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Sample records for tannins astringency wine

  1. Colloidal stability of tannins: astringency, wine tasting and beyond

    NASA Astrophysics Data System (ADS)

    Zanchi, D.; Poulain, C.; Konarev, P.; Tribet, C.; Svergun, D. I.

    2008-12-01

    Tannin-tannin and tannin-protein interactions in water-ethanol solvent mixtures are studied in the context of red wine tasting. While tannin self-aggregation is relevant for the visual aspect of wine tasting (limpidity and related colloidal phenomena), tannin affinities for salivary proline-rich proteins is fundamental for a wide spectrum of organoleptic properties related to astringency. Tannin-tannin interactions are analyzed in water-ethanol wine-like solvents and the precipitation map is constructed for a typical grape tannin. The interaction between tannins and human salivary proline-rich proteins (PRP) are investigated in the framework of the shell model for micellization, known for describing tannin-induced aggregation of β-casein. Tannin-assisted micellization and compaction of proteins observed by SAXS are described quantitatively and discussed in the case of astringency.

  2. Thermodynamics of grape and wine tannin interaction with polyproline: implications for red wine astringency.

    PubMed

    McRae, Jacqui M; Falconer, Robert J; Kennedy, James A

    2010-12-08

    The astringency of red wine is largely due to the interaction between wine tannins and salivary proline-rich proteins and is known to change as wine ages. To further understand the mechanisms behind wine astringency change over time, thermodynamics of the interactions between poly(l-proline) (PLP) and grape seed and skin tannins (preveraison (PV) and commercially ripe) or Shiraz wine tannins (2 years old and 9-10 years old) was analyzed using isothermal titration calorimetry (ITC). The nature of these interactions varied with changes to the tannin structure that are associated with maturation. The change in enthalpy associated with hydrophobic interaction and hydrogen bonding decreased with tannin age and the stoichiometry of binding indicated that grape tannins associated with more proline residues than wine tannins, irrespective of molecular size. These results could provide an explanation for the observed change in wine astringency quality with age.

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

    PubMed

    McRae, Jacqui M; Kennedy, James A

    2011-03-11

    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.

  4. Effect of condensed tannins addition on the astringency of red wines.

    PubMed

    Soares, Susana; Sousa, André; Mateus, Nuno; de Freitas, Victor

    2012-02-01

    Astringency has been defined as a group of sensations involving dryness, tightening, and shrinking of the oral surface. It has been accepted that astringency is due to the tannin-induced interaction and/or precipitation of the salivary proline-rich proteins (PRPs) in the oral cavity, as a result of the ingestion of food products rich in tannins, for example, red wine. The sensory evaluation of astringency is difficult, and the existence of fast and reliable methods to its study in vitro is scarce. So, in this work, the astringency of red wine supplemented with oligomeric procyanidins (condensed tannins), and the salivary proteins (SP) involved in its development were evaluated by high-performance liquid chromatography analysis of human saliva after its interaction with red wine and by sensorial evaluation. The results show that for low concentration of tannins, the decrease of acidic PRPs and statherin is correlated with astringency intensity, with these families having a high relative complexation and precipitation toward condensed tannins comparatively to the other SP. However, for higher concentrations of tannins, the relative astringency between wines seems to correlate's to the glycosylated PRPs changes. This work shows for the first time that the several families of SP could be involved in different stages of the astringency development.

  5. Tannin quantification in red grapes and wine: comparison of polysaccharide- and protein-based tannin precipitation techniques and their ability to model wine astringency.

    PubMed

    Mercurio, Meagan D; Smith, Paul A

    2008-07-23

    Quantification of red grape tannin and red wine tannin using the methyl cellulose precipitable (MCP) tannin assay and the Adams-Harbertson (A-H) tannin assay were investigated. The study allowed for direct comparison between the repeatability of the assays and for the assessment of other practical considerations such as time efficiency, ease of practice, and throughput, and assessed the relationships between tannin quantification by both analytical techniques. A strong correlation between the two analytical techniques was observed when quantifying grape tannin (r(2) = 0.96), and a good correlation was observed for wine tannins (r(2) = 0.80). However, significant differences in the reported tannin values for the analytical techniques were observed (approximately 3-fold). To explore potential reasons for the difference, investigations were undertaken to determine how several variables influenced the final tannin quantification for both assays. These variables included differences in the amount of tannin precipitated (monitored by HPLC), assay matrix variables, and the monomers used to report the final values. The relationship between tannin quantification and wine astringency was assessed for the MCP and A-H tannin assays, and both showed strong correlations with perceived wine astringency (r(2) = 0.83 and r(2) = 0.90, respectively). The work described here gives guidance to those wanting to understand how the values between the two assays relate; however, a conclusive explanation for the differences in values between the MCP and A-H tannin assays remains unclear, and further work in this area is required.

  6. Chemical Affinity between Tannin Size and Salivary Protein Binding Abilities: Implications for Wine Astringency.

    PubMed

    Ma, Wen; Waffo-Teguo, Pierre; Jourdes, Michael; Li, Hua; Teissedre, Pierre-Louis

    2016-01-01

    Astringency perception, as an essential parameter for high-quality red wine, is principally elicited by condensed tannins in diversified chemical structures. Condensed tannins, which are also known as proanthocyanidins (PAs), belong to the flavonoid class of polyphenols and are incorporated by multiple flavan-3-ols units according to their degree of polymerization (DP). However, the influence of DP size of PAs on astringency perception remains unclear for decades. This controversy was mainly attributed to the lack of efficient strategies to isolate the PAs in non-galloylated forms and with individual degree size from grape/wine. In the present study, the astringency intensity of purified and identified grape oligomeric tannins (DP ranged from 1 to 5) was firstly explored. A novel non-solid phase strategy was used to rapidly exclude the galloylated PAs from the non-galloylated PAs and fractionate the latter according to their DP size. Then, a series of PAs with individual DP size and galloylation were purified by an approach of preparative hydrophilic interaction chromatography. Furthermore, purified compounds were identified by both normal phase HPLC-FLD and reverse phase UHPLC-ESI-Q-TOF. Finally, the contribution of the astringency perception of the individual purified tannins was examined with a salivary protein binding ability test. The results were observed by HPLC-FLD and quantified by changes in PA concentration remaining in the filtrate. In summary, a new approach without a solid stationary phase was developed to isolate PAs according to their DP size. And a positive relationship between the DP of PAs and salivary protein affinity was revealed.

  7. Chemical Affinity between Tannin Size and Salivary Protein Binding Abilities: Implications for Wine Astringency

    PubMed Central

    Ma, Wen; Waffo-Teguo, Pierre; Jourdes, Michael; Li, Hua

    2016-01-01

    Astringency perception, as an essential parameter for high-quality red wine, is principally elicited by condensed tannins in diversified chemical structures. Condensed tannins, which are also known as proanthocyanidins (PAs), belong to the flavonoid class of polyphenols and are incorporated by multiple flavan-3-ols units according to their degree of polymerization (DP). However, the influence of DP size of PAs on astringency perception remains unclear for decades. This controversy was mainly attributed to the lack of efficient strategies to isolate the PAs in non-galloylated forms and with individual degree size from grape/wine. In the present study, the astringency intensity of purified and identified grape oligomeric tannins (DP ranged from 1 to 5) was firstly explored. A novel non-solid phase strategy was used to rapidly exclude the galloylated PAs from the non-galloylated PAs and fractionate the latter according to their DP size. Then, a series of PAs with individual DP size and galloylation were purified by an approach of preparative hydrophilic interaction chromatography. Furthermore, purified compounds were identified by both normal phase HPLC-FLD and reverse phase UHPLC-ESI-Q-TOF. Finally, the contribution of the astringency perception of the individual purified tannins was examined with a salivary protein binding ability test. The results were observed by HPLC-FLD and quantified by changes in PA concentration remaining in the filtrate. In summary, a new approach without a solid stationary phase was developed to isolate PAs according to their DP size. And a positive relationship between the DP of PAs and salivary protein affinity was revealed. PMID:27518822

  8. Effect of yeast strain and some nutritional factors on tannin composition and potential astringency of model wines.

    PubMed

    Rinaldi, Alessandra; Blaiotta, Giuseppe; Aponte, Maria; Moio, Luigi

    2016-02-01

    Nine Saccharomyces cerevisiae cultures, isolated from different sources, were tested for their ability to reduce tannins reactive towards salivary proteins, and potentially responsible for wine astringency. Strains were preliminary genetically characterized and evaluated for physiological features of technological interest. Laboratory-scale fermentations were performed in three synthetic media: CT) containing enological grape tannin; CTP) CT supplemented with organic nitrogen sources; CTPV) CTP supplemented with vitamins. Adsorption of total tannins, tannins reactive towards salivary proteins, yellow pigments, phenolics having antioxidant activity, and total phenols, characterizing the enological tannin, was determined by spectrophotometric methods after fermentation. The presence of vitamins and peptones in musts greatly influenced the adsorption of tannins reactive towards salivary proteins (4.24 g/L gallic acid equivalent), thus promoting the reduction of the potential astringency of model wines. With reference to the different phenolic classes, yeast strains showed different adsorption abilities. From a technological point of view, the yeast choice proved to be crucial in determining changes in gustative and mouthfeel profile of red wines and may assist winemakers to modulate colour and astringency of wine. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. NMR and molecular modeling of wine tannins binding to saliva proteins: revisiting astringency from molecular and colloidal prospects.

    PubMed

    Cala, Olivier; Pinaud, Noël; Simon, Cécile; Fouquet, Eric; Laguerre, Michel; Dufourc, Erick J; Pianet, Isabelle

    2010-11-01

    In organoleptic science, the association of tannins to saliva proteins leads to the poorly understood phenomenon of astringency. To decipher this interaction at molecular and colloidal levels, the binding of 4 procyanidin dimers (B1-4) and 1 trimer (C2) to a human saliva proline-rich peptide, IB7(14), was studied. Interactions have been characterized by measuring dissociation constants, sizes of complexes, number, and nature of binding sites using NMR (chemical shift variations, diffusion-ordered spectroscopy, and saturation transfer diffusion). The binding sites were identified using molecular mechanics, and the hydrophilic/hydrophobic nature of the interactions was resolved by calculating the molecular lipophilicity potential within the complexes. The following comprehensive scheme can be proposed: 1) below the tannin critical micelle concentration (CMC), interaction is specific, and the procyanidin anchorage always occurs on the same three IB7(14) sites. The tannin 3-dimensional structure plays a key role in the binding force and in the tannin's ability to act as a bidentate ligand: tannins adopting an extended conformation exhibit higher affinity toward protein and initiate the formation of a network. 2) Above the CMC, after the first specific hydrophilic interaction has taken place, a random hydrophobic stacking occurs between tannins and proteins. The whole process is discussed in the general frame of wine tannins eliciting astringency.

  10. Enhancement of both salivary protein-enological tannin interactions and astringency perception by ethanol.

    PubMed

    Obreque-Slíer, Elías; Peña-Neira, Alvaro; López-Solís, Remigio

    2010-03-24

    Red wine astringency has been associated with interactions of tannins with salivary proteins. Tannins are active protein precipitants. Not much evidence exists demonstrating contribution of other wine components to astringency. We aimed to investigate an eventual role of ethanol both in astringency and salivary protein-enological tannin interactions. A trained sensory panel scored perceived astringency. Salivary protein-tannin interactions were assessed by observing both tannin-dependent changes in salivary protein diffusion on cellulose membranes and tannin-induced salivary protein precipitation. Proanthocyanidins and gallotannins in aqueous and hydroalcoholic solutions were assayed. A biphasic mode of diffusion on cellulose membranes displayed by salivary proteins was unaffected after dilution with water or enological concentrations of ethanol. At those concentrations ethanol was not astringent. In aqueous solution, tannins provoked both restriction of salivary protein diffusion, protein precipitation, and astringency. Those effects were exacerbated by 13% ethanol. In summary, enological concentrations of ethanol exacerbate astringency and salivary protein-tannin interactions.

  11. How do consumers describe wine astringency?

    PubMed

    Vidal, Leticia; Giménez, Ana; Medina, Karina; Boido, Eduardo; Ares, Gastón

    2015-12-01

    Astringency is one of the most important sensory characteristics of red wine. Although a hierarchically structured vocabulary to describe the mouthfeel sensations of red wine has been proposed, research on consumers' astringency vocabulary is lacking. In this context, the aim of this work was to gain an insight on the vocabulary used by wine consumers to describe the astringency of red wine and to evaluate the influence of wine involvement on consumers' vocabulary. One hundred and twenty-five wine consumers completed and on-line survey with five tasks: an open-ended question about the definition of wine astringency, free listing the sensations perceived when drinking an astringent wine, free listing the words they would use to describe the astringency of a red wine, a CATA question with 44 terms used in the literature to describe astringency, and a wine involvement questionnaire. When thinking about wine astringency consumers freely elicited terms included in the Mouth-feel Wheel, such as dryness and harsh. The majority of the specific sub-qualities of the Mouth-feel Wheel were not included in consumer responses. Also, terms not classified as astringency descriptors were elicited (e.g. acid and bitter). Only 17 out of the 31 terms from the Mouth-feel Wheel were used by more than 10% of participants when answering the CATA question. There were no large differences in the responses of consumer segments with different wine involvement. Results from the present work suggest that most of the terms of the Mouth-feel Wheel might not be adequate to communicate the astringency characteristics of red wine to consumers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Exogenous acetaldehyde as a tool for modulating wine color and astringency during fermentation.

    PubMed

    Sheridan, Marlena K; Elias, Ryan J

    2015-06-15

    Wine tannins undergo modifications during fermentation and storage that can decrease their perceived astringency and increase color stability. Acetaldehyde acts as a bridging compound to form modified tannins and polymeric pigments that are less likely to form tannin-protein complexes than unmodified tannins. Red wines are often treated with oxygen in order to yield acetaldehyde, however this approach can lead to unintended consequences due to the generation of reactive oxygen species. The present study employs exogenous acetaldehyde at relatively low and high treatment concentrations during fermentation to encourage tannin modification without promoting potentially deleterious oxidation reactions. The high acetaldehyde treatment significantly increased polymeric pigments in the wine without increasing concentrations of free and sulfite-bound acetaldehyde. Protein-tannin precipitation was also significantly decreased with the addition of exogenous acetaldehyde. These results indicate a possible treatment of wines early in their production to increase color stability and lower astringency of finished wines. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Models based on ultraviolet spectroscopy, polyphenols, oligosaccharides and polysaccharides for prediction of wine astringency.

    PubMed

    Boulet, Jean-Claude; Trarieux, Corinne; Souquet, Jean-Marc; Ducasse, Maris-Agnés; Caillé, Soline; Samson, Alain; Williams, Pascale; Doco, Thierry; Cheynier, Véronique

    2016-01-01

    Astringency elicited by tannins is usually assessed by tasting. Alternative methods involving tannin precipitation have been proposed, but they remain time-consuming. Our goal was to propose a faster method and investigate the links between wine composition and astringency. Red wines covering a wide range of astringency intensities, assessed by sensory analysis, were selected. Prediction models based on multiple linear regression (MLR) were built using UV spectrophotometry (190-400 nm) and chemical analysis (enological analysis, polyphenols, oligosaccharides and polysaccharides). Astringency intensity was strongly correlated (R(2) = 0.825) with tannin precipitation by bovine serum albumin (BSA). Wine absorbances at 230 nm (A230) proved more suitable for astringency prediction (R(2) = 0.705) than A280 (R(2) = 0.56) or tannin concentration estimated by phloroglucinolysis (R(2) = 0.59). Three variable models built with A230, oligosaccharides and polysaccharides presented high R(2) and low errors of cross-validation. These models confirmed that polysaccharides decrease astringency perception and indicated a positive relationship between oligosaccharides and astringency. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Application of the SPI (Saliva Precipitation Index) to the evaluation of red wine astringency.

    PubMed

    Rinaldi, Alessandra; Gambuti, Angelita; Moio, Luigi

    2012-12-15

    The aim of this work was to evaluate the astringency of red wines by means of a SDS-PAGE based-method. The optimization of the in vitro assay, named SPI (Saliva Precipitation Index) that measured the reactivity of salivary proteins towards wine polyphenols, has been performed. Improvements included the choice of saliva:wine ratio, saliva typology (resting or stimulated saliva), and temperature of binding. The LOD (0.05 g/L of condensed tannin) and LOQ (0.1g/L of condensed tannin) for the binding reaction between salivary proteins and tannins added in white wine were also determined. Fifty-seven red wines were analysed by the optimised SPI, the Folin-Ciocalteu Index, the gelatine index, the content of total tannins and the sensory quantitative evaluation of astringency. A significant correlation between the SPI and the astringency of red wines was found (R(2)=0.969), thus indicating that this assay may be useful as estimator of astringency. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Sensory properties of wine tannin fractions: implications for in-mouth sensory properties.

    PubMed

    McRae, Jacqui M; Schulkin, Alex; Kassara, Stella; Holt, Helen E; Smith, Paul A

    2013-01-23

    Different molecular structures of grape tannins have been shown to influence astringency, however, the in-mouth sensory effects of different molecular structures in red wine tannins remains to be established. The objective of this research was to assess the impact of wine tannin structure on in-mouth sensory properties. Wine tannin was isolated from Cabernet Sauvignon wines of two vintages (3 and 7 years old) and separated into two structurally distinct subfractions with liquid-liquid fractionation using butanol and water. The aqueous subfractions had greater mean degree of polymerization (mDp) and contained a higher proportion of epigallocatechin subunits than the butanol-soluble subfractions, while the older wine tannin fractions showed fewer epicatechin gallate subunits than the younger tannin fractions. The red wine had approximately 3:1 mass ratio of the aqueous and butanol tannin subfractions which approximated an equimolar ratio of tannin in each subfraction. Descriptive sensory analysis of the tannin subfractions in model wine at equimolar concentrations revealed that the larger, more water-soluble wine tannin subfractions from both wines were perceived as more astringent than the smaller, more hydrophobic and more highly pigmented butanol-soluble subfractions, which were perceived as hotter and more bitter. Partial least squares analysis indicated that the greater hydrophobicity and color incorporation in the butanol fractions was negatively associated with astringency, and these characteristics are also associated with aged wine tannins. As the larger, water-soluble tannins had a greater impact on the overall wine astringency, winemaking processes that modulate concentrations of these are likely to most significantly influence astringency.

  16. Sensory characterization of the astringency of commercial Uruguayan Tannat wines.

    PubMed

    Vidal, Leticia; Antúnez, Lucía; Giménez, Ana; Medina, Karina; Boido, Eduardo; Ares, Gastón

    2017-12-01

    Astringency is one of the most important characteristics that define the quality of red wine, and is of particular relevance for Tannat, Uruguayan emblematic red wine variety. Astringency is a time-dependant and complex sensory characteristic, related to several sensations, or sub-qualities, that can be simultaneously perceived. The aim of the present study was to obtain a sensory characterization of the astringency of commercial Uruguayan Tannat wines. Forty samples with different characteristics in terms of vintage, price segment and aging in oak barrels were assessed by a panel of 9 trained assessors. Total astringency intensity was evaluated using time-intensity (TI), while astringency sub-qualities were described using a check-all-that-apply (CATA) question composed of sixteen terms. TI and the CATA question provided different information on the astringency of Tannat wines. Regarding global astringency, samples mainly differed in intensity-related parameters rather than in the development of astringency over time, although the variability was moderate. A wide range of sub-qualities, from silky and velvety to harsh and aggressive were used to describe the astringency of the evaluated wines. Four groups of samples with different astringency characteristics were identified, but this sorting was not related to vintage, price segment or aging in oak barrels. Further research is necessary to better understand how astringency characteristics are influenced by production variables, and to understand their relationship to consumers' and experts' perceived quality of Tannat wines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Astringency reduction in red wine by whey proteins.

    PubMed

    Jauregi, Paula; Olatujoye, Jumoke B; Cabezudo, Ignacio; Frazier, Richard A; Gordon, Michael H

    2016-05-15

    Whey is a by-product of cheese manufacturing and therefore investigating new applications of whey proteins will contribute towards the valorisation of whey and hence waste reduction. This study shows for the first time a detailed comparison of the effectiveness of gelatin and β-lactoglobulin (β-LG) as fining agents. Gelatin was more reactive than whey proteins to tannic acid as shown by both the astringency method (with ovalbumin as a precipitant) and the tannins determination method (with methylcellulose as a precipitant). The two proteins showed similar selectivity for polyphenols but β-LG did not remove as much catechin. The fining agent was removed completely or to a trace level after centrifugation followed by filtration which minimises its potential allergenicity. In addition, improved understanding of protein-tannin interactions was obtained by fluorescence, size measurement and isothermal titration calorimetry (ITC). Overall this study demonstrates that whey proteins have the potential of reducing astringency in red wine and can find a place in enology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Ethanol Concentration Influences the Mechanisms of Wine Tannin Interactions with Poly(L-proline) in Model Wine.

    PubMed

    McRae, Jacqui M; Ziora, Zyta M; Kassara, Stella; Cooper, Matthew A; Smith, Paul A

    2015-05-06

    Changes in ethanol concentration influence red wine astringency, and yet the effect of ethanol on wine tannin-salivary protein interactions is not well understood. Isothermal titration calorimetry (ITC) was used to measure the binding strength between the model salivary protein, poly(L-proline) (PLP) and a range of wine tannins (tannin fractions from a 3- and a 7-year old Cabernet Sauvignon wine) across different ethanol concentrations (5, 10, 15, and 40% v/v). Tannin-PLP interactions were stronger at 5% ethanol than at 40% ethanol. The mechanism of interaction changed for most tannin samples across the wine-like ethanol range (10-15%) from a combination of hydrophobic and hydrogen binding at 10% ethanol to only hydrogen binding at 15% ethanol. These results indicate that ethanol concentration can influence the mechanisms of wine tannin-protein interactions and that the previously reported decrease in wine astringency with increasing alcohol may, in part, relate to a decrease tannin-protein interaction strength.

