions showed the change in the release of the nine key aroma compounds. Among them ethyl hexanoate, phenylethyl alcohol, octanoic acid, diethyl succinate, and ethyl octanoate were profoundly increased. Further, the color of red wines was improved in the presence of tartaric acid and tannin. Overall, supplementation of various substances during storage period of three different wines could enormously affect the sensory characteristics in a dose dependent manner.

Effect of Exogenous Abscisic Acid and Methyl Jasmonate on Anthocyanin Composition, Fatty Acids, and Volatile Compounds of Cabernet Sauvignon (Vitis vinifera L.) Grape Berries

The anthocyanin composition, fatty acids, and volatile aromas are important for Cabernet Sauvignon grape quality. This study evaluated the effect of exogenous abscisic acid (ABA) and methyl jasmonate (MeJA) on the anthocyanin composition, fatty acids, lipoxygenase activity, and the volatile compounds of Cabernet Sauvignon grape berries. Exogenous ABA and MeJA improved the content of total anthocyanins (TAC) and individual anthocyanins. Lipoxygenase (LOX) activity also increased after treatment. Furthermore, 16 fatty acids were detected. The linoleic acid concentration gradually increased with ABA concentration. The fatty acid content decreased with increasing MeJA concentration and then increased again, with the exception of linoleic acid. After exogenous ABA and MeJA treatment, the C6 aroma content increased significantly. Interestingly, the exogenous ABA and MeJA treatments improved mainly the content of 1-hexanol, hexanal, and 2-heptanol. These results provide insight into the effect of plant hormones on wine grapes, which is useful for grape quality improvement.

Exogenous application of pectin-derived oligosaccharides to grape berries modifies anthocyanin accumulation, composition and gene expression

Anthocyanins are secondary metabolites synthesized in grape berry skins via the phenylpropanoid pathway, with functions ranging from skin coloration to protection against pathogens or UV light. Accumulation of these compounds is highly variable depending on genetics, environmental factors and viticultural practices. Besides their biological functions, anthocyanins improve wine quality, as a high anthocyanin content in berries has a positive impact on the color, total phenolic concentration and, ultimately, the price of wine. The present work studies the effect of the pre-veraison application of pectin derived oligosaccharides (PDO) on the synthesis and accumulation of these compounds, and associates the changes observed with the expression of key genes in the phenylpropanoid pathways. To this end, pre-veraison Cabernet Sauvignon bunches were treated with PDO to subsequently determine total anthocyanin content, the anthocyanin profile (by HPLC-DAD) and gene expression (by qRT-PCR), using Ethrel and water treatments for comparison. The results show that PDO were as efficient as Ethrel in generating a significant rise in total anthocyanin content at 30 days after treatment (dat), compared with water treatments (1.32, 1.48 and 1.02 mg e.Mv-3G/g FW respectively) without any undesirable effect on berry size, soluble solids, tartaric acid concentration or pH. In addition, a significant alteration in the anthocyanin profile was observed. Specifically, a significant increase in the relative concentration of malvidin was observed for both PDO and Ethrel treatments, compared with water controls (52.8; 55.0 and 48.3%, respectively), with a significant rise in tri-hydroxylated forms and a fall in di-hydroxylated anthocyanins. The results of gene expression analyses suggest that the increment in total anthocyanin content is related to a short term increase in phenylalanine ammonia-lyase (PAL) expression, mediated by a decrease in MYB4A expression. A longer term increase in UDP-glucose flavonoid 3-O-glucosyltransferase (UFGT) expression, probably mediated by a rise in MYBA1 was also observed. Regarding the anthocyanin profile, despite the increase observed in MYB5A expression in PDO and Ethrel treatments, no changes in flavonoid 3'-hydroxylase (F-3'-H); flavonoid 3'5'-hydroxylase (F-3'5'-H) or O-methyltransferase (OMT) could be related with the profile modifications described. Overall, this study highlights that application of PDO is a novel means of altering specific grape berry anthocyanins, and could be a means of positively influencing wine quality without the addition of agrochemicals.

Untargeted metabolomic analysis using liquid chromatography quadrupole time-of-flight mass spectrometry for non-volatile profiling of wines

The current study presents a method for comprehensive untargeted metabolomic fingerprinting of the non-volatile profile of the Graciano Vitis vinifera wine variety, using liquid chromatography/electrospray ionization time of flight mass spectrometry (LC-ESI-QTOF). Pre-treatment of samples, chromatographic columns, mobile phases, elution gradients and ionization sources, were evaluated for the extraction of the maximum number of metabolites in red wine. Putative compounds were extracted from the raw data using the extraction algorithm, molecular feature extractor (MFE). For the metabolite identification the WinMet database was designed based on electronic databases and literature research and includes only the putative metabolites reported to be present in oenological matrices. The results from WinMet were compared with those in the METLIN database to evaluate how much the databases overlap for performing identifications. The reproducibility of the analysis was assessed using manual processing following replicate injections of Vitis vinifera cv. Graciano wine spiked with external standards. In the present work, 411 different metabolites in Graciano Vitis vinifera red wine were identified, including primary wine metabolites such as sugars (4%), amino acids (23%), biogenic amines (4%), fatty acids (2%), and organic acids (32%) and secondary metabolites such as phenols (27%) and esters (8%). Significant differences between varieties Tempranillo and Graciano were related to the presence of fifteen specific compounds.