  19. HPLC retention thermodynamics of grape and wine tannins.

    PubMed

    Barak, Jennifer A; Kennedy, James A

    2013-05-08

    The effect of grape and wine tannin structure on retention thermodynamics under reversed-phase high-performance liquid chromatography conditions on a polystyrene divinylbenzene column was investigated. On the basis of retention response to temperature, an alternative retention factor was developed to approximate the combined temperature response of the complex, unresolvable tannin mixture. This alternative retention factor was based upon relative tannin peak areas separated by an abrupt change in solvent gradient. Using this alternative retention factor, retention thermodynamics were calculated. Van't Hoff relationships of the natural log of the alternative retention factor against temperature followed Kirchoff's relationship. An inverse quadratic equation was fit to the data, and from this the thermodynamic parameters for tannin retention were calculated. All tannin fractions exhibited exothermic, spontaneous interaction, with enthalpy-entropy compensation observed. Normalizing for tannin size, distinct tannin compositional effects on thermodynamic parameters were observed. The results of this study indicate that HPLC can be valuable for measuring the thermodynamics of tannin interaction with a hydrophobic surface and provides a potentially valuable alternative to calorimetry. Furthermore, the information gathered may provide insight into understanding red wine astringency quality.

  20. Relationship between red wine grades and phenolics. 1. Tannin and total phenolics concentrations.

    PubMed

    Mercurio, Meagan D; Dambergs, Robert G; Cozzolino, Daniel; Herderich, Markus J; Smith, Paul A

    2010-12-08

    Measuring chemical composition is a common approach to support decisions about allocating foods and beverages to grades related to market value. Red wine is a particularly complex beverage, and multiple compositional attributes are needed to account for its sensory properties, including measurement of key phenolic components such as anthocyanins, total phenolics, and tannin, which are related to color and astringency. Color has been shown to relate positively to red wine grade; however, little research has been presented that explores the relationship between astringency-related components such as total phenolic or tannin concentration and wine grade. The aim of this research has been to investigate the relationship between the wine grade allocations of commercial wineries and total phenolic and tannin concentrations, respectively, in Australian Shiraz and Cabernet Sauvignon wines. Total phenolic and tannin concentrations were determined using the methyl cellulose precipitable (MCP) tannin assay and then compared to wine grade allocations made by winemaker panels during the companies' postvintage allocation process. Data were collected from wines produced by one Australian wine company over the 2005, 2006, and 2007 vintages and by a further two companies in 2007 (total wines = 1643). Statistical analysis revealed a positive trend toward higher wine grade allocation and wines that had higher concentrations of both total phenolics and tannin, respectively. This research demonstrates that for these companies, in general, Cabernet Sauvignon and Shiraz wines allocated to higher market value grades have higher total phenolics and higher tannin concentrations and suggests that these compositional parameters should be considered in the development of future multiparameter decision support systems for relevant commercial red wine grading processes. In addition, both tannin and total phenolics would ideally be included because although, in general, a positive relationship

  1. Red Wine Tannin Structure-Activity Relationships during Fermentation and Maceration.

    PubMed

    Yacco, Ralph S; Watrelot, Aude A; Kennedy, James A

    2016-02-03

    The correlation between tannin structure and corresponding activity was investigated by measuring the thermodynamics of interaction between tannins isolated from commercial red wine fermentations and a polystyrene divinylbenzene HPLC column. Must and/or wine samples were collected throughout fermentation/maceration from five Napa Valley wineries. By varying winery, fruit source, maceration time, and cap management practice, it was considered that a reasonably large variation in commercially relevant tannin structure would result. Tannins were isolated from samples collected using low pressure chromatography and were then characterized by gel permeation chromatography and acid-catalyzed cleavage in the presence of excess phloroglucinol (phloroglucinolysis). Corresponding tannin activity was determined using HPLC by measuring the thermodynamics of interaction between isolated tannin and a polystyrene divinylbenzene HPLC column. This measurement approach was designed to determine the ability of tannins to hydrophobically interact with a hydrophobic surface. The results of this study indicate that tannin activity is primarily driven by molecular size. Compositionally, tannin activity was positively associated with seed tannins and negatively associated with skin and pigmented tannins. Although measured indirectly, the extent of tannin oxidation as determined by phloroglucinolysis conversion yield suggests that tannin oxidation at this stage of production reduces tannin activity. Based upon maceration time, this study indicates that observed increases in perceived astringency quality, if related to tannin chemistry, are driven by tannin molecular mass as opposed to pigmented tannin formation or oxidation. Overall, the results of this study give new insight into tannin structure-activity relationships which dominate during extraction.

  2. Astringency, bitterness and color changes in dry red wines before and during oak barrel aging: An updated phenolic perspective review.

    PubMed

    Li, Si-Yu; Duan, Chang-Qing

    2018-01-30

    To understand effects of using oak barrels on the astringency, bitterness and color of dry red wines, phenolic reactions in wines before and after barrel aging are reviewed in this paper, which has been divided into three sections. The first section includes an introduction to chemical reactivities of grape-derived phenolic compounds, a summary of the phenolic reactions that occur in dry red wines before barrel aging, and a discussion of the effects of these reactions on wine astringency, bitterness and color. The second section introduces barrel types that determine the oak barrel constituents in wines (primarily oak aldehydes and ellagitannins) and presents reactions between the oak constituents and grape-derived phenolic compounds that may modulate wine astringency, bitterness and color. The final section illustrates the chemical differences between basic oxidation and over-oxidation in wines, discusses oxygen consumption kinetics in wines during barrel aging by comparing different oxygen consumption kinetics observed previously by others, and speculates on the possible preliminary phenolic reactions that occur in dry red wines during oak barrel aging that soften tannins and stabilize pigments via basic oxidation. Additionally, sulfur dioxide (SO 2 ) addition during barrel aging and suitability of adopting oak barrels for aging wines are briefly discussed.

  3. High-performance liquid chromatography determination of red wine tannin stickiness.

    PubMed

    Revelette, Matthew R; Barak, Jennifer A; Kennedy, James A

    2014-07-16

    Red wine astringency is generally considered to be the sensory result of salivary protein precipitation following tannin-salivary protein interaction and/or tannin adhering to the oral mucosa. Astringency in red wine is often described using qualitative terms, such as hard and soft. Differences in qualitative description are thought to be due in part to the tannin structure. Tannin chemistry contributions to qualitative description have been shown to correlate with the enthalpy of interaction between tannin and a hydrophobic surface. On the basis of these findings, a method was developed that enabled the routine determination of the thermodynamics of the tannin interaction with a hydrophobic surface (polystyrene divinylbenzene) for tannins in red wine following direct injection. The optimized analytical method monitored elution at four different column temperatures (25-40 °C, in 5 °C increments), had a 20 min run time, and was monitored at 280 nm. The results of this study confirm that the calculated thermodynamics of the interaction are intensive and, therefore, provide specific thermodynamic information. Variation in the enthalpy of interaction between tannin and a hydrophobic surface (tannin stickiness) is a unique, concentration-independent analytical parameter. The method, in addition to providing information on tannin stickiness, provides the tannin concentration.

  4. Understanding the Relationship between Red Wine Matrix, Tannin Activity, and Sensory Properties.

    PubMed

    Watrelot, Aude A; Byrnes, Nadia K; Heymann, Hildegarde; Kennedy, James A

    2016-11-30

    One major red wine mouthfeel characteristic, astringency, is derived from grape-extracted tannins and is considered to be a result of interaction with salivary proteins and the oral mucosa. To improve our understanding of the role that the enthalpy of interaction of tannin with a hydrophobic surface (tannin activity) has in astringency perception, a chromatographic method was used to determine the tannin concentration and activity of 34 Cabernet Sauvignon wines, as well as sensory analysis done on 13 of those wines. In addition, astringency-relevant matrix parameters (pH, titratable acidity, ethanol, glucose, and fructose) were measured across all wines. Tannin activity was not significantly correlated with any matrix variables, and the perception of drying and grippy was not correlated with tannin concentration and activity. However, ethanol content was well related to mouthfeel attributes and appeared to drive perceived drying. Although fructose and glucose content were well correlated, they did not drive the perception of sweetness, which is explained by the well-known mixture suppression effect.

  5. The effect of supplementation with three commercial inactive dry yeasts on the colour, phenolic compounds, polysaccharides and astringency of a model wine solution and red wine.

    PubMed

    González-Royo, Elena; Esteruelas, Mireia; Kontoudakis, Nikolaos; Fort, Francesca; Canals, Joan Miquel; Zamora, Fernando

    2017-01-01

    Nowadays supplementing red wines with commercial inactive dry yeasts is a widespread practice in winemaking because it leads to better balanced wines through increased mouthfeel and smooth astringency. The aim of this article is to study, in a red wine and in a model wine solution, how supplementation with three commercial inactive dry yeasts affects chemical composition and astringency. This will give us a better understanding of the action mechanism involved. The results suggest that this action mechanism is related to two different phenomena. The first is that inactive yeasts release polysaccharides and oligosaccharides which can increase mouthfeel and inhibit interactions between salivary protein and tannins. The second is that they have a direct effect on the precipitation or absorption of proanthocyanidins, especially the larger polymers, which have been described as the most astringent. It can be concluded that supplementation with inactive yeasts is indeed a useful tool for smoothing the astringency of red wines. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. New method for evaluating astringency in red wine.

    PubMed

    Llaudy, María C; Canals, Roser; Canals, Joan-Miquel; Rozés, Nicolas; Arola, Lluís; Zamora, Fernando

    2004-02-25

    Astringency is an important sensory attribute of red wine. It is usually estimated by tasting and is subject to a certain subjectivity. It can also be estimated by using the gelatin index. This procedure is not very reproducible because there are many gelatins on the market with a heterogeneous composition. Furthermore, the gelatin index determines procyanidin concentration by acid hydrolysis that gives only an approximate result. This paper proposes a new and reproducible method that determines astringency by using ovalbumin as the precipitation agent and tannic acid solutions as standards. Statistical analysis of the results indicates that this method is more reproducible (RSD = 5%) than the gelatin index (RSD = 12%) and correlates better with sensorial analysis.

  7. Sensorial properties of red wine polyphenols: Astringency and bitterness.

    PubMed

    Soares, Susana; Brandão, Elsa; Mateus, Nuno; de Freitas, Victor

    2017-03-24

    Polyphenols have been the subject of numerous research over the past years, being referred as the nutraceuticals of modern life. The healthy properties of these compounds have been associated to a natural chemoprevention of 21st century major diseases such as cancer and neurodegenerative diseases (e.g. Parkinson's and Alzheimer's). This association led to an increased consumption of foodstuffs rich in these compounds such as red wine. Related to the ingestion of polyphenols are the herein revised sensorial properties (astringency and bitterness) which are not still pleasant. This review intends to be an outline both at a sensory as a molecular level of the mechanisms underlying astringency and bitterness of polyphenols. Up-to-date knowledge of this matter is discussed in detail.

  8. Effect of wine pH and bottle closure on tannins.

    PubMed

    McRae, Jacqui M; Kassara, Stella; Kennedy, James A; Waters, Elizabeth J; Smith, Paul A

    2013-11-27

    The impact of wine pH and closure type on color, tannin concentration, and composition was investigated. A single vintage of Cabernet Sauvignon wine was divided into three batches, the pH was adjusted to 3.2, 3.5 or 3.8, and the wines were bottled under screw caps with either SaranTin (ST) or Saranex (Sx) liners. After 24 months, the tannin concentration, tannin percent yield (relating to the proportion of acid-labile interflavan bonds), and the mean degree of polymerization (mDp) had decreased significantly, all of which can contribute to the softening of wine astringency with aging. The higher pH wines contained less percent (-)-epicatechin 3-O-gallate subunits, whereas the Sx pH 3.2 wines were significantly lower in percent yield and mDp than the other wines. Overall, the tannin structure and wine color of the lower pH wines (pH 3.2) bottled under Sx screw caps changed more rapidly with aging than those of the higher pH wines (pH 3.8) bottled under ST screw caps.

  9. A saliva molecular imprinted localized surface plasmon resonance biosensor for wine astringency estimation.

    PubMed

    Guerreiro, J Rafaela L; Teixeira, Natércia; De Freitas, Victor; Sales, M Goreti F; Sutherland, Duncan S

    2017-10-15

    Wine astringency was evaluated based on the interaction of two complex matrices (red wine and saliva) by combining localized surface plasmon resonance (LSPR) and molecular imprinted polymers (MIP) at gold nanodisks as an alternative to sensorial analysis. The main objective of the work was to simulate wine astringency inside the mouth by mimicking this biological system. The LSPR/MIP sensor provided a linear response for astringency expressed in pentagalloyl glucose (PGG) units in concentrations ranging from 1 to 140μmol/L. The sensor was also applied to wine samples correlating well with sensorial analysis obtained by a trained panel. The correlation of astringency and wine composition was also evaluated showing that anthocyanins may have an important role, not only for pigmentation but also in astringency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. The role of wine polysaccharides on salivary protein-tannin interaction: A molecular approach.

    PubMed

    Brandão, Elsa; Silva, Mafalda Santos; García-Estévez, Ignacio; Williams, Pascale; Mateus, Nuno; Doco, Thierry; de Freitas, Victor; Soares, Susana

    2017-12-01

    Polysaccharides are described to inhibit aggregation between food polyphenols and salivary proteins (SP) and may hence lead to astringency modulation. In this work, the effect of two wine polysaccharides (arabinogalactan proteins-AGPs and rhamnogalacturonan II- RGII) on SP-polyphenol interaction was evaluated. In general, both polysaccharides were effective to inhibit or reduce SP-polyphenol interaction and aggregation. They can act by two different mechanisms (ternary or competitive) depending on the SP-tannin pair. In the case of salivary P-B peptide, AGPs and RGII seem to act by a ternary mechanism, in which they surround this complex, enhancing its solubility. Concerning acidic proline-rich proteins (aPRPs), it was possible to observe both mechanisms, depending on the tannin and the polysaccharide involved. Overall, this work point out for a specific property of wine polysaccharides important to modulate this and other beverages and food astringency perception. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Reactivity of polymeric proanthocyanidins toward salivary proteins and their contribution to young red wine astringency.

    PubMed

    Sun, Baoshan; de Sá, Marta; Leandro, Conceição; Caldeira, Ilda; Duarte, Filomena L; Spranger, Isabel

    2013-01-30

    Recent studies have indicated the presence of significant amount of highly polymerized and soluble proanthocyanidins in red wine and such compounds interacted readily with proteins, suggesting that they might be particularly astringent. Thus, the objective of this work was to verify the astringency of polymeric proanthocyanidins and their contribution to red wine astringency. The precipitation reactions of the purified oligomeric procyanidins (degree of polymerization ranging from 2 to 12-15) and polymeric procyanidins (degree of polymerization ranging from 12-15 to 32-34) with human salivary proteins were studied; salivary proteins composition changes before and after the reaction was verified by SDS-PAGE and procyanidins composition changes by spectrometric, direct HPLC and thiolysis-HPLC methods. The astringency intensity of these two procyanidin fractions was evaluated by a sensory analysis panel. For verifying the correlation between polymeric proanthocyanidins and young red wine astringency, the levels of total oligomeric and total polymeric proanthocyanidins and other phenolic composition in various young red wines were quantified and the astringency intensities of these wines were evaluated by a sensory panel. The results showed that polymeric proanthocyanidins had much higher reactivity toward human salivary proteins and higher astringency intensity than the oligomeric ones. Furthermore, young red wine astringency intensities were highly correlated to levels of polymeric proanthocyanidins, particularly at low concentration range (correlation coefficient r = 0.9840) but not significant correlated to total polyphenols (r = 0.2343) or other individual phenolic compounds (generally r < 0.3). These results indicate the important contribution of polymeric proanthocyanidins to red wine astringency and the levels of polymeric polyphenols in red wines may be used as an indicator for its astringency.

  12. Sensory assessment and chemical measurement of astringency of Greek wines: Correlations with analytical polyphenolic composition.

    PubMed

    Kallithraka, S; Kim, D; Tsakiris, A; Paraskevopoulos, I; Soleas, G

    2011-06-15

    The purpose of this study was to measure the astringency of selected Greek red wines and to assess the relationship between sensory and chemical data. Nine red wines produced by three native Greek grape varieties (agiorgitiko, xinomavro and mavrodafni) were used and their astringency and bitterness was assessed by a trained panel. In addition, their astringency was estimated chemically employing the ovalbumin precipitation method. Their polyphenolic composition was also determined by High Performance Liquid Chromatography (HPLC). The sensory data showed that mandilaria was the most astringent variety whereas agiorgitiko was the least. Statistical analysis of the results indicated that the chemical data obtained for astringency significantly correlated with the sensory determinations. In addition, significant correlations were obtained between the sensory data and the wine polyphenolic composition. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Measuring the molecular dimensions of wine tannins: comparison of small-angle X-ray scattering, gel-permeation chromatography and mean degree of polymerization.

    PubMed

    McRae, Jacqui M; Kirby, Nigel; Mertens, Haydyn D T; Kassara, Stella; Smith, Paul A

    2014-07-23

    The molecular size of wine tannins can influence astringency, and yet it has been unclear as to whether the standard methods for determining average tannin molecular weight (MW), including gel-permeation chromatography (GPC) and depolymerization reactions, are actually related to the size of the tannin in wine-like conditions. Small-angle X-ray scattering (SAXS) was therefore used to determine the molecular sizes and corresponding MWs of wine tannin samples from 3 and 7 year old Cabernet Sauvignon wine in a variety of wine-like matrixes: 5-15% and 100% ethanol; 0-200 mM NaCl and pH 3.0-4.0, and compared to those measured using the standard methods. The SAXS results indicated that the tannin samples from the older wine were larger than those of the younger wine and that wine composition did not greatly impact on tannin molecular size. The average tannin MWs as determined by GPC correlated strongly with the SAXS results, suggesting that this method does give a good indication of tannin molecular size in wine-like conditions. The MW as determined from the depolymerization reactions did not correlate as strongly with the SAXS results. To our knowledge, SAXS measurements have not previously been attempted for wine tannins.

  14. Analysis of total phenolic, flavonoids, anthocyanins and tannins content in Romanian red wines: prediction of antioxidant activities and classification of wines using artificial neural networks.

    PubMed

    Hosu, Anamaria; Cristea, Vasile-Mircea; Cimpoiu, Claudia

    2014-05-01

    Wine is one of the most consumed beverages over the world containing large quantities of polyphenolic compounds. These compounds are responsible for quality of red wines, influencing the antioxidant activity, astringency, bitterness and colour, their composition in wine being influenced by the varieties, the vintage and the wineries. The aim of the present work is to build software instruments intended to work as data-mining tools for predicting valuable properties of wine and for revealing different wine classes. The developed ANNs are able to reveal the relationships between the concentration of total phenolic, flavonoids, anthocyanins, and tannins content, associated to the antioxidant activity, and the wine distinctive classes determined by the wine variety, harvesting year or winery. The presented ANNs proved to be reliable software tools for assessment or validation of the wine essential characteristics and authenticity and may be further used to establish a database of analytical characteristics of wines. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Relationship between the sensory-determined astringency and the flavanolic composition of red wines.

    PubMed

    Quijada-Morín, Natalia; Regueiro, Jorge; Simal-Gándara, Jesús; Tomás, Esperanza; Rivas-Gonzalo, Julián C; Escribano-Bailón, M Teresa

    2012-12-19

    The relationship between the proanthocyanidin profile and the perceived astringency was assessed in 13 commercial Tempranillo red wines. The concentration and compositional information were obtained by liquid chromatography with diode array detection coupled to electrospray ionization mass spectrometry after acid-catalyzed depolymerization of wine proanthocyanidins in the presence of excess phloroglucinol. Statistical analysis of the results showed significant correlations between sensory and chemical determinations. Astringency was more affected by the subunit composition than by the total concentration or the average degree of polymerization of wine proanthocyanidins. Higher proportions of epicatechin (EC) subunits in extension positions and gallocatechin (GC) subunits in terminal positions were shown to increase astringency. On the contrary, the amount of epigallocatechin (EGC) in both extension and terminal positions was negatively correlated with the perceived astringency.

  16. Condensed Tannin Reacts with SO2 during Wine Aging, Yielding Flavan-3-ol Sulfonates.

    PubMed

    Ma, Lingjun; Watrelot, Aude A; Addison, Bennett; Waterhouse, Andrew L

    2018-06-08

    Numerous monomeric and oligomeric flavanol sulfonation products were observed in 10 wines. Levels of 0.85-20.06 and 0-14.72 mg/L were quantified for two monomeric sulfonated flavan-3-ols and, surprisingly, were generally higher than the well-known native flavan-3-ol monomers. Increasing SO 2 levels during wine aging increased the sulfonate-modified flavan-3-ol monomers and dimers along with higher concentrations of native monomers. The results indicate that >10% of SO 2 is reacting with the C-4 carbocation, formed from acid cleavage of the interflavan bond, perhaps by a bimolecular S N 2-type reaction, and as a reducing agent. In addition, the high SO 2 wine had the lowest protein-binding tannin levels, tannin activity, and mean degree of polymerization (mDP), and acidic SO 2 treatment of condensed tannin abolishes protein binding. Thus, SO 2 changes tannin composition during wine aging, and the substantial formation of sulfonate-modified flavan-3-ols may provide an additional explanation for the reduction in astringency of aged red wines.

  17. Red wine tannins fluidify and precipitate lipid liposomes and bicelles. A role for lipids in wine tasting?

    PubMed

    Furlan, Aurélien L; Castets, Aurore; Nallet, Frédéric; Pianet, Isabelle; Grélard, Axelle; Dufourc, Erick J; Géan, Julie

    2014-05-20

    Sensory properties of red wine tannins are bound to complex interactions between saliva proteins, membranes taste receptors of the oral cavity, and lipids or proteins from the human diet. Whereas astringency has been widely studied in terms of tannin-saliva protein colloidal complexes, little is known about interactions between tannins and lipids and their implications in the taste of wine. This study deals with tannin-lipid interactions, by mimicking both oral cavity membranes by micrometric size liposomes and lipid droplets in food by nanometric isotropic bicelles. Deuterium and phosphorus solid-state NMR demonstrated the membrane hydrophobic core disordering promoted by catechin (C), epicatechin (EC), and epigallocatechin gallate (EGCG), the latter appearing more efficient. C and EGCG destabilize isotropic bicelles and convert them into an inverted hexagonal phase. Tannins are shown to be located at the membrane interface and stabilize the lamellar phases. These newly found properties point out the importance of lipids in the complex interactions that happen in the mouth during organoleptic feeling when ingesting tannins.

  18. Contribution of Human Oral Cells to Astringency by Binding Salivary Protein/Tannin Complexes.

    PubMed

    Soares, Susana; Ferrer-Galego, Raúl; Brandão, Elsa; Silva, Mafalda; Mateus, Nuno; Freitas, Victor de

    2016-10-10

    The most widely accepted mechanism to explain astringency is the interaction and precipitation of salivary proteins by food tannins, in particular proline-rich proteins. However, other mechanisms have been arising to explain astringency, such as binding of tannins to oral cells. In this work, an experimental method was adapted to study the possible contribution of both salivary proteins and oral cells to astringency induced by grape seed procyanidin fractions. Overall, in the absence of salivary proteins, the extent of procyanidin complexation with oral cells increased with increasing procyanidin degree of polymerization (mDP). Procyanidin fractions rich in monomers were the ones with the lowest ability to bind to oral cells. In the presence of salivary proteins and for procyanidins with mDP 2 the highest concentrations (1.5 and 2.0 mM) resulted in an increased binding of procyanidins to oral cells. This was even more evident for fractions III and IV at 1.0 mM and upper concentrations. Regarding the salivary proteins affected, it was possible to observe a decrease of P-B peptide and aPRP proteins for fractions II and III. This decrease is greater as the procyanidins' mDP increases. In fact, for fraction IV an almost total depletion of all salivary proteins was observed. This decrease is due to the formation of insoluble salivary protein/procyanidin complexes. Altogether, these data suggest that some procyanidins are able to bind to oral cells and that the salivary proteins interact with procyanidins forming salivary protein/procyanidin complexes that are also able to link to oral cells. The procyanidins that remain unbound to oral cells are able to bind to salivary proteins forming a large network of salivary protein/procyanidin complexes. Overall, the results presented herein provide one more step to understand food oral astringency onset.

  19. Influence of wine pectic polysaccharides on the interactions between condensed tannins and salivary proteins.

    PubMed

    Carvalho, Elisabete; Mateus, Nuno; Plet, Benoit; Pianet, Isabelle; Dufourc, Erick; De Freitas, Victor

    2006-11-15

    Alpha-amylase, a major human salivary protein, and IB8c, a representative of the proline-rich proteins, were obtained by isolation from saliva and by solid-phase synthesis, respectively. The interactions between these proteins and condensed tannins isolated from grape seeds were studied at different protein and tannin concentrations by measuring their aggregation. Pectic polysaccharides were isolated from wine, and their effect on protein tannin aggregation was assessed. The results presented in this study showed that the most acidic fractions of arabinogalactan proteins have the ability to inhibit the formation of aggregates between the grape seed tannins and the two different salivary proteins. Rhamnogalacturonan II has the same ability toward alpha-amylase but not IB8c under the conditions of the present study. Polysaccharides show effects at concentrations at which they are present in wine, which could mean an influence in wine astringency. The interaction between condensed tannins and alpha-amylase is differently affected by ionic strength when compared with IB8c.

  20. Polyphenolic, polysaccharide and oligosaccharide composition of Tempranillo red wines and their relationship with the perceived astringency.

    PubMed

    Quijada-Morín, Natalia; Williams, Pascale; Rivas-Gonzalo, Julián C; Doco, Thierry; Escribano-Bailón, M Teresa

    2014-07-01

    The influence of the proanthocyanidic, polysaccharide and oligosaccharide composition on astringency perception of Tempranillo wines has been evaluated. Statistical analyses revealed the existence of relationships between chemical composition and perceived astringency. Proanthocyanidic subunit distribution had the strongest contribution to the multiple linear regression (MLR) model. Polysaccharide families showed clear opposition to astringency perception according to principal component analysis (PCA) results, being stronger for mannoproteins and rhamnogalacturonan-II (RG-II), but only Polysaccharides Rich in Arabinose and Galactose (PRAGs) were considered in the final fitted MLR model, which explained 96.8% of the variability observed in the data. Oligosaccharides did not show a clear opposition, revealing that structure and size of carbohydrates are important for astringency perception. Mannose and galactose residues in the oligosaccharide fraction are positively related to astringency perception, probably because its presence is consequence of the degradation of polysaccharides. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Evolution of phenolic compounds and astringency during aging of red wine: effect of oxygen exposure before and after bottling.

    PubMed

    Gambuti, Angelita; Rinaldi, Alessandra; Ugliano, Maurizio; Moio, Luigi

    2013-02-27

    The aim of this study was to evaluate the effect of oxygen exposure of red wine, before (micro-oxygenation) and after (nano-oxygenation) bottling, on the phenolic composition and astringency of wine. The astringency was evaluated by sensory analysis and by a method based on the SDS-PAGE of salivary proteins after reaction of saliva with wine (SPI, saliva precipitation index). Micro-oxygenation caused a stabilization of color, but this effect disappeared after long aging. For the wine with the lower pH a decrease of wine astringency and SPI was observed 42 months after micro-oxygenation. Oxygen ingress through the closure postbottling was positively correlated with the decrease of SPI. Therefore, the astringency and reactivity of wines toward salivary proteins of a bottled red wine can be modulated by controlled oxygen exposure during aging. For both experiments the effect of oxygen exposure depended on wine composition.

  2. Alcohol, Tannins, and Mannoprotein and their Interactions Influence the Sensory Properties of Selected Commercial Merlot Wines: A Preliminary Study.

    PubMed

    Diako, Charles; McMahon, Kenneth; Mattinson, Scott; Evans, Marc; Ross, Carolyn

    2016-08-01

    The objective of this study was to assess the influence of the interaction among alcohol, tannins, and mannoproteins on the aroma, flavor, taste, and mouthfeel characteristics of selected commercial Merlot wines. Merlot wines (n = 61) were characterized for wine chemistry parameters, including pH, titratable acidity, alcohol, glucose, fructose, tannin profile, total proteins, and mannoprotein content. Agglomerative clustering of these physicochemical characteristics revealed 6 groups of wines. Two wines were selected from each group (n = 12) and profiled by a trained sensory evaluation panel. One wine from each group was evaluated using the electronic tongue (e-tongue). Sensory evaluation results showed complex effects among tannins, alcohol, and mannoproteins on the perception of most aromas, flavors, tastes, and mouthfeel attributes (P < 0.05). The e-tongue showed distinct differences among the taste attributes of the 6 groups of wines as indicated by a high discrimination index (DI = 95). Strong correlations (r(2) > 0.930) were reported between the e-tongue and sensory perception of sweet, sour, bitter, burning, astringent, and metallic. This study showed that interactions among wine matrix components influence the resulting sensory perceptions. The strong correlation between the e-tongue and trained panel evaluations indicated the e-tongue can complement sensory evaluations to improve wine quality assessment. © 2016 Institute of Food Technologists®

  3. Opponency of astringent and fat sensations.

    PubMed

    des Gachons, Catherine Peyrot; Mura, Emi; Speziale, Camille; Favreau, Charlotte J; Dubreuil, Guillaume F; Breslin, Paul A S

    2012-10-09

    In most cultures, people ingest a variety of astringent foods and beverages during meals, but the reasons for this practice are unclear. Many popular beliefs and heuristics, such as high tannin wines should be balanced with fatty foods, for example 'red wine with red meat', suggest that astringents such as pickles, sorbets, wines, and teas 'cleanse' the palate while eating. Oral astringents elicit 'dry, rough' sensations [1], in part, by breaking down mucinous lubricating proteins in saliva [2,3]. The introduction of oral lubricants, including fats, partially diminishes strong astringent sensations [4,5]. Thus, it appears that astringency and fattiness can oppose each other perceptually on an oral rheological spectrum. Most teas, wines, and 'palate cleansers', however, are only mildly astringent and an explanation of how they could oppose the fattiness of meals is lacking. Here, we demonstrate that weakly astringent stimuli can elicit strong sensations after repeated sampling. Astringency builds with exposures [6] to an asymptotic level determined by the structure and concentration of the compound. We also establish that multiple sips of a mild astringent solution, similar to a wine or tea, decrease oral fat sensations elicited by fatty food consumption when astringent and fatty stimuli alternate, mimicking the patterning that occurs during a real meal. Consequently, we reveal a principle underlying the international practice of 'palate cleansing'. Repeatedly alternating samples of astringent beverages with fatty foods yielded ratings of fattiness and astringency that were lower than if rinsing with water or if presented alone without alternation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Orosensory-directed identification of astringent mouthfeel and bitter-tasting compounds in red wine.

    PubMed

    Hufnagel, Jan Carlos; Hofmann, Thomas

    2008-02-27

    Application of sequential solvent extraction, followed by HPLC combined with the taste dilution analysis, enabled the localization of the most intense velvety astringent, drying, and puckering astringent, as well as bitter-tasting, compounds in red wine, respectively. Isolation of the taste components involving gel adsorption chromatography, ultrafiltration, and synthesis revealed the identification of 26 sensory-active nonvolatiles, among which several hydroxybenzoic acids, hydroxycinnamic acids, flavon-3-ol glycosides, and dihydroflavon-3-ol rhamnosides as well as a structurally undefined polymeric fraction (>5 kDa) were identified as the key astringent components. In contradiction to literature suggestions, flavan-3-ols were found to be not of major importance for astringency and bitter taste, respectively. Surprisingly, a series of hydroxybenzoic acid ethyl esters and hydroxycinnamic acid ethyl esters were identified as bitter compounds in wine. Taste qualities and taste threshold concentrations of the individual wine components were determined by means of a three-alternative forced-choice test and the half-mouth test, respectively.

  5. Influence of micro-oxygenation treatment before oak aging on phenolic compounds composition, astringency, and color of red wine.

    PubMed

    Llaudy, María del Carmen; Canals, Roser; González-Manzano, Susana; Canals, Joan Miquel; Santos-Buelga, Celestino; Zamora, Fernando

    2006-06-14

    Micro-oxygenation is usually applied to red wines as a cheaper alternative to oak aging. It has been suggested, however, that micro-oxygenation can also be used to complement oak aging in order to improve the quality of very astringent and herbaceous red wines. In this paper we study how applying the micro-oxygenation technique before oak aging affects the composition and quality of astringent red wines. When this technique is applied prior to oak aging, the wines have a slightly less intense red color and significantly higher levels of combined and free anthocyanins and ethyl-bridged anthocyanin-flavanol pigments. On the other hand, no differences in other newly formed pigments are found. Applying micro-oxygenation before oak aging does not affect the total proanthocyanidin concentration, but it produces wines with a slightly (though significantly) higher mean degree of proanthocyanidin polymerization and a drastically lower astringency. These wines also present a clearer impact of wood aromas.

  6. Insights on the chemical basis of the astringency of Spanish red wines.

    PubMed

    Sáenz-Navajas, María-Pilar; Avizcuri, José-Miguel; Ferreira, Vicente; Fernández-Zurbano, Purificación

    2012-10-01

    The main goal of the present study is to provide an insight on the role played by non-volatile molecules on the different in-mouth attributes, particularly astringency. For achieving such goal, the main in-mouth sensory attributes of 34 oaked Spanish red wines were measured by a trained panel. The wine content in 30 sensory-active molecules was analysed by different HPLC based methodologies together with classical enological parameters and two proanthocyanidin indexes. Fourteen compounds (aconitic acids, polymeric proanthocyanidins, caftaric, caffeic and coutaric acids and seven quercetins) were found to be at concentrations above reported taste thresholds and to have a reasonably high range of occurrence. Two highly statistically significant models for astringency were built with those compounds. Even if the models could not be fully validated by sensory addition experiments, the research has demonstrated that wine astringency is driven by polymeric proanthocyanidins and by certain phenolic acids, the rate trans/cis-aconitic acid and flavonol profiles. The research has highlighted the existence of extremely complex interactions between non-volatile compounds on the in-mouth sensory perception. Particularly remarkable is the lack of additivity and potential antagonism found between the pairs cis/trans-aconitic acids, between aconitic and caffeic acids and between quercetin-3-O-galactoside and quercetin-3-O-glucoside. Also remarkable was the sweetness×astringent interaction and the matrix-dependence of the sensory responses elicited by flavonols. These results suggest the need for new paradigms and experimental procedures for fully decoding the real sensory relevance of individual non-volatile compounds in the overall wine flavour. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. A role for anthocyanin in determining wine tannin concentration in Shiraz.

    PubMed

    Kilmister, Rachel L; Mazza, Marica; Baker, Nardia K; Faulkner, Peta; Downey, Mark O

    2014-01-01

    Four wines were made to investigate the effect of different anthocyanin and tannin fruit concentrations on wine phenolics and colour. Wines that were made from fruit with high anthocyanin concentration had high tannin concentrations regardless of the concentration of tannin in fruit, while wines made from fruit with low anthocyanin also had low tannin concentration. It was found that fruit anthocyanin concentration correlated with wine tannin concentration, wine colour and polymeric pigment formation. Anthocyanin concentration might be a key component for increasing tannin solubility and extraction into wine and the formation of polymeric pigments. Industry implications include managing tannin and anthocyanin fruit concentration for targeting tannin extraction and polymeric pigment formation in wine. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

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

    PubMed

    Kassara, Stella; Kennedy, James A

    2011-08-10

    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.

  9. Tannin profile of different Monastrell wines and its relation to projected market prices.

    PubMed

    Gómez-Plaza, Encarna; Olmos, Oscar; Bautista-Ortín, Ana Belén

    2016-08-01

    This study focuses on the differences or similarities in tannin composition and concentration in Monastrell wines from different wineries from the same geographic area and, within each winery, from wines elaborated based on different projected market prices, to determine whether there is any relationship between the wine tannin composition and the projected price. The tannin composition of the different wines, all of them analyzed at the same point during winemaking, indicated that those elaborated as premium wines presented higher phenol and tannin contents. The mean degree of polymerization of these wines was also positively related with the projected price, which agreed with the results obtained by size exclusion chromatography, that showed that wines with high projected prices had a higher proportion of polymeric tannins, suggesting that techniques favoring the extraction of skin tannins were mostly used in those wines projected as premium wines, probably looking for greater mouthfeel complexity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Grape tannin catechin and ethanol fluidify oral membrane mimics containing moderate amounts of cholesterol: Implications on wine tasting?

    PubMed

    Furlan, Aurélien L; Saad, Ahmad; Dufourc, Erick J; Géan, Julie

    2016-11-01

    Wine tasting results in interactions of tannin-ethanol solutions with proteins and lipids of the oral cavity. Among the various feelings perceived during tasting, astringency and bitterness most probably result in binding events with saliva proteins, lipids and receptors. In this work, we monitored the conjugated effect of the grape polyphenol catechin and ethanol on lipid membranes mimicking the different degrees of keratinization of oral cavity surfaces by varying the amount of cholesterol present in membranes. Both catechin and ethanol fluidify the membranes as evidenced by solid-state 2 H NMR of perdeuterated lipids. The effect is however depending on the cholesterol proportion and may be very important and cumulative in the absence of cholesterol or presence of 18 mol % cholesterol. For 40 mol % cholesterol, mimicking highly keratinized membranes, both ethanol and catechin can no longer affect membrane dynamics. These observations can be accounted for by phase diagrams of lipid-cholesterol mixtures and the role played by membrane defects for insertion of tannins and ethanol when several phases coexist. These findings suggest that the behavior of oral membranes in contact with wine should be different depending of their cholesterol content. Astringency and bitterness could be then affected; the former because of a potential competition between the tannin-lipid and the tannin-saliva protein interaction, and the latter because of a possible fluidity modification of membranes containing taste receptors. The lipids that have been up to now weakly considered in oenology may be become a new actor in the issue of wine tasting. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  11. Effect of flavonols on wine astringency and their interaction with human saliva.

    PubMed

    Ferrer-Gallego, Raúl; Brás, Natércia F; García-Estévez, Ignacio; Mateus, Nuno; Rivas-Gonzalo, Julián C; de Freitas, Victor; Escribano-Bailón, M Teresa

    2016-10-15

    The addition of external phenolic compounds to wines in order to improve their sensory quality is an established winemaking practice. This study was aimed at evaluating the effect of the addition of quercetin 3-O-glucoside on the astringency and bitterness of wines. Sensory results showed that the addition of this flavonol to wines results in an increase in astringency and bitterness. Additionally, flavonol-human salivary protein interactions were studied using fluorescence spectroscopy, dynamic light scattering and molecular dynamic simulations (MD). The apparent Stern-Volmer (KsvApp) and the apparent bimolecular quenching constants (kqApp) were calculated from fluorescence spectra. The KsvApp was 12620±390M(-1), and the apparent biomolecular constant was 3.94×10(12)M(-1)s(-1), which suggests that a complex was formed between the human salivary proteins and quercetin 3-O-glucoside. MD simulations showed that the quercetin 3-O-glucoside molecules have the ability to bind to the IB937 model peptide. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Influence of Grape Seeds and Stems on Wine Composition and Astringency.

    PubMed

    Pascual, Olga; González-Royo, Elena; Gil, Mariona; Gómez-Alonso, Sergio; García-Romero, Esteban; Canals, Joan Miquel; Hermosín-Gutíerrez, Isidro; Zamora, Fernando

    2016-08-31

    The aim of this paper is to study the real influence of seeds and stems on wine composition, astringency, and bitterness. A decolored grape juice and a grape juice macerated for 4 days from the same Cabernet Sauvignon grapes were fermented with or without supplementation with 100% seeds, 300% seeds, or 100% stems. Once alcoholic fermentation had finished, the wines were analyzed and tasted. The presence of seeds and stems increased the concentration of flavan-3-ol monomers with respect to the controls. However, the seeds mainly released (+)-catechin and (-)-epicatechin, whereas the stems mainly released (+)-catechin and (+)-gallocatechin. The seeds and stems also released proanthocyanidins; those from seeds have a lower mDP and a high percentage of galloylation, whereas those from stems have a higher mDP and a relatively high percentage of prodelphinidins. The presence of seeds and stems brought about a slight but significant increase in pH and lowered titratable acidity and ethanol content. The presence of seeds boosted color intensity, whereas stems had the opposite effect. Finally, both seeds and stems increased wine astringency and bitterness.

  13. Three-dimensional structure and dynamics of wine tannin-saliva protein complexes. A multitechnique approach.

    PubMed

    Simon, Cécile; Barathieu, Karine; Laguerre, Michel; Schmitter, Jean-Marie; Fouquet, Eric; Pianet, Isabelle; Dufourc, Erick J

    2003-09-09

    The interactions between the B3 (catechin-4alpha,8-catechin) red wine tannin and the human salivary protein fragment IB7(14) (SPPGKPQGPPPQGG) were monitored by (1)H magic angle spinning NMR, circular dichroism, electrospray ionization mass spectrometry, and molecular modeling. It is found that the secondary structure of IB7(14) is made of a type II helix (collagen helix) and random coil. The central glycine 8 appears to act as a flexible rotula separating two helix II regions. Three tannin molecules tightly complex the peptide, without modifying its secondary structure, but seem to reduce its conformational dynamics. The binding dissociation constant is in the millimolar range. B3 tannins with a "tweezers" conformation bind to the hydrophilic side of the saliva peptide, suggesting that the principal driving forces toward association are governed by hydrogen bonding between the carbonyl functions of proline residues and both the phenol and catechol OH groups. These findings are further discussed in the frame of an astringency phenomenon.

  14. Yeast effects on Pinot noir wine phenolics, color, and tannin composition.

    PubMed

    Carew, Anna L; Smith, Paul; Close, Dugald C; Curtin, Chris; Dambergs, Robert G

    2013-10-16

    Extraction and stabilization of wine phenolics can be challenging for wine makers. This study examined how yeast choice affected phenolic outcomes in Pinot noir wine. Five yeast treatments were applied in replicated microvinification, and wines were analyzed by UV-visible spectrophotometry. At bottling, yeast treatment Saccharomyces cerevisiae RC212 wine had significantly higher concentrations of total pigment, free anthocyanin, nonbleachable pigment, and total tannin and showed high color density. Some phenolic effects were retained at 6 months' bottle age, and RC212 and S. cerevisae EC1118 wines showed increased mean nonbleachable pigment concentrations. Wine tannin composition analysis showed three treatments were associated with a higher percentage of trihydroxylated subunits (skin tannin indicator). A high degree of tannin polymerization was observed in wines made with RC212 and Torulaspora delbruekii , whereas tannin size by gel permeation chromatography was higher only in the RC212 wines. The results emphasize the importance of yeast strain choice for optimizing Pinot noir wine phenolics.