Key changes in wine aroma active compounds during bottle storage of Spanish red wines under different oxygen levels

Samples from 16 Spanish red wines have been stored for 6 months at 25 °C under different levels of oxygen (0-56 mg/L). Amino acids, metals, and phenolic compounds were analyzed and related to the production or depletion of key oxidation- and reduction-related aroma compounds. Oxidation brings about sensory-relevant increases in Strecker aldehydes, 1-octen-3-one, and vanillin. Formation of Strecker aldehydes correlates to the wine content on the corresponding amino acid precursor, Zn, and caffeic acid ethyl ester and negatively to some flavonols and anthocyanin derivatives. Formation of most carbonyls correlates to wine-combined SO2, suggesting that part of the increments are the result of the release of aldehydes forming bisulfite combinations once SO2 is oxidized. Methanethiol (MeSH) and dimethylsulfide (DMS), but not H2S levels, increase during storage. MeSH increments correlate to methionine levels and proanthocyanidins and negatively to resveratrol and aluminum. H2S, MeSH, and DMS levels all decreased with oxidation, and for the latter two, there are important effects of Mn and pH, respectively.

HPLC-DAD-ESI-MS/MS screening of bioactive components from Rhus coriaria L. (Sumac) fruits

Rhus coriaria L. (sumac) is an important crop widely used in the Mediterranean basin as a food spice, and also in folk medicine, due to its health-promoting properties. Phytochemicals present in plant foods are in part responsible for these consequent health benefits. Nevertheless, detailed information on these bioactive compounds is still scarce. Therefore, the present work was aimed at investigating the phytochemical components of sumac fruit epicarp using HPLC-DAD-ESI-MS/MS in two different ionisation modes. The proposed method provided tentative identification of 211 phenolic and other phyto-constituents, most of which have not been described so far in R. coriaria fruits. More than 180 phytochemicals (tannins, (iso)flavonoids, terpenoids, etc.) are reported herein in sumac fruits for the first time. The obtained results highlight the importance of R. coriaria as a promising source of functional ingredients, and boost its potential use in the food and nutraceutical industries.

Taste and mouthfeel properties of red wines proanthocyanidins and their relation to the chemical composition

The aim of this work is to assess the relationship between the in-mouth sensory properties of proanthocyanidins (PAs) and its chemical composition. To achieve such a goal, the proanthocyanidin fraction from six different young commercial red wines was obtained by gel permeation chromatography. A sensory panel, selected on the basis of their PROP status and trained in taste and mouthfeel sensations, described both the wines and fractions. MALDI-TOF-MS and UPLC-MS were used to identify thoroughly the polyphenolic composition of each proanthocyanidin fraction. The results showed that the PAs fractions were exclusively described as astringent and persistent. The astringent subqualities studied (velvety and puckering/drying) were mainly related to the quantity of proanthocyanidins and the proportion of the extension flavanol units linked to proanthocyanidins. A significant negative correlation was found between both of the astringencies (velvety and puckering/drying). Furthermore, both subqualities appeared to contribute to the persistence. A significant correlation was observed between the astringency and the persistence data of the wines and fractions. Significant multiple linear regressions were found between the sensory astringency data and the chemical compounds analyzed. The concentration of proanthocyanidins present in young red wines is the major determinant of the differences perceived in the astringency. Additionally, the extension flavanol units linked to the proanthocyanidins seem to have a different impact on the astringent subqualities.

Assessment of the impact of the addition of antimicrobial plant extracts to wine: volatile and phenolic composition

BACKGROUND

Antimicrobial plant phenolic-rich extracts have been proposed as alternative to sulfites in the control of the malolactic fermentation (MLF) during winemaking. This addition may affect wine organoleptic properties. In this paper, we have investigated the changes in wine volatile and phenolic composition, after MLF, of a red wine treated with antimicrobial extracts from eucalyptus leaves and almond skins.

RESULTS

Although addition of both extracts led to statistically significant changes (P < 0.05) in the concentration of several esters, alcohols, C13 nor-isoprenoids and volatile phenols, only few of these volatile compounds showed values of odour activity > 1 aroma unit; that is to say, whose concentrations were higher than their corresponding odour thresholds. With regard to phenolic compounds, the addition of both extracts did not significantly modify the content of anthocyanins, which predicts minor changes in wine colour. However, the content of non-anthocyanin phenolics was significantly higher in the wines treated with antimicrobial extracts, especially for flavonols, being the dose-over-taste factor for these wines significantly higher. Finally, principal component analysis showed that wines were mainly differentiated on the basis of whether MLF was conducted or not, and its method of performance (inoculated/spontaneous).

CONCLUSION

Addition of antimicrobial extracts leads to some compositional changes in the wine, whose relevance needs to be addressed in future experiments, including wine sensorial analysis.

Polyphenol compounds and anti-inflammatory activities of Korean black raspberry ( Rubus coreanus Miquel) wines produced from juice supplemented with pulp and seed

Three types of Korean black raspberry wine were produced via alcoholic fermentation from juice, juice-pulp, and juice-pulp-seed, respectively. These wines were compared in terms of their anti-inflammatory activities and polyphenol contents. The total content of polyphenol compounds in wines was increased by 22.4% after supplementation with pulp and by 56.7% after supplementation with both pulp and seed. The reduction rate of NO evolution was highest in the order juice-pulp-seed wine, juice-pulp wine, and juice wine. Addition of the juice-pulp-seed wine at a level of 62.5-500 mg/L decreased the NO evolution rate by 40.5-94.2%. Eight fractions were obtained from juice-pulp-seed wine via ethyl acetate extraction and silica gel chromatography. Of these, the AF fraction, which exhibited the highest in vitro anti-inflammatory activity, exerted inhibitory effects on ear edema, writhing response, and vein membrane vascular permeability in mice. 3,4-Dihydroxybenzoic acid accounted for 37.6% of the total polyphenol content in the AF fraction.

Contribution of non-volatile and aroma fractions to in-mouth sensory properties of red wines: wine reconstitution strategies and sensory sorting task

This work explores to what extent the aroma or the non-volatile fractions of red wines are responsible for the overall flavor differences perceived in-mouth. For this purpose, 14 samples (4 commercial and 10 reconstituted wines), were sorted by a panel of 30 trained assessors according to their sensory in-mouth similarities. Reconstituted wines were prepared by adding the same volatile fraction (coming from a red wine) to the non-volatile fraction of 10 different red wines showing large differences in perceived astringency. Sorting was performed under three different conditions: (a) no aroma perception: nose-close condition (NA), (b) retronasal aroma perception only (RA), and (c) allowing retro- and involuntary orthonasal aroma perception (ROA). Similarity estimates were derived from the sorting and submitted to multidimensional scaling (MDS) followed by hierarchical cluster analysis (HCA). Results have clearly shown that, globally, aroma perception is not the major driver of the in-mouth sensory perception of red wine, which is undoubtedly primarily driven by the perception of astringency and by the chemical compounds causing it, particularly protein precipitable proanthocyanidins (PAs). However, aroma perception plays a significant role on the perception of sweetness and bitterness. The impact of aroma seems to be more important whenever astringency, total polyphenols and protein precipitable PAs levels are smaller. Results also indicate that when a red-black fruit odor nuance is clearly perceived in conditions in which orthonasal odor perception is allowed, a strong reduction in astringency takes place. Such red-black fruit odor nuance seems to be the result of a specific aroma release pattern as a consequence of the interaction between aroma compounds and the non-volatile matrix.

Relationship between red wine grade and phenolics. 2. Tannin composition and size

Commercial red wines ( Vitis vinifera L. cv. Shiraz) produced during the 2009 vintage underwent winemaker assessment for allocation grade soon after production. The wines were then subjected to phenolic analysis to measure wine color (total anthocyanin, SO(2) nonbleachable pigment, and wine color density) and tannins (concentration, composition, and average degree of polymerization). A positive relationship was found between wine phenolic concentration and projected bottle price. Tannin compositional analysis suggested that there was specifically a relationship between wine grade and skin-derived tannins. These results suggest that maximization of skin tannin concentration and/or proportion is related to an increase in projected wine bottle price.

Quality and aromatic sensory descriptors (mainly fresh and dry fruit character) of Spanish red wines can be predicted from their aroma-active chemical composition

A satisfactory model explaining quality could be built in a set of 25 high quality Spanish red wines, by aroma-active chemical composition. The quality of the wines was positively correlated with the wine content in fruity esters, acids, enolones, and wood derived compounds, and negatively with phenylacetaldehyde, acetic acid, methional, and 4-ethylphenol. Wine fruitiness was demonstrated to be positively related not only to the wine content on fruity esters and enolones, but to wine volatile fatty acids. Fruitiness is strongly suppressed by 4-ethylphenol, acetic acid, phenylacetaldehyde, and methional, this involved in the perception of dry-fruit notes. Sensory effects were more intense in the presence of β-damascenone and β-ionone. A satisfactory model explaining animal notes could be built. Finally, the vegetal character of this set of wines could be related to the combined effect of dimethylsulfide (DMS), 1-hexanol, and methanethiol.

Wine and grape tannin interactions with salivary proteins and their impact on astringency: a review of current research

Astringency is an important characteristic of red wine quality. The sensation is generally thought to be produced by the interaction of wine tannins with salivary proteins and the subsequent aggregation and precipitation of protein-tannin complexes. The importance of wine astringency for marketability has led to a wealth of research on the causes of astringency and how tannins impact the quality of the sensation, particularly with respect to tannin structure. Ultimately, the understanding of how tannin structure impacts astringency will allow the controlled manipulation of tannins via such methods as micro-oxygenation or fining to improve the quality of wines.