  15. Natural astringency in foodstuffs--a molecular interpretation.

    PubMed

    Halsam, E; Lilley, T H

    1988-01-01

    The structures of plant polyphenols (vegetable tannins) are briefly reviewed. Their interactions with proteins, polysaccharides, and the alkaloid caffeine are discussed at the molecular level, and these fundamental properties are related to the quality of astringency that polyphenols possess. The various ways in which astringency may be modified and ultimately lost are outlined in relation to the aging of red wines, the formation of nonbiological hazes in beers and lagers, and the ripening of fruit.

  16. Inhibition of trypsin by condensed tannins and wine.

    PubMed

    Gonçalves, Rui; Soares, Susana; Mateus, Nuno; de Freitas, Victor

    2007-09-05

    Phenolic compounds are abundant vegetable secondary metabolites in the human diet. The ability of procyanidin oligomers and wine polyphenols to inhibit trypsin activity was studied using a versatile and reliable in vitro method. The hydrolysis of the chromogenic substrate N-benzoyl-d,l-arginine-p-nitroanilide (BApNA) by trypsin was followed by spectrophotometry in the presence and absence of condensed tannins and wine. A clear relationship between the degree of polymerization of procyanidins and enzymatic inhibition was observed. Trypsin activity inhibition was also detected in several types of wine. In general, the inhibition increased with the concentration of phenolic compounds in wines. These results may be relevant when considering these compounds as antinutritional factors, thereby contributing to a reduced absorption of nutrients.

  17. The Effects of Pre-Fermentative Addition of Oenological Tannins on Wine Components and Sensorial Qualities of Red Wine.

    PubMed

    Chen, Kai; Escott, Carlos; Loira, Iris; Del Fresno, Juan Manuel; Morata, Antonio; Tesfaye, Wendu; Calderon, Fernando; Benito, Santiago; Suárez-Lepe, Jose Antonio

    2016-10-31

    Today in the wine industry, oenological tannins are widely used to improve wine quality and prevent oxidation in wine aging. With the development of tannin products, new oenological tannins are developed with many specific functions, such as modifying antioxidant effect, colour stabilization and aroma modifications. The aim of this work is to investigate effects of pre-fermentative addition of oenological tannins on wine colour, anthocyanins, volatile compounds and sensorial properties. In this case, Syrah juice was extracted with classic flash thermovinification from fresh must in order to release more colour and tannins. Three types of oenological tannins, which are, respectively, derived from grape skin, seed ( Vitis vinifera ) and French oak ( Quercus robur and Querrus petraea ), were selected to carry out the experiments with seven treatments. Results indicated that tannin treatments significantly improved wine aroma complexity and sensorial properties. However, the concentration of some stable pigments such as Vitisin A, Vitisin A-Ac and Vitisin B was negatively affected by tannin additions. Nevertheless, by means of cluster analysis and principal component analysis, it was observed that higher alcohols were significantly promoted by grape seed tannin while most anthocyanins can be improved by addition of grape tannins. In conclusion, low amount of oenological tannin derived from grape seed is a promising method to be applied especially for young red wine making.

  18. Grape variety effect on proanthocyanidin composition and sensory perception of skin and seed tannin extracts from bordeaux wine grapes (Cabernet Sauvignon and Merlot) for two consecutive vintages (2006 and 2007).

    PubMed

    Chira, Kleopatra; Schmauch, Gregory; Saucier, Cédric; Fabre, Sandy; Teissedre, Pierre-Louis

    2009-01-28

    Grape variety [Cabernet Sauvignon (CS) and Merlot (M)] effect on the proanthocyanidin composition and sensory perception of wine grapes from Bordeaux vineyards for two successive vintages (2006 and 2007) is reported. The flavan-3-ol monomers [(+)-catechin = C, (-)-epicatechin = EC, (-)-epicatechin-O-gallatte = ECG] and the proanthocyanidin oligomers [dimers B1, B2, B3, and B4 and trimer Cat-Cat-Epi (T)] in grape seed and skin tannin extracts were identified and quantified at harvest. Proanthocyanidin subunit compositions, percentage of galloylation (%G), and percentage of prodelphinidins (%P) as well as mean degree of polymerization (mDP) of the proanthocyanidin fraction were determined. Sensory analysis concerning the astringency and bitterness intensity of the proanthocyanidins of skin and seed tannin extracts was also performed. The results showed that proanthocyanidin composition can be greatly affected by grape variety. For both vintages between CS and M, significant differences were found on mDP (p < 0.05) in seed tannin extracts, whereas in skin tannin extracts, significant differences were observed for %G and %P (p < 0.05). Sensory analysis showed that grape variety influenced neither astringency nor bitterness intensity perception for both skin and seed tannin extracts for the two successive vintages studied. A positive correlation was found between astringency intensity, mDP, and B3 content in skin tannin extracts.

  19. Effect of the prefermentative addition of five enological tannins on anthocyanins and color in red wines.

    PubMed

    Liu, Yan-Xia; Liang, Na-Na; Wang, Jun; Pan, Qiu-Hong; Duan, Chang-Qing

    2013-01-01

    The effects of prefermentation addition of 5 exogenous tannins with different-origin anthocyanins and color characteristics were investigated in "Cabernet Sauvignon wines" at the end of alcoholic fermentation and the end of malolactic fermentation, and after 6 mo and 9 mo of bottle aging, respectively. The results showed that the application of GSKT2 could significantly retard the degradation of most anthocyanins in the process of alcoholic fermentation and the decrease of some pyranoanthocyanins during the subsequent 3 stages, thus causing more yellowness of wine in comparison with the control. Three other condensed tannins, GSKT1, QUET, and GSET, had a positive impact only on several anthocyanin components. Four condensed tannins all contributed to more redness, suggesting that the action mechanism might be to protect wine against oxidation or contribute to form copigmented anthocyanidins, or polymeric pigments. The application of FOLT (hydrolysable tannin) did not produce any influence on wine redness even after 9 mo of bottle aging. This work provides some reasons for the reasonable application of tannin additives. The prefermentative application of condensed tannins overall could protect some pigment components from degradation and enhance wine redness. Tannin additives with different origins have different effectiveness. The tannin additive obtained from grape skins, like GSKT2, could produce significant promotion on both redness and yellowness in wine. The prefermentation addition of hydroxylase tannin like FOLT seems not to have a significant effect on wine color. © 2012 Institute of Food Technologists®

  20. Pre-fermentation addition of grape tannin increases the varietal thiols content in wine.

    PubMed

    Larcher, Roberto; Tonidandel, Loris; Román Villegas, Tomás; Nardin, Tiziana; Fedrizzi, Bruno; Nicolini, Giorgio

    2015-01-01

    The recent finding that grape tannin may contain significant amount of S-glutathionylated (GSH-3MH) and S-cysteinylated (Cys-3MH) precursors of the varietal thiols 3-mercapto-1-hexanol and 3-mercaptohexyl acetate, characteristic of Sauvignon blanc wines, offers new opportunities for enhancing the tropical aroma in fermented beverages. In this study this new hypothesis was investigated: Müller Thurgau (17 samples) and Sauvignon blanc (15 samples) grapes were fermented with and without addition of a selected grape tannin. As expected, the tannin-added juices were higher in precursors, and they produced wines with increased free thiols. Preliminary informal sensory tests confirmed that in particular the Sauvignon wines produced with the tannin addition were often richer with increased "fruity/green" notes than the corresponding reference wines. This outcome confirms that grape tannin addition prior to fermentation can fortify the level of these compounds. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Heating and reduction affect the reaction with tannins of wine protein fractions differing in hydrophobicity.

    PubMed

    Marangon, Matteo; Vincenzi, Simone; Lucchetta, Marco; Curioni, Andrea

    2010-02-15

    During the storage, bottled white wines can manifest haziness due to the insolubilisation of the grape proteins that may 'survive' in the fermentation process. Although the exact mechanism of this occurrence is not fully understood, proteins and tannins are considered two of the key factors involved in wine hazing, since their aggregation leads to the formation of insoluble particles. To better understand this complex interaction, proteins and tannins from the same unfined Pinot grigio wine were separated. Wine proteins were then fractionated by hydrophobic interaction chromatography (HIC). A significant correlation between hydrophobicity of the wine protein fractions and the haze formed after reacting with wine tannins was found, with the most reactive fractions revealing (by SDS-PAGE and RP-HPLC analyses) the predominant presence of thaumatin-like proteins. Moreover, the effects of both protein heating and disulfide bonds reduction (with dithiotreithol) on haze formation in the presence of tannins were assessed. These treatments generally resulted in an improved reactivity with tannins, and this phenomenon was related to both the surface hydrophobicity and composition of the protein fractions. Therefore, haze formation in wines seems to be related to hydrophobic interactions occurring among proteins and tannins. These interactions should occur on hydrophobic tannin-binding sites, whose exposition on the proteins can depend on both protein heating and reduction. Copyright 2009 Elsevier B.V. All rights reserved.

  2. Oxygen consumption rates by different oenological tannins in a model wine solution.

    PubMed

    Pascual, Olga; Vignault, Adeline; Gombau, Jordi; Navarro, Maria; Gómez-Alonso, Sergio; García-Romero, Esteban; Canals, Joan Miquel; Hermosín-Gutíerrez, Isidro; Teissedre, Pierre-Louis; Zamora, Fernando

    2017-11-01

    The kinetics of oxygen consumption by different oenological tannins were measured in a model wine solution using the non-invasive method based on luminiscence. The results indicate that the oxygen consumption rate follows second-order kinetics depending on tannin and oxygen concentrations. They also confirm that the oxygen consumption rate is influenced by temperature in accordance with Arrhenius law. The indications are that ellagitannins are the fastest oxygen consumers of the different oenological tannins, followed in decreasing order by quebracho tannins, skin tannins, seed tannins and finally gallotannins. This methodology can therefore be proposed as an index for determining the effectiveness of different commercial tannins in protecting wines against oxidation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Molecular progress in research on fruit astringency.

    PubMed

    He, Min; Tian, Henglu; Luo, Xiaowen; Qi, Xiaohua; Chen, Xuehao

    2015-01-15

    Astringency is one of the most important components of fruit oral sensory quality. Astringency mainly comes from tannins and other polyphenolic compounds and causes the drying, roughening and puckering of the mouth epithelia attributed to the interaction between tannins and salivary proteins. There is growing interest in the study of fruit astringency because of the healthy properties of astringent substances found in fruit, including antibacterial, antiviral, anti-inflammatory, antioxidant, anticarcinogenic, antiallergenic, hepatoprotective, vasodilating and antithrombotic activities. This review will focus mainly on the relationship between tannin structure and the astringency sensation as well as the biosynthetic pathways of astringent substances in fruit and their regulatory mechanisms.

  4. Chemical and sensory evaluation of Bordeaux wines (Cabernet-Sauvignon and Merlot) and correlation with wine age.

    PubMed

    Chira, Kleopatra; Pacella, Nicola; Jourdes, Michael; Teissedre, Pierre-Louis

    2011-06-15

    Wine quality study was carried out with 24 vintages of Cabernet-Sauvignon (CS) and 7 vintages of Merlot (M) produced by two different Bordeaux wine-growing areas. Proanthocyanidin monomers and oligomers were identified and quantified by HPLC-UV-Fluo. Percentage of galloylation (%G), of prodelphinidins (%P) as well as mean degree of polymerisation (mDP) were also determined. Total phenolic compounds, total anthocyanins, total tannins, hue, CI (colour intensity), titratable acidity, ethanol level and pH were evaluated. Sensory analysis concerning astringency and bitterness intensity was also performed. Total phenolic compounds, total anthocyanins, total tannins, tannin monomers, hue, CI, % G, % P, mDP and astringency intensity differentiate both wines (M and CS) according to vintage. Correlations between wine age and: mDP, hue, astringency and tannin monomers (C+EC) are obtained. Qualitative tannin characterisation is established by correlation between astringency and mDP (R(2)=0.509, p=0.051, CS; R(2)=0.780, p=0.000M). In addition, mDP decreases significantly during ageing (R(2)=0.796, p=0.000; CS and R(2)=0.946, p=0.000; M). Scale patterns between wine mDP and tannin perception (astringency) are proposed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Interactions between wine phenolic compounds and human saliva in astringency perception.

    PubMed

    García-Estévez, Ignacio; Ramos-Pineda, Alba María; Escribano-Bailón, María Teresa

    2018-03-01

    Astringency is a complex perceptual phenomenon involving several sensations that are perceived simultaneously. The mechanism leading to these sensations has been thoroughly and controversially discussed in the literature and it is still not well understood since there are many contributing factors. Although we are still far from elucidating the mechanisms whereby astringency develops, the interaction between phenolic compounds and proteins (from saliva, oral mucosa or cells) seems to be most important. This review summarizes the recent trends in the protein-phenol interaction, focusing on the effect of the structure of the phenolic compound on the interaction with salivary proteins and on methodologies based on these interactions to determine astringency.

  6. Comparative study of wine tannin classification using Fourier transform mid-infrared spectrometry and sensory analysis.

    PubMed

    Fernández, Katherina; Labarca, Ximena; Bordeu, Edmundo; Guesalaga, Andrés; Agosin, Eduardo

    2007-11-01

    Wine tannins are fundamental to the determination of wine quality. However, the chemical and sensorial analysis of these compounds is not straightforward and a simple and rapid technique is necessary. We analyzed the mid-infrared spectra of white, red, and model wines spiked with known amounts of skin or seed tannins, collected using Fourier transform mid-infrared (FT-MIR) transmission spectroscopy (400-4000 cm(-1)). The spectral data were classified according to their tannin source, skin or seed, and tannin concentration by means of discriminant analysis (DA) and soft independent modeling of class analogy (SIMCA) to obtain a probabilistic classification. Wines were also classified sensorially by a trained panel and compared with FT-MIR. SIMCA models gave the most accurate classification (over 97%) and prediction (over 60%) among the wine samples. The prediction was increased (over 73%) using the leave-one-out cross-validation technique. Sensory classification of the wines was less accurate than that obtained with FT-MIR and SIMCA. Overall, these results show the potential of FT-MIR spectroscopy, in combination with adequate statistical tools, to discriminate wines with different tannin levels.

  7. Spectrophotometric determination of the tannin contents of various Turkish black tea, beer and wine samples.

    PubMed

    Tinkiliç, N; Uyanik, A

    2001-05-01

    This study reports tannin contents of various tea (19), beer (6) and wine (6) samples, produced or sold in Turkey under different brand names. Determinations were carried out by employing a previously reported UV-vis spectrophotometric method. The standard addition procedure was also compared to the direct determination procedure and found to be more reliable. The tannin contents of hot water extracts of tea, tea bag and herbal tea samples ranged between 6.20-8.33, 8.03-6.59 and 2.76-6.54 percent (w/w) respectively. Tannin contents of beer and wine samples determined without extraction were found ranging between 66.36-77.26 and 67.18-107.62 micrograms/mL respectively. Iron contents of analysed wine samples were also found ranging between 0.36 and 10.33 ppm by AAS and no relation is found between tannin and iron contents.

  8. Relationship of Soluble Grape-Derived Proteins to Condensed Tannin Extractability during Red Wine Fermentation.

    PubMed

    Springer, Lindsay F; Chen, Lei-An; Stahlecker, Avery C; Cousins, Peter; Sacks, Gavin L

    2016-11-02

    In red winemaking, the extractability of condensed tannins (CT) can vary considerably even under identical fermentation conditions, and several explanations for this phenomenon have been proposed. Recent work has demonstrated that grape pathogenesis-related proteins (PRPs) may limit retention of CT added to finished wines, but their relevance to CT extractability has not been evaluated. In this work, Vitis vinifera and interspecific hybrids (Vitis ssp.) from both hot and cool climates were vinified under small-scale, controlled conditions. The final CT concentration in wine was well modeled from initial grape tannin and juice protein concentrations using the Freundlich equation (r 2 = 0.686). In follow-up experiments, separation and pretreatment of juice by bentonite, heating, freezing, or exogenous tannin addition reduced protein concentrations in juices from two grape varieties. The bentonite treatment also led to greater wine CT for one of the varieties, indicating that prefermentation removal of grape protein may be a viable approach to increasing wine CT.

  9. Evolution of Sangiovese Wines With Varied Tannin and Anthocyanin Ratios During Oxidative Aging.

    PubMed

    Gambuti, Angelita; Picariello, Luigi; Rinaldi, Alessandra; Moio, Luigi

    2018-01-01

    Changes in phenolic compounds, chromatic characteristics, acetaldehyde, and protein-reactive tannins associated with oxidative aging were studied in Sangiovese wines with varied tannin T/anthocyanin A ratios. For this purpose, three Sangiovese vineyards located in Tuscany were considered in the 2016 vintage. To obtain wines with different T/A ratios, two red wines were produced from each vinification batch: a free run juice with a lower T/A ratio and a marc pressed wine with a higher T/A ratio. An overall of six wines with T/A ratios ranging between 5 and 23 were produced. An oxidation treatment (four saturation cycles) was applied to each wine. Average and initial oxygen consumption rates (OCR) were positively correlated to VRF/mA (vanilline reactive flavans/monomeric anthocyanins) and T/A ratios while OCRs were negatively related to the wine content in monomeric and total anthocyanins. The higher the A content was, the greater the loss of total and free anthocyanins. A significant lower production of polymeric pigments was detected in all pressed wines with respect to the correspondant free run one. A gradual decrease of tannin reactivity toward saliva proteins after the application of oxygen saturation cycles was detected. The results obtained in this experiment indicate that VRF/mA and T/A ratios are among the fundamental parameters to evaluate before choosing the antioxidant protection to be used and the right oxidation level to apply for a longer shelf-life of red wine.

  10. Evolution of Sangiovese Wines with Varied Tannin and Anthocyanin Ratios during Oxidative Aging

    NASA Astrophysics Data System (ADS)

    Gambuti, Angelita; Picariello, Luigi; Rinaldi, Alessandra; Moio, Luigi

    2018-03-01

    Changes in phenolic compounds, chromatic characteristics, acetaldehyde, and protein-reactive tannins associated with oxidative aging were studied in Sangiovese wines with varied tannin T/anthocyanin A ratios. For this purpose, three Sangiovese vineyards located in Tuscany were considered in the 2016 vintage. To obtain wines with different T/A ratios, two red wines were produced from each vinification batch: a free run juice with a lower T/A ratio and a marc pressed wine with a higher T/A ratio. An overall of 6 wines with T/A ratios ranging between 5 and 23 were produced. An oxidation treatment (four saturation cycles) was applied to each wine. Average and initial oxygen consumption rates (OCR) were positively correlated to VRF/mA (vanilline reactive flavans/monomeric anthocyanins) and T/A ratios while OCRs were negatively related to the wine content in monomeric and total anthocyanins. The higher the A content was, the greater the loss of total and free anthocyanins. A significant lower production of polymeric pigments was detected in all pressed wines with respect to the correspondant free run one. A gradual decrease of tannin reactivity towards saliva proteins after the application of oxygen saturation cycles was detected. The results obtained in this experiment indicate that VRF/mA and T/A ratios are among the fundamental parameters to evaluate before choosing the antioxidant protection to be used and the right oxidation level to apply for a longer shelf-life of red wine.

  11. Influence of Tannin Extract and Yeast Extract on Color Preservation and Anthocyanin Content of Mulberry Wine.

    PubMed

    You, Yilin; Li, Na; Han, Xue; Guo, Jielong; Liu, Guojie; Huang, Weidong; Zhan, Jicheng

    2018-04-01

    The color of mulberry wine is extremely unstable in processing and aging. This paper investigates the effects of tannin extract and yeast extract on the color and color-preserving characteristics of mulberry wine made from the Dashi cultivar. The results showed that the maximum absorption wavelength in both tannin extract and yeast extract groups changed generating the red shift effect. The color of the tannin extract maintained a good gloss in the first 4 months, while the yeast extract group showed remarkable color preservation for the first 3 months. The total anthocyanin and cyanidin-3-rutinoside contents in both experiment groups were significantly higher than that of the control group, thus proving that tannin extract and yeast extract both exert a remarkably positive effect on preserving the color of mulberry wine during its aging. Moreover, sensory analysis indicated that the quality of mulberry wine treated with tannin extract was significantly higher than that of the control. The distinct color of mulberry wine is one of the foremost qualities that imprints on consumers' senses, but it is extremely unstable in processing and aging. However, the color protection of mulberry wine was not studied previously. In this study, we found that tannin extract and yeast extract both exert a remarkably positive effect on preserving the color of mulberry wine during aging. The study is of great significance as a guide to improving the color stability of mulberry wine, thereby also improving and promoting the development of the mulberry deep processing industry. © 2018 Institute of Food Technologists®.

  12. Saliva tannin interactions.

    PubMed

    Prinz, J F; Lucas, P W

    2000-11-01

    Many plant foods contain tannins, compounds that bind proteins, such as mammalian enzymes. Although described as tasteless, tannins can be detected orally by their astringency. However, the actual mechanism of oral detection and the effect of tannins on mastication and swallowing have been little investigated. Here, we show from in vitro tests that tannic acid, a common standard in tests used to detect tannins, significantly reduces the lubricating qualities of human saliva both by decreasing its viscosity and increasing friction, both factors lending support to the notion that astringency is a tactile phenomenon. From the literature, it is clear that this effect depends on the presence of salivary proline-rich proteins (PRP). In a mammalian context, ingestion of tannin-rich foods in a species with salivary PRP will be signalled by interference with bolus formation during mastication while the increase in friction may also be detectable and lead to increased tooth wear if the signal is ignored. In a human context, cross-cultural preferences for tannin-rich beverages such as tea, coffee and red wine at the end of meals may be explained by reduction in adhesion of food particles to the oral mucosa allowing their rapid oral clearance.

  13. Phenolic compositions of 50 and 30 year sequences of Australian red wines: the impact of wine age.

    PubMed

    McRae, Jacqui M; Dambergs, Robert G; Kassara, Stella; Parker, Mango; Jeffery, David W; Herderich, Markus J; Smith, Paul A

    2012-10-10

    The phenolic composition of red wine impacts upon the color and mouthfeel and thus quality of the wine. Both of these characteristics differ depending on the age of a wine, with the purple of young wines changing to brick red and the puckering or aggressive astringency softening in older wines. This study investigated the color parameters, tannin concentrations and tannin composition of a 50 year series of Cabernet Sauvignon wines from a commercial label as well as 30 year series of Cabernet Sauvignon and Shiraz wines from a separate commercial label to assess the impact of wine age on phenolic composition and concentration. The wine color density in wines of 40 to 50 years old was around 5 AU compared with 16 AU of wine less than 12 months old, which correlated well with the concentration of non-bleachable pigments and pigmented polymers. Conversely, the anthocyanin concentrations in 10 year old wines were substantially lower than that of recently bottled wines (around 100 mg/L compared with 627 mg/L, respectively), adding further evidence that non-bleachable pigments including pigmented polymers play a much larger role in long-term wine color than anthocyanins. No age-related trend was observed for tannin concentration, indicating that the widely noted softer astringency of older red wines cannot necessarily be directly related to lower concentrations of soluble wine tannin and is potentially a consequence of changes in tannin structure. Wine tannins from older wines were generally larger than tannins from younger wines and showed structural changes consistent with oxidation.

  14. Membrane lipids protected from oxidation by red wine tannins: a proton NMR study.

    PubMed

    Furlan, Aurélien L; Jobin, Marie-Lise; Buchoux, Sébastien; Grélard, Axelle; Dufourc, Erick J; Géan, Julie

    2014-12-01

    Dietary polyphenols widespread in vegetables and beverages like red wine and tea have been reported to possess antioxidant properties that could have positive effects on human health. In this study, we propose a new in situ and non-invasive method based on proton liquid-state nuclear magnetic resonance (NMR) to determine the antioxidant efficiency of red wine tannins on a twice-unsaturated phospholipid, 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (DLiPC), embedded in a membrane model. Four tannins were studied: (+)-catechin (C), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG). The lipid degradation kinetics was determined by measuring the loss of the bis-allylic protons during oxidation induced by a radical initiator, 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH). The antioxidant efficiency, i.e. the ability of tannins to slow down the lipid oxidation rate, was shown to be higher for galloylated tannins, ECG and EGCG. Furthermore, the mixture of four tannins was more efficient than the most effective tannin, EGCG, demonstrating a synergistic effect. To better understand the antioxidant action mechanism of polyphenols on lipid membranes, the tannin location was investigated by NMR and molecular dynamics. A correlation between antioxidant action of tannins and their location at the membrane interface (inserted at the glycerol backbone level) could thus be established. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  15. Wine phenolics.

    PubMed

    Waterhouse, Andrew L

    2002-05-01

    Wine contains many phenolic substances, most of which originate in the grape berry. The phenolics have a number of important functions in wine, affecting the tastes of bitterness and astringency, especially in red wine. Second, the color of red wine is caused by phenolics. Third, the phenolics are the key wine preservative and the basis of long aging. Lastly, since phenolics oxidize readily, they are the component that suffers owing to oxidation and the substance that turns brown in wine (and other foods) when exposed to air. Wine phenolics include the non-flavonoids: hydroxycinnamates, hydroxybenzoates and the stilbenes; plus the flavonoids: flavan-3-ols, the flavonols, and the anthocyanins. While polymeric condensed tannins and pigmented tannins constitute the majority of wine phenolics, their large size precludes absorption and thus they are not likely to have many health effects (except, perhaps, in the gut). The total amount of phenols found in a glass of red wine is on the order of 200 mg versus about 40 mg in a glass of white wine.

  16. Hypotheses on the effects of enological tannins and total red wine phenolic compounds on Oenococcus oeni.

    PubMed

    Chasseriaud, Laura; Krieger-Weber, Sibylle; Déléris-Bou, Magali; Sieczkowski, Nathalie; Jourdes, Michael; Teissedre, Pierre Louis; Claisse, Olivier; Lonvaud-Funel, Aline

    2015-12-01

    Lot of articles report on the impact of polyphenols on wine lactic acid bacteria, but it is clear that the results still remain confusing, because the system is complicated both in term of chemical composition and of diversity of strains. In addition, red wines polyphenols are multiple, complex and reactive molecules. Moreover, the final composition of wine varies according to grape variety and to extraction during winemaking. Therefore it is nearly impossible to deduce their effects on bacteria from experiments in oversimplified conditions. In the present work, effect of tannins preparations, currently considered as possible technological adjuvants, was assessed on growth and malolactic fermentation for two malolactic starters. Experiments were conducted in a laboratory medium and in a white wine. Likewise, impact of total polyphenolic extracts obtained from different grape variety red wines was evaluated in the white wine as culture medium. As expected growth and activity of both strains were affected whatever the additions. Results suggest some interpretations to the observed impacts on bacterial populations. Influence of tannins should be, at least partly, due to redox potential change. Results on wine extracts show the need for investigating the bacterial metabolism of some galloylated molecules. Indeed, they should play on bacterial physiology and probably affect the sensory qualities of wines. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Evolution of Sangiovese Wines With Varied Tannin and Anthocyanin Ratios During Oxidative Aging

    PubMed Central

    Gambuti, Angelita; Picariello, Luigi; Rinaldi, Alessandra; Moio, Luigi

    2018-01-01

    Changes in phenolic compounds, chromatic characteristics, acetaldehyde, and protein-reactive tannins associated with oxidative aging were studied in Sangiovese wines with varied tannin T/anthocyanin A ratios. For this purpose, three Sangiovese vineyards located in Tuscany were considered in the 2016 vintage. To obtain wines with different T/A ratios, two red wines were produced from each vinification batch: a free run juice with a lower T/A ratio and a marc pressed wine with a higher T/A ratio. An overall of six wines with T/A ratios ranging between 5 and 23 were produced. An oxidation treatment (four saturation cycles) was applied to each wine. Average and initial oxygen consumption rates (OCR) were positively correlated to VRF/mA (vanilline reactive flavans/monomeric anthocyanins) and T/A ratios while OCRs were negatively related to the wine content in monomeric and total anthocyanins. The higher the A content was, the greater the loss of total and free anthocyanins. A significant lower production of polymeric pigments was detected in all pressed wines with respect to the correspondant free run one. A gradual decrease of tannin reactivity toward saliva proteins after the application of oxygen saturation cycles was detected. The results obtained in this experiment indicate that VRF/mA and T/A ratios are among the fundamental parameters to evaluate before choosing the antioxidant protection to be used and the right oxidation level to apply for a longer shelf-life of red wine. PMID:29600246

  18. Regulated deficit irrigation alters anthocyanins, tannins and sensory properties of cabernet sauvignon grapes and wines.

    PubMed

    Casassa, Luis Federico; Keller, Markus; Harbertson, James F

    2015-04-29

    Four regulated deficit irrigation (RDI) regimes were applied to Cabernet Sauvignon grapes, which were analyzed for phenolics and also made into wine over three consecutive growing seasons. Relative to an industry standard regime (IS), yield was reduced over the three years by 37% in a full-deficit (FD) regime and by 18% in an early deficit (ED) regime, whereas no yield reduction occurred with a late deficit (LD) regime. Relative to IS, skin anthocyanin concentration (fresh weight basis) was 18% and 24% higher in ED and FD, respectively, whereas no effect was seen in LD. Seed tannin concentration was 3% and 8% higher in ED and FD, respectively, relative to the other two RDI regimes, whereas seed tannin content (amount per berry) was higher in IS than in FD. There were no practically relevant effects on the basic chemistry of the wines. The finished wines showed concentrations of tannins and anthocyanins that generally mirrored observed differences in skin and seed phenolic concentrations, although these were amplified in FD wines. Descriptive sensory analysis of the 2008 wines showed that FD wines were the most saturated in color, with higher purple hue, roughness, dryness and harshness, followed by ED wines, whereas IS and LD wines were less saturated in color and with higher brown and red hues. Overall, FD and ED seemed to yield fruit and wine with greater concentrations of phenolics than IS and LD, with the additional advantage of reducing water usage. However, these apparent benefits need to be balanced out with reductions in crop yields and potential long-term effects associated with pre-véraison water deficits.

  19. Quantitative analysis of red wine tannins using Fourier-transform mid-infrared spectrometry.

    PubMed

    Fernandez, Katherina; Agosin, Eduardo

    2007-09-05

    Tannin content and composition are critical quality components of red wines. No spectroscopic method assessing these phenols in wine has been described so far. We report here a new method using Fourier transform mid-infrared (FT-MIR) spectroscopy and chemometric techniques for the quantitative analysis of red wine tannins. Calibration models were developed using protein precipitation and phloroglucinolysis as analytical reference methods. After spectra preprocessing, six different predictive partial least-squares (PLS) models were evaluated, including the use of interval selection procedures such as iPLS and CSMWPLS. PLS regression with full-range (650-4000 cm(-1)), second derivative of the spectra and phloroglucinolysis as the reference method gave the most accurate determination for tannin concentration (RMSEC = 2.6%, RMSEP = 9.4%, r = 0.995). The prediction of the mean degree of polymerization (mDP) of the tannins also gave a reasonable prediction (RMSEC = 6.7%, RMSEP = 10.3%, r = 0.958). These results represent the first step in the development of a spectroscopic methodology for the quantification of several phenolic compounds that are critical for wine quality.

  20. Effect of addition of commercial grape seed tannins on phenolic composition, chromatic characteristics, and antioxidant activity of red wine.

    PubMed

    Neves, Ana C; Spranger, Maria I; Zhao, Yuqing; Leandro, Maria C; Sun, Baoshan

    2010-11-24

    The effect of addition of grape seed tannins on the phenolic composition, chromatic characteristics, and antioxidant activity of red wine was studied. Two highly pure commercial grape seed tannins (GSE100 and GSE300) were selected, and their phenolic compositions were determined. Two types of red wines were made with Castelão/Tinta Miúda (3/2, w/w) grapevine varieties by fermentation on skin using two different maceration times, which correspond to the wines rich and poor in polyphenols, respectively. Each of these wines was used for experimentation with the addition of GSE100 and GSE300 before and immediately after alcoholic fermentation. Phenolic composition, chromatic characteristics, and antioxidant activity of the finished red wines were analyzed by HPLC-DAD, CIElab 76 convention, and DPPH radical test, respectively. The results showed that the addition of grape seed tannins had obvious effects of increasing color intensity and antioxidant activity only in the wines poor in polyphenols. Although GSE300 contained much higher amounts of di- and trimer procyanidins and a lower amount of polymeric proanthocyanidins, it provided effects of increasing the color intensity and antioxidant activity of the wines poor in polyphenols similar to those of GSE100. Furthermore, GSE100 released more gallic acid to wines than GSE300, although no gallic acid was detected in GSE100. Tannins added after alcoholic fermentation had a better effect on phenolic composition of red wine than tannins added before alcoholic fermentation.

  1. Enological Tannin Effect on Red Wine Color and Pigment Composition and Relevance of the Yeast Fermentation Products.

    PubMed

    García-Estévez, Ignacio; Alcalde-Eon, Cristina; Puente, Víctor; Escribano-Bailón, M Teresa

    2017-11-23

    Enological tannins are widely used in the winemaking process either to improve different wine characteristics (color stability, among others) or to compensate for low tannin levels. In this work, the influence of the addition of two different enological tannins, mainly composed of hydrolysable (ellagitannins) and condensed tannins, on the evolution of color and pigment composition of two different types of model systems containing the five main grape anthocyanins was studied. In addition, the effect of the addition of an enological tannin on the color and pigment composition of red wines made from Vitis vinifera L. cv Tempranillo grapes was also studied by high-performance liquid chromatography with diode array detection coupled to mass spectrometry (HPLC-DAD-MS). Results showed that, in model systems, the addition of the enological tannin favored the formation of anthocyanin-derived pigments, such as A-type and B-type vitisins and flavanol-anthocyanin condensation products, provided that the yeast precursors were previously supplied. Moreover, model systems containing the enological tannins were darker and showed higher values of chroma at the end of the study than control ones. The higher formation of these anthocyanin-derived pigments was also observed in the red wines containing the enological tannin. Moreover, these wine also showed lower lightness (L*) values and higher chroma (C* ab ) values than control wines, indicating a higher stabilization of color.

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

    PubMed

    Li, Sijing; Bindon, Keren; Bastian, Susan E P; Jiranek, Vladimir; Wilkinson, Kerry L

    2017-02-22

    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.

  3. Interactions of grape tannins and wine polyphenols with a yeast protein extract, mannoproteins and β-glucan.

    PubMed

    Mekoue Nguela, J; Poncet-Legrand, C; Sieczkowski, N; Vernhet, A

    2016-11-01

    At present, there is a great interest in enology for yeast derived products to replace aging on lees in winemaking or as an alternative for wine fining. These are yeast protein extracts (YPE), cell walls and mannoproteins. Our aim was to further understand the mechanisms that drive interactions between these components and red wine polyphenols. To this end, interactions between grape skin tannins or wine polyphenols or tannins and a YPE, a mannoprotein fraction and a β-glucan were monitored by binding experiments, ITC and DLS. Depending on the tannin structure, a different affinity between the polyphenols and the YPE was observed, as well as differences in the stability of the aggregates. This was attributed to the mean degree of polymerization of tannins in the polyphenol fractions and to chemical changes that occur during winemaking. Much lower affinities were found between polyphenols and polysaccharides, with different behaviors between mannoproteins and β-glucans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Robust Ultraviolet-Visible (UV-Vis) Partial Least-Squares (PLS) Models for Tannin Quantification in Red Wine.

    PubMed

    Aleixandre-Tudo, José Luis; Nieuwoudt, Helené; Aleixandre, José Luis; Du Toit, Wessel J

    2015-02-04

    The validation of ultraviolet-visible (UV-vis) spectroscopy combined with partial least-squares (PLS) regression to quantify red wine tannins is reported. The methylcellulose precipitable (MCP) tannin assay and the bovine serum albumin (BSA) tannin assay were used as reference methods. To take the high variability of wine tannins into account when the calibration models were built, a diverse data set was collected from samples of South African red wines that consisted of 18 different cultivars, from regions spanning the wine grape-growing areas of South Africa with their various sites, climates, and soils, ranging in vintage from 2000 to 2012. A total of 240 wine samples were analyzed, and these were divided into a calibration set (n = 120) and a validation set (n = 120) to evaluate the predictive ability of the models. To test the robustness of the PLS calibration models, the predictive ability of the classifying variables cultivar, vintage year, and experimental versus commercial wines was also tested. In general, the statistics obtained when BSA was used as a reference method were slightly better than those obtained with MCP. Despite this, the MCP tannin assay should also be considered as a valid reference method for developing PLS calibrations. The best calibration statistics for the prediction of new samples were coefficient of correlation (R 2 val) = 0.89, root mean standard error of prediction (RMSEP) = 0.16, and residual predictive deviation (RPD) = 3.49 for MCP and R 2 val = 0.93, RMSEP = 0.08, and RPD = 4.07 for BSA, when only the UV region (260-310 nm) was selected, which also led to a faster analysis time. In addition, a difference in the results obtained when the predictive ability of the classifying variables vintage, cultivar, or commercial versus experimental wines was studied suggests that tannin composition is highly affected by many factors. This study also discusses the correlations in tannin values between the methylcellulose and protein

  5. Protein-precipitable tannin in wines from Vitis vinifera and interspecific hybrid grapes (Vitis ssp.): differences in concentration, extractability, and cell wall binding.

    PubMed

    Springer, Lindsay F; Sacks, Gavin L

    2014-07-30

    Although they possess significant viticultural advantages, interspecific hybrid grapes (Vitis spp.) are reported to produce wine with lower tannin concentrations than European wine varieties (Vitis vinifera). However, extensive quantitative data on this phenomenon as well as mechanistic explanations for these differences are lacking. A survey of primarily commercial wines from the Finger Lakes American Viticultural Area (New York) using a protein precipitation method determined that hybrid-based wines had >4-fold lower tannin concentrations than vinifera wines. To elucidate factors responsible for differences in wine tannin, 24 wines were produced from both red hybrid and vinifera cultivars under identical conditions. Lower wine tannin in French-American hybrid- than vinifera-based wines could be partially explained by lower grape tannin. However, experiments in which cell wall material was incubated with tannin indicated that cell wall binding may be of equal or greater importance in explaining lower wine tannin concentrations in hybrid-based wines. Subsequent characterization of cell wall material revealed that protein in flesh cell walls and, to a lesser extent, pectin in skin cell walls were correlated with cell wall binding.

  6. Antibacterial Action of a Condensed Tannin Extracted from Astringent Persimmon as a Component of Food Addictive Pancil PS-M on Oral Polymicrobial Biofilms

    PubMed Central

    Tomiyama, Kiyoshi; Mukai, Yoshiharu; Saito, Masahiro; Watanabe, Kiyoko; Kumada, Hidefumi; Nihei, Tomotaro; Hamada, Nobushiro; Teranaka, Toshio

    2016-01-01

    The purpose of this study was to evaluate the antibacterial activity against polymicrobial (PM) biofilms of a condensed tannin extracted from astringent persimmon (PS-M), which is contained in refreshing beverages commercially available in Japan. Salivary PM biofilms were formed anaerobically on glass coverslips for 24 and 72 h and were treated for 5 min with sterilized deionized water (DW), 0.05 and 0.2 wt% chlorhexidine digluconate (CHX), and 0.5–4.0 wt% PS-M solution. The colony forming units (CFU/mL) were determined and morphological changes of the biofilms were observed by scanning electron microscopy (SEM). The CFUs were lower in all PS-M and CHX groups compared to the DW group. PS-M exerted a dose-dependent effect. PS-M (1.53 × 107) at a dose of 4.0 wt% had the same effect as 0.2 wt% CHX (2.03 × 107), regardless of the culture period. SEM revealed the biofilm structures were considerably destroyed in the 4.0 wt% PS-M and 0.2 wt% CHX. These findings indicate that the antibacterial effects of PS-M, a naturally derived substance, are comparable to those of CHX. PS-M may keep the oral cavity clean and prevent dental caries and periodontal disease related to dental plaque, as well as systemic disease such as aspiration pneumonitis. PMID:26981533

  7. Identification of spectral regions for the quantification of red wine tannins with fourier transform mid-infrared spectroscopy.

    PubMed

    Jensen, Jacob S; Egebo, Max; Meyer, Anne S

    2008-05-28

    Accomplishment of fast tannin measurements is receiving increased interest as tannins are important for the mouthfeel and color properties of red wines. Fourier transform mid-infrared spectroscopy allows fast measurement of different wine components, but quantification of tannins is difficult due to interferences from spectral responses of other wine components. Four different variable selection tools were investigated for the identification of the most important spectral regions which would allow quantification of tannins from the spectra using partial least-squares regression. The study included the development of a new variable selection tool, iterative backward elimination of changeable size intervals PLS. The spectral regions identified by the different variable selection methods were not identical, but all included two regions (1485-1425 and 1060-995 cm(-1)), which therefore were concluded to be particularly important for tannin quantification. The spectral regions identified from the variable selection methods were used to develop calibration models. All four variable selection methods identified regions that allowed an improved quantitative prediction of tannins (RMSEP = 69-79 mg of CE/L; r = 0.93-0.94) as compared to a calibration model developed using all variables (RMSEP = 115 mg of CE/L; r = 0.87). Only minor differences in the performance of the variable selection methods were observed.

  8. Platelet rebound effect of alcohol withdrawal and wine drinking in rats. Relation to tannins and lipid peroxidation.

    PubMed

    Ruf, J C; Berger, J L; Renaud, S

    1995-01-01

    We investigated in rats fed a purified diet for 2 and 4 months whether wine drinking was associated with the rebound effect on thrombin-induced platelet aggregation observed after alcohol withdrawal. With 6% ethanol drinking or its equivalent in red or white wine, platelet aggregation was reduced similarly by 70% when the animals drank the alcoholic beverages up to the venipuncture. Depriving the rats of alcoholic beverages for 18 hours was associated with an increase in the platelet response of 124% in those receiving 6% ethanol, of 46% with white wine but a decrease of 59% in those with red wine. The protective effect of red wine on platelets could be reproduced by tannins (procyanidins) extracted from grape seeds or red wine and added to 6% ethanol, but not by glycerol or wine without alcohol. That was related to inhibition of the alcohol-induced lipid peroxidation as shown by the lowering of conjugated dienes, lipid peroxides, and the increase in vitamin E in plasma. Owing to tannins, the platelets of rats drinking red wine did not exhibit the rebound effect observed hours after alcohol drinking, eventually associated with sudden death and stroke in humans.

  9. Towards a molecular interpretation of astringency: synthesis, 3D structure, colloidal state, and human saliva protein recognition of procyanidins.

    PubMed

    Cala, Olivier; Fabre, Sandy; Pinaud, Noël; Dufourc, Erick J; Fouquet, Eric; Laguerre, Michel; Pianet, Isabelle

    2011-07-01

    Astringency is a sensation in the mouth used in judging the quality of red wine. The rough, dry, and puckering sensation called astringency is the result of an interaction between tannins and saliva proteins, mainly proline-rich proteins (PRP), which leads to the formation and precipitation of a complex. A dry and rough sensation is then perceived in the mouth. To get an insight into astringency at the molecular level we investigated: (i) An efficient and iterative method for 4-8 procyanidin synthesis, which gives rise to all possible 4-8 procyanidins up to the tetramer with total control of degree of oligomerization and stereochemistry. (ii) The 3D-structural preferences, which take into account their internal movements, using 2D NMR and molecular modeling. (iii) The self-association process in water or hydroalcoholic solutions using diffusion NMR spectroscopy that gives the active proportion of tannins able to fix proteins. (iv) A comprehensive description of the PRP-procyanidin complex formation to get information about stoichiometry, binding site localization, and affinity constants for different procyanidins. The data collected suggest that the interactions are controlled by both procyanidin conformational and colloidal state preferences. All these results provide new insights into the molecular interpretation of tannin astringency. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Comparison of extraction protocols to determine differences in wine-extractable tannin and anthocyanin in Vitis vinifera L. cv. Shiraz and Cabernet Sauvignon grapes.

    PubMed

    Bindon, Keren A; Kassara, Stella; Cynkar, Wieslawa U; Robinson, Ella M C; Scrimgeour, Neil; Smith, Paul A

    2014-05-21

    Cabernet Sauvignon and Shiraz grapes were sourced from different regions within Australia, and microvinified with a skin contact period of 6 days. Grape samples were extracted using two protocols: a 15% v/v ethanol, 10 g/L tartaric acid extract of gently crushed berries (wine-like, WL) and a 50% v/v ethanol, pH 2 extract of grape berry homogenate. It was found that in WL extracts, grape tannin and anthocyanin concentrations were strongly related to wine tannin, anthocyanin and color density achieved during the skin contact period. No relationship was observed for grape tannin concentration analyzed in homogenate extracts and wine tannin, but a strong, positive relationship was found for anthocyanin concentration. When the data obtained from homogenate extraction was treated separately by grape variety, a stronger relationship between grape and wine tannin concentration was observed. Tannin compositional analysis in wines indicated that higher tannin concentrations were due to the extraction of tannin of higher molecular mass during fermentation, most likely from grape skins.

  11. Use of non-Saccharomyces yeasts and oenological tannin in red winemaking: Influence on colour, aroma and sensorial properties of young wines.

    PubMed

    Chen, Kai; Escott, Carlos; Loira, Iris; Del Fresno, Juan Manuel; Morata, Antonio; Tesfaye, Wendu; Calderon, Fernando; Suárez-Lepe, Jose Antonio; Han, Shunyu; Benito, Santiago

    2018-02-01

    Today, many non-Saccharomyces strains have been verified can be positive for the development of wine anthocyanin and aroma in different fermentation scenarios. Moreover, oenological tannins are widely used in wine industry to improve the colour profile and aroma complexity. The aim of this work is to analyze the fermentation characters of non-Saccharomyces strains and investigate the effects of pre-fermentative addition of oenological tannins on the wine components as well as sensory properties. For this purpose, five selected non-Saccharomyces strains and grape seed tannin were used to carry out the different fermentation trials. As a result, the grape seed tannin were less likely to influence growth kinetics of non-Saccharomyces strains. Schizosaccharomyces pombe has been proved can be effective to reduce the malic acid content while increase the level of vinylphenolic pyranoanthocyanin, which is positive for wine colour stability. Pre-fermentative use of oenological tannin was verified could be beneficial for the wines fermented with non-Saccharomyces regarding the improvement of wine colour, anthocyanin composition and the complexity of volatile compounds. Nevertheless, sensory analysis showed that oenological tannin could be less effective to modify the aroma impression of non-Saccharomyces wines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Properties of wine polymeric pigments formed from anthocyanin and tannins differing in size distribution and subunit composition.

    PubMed

    Bindon, Keren; Kassara, Stella; Hayasaka, Yoji; Schulkin, Alex; Smith, Paul

    2014-11-26

    To explore the effect of tannin composition on pigment formation, model ferments of purified 3-O-monoglucoside anthocyanins (ACN) were conducted either alone or in the presence of two different tannins. Tannins were isolated from grape seeds (Sd) or skins (Sk) following exhaustive extraction in 70% v/v acetone. The Sd and Sk tannin fractions had a mean degree of polymerization of 5.2 and 25.6, respectively. The Sd fraction was highly galloylated, at 22%, but galloylation was <2% in the Sk fraction. The Sk fraction was distinguished by a high proportion of prodelphinidin, at 58%. After a 6 month aging period, polymeric pigments were quantified and their color properties determined following isolation by solid-phase extraction. Wine color and polymeric pigment were highest in the treatment containing ACN+Sd and similar in the ACN+Sk and ACN treatments. The same trend between treatments was observed for total and polymeric nonbleachable pigments. Only minor changes in tannin subunit composition were found following ACN incorporation, but the size distribution of polymeric pigments determined by gel permeation chromatography decreased, in particular for the ACN+Sk treatment. Color incorporation in the higher molecular mass range was lower for ACN+Sk wines than for ACN+Sd wines. Compositional differences between the two tannin fractions may therefore limit the incorporation of ACNs in the colored form. The results suggest that in the ACN+Sk and ACN treatments, the formation of lower molecular mass oligomeric pigments was favored. In polymeric pigments derived from ACNs, the presence of ethyl- and vinyl-linked ACNs to the level of trimers was identified using mass spectrometry.

  13. The colloidal state of tannins impacts the nature of their interaction with proteins: the case of salivary proline-rich protein/procyanidins binding.

    PubMed

    Cala, Olivier; Dufourc, Erick J; Fouquet, Eric; Manigand, Claude; Laguerre, Michel; Pianet, Isabelle

    2012-12-18

    While the definition of tannins has been historically associated with its propensity to bind proteins in a nonspecific way, it is now admitted that specific interaction also occurs. The case of the astringency perception is a good example to illustrate this phenomenon: astringency is commonly described as a tactile sensation induced by the precipitation of a complex composed of proline-rich proteins present in the human saliva and tannins present in beverages such as tea or red wines. In the present work, the interactions between a human saliva protein segment and three different procyanidins (B1, B3, and C2) were investigated at the atomic level by NMR and molecular dynamics. The data provided evidence for (i) an increase in affinity compared to shortest human saliva peptides, which is accounted for by protein "wraping around" the tannin, (ii) a specificity in the interaction below tannin critical micelle concentration (CMC) of ca. 10 mM, with an affinity scale such that C2 > B1 > B3, and (iii) a nonspecific binding above tannin CMC that conducts irremediably to the precipitation of the tannins/protein complex. Such physicochemical findings describe in accurate terms saliva protein-tannin interactions and provide support for a more subtle description by oenologists of wine astringency perception in the mouth.

  14. Microbial dynamics and metabolite changes in Chinese Rice Wine fermentation from sorghum with different tannin content.

    PubMed

    Xu, Jialiang; Wu, Huijun; Wang, Zhiwei; Zheng, Fuping; Lu, Xin; Li, Zhenpeng; Ren, Qing

    2018-03-15

    Chinese rice wine (CRW) is the oldest kind of wine in China and is mainly fermented by wheat Qu and yeast with rice, millet, etc. This gives CRW a unique quality, but the flavor components are complex. Its formation is related to microorganisms, but the link between CRW and microorganisms is poorly understood. Here, we used two kinds of sorghum (JZ22 and JB3, of which JZ22 has a higher tannin content) as the raw materials to brew and determined the structural and functional dynamics of the microbiota by metagenomics and flavor analyses. We detected 106 (JZ22) and 109 (JB3) volatile flavor compounds and 8 organic acids. By correlation analysis, we established 687 (JZ22) and 496 (JB3) correlations between the major flavor compounds and microbes. In JZ22, Blautia, Collinsella, Bifidobacterium, Faecalibacterium and Prevotella had the most correlations with flavor production. In JB3, the top 5 genera were Stenotrophomonas, Bdellovibrio, Solibacillus, Sulfuritalea and Achromobacter. In addition, more esters were detected, and more microorganisms correlated with ester generation in JZ22. This study provides a new idea for the micro ecological diversity of CRW fermented with sorghum. This is of significance for improving the quality and broadening the CRW varieties.

  15. Glucose, fructose and sucrose increase the solubility of protein-tannin complexes and at high concentration, glucose and sucrose interfere with bisulphite bleaching of wine pigments.

    PubMed

    Harbertson, James F; Yuan, Chunlong; Mireles, Maria S; Hanlin, Rachel L; Downey, Mark O

    2013-05-01

    Wines were modified with increasing sugar concentrations and decreasing tannin concentrations and analysed by a combination of protein precipitation and bisulphite bleaching. Increasing sugar concentration decreased the precipitation of tannin and protein-precipitable polymeric pigments (PPP). The use of a hydrogen bond disruptor (urea) to reduce protein-tannin and protein-pigment complex formation showed that the effect of sugar concentration occurred by increasing the solubility of the tannin-protein complex, not by interfering with protein-tannin complex formation. By increasing the solubility of pigment-protein complexes, non-protein-precipitable polymeric pigments (nPPP) appeared to increase. There was also an increase in total polymeric pigments at each tannin concentration with increasing glucose and sucrose concentration, indicating that sugar concentration might also affect bisulphite bleaching of wine pigments. While a significant effect of sugar concentration on tannin-protein complex solubility was observed, these effects were greatest at sugar concentrations far in excess of normal wine making conditions. Under normal wine making conditions, sugar concentration will have a negligible effect on protein-precipitable tannin, PPP and nPPP concentrations. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Rapid measurement of methyl cellulose precipitable tannins using ultraviolet spectroscopy with chemometrics: application to red wine and inter-laboratory calibration transfer.

    PubMed

    Dambergs, Robert G; Mercurio, Meagan D; Kassara, Stella; Cozzolino, Daniel; Smith, Paul A

    2012-06-01

    Information relating to tannin concentration in grapes and wine is not currently available simply and rapidly enough to inform decision-making by grape growers, winemakers, and wine researchers. Spectroscopy and chemometrics have been implemented for the analysis of critical grape and wine parameters and offer a possible solution for rapid tannin analysis. We report here the development and validation of an ultraviolet (UV) spectral calibration for the prediction of tannin concentration in red wines. Such spectral calibrations reduce the time and resource requirements involved in measuring tannins. A diverse calibration set (n = 204) was prepared with samples of Australian wines of five varieties (Cabernet Sauvignon, Shiraz, Merlot, Pinot Noir, and Durif), from regions spanning the wine grape growing areas of Australia, with varying climate and soils, and with vintages ranging from 1991 to 2007. The relationship between tannin measured by the methyl cellulose precipitation (MCP) reference method at 280 nm and tannin predicted with a multiple linear regression (MLR) calibration, using ultraviolet (UV) absorbance at 250, 270, 280, 290, and 315 nm, was strong (r(2)val = 0.92; SECV = 0.20 g/L). An independent validation set (n = 85) was predicted using the MLR algorithm developed with the calibration set and gave confidence in the ability to predict new samples, independent of the samples used to prepare the calibration (r(2)val = 0.94; SEP = 0.18 g/L). The MLR algorithm could also predict tannin in fermenting wines (r(2)val = 0.76; SEP = 0.18 g/L), but worked best from the second day of ferment on. This study also explored instrument-to-instrument transfer of a spectral calibration for MCP tannin. After slope and bias adjustments of the calibration, efficient calibration transfer to other laboratories was clearly demonstrated, with all instruments in the study effectively giving identical results on a transfer set.

  17. Chemical and sensory characterization of DOC red wines from Marche (Italy) related to vintage and grape cultivars.

    PubMed

    Boselli, Emanuele; Boulton, Roger B; Thorngate, John H; Frega, Natale G

    2004-06-16

    Monomeric phenols, color and copigmentation parameters, pigments with different chemical structure, tannin, glucose, fructose, glycerol, ethanol, and organic acids were determined in DOC red wines from Marche (Italy), obtained during three different vintages ranging from 1996 to 2000. The intensity of the bitter and astringent tastes of the wines was determined with panel tastings. Lacrima di Morro and Vernaccia di Serrapetrona (obtained from local cultivars) were different from Rosso Piceno, Rosso Piceno Superiore, and Rosso Conero (produced from different percentages of Sangiovese and Montepulciano). Vernaccia, a red, sweet, "spumante" wine, was an outlier. Lacrima showed a low tannin content, a high content of small pigments and phenols, and a high ratio of copigmented color, which persisted after 3 years of aging. The chemical determinations accounted for a high percentage of variability of measured panel astringency, copigmented color, and measured wine absorbance at 520 nm. It was not possible to create a predictive model for bitterness.

  18. Effect of complex polyphenols and tannins from red wine (WCPT) on chemically induced oxidative DNA damage in the rat.

    PubMed

    Casalini, C; Lodovici, M; Briani, C; Paganelli, G; Remy, S; Cheynier, V; Dolara, P

    1999-08-01

    Flavonoids are polyphenolic antioxidants occurring in vegetables and fruits as well as beverages such as tea and wine which have been thought to influence oxidative damage. We wanted to verify whether a complex mixture of wine tannins (wine complex polyphenols and tannins, WCPT) prevent chemically-induced oxidative DNA damage in vivo. Oxidative DNA damage was evaluated by measuring the ratio of 8-hydroxy-2'-deoxyguanosine (80HdG)/ 2-deoxyguanosine (2dG) x 10(-6) in hydrolyzed DNA using HPLC coupled with electrochemical and UV detectors. We treated rats with WCPT (57 mg/kg p.o.) for 14 d, a dose 10-fold higher than what a moderate wine drinker would be exposed to. WCPT administration significantly reduced the ratio of 80HdG/2dG x 10(-6) in liver DNA obtained from rats treated with 2-nitropropane (2NP) relative to controls administered 2NP only (33. 3 +/- 2.5 vs. 44.9 +/- 3.2 x 10(-6) 2dG; micro +/- SE; p<0.05). On the contrary, pretreatment with WCPT for 10 d did not protect the colon mucosa from oxidative DNA damage induced by 1, 2-dimethylhydrazine (DMH). 2NP and DMH are hepatic and colon carcinogens, respectively, capable of inducing oxidative DNA damage. WCPT have protective action against some types of chemically-induced oxidative DNA damage in vivo.

  19. Effect of SO2 concentration on polyphenol development during red wine micro-oxygenation.

    PubMed

    Tao, Jianxiong; Dykes, Stuart I; Kilmartin, Paul A

    2007-07-25

    A Merlot wine in 15 L research tanks was subjected to micro-oxygenation at 10 mL O2 per liter of wine per month over a 16 week period with additions of 0, 50, 100, and 200 mg/L SO2. A large decrease in monomeric anthocyanins and flavan-3-ols was seen in wines with a lower concentration of SO2, coupled with an increase in nonbleachable pigments; an increase in tannin, measured using precipitation with methyl cellulose; and a greater size and red coloration of a proanthocyanidin extract obtained using Sephadex LH-20. These changes were largely suppressed in wines initially treated with 200 mg/L SO2 and occurred more slowly in wines stored in bottles in the absence of O2. The concentration of SO2 is shown to regulate the polyphenol chemistry involved in the formation of polymeric pigments and changes in tannin structure affecting wine astringency.

  20. Microoxidation in wine production.

    PubMed

    Kilmartin, Paul A

    2010-01-01

    Microoxygenation (MOX) is now widely applied for the maturation of red wines as an alternative to barrel aging. The proposed improvements in wine quality arising from MOX include color stabilization, removal of unwanted off-odors, and improvements in wine mouthfeel. In this review, an outline is provided of oxygenation systems, particularly microbullage and polymer membrane delivery, and of the current understanding of wine oxidation processes. A summary of the results from published studies into red wine MOX is then provided, beginning with observations on O(2) and acetaldehyde accumulation, and the moderating effect of added sulfur dioxide. Effects upon red wine color, particularly the more rapid formation of polymeric pigments and higher color retention, have been consistently demonstrated in MOX studies, along with further effects on specific polyphenol compounds. A few reports have recently examined the effect of MOX on red wine aromas, but these have yet to identify compounds that consistently change in a manner that would explain sensory observations regarding a lowering of herbaceous and reductive odors. Likewise, tannin analyses have been undertaken in several studies, but explanations of the decline in wine astringency remain to be developed. The accelerated growth of unwanted microorganisms has also been examined in a limited number of studies, but no major problems have been identified in this area. Copyright © 2010 Elsevier Inc. All rights reserved.

  1. Effect of complex polyphenols and tannins from red wine on DNA oxidative damage of rat colon mucosa in vivo.

    PubMed

    Giovannelli, L; Testa, G; De Filippo, C; Cheynier, V; Clifford, M N; Dolara, P

    2000-10-01

    Dietary polyphenols have been reported to have a variety of biological actions, including anti-carcinogenic, antioxidant and anti-inflammatory activities. In the present study we have evaluated the effect of an oral treatment with complex polyphenols and tannins from red wine and tea on DNA oxidative damage in the rat colon mucosa. Isolated colonocytes were prepared from the colon mucosa of rats treated for ten days with either wine complex polyphenols (57.2 mg/kg/d) or thearubigin (40 mg/kg/d) by oral gavage. Colonocyte oxidative DNA damage was analysed at the single cell level using a modification of the comet assay technique. The results show that wine complex polyphenols and tannins induce a significant decrease (-62% for pyrimidine and -57% for purine oxidation) in basal DNA oxidative damage in colon mucosal cells without affecting the basal level of single-strand breaks. On the other hand, tea polyphenols, namely a crude extract of thearubigin, did not affect either strand breaks or pyrimidine oxidation in colon mucosal cells. Our experiments are the first demonstration that dietary polyphenols can modulate in vivo oxidative damage in the gastrointestinal tract of rodents. These data support the hypothesis that dietary polyphenols might have both a protective and a therapeutic potential in oxidative damage-related pathologies.

  2. Chemical, chromatic, and sensory attributes of 6 red wines produced with prefermentative cold soak.

    PubMed

    Casassa, L Federico; Bolcato, Esteban A; Sari, Santiago E

    2015-05-01

    Six red grape cultivars, Barbera D'Asti, Cabernet Sauvignon, Malbec, Merlot, Pinot Noir and Syrah, were produced with or without prefermentative cold soak (CS). Cold soak had no effect on the basic chemical composition of the wines. At pressing, CS wines were more saturated and with a higher red component than control wines. After 1 year of bottle aging, CS wines retained 22% more anthocyanins than control wines, but tannins and total phenolics remained unaffected. Both saturation and the red component of colour were slightly higher in CS wines. From a sensory standpoint, CS only enhanced colour intensity in Barbera D'Asti and Cabernet Sauvignon wines, whereas it diminished colour intensity in Pinot Noir. Cold soak had no effect on perceived aroma, bitterness, astringency, and body of the wines. Principal Component Analysis suggested that the outcome of CS is contingent upon the specific cultivar to which the CS technique is applied. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Toward the optical tongue: flow-through sensing of tannin-protein interactions based on FTIR spectroscopy.

    PubMed

    Edelmann, Andrea; Lendl, Bernhard

    2002-12-11

    The interaction of polyphenols (tannins) with proline-rich proteins (gelatin) has been studied using an automated flow injection system with Fourier transform infrared spectroscopic detection to gain insight into chemical aspects related to astringency. In the perception of astringency, a major taste property in red wines and other beverages such as beer, tea, or fruit juices, an interaction between proline-rich salivary proteins and tannins present in the sample takes place. To study this interaction, agarose beads carrying gelatin (a proline-rich protein) were placed in the IR flow cell in such a way that the beads were probed by the IR beam. Using an automated flow system, we injected samples in a carrier stream and flushed over the proteins in a highly reproducible manner. Simultaneously, any retardation due to tannin-protein interactions taking place inside the flow cell was monitored by infrared spectroscopy. Tannins of different sources (grapes, wooden barrels, formulations used in wine making) were investigated, and their flow-through behavior was characterized. Significant differences in their affinity toward gelatin could be observed. Furthermore, because of small but characteristic differences in the IR spectrum, it is possible to distinguish condensed from hydrolyzable tannins. Nonastringent substances such as alcohols, sugars, and acids did not show retention on gelatin. The selectivity of the flow-through sensor was also demonstrated on the example of red and white wine. In contrast to white wine, where no interaction could be observed, in red wine a major interaction of the red wine tannins was found.

  4. Exploring mouthfeel in model wines: Sensory-to-instrumental approaches.

    PubMed

    Laguna, Laura; Sarkar, Anwesha; Bryant, Michael G; Beadling, Andrew R; Bartolomé, Begoña; Victoria Moreno-Arribas, M

    2017-12-01

    Wine creates a group of oral-tactile stimulations not related to taste or aroma, such as astringency or fullness; better known as mouthfeel. During wine consumption, mouthfeel is affected by ethanol content, phenolic compounds and their interactions with the oral components. Mouthfeel arises through changes in the salivary film when wine is consumed. In order to understand the role of each wine component, eight different model wines with/without ethanol (8%), glycerol (10g/L) and commercial tannins (1g/L) were described using a trained panel. Descriptive analysis techniques were used to train the panel and measure the intensity of the mouthfeel attributes. Alongside, the suitability of different instrumental techniques (rheology, particle size, tribology and microstructure, using Transmission Electron Microscopy (TEM)) to measure wine mouthfeel sensation was investigated. Panelists discriminated samples based on their tactile-related components (ethanol, glycerol and tannins) at the levels found naturally in wine. Higher scores were found for all sensory attributes in the samples containing ethanol. Sensory astringency was associated mainly with the addition of tannins to the wine model and glycerol did not seem to play a discriminating role at the levels found in red wines. Visual viscosity was correlated with instrumental viscosity (R=0.815, p=0.014). Hydrodynamic diameter of saliva showed an increase in presence of tannins (almost 2.5-3-folds). However, presence of ethanol or glycerol decreased hydrodynamic diameter. These results were related with the sensory astringency and earthiness as well as with the formation of nano-complexes as observed by TEM. Rheologically, the most viscous samples were those containing glycerol or tannins. Tribology results showed that at a boundary lubrication regime, differences in traction coefficient lubrication were due by the presence of glycerol. However, no differences in traction coefficients were observed in presence

  5. Chemo-sensory approach for the identification of chemical compounds driving green character in red wines.

    PubMed

    Sáenz-Navajas, María-Pilar; Arias, Ignacio; Ferrero-Del-Teso, Sara; Fernández-Zurbano, Purificación; Escudero, Ana; Ferreira, Vicente

    2018-07-01

    The present work seeks to define the "green character" of red wines and characterise the groups of molecules potentially involved in that perception. Fifty-four wines were screened by wine experts for different levels of green character. Six different phenolic fractions were obtained by liquid chromatography (LC) and further submitted to sensory and chemical characterisation. The volatile fraction was screened by semipreparative LC, Gas Chromatography-Olfactometry (GC-O) and quantitative analysis. The green character was linked to vegetal aroma, astringency, green and dry tannins according to experts of the Somontano region. Non-volatile fractions containing tannins with mean degree of polymerisation of ten and smaller anthocyanin-derivative pigments (astringency-related sensations such as dryness and stickiness, respectively. No specific aroma compounds were identified in the GC-O study of green wines, however the wines contained significantly higher levels of fusel alcohols. The interaction between isoamyl alcohol and the anthocyanin-derivative fraction and/or tannins is suggested to be involved in the formation of green character in red wines. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Antioxidant activity of commercial food grade tannins exemplified in a wine model.

    PubMed

    Ricci, Arianna; Olejar, Kenneth J; Parpinello, Giuseppina P; Mattioli, Alessia U; Teslić, Nemanja; Kilmartin, Paul A; Versari, Andrea

    2016-12-01

    Although commercial tannins are widely used in foods and beverages, an improved understanding of the structure and composition of vegetable tannins is needed to promote the exploitation of agri-food by-products and waste and their valorisation in more sustainable industrial applications. This study aims to characterise the phytochemical composition and antioxidant activity of 13 food grade tannins using multiple analytical approaches, including spectrophotometry and HPLC-ECD to determine the amount of targeted polyphenolic compounds. Moreover, the antioxidant activity of tannins was assessed in terms of radical scavenging activity (DPPH• assay), reducing power (FRAP assay), and redox properties (cyclic voltammetry, CV). A statistical univariate and multivariate correlation analysis was performed on 17 parameters including tannin content (range: 0.71-1.62 mM), gallic acid, (+)-catechin, syringic acid and (‒)-epicatechin. The compositional profile of tannins was related to their chemical moiety, antioxidant activity and the botanical origin of the extracts. In particular, the CV signal at 500 mV was highly correlated with DPPH• value due to the catechol ring of flavonoids and trigalloyl moieties of gallic acid-based compounds. Practical examples of tannins application in winemaking are discussed.

  7. Augmentation of chemical and organoleptic properties in Syzygium cumini wine by incorporation of grape seeds during vinification.

    PubMed

    VenuGopal, K S; Cherita, Chris; Anu-Appaiah, K A

    2018-03-01

    The role of grape seed tannins on improving organoleptic properties and its involvement in color stabilization in red wine are well established. The addition of grape seeds as the source of condensed tannins in fruit wine may provide a solution for its color instability and improvement of sensory attributes. Syzgium cumini is traditionally known for its therapeutic properties. In the current study, the influence of yeasts and grape seed addition during fermentation on the chromatic, phenolic and sensory attributes of the wine was accessed. Grape seed addition improved the color characteristics of wine and increased overall phenolic composition. Analysis by HPLC revealed 6 major anthocyanins, among which 3, 5-diglucoside form of delphidin and petunidin was found to be the major components. Cluster and PLSR analysis explained the impact of seed addition on the yeasts, as well as on the perception of panelists, with bitterness and astringency as the dominating attributes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. A physiological model of tea-induced astringency.

    PubMed

    Nayak, A; Carpenter, G H

    2008-10-20

    The mechanism by which solutions containing polyphenols are perceived as astringent is not clearly understood. Salivary proline-rich proteins and histatins are products of salivary glands and rapidly bind polyphenols - thought to be the main astringent compound in such as tea and wine. However it is unclear how this interaction leads to the altered oral mouthfeel known as astringency which is characterised by a dry, puckered feeling all around the mouth. To determine the role of saliva in the perception of astringency a protocol was used to decrease the volume of saliva from the mouth (by washing with water) and then by chewing to increase the volume of saliva above resting levels. Following each of these conditions subjects tasted the same solution of black tea and were asked to rate the relative astringency. Compared to the astringency rating of black tea at rest the majority of subjects (10 out of 15) perceived an increase in astringency following washing the mouth with water. Most subjects then perceived a decrease in astringency following chewing compared to the previous state. In all subjects a reduction in salivary proteins was detected following water washout and an increase above resting levels detected following chewing although there was no change in oral mucosal wetness. A separate experiment revealed several of the proteins interacting following the water washout were salivary in origin. We conclude that salivary proteins in solution inhibit the mouthfeeling of astringency which is mediated, at least in part, by salivary proteins adhered to buccal mucosal cells.

  9. Mechanisms underlying astringency: introduction to an oral tribology approach

    NASA Astrophysics Data System (ADS)

    Upadhyay, Rutuja; Brossard, Natalia; Chen, Jianshe

    2016-03-01

    Astringency is one of the predominant factors in the sensory experience of many foods and beverages ranging from wine to nuts. The scientific community is discussing mechanisms that explain this complex phenomenon, since there are no conclusive results which correlate well with sensory astringency. Therefore, the mechanisms and perceptual characteristics of astringency warrant further discussion and investigation. This paper gives a brief introduction of the fundamentals of oral tribology forming a basis of the astringency mechanism. It discusses the current state of the literature on mechanisms underlying astringency describing the existing astringency models. The review discusses the crucial role of saliva and its physiology which contributes significantly in astringency perception in the mouth. It also provides an overview of research concerned with the physiological and psychophysical factors that mediate the perception of this sensation, establishing the ground for future research. Thus, the overall aim of the review is to establish the critical roles of oral friction (thin-film lubrication) in the sensation of astringency and possibly of some other specific sensory features.

  10. Determination of total iron-reactive phenolics, anthocyanins and tannins in wine grapes of skins and seeds based on near-infrared hyperspectral imaging.

    PubMed

    Zhang, Ni; Liu, Xu; Jin, Xiaoduo; Li, Chen; Wu, Xuan; Yang, Shuqin; Ning, Jifeng; Yanne, Paul

    2017-12-15

    Phenolics contents in wine grapes are key indicators for assessing ripeness. Near-infrared hyperspectral images during ripening have been explored to achieve an effective method for predicting phenolics contents. Principal component regression (PCR), partial least squares regression (PLSR) and support vector regression (SVR) models were built, respectively. The results show that SVR behaves globally better than PLSR and PCR, except in predicting tannins content of seeds. For the best prediction results, the squared correlation coefficient and root mean square error reached 0.8960 and 0.1069g/L (+)-catechin equivalents (CE), respectively, for tannins in skins, 0.9065 and 0.1776 (g/L CE) for total iron-reactive phenolics (TIRP) in skins, 0.8789 and 0.1442 (g/L M3G) for anthocyanins in skins, 0.9243 and 0.2401 (g/L CE) for tannins in seeds, and 0.8790 and 0.5190 (g/L CE) for TIRP in seeds. Our results indicated that NIR hyperspectral imaging has good prospects for evaluation of phenolics in wine grapes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Maceration enzymes and mannoproteins: a possible strategy to increase colloidal stability and color extraction in red wines.

    PubMed

    Guadalupe, Zenaida; Palacios, Antonio; Ayestaran, Belén

    2007-06-13

    Different strategies were adopted to achieve increases in color stability in Tempranillo wines: (i) addition of maceration enzymes directly to the must, (ii) addition of commercial mannoproteins to the must, and (iii) inoculation of must with yeast overexpressed of mannoproteins. The addition of enzymes favored color extraction, and the wines obtained presented higher values of wine color, color intensity, bisulfite-stable color, and visually enhanced color intensity. The enzyme hydrolytic activity produced an increase in the acid polysaccharide content and polyphenol index and yielded to wines with more astringency, tannin, and length. Added mannoproteins had clearer effects on the analyzed parameters than yeast. Contrary to what may be thought, mannoproteins did not maintain the extracted polyphenols in colloidal dispersion and neither ensured color stability. These compounds clearly modified the gustative structure of the wines, enhancing the sweetness and roundness.

  12. Ethylidene-bridged Flavan-3-ols in red wine and correlation with wine age.

    PubMed

    Drinkine, Jessica; Lopes, Paulo; Kennedy, James A; Teissedre, Pierre-Louis; Saucier, Cedric

    2007-07-25

    Condensed tannins are responsible for astringency and bitterness and participate in the color stability of red wines. During wine making and aging, they undergo chemical changes including, for example, acetaldehyde-induced polymerization. Following this study, the ethylidene-bridged flavan-3-ols were monitored in different vintage wines made from grapes collected in the same vineyard in three wineries in Bordeaux, Pauillac, and Saint Julien. Flavan-3-ol ethylidene bridges were quantified by wine 2,2'-ethylidenediphloroglucinol (EDP) phloroglucinolysis. This method was based upon the analysis of EDP, a product formed after acid-catalyzed cleavage of wine flavan-3-ols in the presence of excess phloroglucinol. The flavan-3-ol ethylidene bridges were then compared to flavan-3-ol contents (phloroglucinolysis), phenolic contents, and color measurements. Low amounts of flavan-3-ol ethylidene bridges (0.8-2.5 mg L(-1)) were quantified in wines. Flavan-3-ol ethylidene bridges represent less than 4% of flavan-3-ol bonds, but the proportion of these linkages relative to native interflavan bonds increased with wine age. This proportion correlated with pigmented polymers.

  13. Evolution of phenolic composition of red wine during vinification and storage and its contribution to wine sensory properties and antioxidant activity.

    PubMed

    Sun, Baoshan; Neves, Ana C; Fernandes, Tiago A; Fernandes, Ana L; Mateus, Nuno; De Freitas, Vítor; Leandro, Conceição; Spranger, Maria I

    2011-06-22

    The objective of this work was to study the evolution of the phenolic composition of red wine during vinification and storage and its relationship with some sensory properties (astringency and bitterness) and antioxidant activities. Thus, red wine was made by a classic vinification method with Castelão and Tinta Miúda grapes (Vitis vinifera L.) harvested at maturity (3:2; w/w). Samples were taken at 2 and 7 days of maceration, at second racking, at the time of bottling and at 6 and 14 months after bottling. The total polyphenols extract (TPx) in each sample was isolated by column chromatography. The phenolic composition (anthocyanins and proanthocyanidins), in vitro antioxidant activity, and sensory property (astringency, bitterness) of the isolated TPx from different winemaking stages were evaluated through high-performance liquid chromatography-diode array detection, 1,1-diphenyl-2-picrylhidrazyl radical test, ferric reducing antioxidant power assay, total phenolic index, MWI (polyphenol molecular weight index), TSA (tannin specific activity), and sensory panel tasting. The results showed that the phenolic composition of red wine varied significantly during winemaking. The intensity of astringency (IA) and the intensity bitterness (IB) of the isolated TPx from different winemaking stages increased from 2 days of maceration until second racking and then decreased. Furthermore, MWI and TSA are positively correlated with IA and IB. The in vitro antioxidant activity of the isolated TPx from different winemaking stages maintained unchanged after alcoholic fermentation, which was independent of the variation of phenolic composition and sensory properties.

  14. Consumer perception of astringency in clear acidic whey protein beverages.

    PubMed

    Childs, Jessica L; Drake, MaryAnne

    2010-01-01

    Acidic whey protein beverages are a growing component of the functional food and beverage market. These beverages are also astringent, but astringency is an expected and desirable attribute of many beverages (red wine, tea, coffee) and may not necessarily be a negative attribute of acidic whey protein beverages. The goal of this study was to define the consumer perception of astringency in clear acidic whey protein beverages. Six focus groups (n=49) were held to gain understanding of consumer knowledge of astringency. Consumers were presented with beverages and asked to map them based on astringent mouthfeel and liking. Orthonasal thresholds for whey protein isolate (WPI) in water and flavored model beverages were determined using a 7-series ascending forced choice method. Mouthfeel/basic taste thresholds were determined for WPI in water. Acceptance tests on model beverages were conducted using consumers (n=120) with and without wearing nose clips. Consumers in focus groups were able to identify astringency in beverages. Astringency intensity was not directly related to dislike. The orthonasal threshold for WPI in water was lower (P < 0.05) than the mouthfeel/basic taste threshold of WPI in water. Consumer acceptance of beverages containing WPI was lower (P < 0.05) when consumers were not wearing nose clips compared to acceptance scores of beverages when consumers were wearing nose clips. These results suggest that flavors contributed by WPI in acidic beverages are more objectionable than the astringent mouthfeel and that both flavor and astringency should be the focus of ongoing studies to improve the palatability of these products. © 2010 Institute of Food Technologists®

  15. Astringency: A More Stringent Definition

    PubMed Central

    Gong, Naihua N.; Matsunami, Hiroaki

    2014-01-01

    Despite being an everyday sensory experience, the nature of astringency perception is not clear. In this issue of Chemical Senses, Schöbel et al. demonstrate that astringency is a trigeminal sensation in human, and astringents trigger a G protein-coupled pathway in trigeminal ganglion cells in the mouse. PMID:24860069

  16. Wine consumers' subjective responses to wine mouthfeel and understanding of wine body.

    PubMed

    Niimi, Jun; Danner, Lukas; Li, Luxing; Bossan, Hélène; Bastian, Susan E P

    2017-09-01

    Wine mouthfeel is considered important for wine quality by experts, while consumers understanding of mouthfeel and the role of wine body in their wine choice is unknown. One experiment determined the influence of intrinsic wine mouthfeel on consumers' wine liking and emotions, and the other, how consumers understand the term wine body. The first experiment used a 2 astringency level×2 body level experimental design. The samples were base wine with; nothing added (control), added xanthan gum (for increased body), added grape seed extract (GSE, for increased astringency), and with both added xanthan gum and GSE. The consumer taste trial (n=112) indicated that wine with increased body did not influence wine liking and emotions; while increased astringency decreased liking and elicited more intense negative emotions. The second experiment examined consumers' knowledge of wine body through an online survey (n=136). Consumers described wine body most frequently using words such as flavour, fullness, and strength. Wine body was therefore understood by consumers predominantly as a holistic multi-sensory perception of flavour. Wine flavour was indicated by consumers to be the most important factor driving purchase decisions followed by balance of flavours and wine body. It is crucial that wine professionals carefully communicate wine characteristics to consumers to prevent possible misunderstandings such as the meaning of wine body and as a result better meet consumer expectations. In future, the term body may benefit from a clearer definition for academic research as well as industry. Copyright © 2017. Published by Elsevier Ltd.

  17. Bitterness in wine.

    PubMed

    Noble, A C

    1994-12-01

    Bitterness in wine is elicited primarily by flavonoid phenols, which are bitter and astringent, and by ethanol. Monomeric flavonoid phenols are primarily bitter but as the molecular weight increases upon polymerization, astringency increases more rapidly than bitterness. The chiral difference between the two wine flavan-3-ol monomers produces a significant difference in temporal perception of bitterness: (-)-epicatechin is significantly more bitter and had significantly longer duration of bitterness than (+)-catechin. Ethanol enhances bitterness intensity and duration, whereas varying wine pH has little or no effect on perceived bitterness. Whereas PROP status had no significant effect on temporal perception of bitterness or astringency, subjects with low salivary flow rates took longer to reach maximum bitterness and astringency intensity and reported longer persistence of both attributes than high-flow subjects.

  18. Turbidity as a measure of salivary protein reactions with astringent substances.

    PubMed

    Horne, John; Hayes, John; Lawless, Harry T

    2002-09-01

    Binding of tannins to proline-rich proteins has been proposed as an initial step in the development of astringent sensations. In beer and fruit juices, formation of tannin-protein complexes leads to the well-known effect of haze development or turbidity. Two experiments examined the development of turbidity in human saliva when mixed with tannins as a potential in vitro correlate of astringent sensations. In the first study, haze was measured in filtered human saliva mixed with a range of tannic acid concentrations known to produce supra-threshold psychophysical responses. The second study examined relationships among individual differences in haze development and the magnitude of astringency ratings. Mostly negative correlations were found, consistent with the notion that high levels of salivary proteins protect oral tissues from the drying effects of tannic acid.

  19. Major phenolic and volatile compounds and their influence on sensorial aspects in stem-contact fermentation winemaking of Primitivo red wines.

    PubMed

    Suriano, S; Alba, V; Di Gennaro, D; Basile, T; Tamborra, M; Tarricone, L

    2016-08-01

    In red winemaking de-stemming is crucial since the stems contain polymeric phenolic compounds responsible for the astringency of wine. Wine such as Primitivo has low phenolic constituents and tannins and stems affect aroma, taste body and olfactory characteristics. The aim of the study was to evaluate the effects of presence of stems during fermentation on polyphenolic, volatile compounds and sensory characteristics of wine. Primitivo grapes vinified in presence of different percentage of stems: 100 % de-stemmed (D100), 75 % de-stemmed (D75) and 50 % de-stemmed (D50). Results confirmed that the wines vinified in presence of stems were higher in tannins, flavans, to vanillin and proanthocyanidins, colour intensity with lower anthocyanins. The presence of stems during fermentation conferred more structure and flavour to wines. They facilitated must aeration thus promoting synthesis of higher alcohols and ethyl esters by yeast. In particular, a higher content of hexan-1-ol, hex-3-en-1-ol and 2-phenyl ethanol in D50 and D75 gave the wines that suggest green grass, herb and floral. Wine from D75 seemed to be better than D50 in terms of volatile compounds as well as fruity, floral and balsamic components preserved, without any unpleasant taste of long chain fatty acids found in D50.

  20. High throughput analysis of red wine and grape phenolics-adaptation and validation of methyl cellulose precipitable tannin assay and modified Somers color assay to a rapid 96 well plate format.

    PubMed

    Mercurio, Meagan D; Dambergs, Robert G; Herderich, Markus J; Smith, Paul A

    2007-06-13

    The methyl cellulose precipitable (MCP) tannin assay and a modified version of the Somers and Evans color assay were adapted to high-throughput (HTP) analysis. To improve efficiency of the MCP tannin assay, a miniaturized 1 mL format and a HTP format using 96 well plates were developed. The Somers color assay was modified to allow the standardization of pH and ethanol concentrations of wine samples in a simple one-step dilution with a buffer solution, thus removing inconsistencies between wine matrices prior to analysis and allowing for its adaptation to a HTP format. Validation studies showed that all new formats were efficient, and results were reproducible and analogous to the original formats.

  1. Tannins, peptic ulcers and related mechanisms.

    PubMed

    de Jesus, Neyres Zinia Taveira; de Souza Falcão, Heloina; Gomes, Isis Fernandes; de Almeida Leite, Thiago Jose; de Morais Lima, Gedson Rodrigues; Barbosa-Filho, Jose Maria; Tavares, Josean Fechine; da Silva, Marcelo Sobral; de Athayde-Filho, Petrônio Filgueiras; Batista, Leonia Maria

    2012-01-01

    This review of the current literature aims to study correlations between the chemical structure and gastric anti-ulcer activity of tannins. Tannins are used in medicine primarily because of their astringent properties. These properties are due to the fact that tannins react with the tissue proteins with which they come into contact. In gastric ulcers, this tannin-protein complex layer protects the stomach by promoting greater resistance to chemical and mechanical injury or irritation. Moreover, in several experimental models of gastric ulcer, tannins have been shown to present antioxidant activity, promote tissue repair, exhibit anti Helicobacter pylori effects, and they are involved in gastrointestinal tract anti-inflammatory processes. The presence of tannins explains the anti-ulcer effects of many natural products.

  2. Tannins, Peptic Ulcers and Related Mechanisms

    PubMed Central

    de Jesus, Neyres Zinia Taveira; de Souza Falcão, Heloina; Gomes, Isis Fernandes; de Almeida Leite, Thiago Jose; de Morais Lima, Gedson Rodrigues; Barbosa-Filho, Jose Maria; Tavares, Josean Fechine; da Silva, Marcelo Sobral; de Athayde-Filho, Petrônio Filgueiras; Batista, Leonia Maria

    2012-01-01

    This review of the current literature aims to study correlations between the chemical structure and gastric anti-ulcer activity of tannins. Tannins are used in medicine primarily because of their astringent properties. These properties are due to the fact that tannins react with the tissue proteins with which they come into contact. In gastric ulcers, this tannin-protein complex layer protects the stomach by promoting greater resistance to chemical and mechanical injury or irritation. Moreover, in several experimental models of gastric ulcer, tannins have been shown to present antioxidant activity, promote tissue repair, exhibit anti Helicobacter pylori effects, and they are involved in gastrointestinal tract anti-inflammatory processes. The presence of tannins explains the anti-ulcer effects of many natural products. PMID:22489149

  3. Further Highlighting on the Prevention of Oxidative Damage by Polyphenol-Rich Wine Extracts.

    PubMed

    Salucci, Sara; Burattini, Sabrina; Giordano, Francesco Maria; Lucarini, Simone; Diamantini, Giuseppe; Falcieri, Elisabetta

    2017-04-01

    Wine contains various polyphenols such as flavonoids, anthocyanins, and tannins. These molecules are responsible for the quality of wines, influencing their astringency, bitterness, and color and they are considered to have antioxidant activity. Polyphenols, extracted from grapes during the processes of vinification, could protect the body cells against reactive oxygen species level increase and could be useful to rescue several pathologies where oxidative stress represents the main cause. For that, in this study, red and white wine, provided by an Italian vinery (Marche region), have been analyzed. Chromatographic and morphofunctional analyses have been carried out for polyphenol extraction and to evaluate their protective effect on human myeloid U937 cells exposed to hydrogen peroxide. Both types of wines contained a mix of phenolic compounds with antioxidant properties and their content decreased, as expected, in white wine. Ultrastructural observations evidenced that wines, in particular red wine, strongly prevent mitochondrial damage and apoptotic cell death. In conclusion, the considered extracts show a relevant polyphenol content with strong antioxidant properties and abilities to prevent apoptosis. These findings suggest, for these compounds, a potential role in all pathological conditions where the body antioxidant system is overwhelmed.

  4. Effect of micro-oxygenation and wood type on the phenolic composition and color of an aged red wine.

    PubMed

    Sánchez-Iglesias, Montserrat; González-Sanjosé, Ma Luisa; Pérez-Magariño, Silvia; Ortega-Heras, Miriam; González-Huerta, Carlos

    2009-12-23

    Many studies have recently been published focused on the effects of micro-oxygenation on the quality of wines, its application modes, and doses, etc. However, there are still few scientific papers on how previously micro-oxygenated wines perform during storage or barrel aging. This study focused on the evolution of the phenolic composition, especially of anthocyanins, and color, together with astringency and tannins, during micro-oxygenation before barrel aging. In addition, to evaluate whether wine evolution during aging depends on barrel type, wines were aged in four different oak barrel types. Tempranillo wines, some micro-oxygenated before malolactic fermentation and others not, were aged for 12 months in American, French, Central European, and Spanish oak, following wine evolution during that period. The study was carried out for two consecutive vintages. Results showed that all wines evolved similarly; therefore, the micro-oxygenation treatment neither accelerated nor delayed the typical changes of aging. Slightly different evolutions were detected according to the barrel wood type, whether or not the wine was micro-oxygenated. The varied evolutions must therefore be associated with the differences from each oak type (structure, grain and density, composition, etc.).

  5. Spectrophotometric Analysis of Phenolic Compounds in Grapes and Wines.

    PubMed

    Aleixandre-Tudo, Jose Luis; Buica, Astrid; Nieuwoudt, Helene; Aleixandre, Jose Luis; du Toit, Wessel

    2017-05-24

    Phenolic compounds are of crucial importance for red wine color and mouthfeel attributes. A large number of enzymatic and chemical reactions involving phenolic compounds take place during winemaking and aging. Despite the large number of published analytical methods for phenolic analyses, the values obtained may vary considerably. In addition, the existing scientific knowledge needs to be updated, but also critically evaluated and simplified for newcomers and wine industry partners. The most used and widely cited spectrophotometric methods for grape and wine phenolic analysis were identified through a bibliometric search using the Science Citation Index-Expanded (SCIE) database accessed through the Web of Science (WOS) platform from Thompson Reuters. The selection of spectrophotometry was based on its ease of use as a routine analytical technique. On the basis of the number of citations, as well as the advantages and disadvantages reported, the modified Somers assay appears as a multistep, simple, and robust procedure that provides a good estimation of the state of the anthocyanins equilibria. Precipitation methods for total tannin levels have also been identified as preferred protocols for these types of compounds. Good reported correlations between methods (methylcellulose precipitable vs bovine serum albumin) and between these and perceived red wine astringency, in combination with the adaptation to high-throughput format, make them suitable for routine analysis. The bovine serum albumin tannin assay also allows for the estimation of the anthocyanins content with the measurement of small and large polymeric pigments. Finally, the measurement of wine color using the CIELab space approach is also suggested as the protocol of choice as it provides good insight into the wine's color properties.

  6. Anthocyanins influence tannin-cell wall interactions.

    PubMed

    Bautista-Ortín, Ana Belén; Martínez-Hernández, Alejandro; Ruiz-García, Yolanda; Gil-Muñoz, Rocío; Gómez-Plaza, Encarna

    2016-09-01

    The rate of tannin extraction was studied in a vinification of red grapes and the results compared with another vinification made with white grapes fermented as for typical red wine, in the presence of skins and seeds. Even though the grapes presented a quite similar skin and seed tannin content, the differences in tannin concentration between both vinifications was very large, despite the fact that the only apparent difference between the phenolic composition of both wines was the anthocyanin content. This suggests that anthocyanins play an important role in tannin extractability, perhaps because they affect the extent of the tannin-cell wall interaction, a factor that largely controls the resulting quantity of tannins in wines. To confirm this observation, the effect of anthocyanins on the tannin extractability from grape seeds and skin and on the interaction between tannins and grape cell walls suspended in model solutions were studied. The results indicated that anthocyanins favored skin and seed tannin extraction and that there is a competition for the adsorption sites between anthocyanins and tannins that increases the tannin content when anthocyanins are present. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Statistical correlations between the in-mouth textural characteristics and the chemical composition of Shiraz wines.

    PubMed

    Gawel, Richard; Francis, Leigh; Waters, Elizabeth J

    2007-04-04

    The relationships between the levels of polyphenols, acidity, and red pigments in Shiraz wines and their perceived textural profiles as quantified by a trained sensory descriptive analysis panel were explored. A "chamois-like" feeling when the wine was held in the mouth appeared to be related to an absence of polyphenols. The in-mouth "chalk-like" texture was strongly associated with anthocyanin concentration and was negatively associated with alcohol level and acidity. The astringent subqualities of "velvet-like" and "emery-like" roughing were mostly related to polyphenol levels, but these attributes could not be adequately differentiated by the compositional variables under study. Wines that elicited a "puckery" sensation were characterized by relatively low anthocyanin levels, high acidity, and high pigmented polymer and tannin concentrations. The results of the study suggest that the in-mouth textural properties of Shiraz red wine are associated not only with their tannin composition and concentration but also with their acidity and anthocyanin and alcohol concentrations.

  8. Precipitation of salivary proteins after the interaction with wine: the effect of ethanol, pH, fructose, and mannoproteins.

    PubMed

    Rinaldi, Alessandra; Gambuti, Angelita; Moio, Luigi

    2012-04-01

    Astringency is a complex sensation mainly caused by the precipitation of salivary proteins with polyphenols. In wine it can be enhanced or reduced depending on the composition of the medium. In order to investigate the effect of ethanol, tartaric acid, fructose, and commercial mannoproteins (MPs) addition on the precipitation of salivary proteins, the saliva precipitation index (SPI) was determined by means of the sodium dodecyl sulphate polyacrylamide gel electrophoresis of human saliva after the reaction with Merlot wines and model solutions. Gelatin index, ethanol index, and Folin-Ciocalteu index were also determined. As resulted by Pearson's correlation, data on SPI were well correlated with the sensory analysis performed on the same samples. In a second experiment, increasing the ethanol (11%-13%-17%), MPs (0-2-8 g/L), fructose (0-2-6 g/L) level, and pH values (2.9-3.0-3.6), a decrease in the precipitation of salivary proteins was observed. A difference in the SPI between model solution and red wine stated that an influence of wine matrix on the precipitation of salivary proteins occurred. Results provide interesting suggestions for enologists, which could modulate the astringency of red wine by: (i) leaving some residual reducing sugars (such as fructose) in red wine during winemaking of grapes rich in tannins; (ii) avoiding the lowering of pH; (iii) adding commercial mannoproteins or promoting a "sur lie" aging; and (iv) harvesting grapes at high technological maturity in order to obtain wines with a satisfactory alcoholic content when possible. © 2012 Institute of Food Technologists®

  9. Free the tannins: the role of grape pathogenesis-related proteins in limiting condensed tannin extraction during winemaking

    USDA-ARS?s Scientific Manuscript database

    Grape-derived condensed tannins (CT) are important to the mouthfeel of red wines, but CT concentrations in red wines produced from wild Vitis species or their hybrids are often lower than corresponding wines produced from European wine grapes (V. vinifera), potentially decreasing their utility. Thes...

  10. Isolation and Expression of NAC Genes during Persimmon Fruit Postharvest Astringency Removal

    PubMed Central

    Min, Ting; Wang, Miao-Miao; Wang, Hongxun; Liu, Xiaofen; Fang, Fang; Grierson, Donald; Yin, Xue-Ren; Chen, Kun-Song

    2015-01-01

    NAC genes have been characterized in numerous plants, where they are involved in responses to biotic and abiotic stress, including low oxygen stress. High concentration of CO2 is one of the most effective treatments to remove astringency of persimmon fruit owing to the action of the accumulated anoxia metabolite acetaldehyde. In model plants, NAC genes have been identified as being responsive to low oxygen. However, the possible relationship between NAC transcription factors and persimmon astringency removal remains unexplored. In the present research, treatment with a high concentration of CO2 (95%) effectively removed astringency of “Mopan” persimmon fruit by causing decreases in soluble tannin. Acetaldehyde content increased in response to CO2 treatment concomitantly with astringency removal. Using RNA-seq and Rapid amplification of cDNA ends (RACE), six DkNAC genes were isolated and studied. Transcriptional analysis indicated DkNAC genes responded differentially to CO2 treatment; DkNAC1, DkNAC3, DkNAC5 and DkNAC6 were transiently up-regulated, DkNAC2 was abundantly expressed 3 days after treatment, while the DkNAC4 was suppressed during astringency removal. It is proposed that DkNAC1/3/5/6 could be important candidates as regulators of persimmon astringency removal and the roles of other member are also discussed. PMID:25599529

  11. Double maturation raisonnée: the impact of on-vine berry dehydration on the berry and wine composition of Merlot (Vitis vinifera L.).

    PubMed

    Rusjan, Denis; Mikulic-Petkovsek, Maja

    2017-11-01

    Double maturation raisonnée (DMR) is a potential canopy measure that affects grape and wine composition. The aim of this work was to study for the first time the DMR impact on the physical, biochemical and sensorial characteristics of the berries and wines of Merlot, one of the world's fastest-expanding grapevine varieties. DMR significantly increased the content of soluble solids (1.2-fold), free amino nitrogen (1.8-fold) and acidity in berries but decreased the weight of 100 berries on harvest (approx. 28%). Irrespective of the vintage, DMR-treated grapes had a significantly higher content of non-astringent tannins (0.73-0.78 mg L -1 ) and anthocyanin extractability (34.7-36.4%) but a lower index of astringency (31.2-33.7) when compared to the control. Consequently, the DMR wines achieved higher alcohol, total acidity and extract, hydroxycinnamic acids, flavanol and flavonol contents, whereas the content of anthocyanins was similar to that of the control. Sensorial evaluation showed that DMR wines were not rated higher and would not be appreciated more than control wines. Changes in berries during DMR altered the wine characteristics only in terms of primary metabolites. A reduced accumulation of phenolics, especially anthocyanin content, in the berry skin of DMR-treated grapes was not reflected in their presence in wines. To the best of our knowledge, this is the first paper that has reported an impact of DMR on the grape and wine composition of Merlot, as one of the most promising red varieties. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Salivary amylase induction by tannin-enriched diets as a possible countermeasure against tannins.

    PubMed

    da Costa, G; Lamy, E; Capela e Silva, F; Andersen, J; Sales Baptista, E; Coelho, A V

    2008-03-01

    Tannins are characterized by protein-binding affinity. They have astringent/bitter properties that act as deterrents, affecting diet selection. Two groups of salivary proteins, proline-rich proteins and histatins, are effective precipitators of tannin, decreasing levels of available tannins. The possibility of other salivary proteins having a co-adjuvant role on host defense mechanisms against tannins is unknown. In this work, we characterized and compared the protein profile of mice whole saliva from animals fed on three experimental diets: tannin-free diet, diet with the incorporation of 5% hydrolyzable tannins (tannic acid), or diet with 5% condensed tannins (quebracho). Protein analysis was performed by one-dimensional gel electrophoresis combined with Matrix-Assisted Laser Desorption Ionization-Time of Flight mass spectrometry to allow the dynamic study of interactions between diet and saliva. Since abundant salivary proteins obscure the purification and identification of medium and low expressed salivary proteins, we used centrifugation to obtain saliva samples free from proteins that precipitate after tannin binding. Data from Peptide Mass Fingerprinting allowed us to identify ten different proteins, some of them showing more than one isoform. Tannin-enriched diets were observed to change the salivary protein profile. One isoform of alpha-amylase was overexpressed with both types of tannins. Aldehyde reductase was only identified in saliva of the quebracho group. Additionally, a hypertrophy of parotid salivary gland acini was observed by histology, along with a decrease in body mass in the first 4 days of the experimental period.

  13. First evidence of epicatechin vanillate in grape seed and red wine.

    PubMed

    Ma, Wen; Waffo-Téguo, Pierre; Jourdes, Michäel; Li, Hua; Teissedre, Pierre-Louis

    2018-09-01

    Flavan-3-ols are units incorporating condensed tannin, which are widely present in grape and wine. They play a considerable role in wine sensory perception such as astringency, bitterness and mouth-feel. In grape and wine, the flavan-3-ols reported to date are (epi)catechin, (epi)gallocatechin, (epi)gallocatechin gallate and (epi)catechin glycoside. This study now shows the presence of a new flavan-3-ol epicatechin vanillate in grape seed and red wine. A putative unknown flavan-3-ol derived from grape seed was targeted by LC-HRMS/MS. Fractionation and purification by centrifugal partition chromatography and Prep HPLC allowed us to obtain the pure new flavan-3-ol. NMR and HRMS data revealed this compound to be epicatechin-3-O-vanillate. Quantification analysis results showed that epicatechin vanillate present in grape seed and red wine in the μg/g dry seed and the μg/L concentration range, respectively. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Astringency is a trigeminal sensation that involves the activation of G protein-coupled signaling by phenolic compounds.

    PubMed

    Schöbel, Nicole; Radtke, Debbie; Kyereme, Jessica; Wollmann, Nadine; Cichy, Annika; Obst, Katja; Kallweit, Kerstin; Kletke, Olaf; Minovi, Amir; Dazert, Stefan; Wetzel, Christian H; Vogt-Eisele, Angela; Gisselmann, Günter; Ley, Jakob P; Bartoshuk, Linda M; Spehr, Jennifer; Hofmann, Thomas; Hatt, Hanns

    2014-07-01

    Astringency is an everyday sensory experience best described as a dry mouthfeel typically elicited by phenol-rich alimentary products like tea and wine. The neural correlates and cellular mechanisms of astringency perception are still not well understood. We explored taste and astringency perception in human subjects to study the contribution of the taste as well as of the trigeminal sensory system to astringency perception. Subjects with either a lesion or lidocaine anesthesia of the Chorda tympani taste nerve showed no impairment of astringency perception. Only anesthesia of both the lingual taste and trigeminal innervation by inferior alveolar nerve block led to a loss of astringency perception. In an in vitro model of trigeminal ganglion neurons of mice, we studied the cellular mechanisms of astringency perception. Primary mouse trigeminal ganglion neurons showed robust responses to 8 out of 19 monomeric phenolic astringent compounds and 8 polymeric red wine polyphenols in Ca(2+) imaging experiments. The activating substances shared one or several galloyl moieties, whereas substances lacking the moiety did not or only weakly stimulate responses. The responses depended on Ca(2+) influx and voltage-gated Ca(2+) channels, but not on transient receptor potential channels. Responses to the phenolic compound epigallocatechin gallate as well as to a polymeric red wine polyphenol were inhibited by the Gαs inactivator suramin, the adenylate cyclase inhibitor SQ, and the cyclic nucleotide-gated channel inhibitor l-cis-diltiazem and displayed sensitivity to blockers of Ca(2+)-activated Cl(-) channels. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Sensory perception of and salivary protein response to astringency as a function of the 6-n-propylthioural (PROP) bitter-taste phenotype.

    PubMed

    Melis, Melania; Yousaf, Neeta Y; Mattes, Mitchell Z; Cabras, Tiziana; Messana, Irene; Crnjar, Roberto; Tomassini Barbarossa, Iole; Tepper, Beverly J

    2017-05-01

    Individual differences in astringency perception are poorly understood. Astringency from tannins stimulates the release of specific classes of salivary proteins. These proteins form complexes with tannins, altering their perceived astringency and reducing their bioavailability. We studied the bitter compound, 6-n-propylthioural (PROP), as a phenotypic marker for variation in astringency perception and salivary protein responses. Seventy-nine subjects classified by PROP taster status rated cranberry juice cocktail (CJC; with added sugar) supplemented with 0, 1.5 or 2.0g/L tannic acid (TA). Saliva for protein analyses was collected at rest, or after stimulation with TA or cranberry juice (CJ; without added sugar). CJC with 1.5g/L tannic acid was found to be less astringent, and was liked more by PROP non-taster males than PROP taster males, consistent with the expectation that non-tasters are less sensitive to astringency. Levels of acidic Proline Rich Proteins (aPRPs) and basic Proline Rich Proteins (bPRPs) decreased after TA, while levels of aPRPs, bPRPs and Cystatins unexpectedly rose after CJ. Increases in bPRPs and Cystatins were only observed in PROP tasters. The PROP phenotype plays a gender-specific, but somewhat limited role in the perceived astringency of tannic-acid supplemented, cranberry juice cocktail. The PROP phenotype (regardless of gender) may also be involved in the release of salivary proteins previously implicated in oral health. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. The mouthfeel of white wine.

    PubMed

    Gawel, Richard; Smith, Paul A; Cicerale, Sara; Keast, Russell

    2017-07-05

    White wine mouthfeel which encompasses the tactile, chemosensory and taste attributes of perceived viscosity, astringency, hotness and bitterness is increasingly being recognized as an important component of overall white wine quality. This review summarizes the physiological basis for the perception of white wine mouthfeel and the direct and interactive effects of white wine composition, specifically those of low molecular weight phenolic compounds, polysaccharides, pH, ethanol, glycerol, dissolved carbon dioxide, and peptides. Ethyl alcohol concentration and pH play a direct role in determining most aspects of mouthfeel perception, and provide an overall framework on which the other minor wine components can interact to influence white wine mouthfeel. Phenolic compounds broadly impact on the mouthfeel by contributing to its viscosity, astringency, hotness and bitterness. Their breadth of influence likely results from their structural diversity which would allow them to activate multiple sensory mechanisms involved in mouthfeel perception. Conversely, polysaccharides have a small modulating effect on astringency and hotness perception, and glycerol does not affect perceived viscosity within the narrow concentration range found in white wine. Many of the major sensory attributes that contribute to the overall impression of mouthfeel are elicited by more than one class compound suggesting that different physiological mechanisms may be involved in the construct of mouthfeel percepts.

  17. Sugar and organic acid content of astringent, non-astringent, and pollination variant persimmons (abstract)

    USDA-ARS?s Scientific Manuscript database

    Although persimmons are native (Diospyros virginiana) to the United States, commercial production consists almost exclusively of the Asian persimmon, Diospyros kaki. Cultivars within this species are classified by their astringency type; non-astringent, astringent, and pollination variant. In the U...

  18. Mass spectrometry in grape and wine chemistry. Part I: polyphenols.

    PubMed

    Flamini, Riccardo

    2003-01-01

    Mass spectrometry, had and still has, a very important role for research and quality control in the viticulture and enology field, and its analytical power is relevant for structural studies on aroma and polyphenolic compounds. Polyphenols are responsible for the taste and color of wine, and confer astringency and structure to the beverage. The knowledge of the anthocyanic structure is very important to predict the aging attitude of wine, and to attempt to resolve problems about color stability. Moreover, polyphenols are the main compounds related to the benefits of wine consumption in the diet, because of their properties in the treatment of circulatory disorders such as capillary fragility, peripheral chronic venous insufficiency, and microangiopathy of the retina. Liquid Chromatography-Mass Spectrometry (LC-MS) techniques are nowadays the best analytical approach to study polyphenols in grape extracts and wine, and are the most effective tool in the study of the structure of anthocyanins. The MS/MS approach is a very powerful tool that permits anthocyanin aglycone and sugar moiety characterization. LC-MS allows the characterization of complex structures of grape polyphenols, such as procyanidins, proanthocyanidins, prodelphinidins, and tannins, and provides experimental evidence for structures that were previously only hypothesized. The matrix-assisted-laser-desorption-ionization-time-of-flight (MALDI-TOF) technique is suitable to determine the presence of molecules of higher molecular weight with high accuracy, and it has been applied with success to study procyanidin oligomers up to heptamers in the reflectron mode, and up to nonamers in the linear mode. The levels of resveratrol in wine, an important polyphenol well-known for its beneficial effects, have been determined by SPME and LC-MS, and the former approach led to the best results in terms of sensitivity. Copyright 2003 Wiley Periodicals, Inc.

  19. Factors regulating astringency of whey protein beverages.

    PubMed

    Beecher, J W; Drake, M A; Luck, P J; Foegeding, E A

    2008-07-01

    A rapidly growing area of whey protein use is in beverages. There are 2 types of whey protein-containing beverages: those at neutral pH and those at low pH. Astringency is very pronounced at low pH. Astringency is thought to be caused by compounds in foods that bind with and precipitate salivary proteins; however, the mechanism of astringency of whey proteins is not understood. The effect of viscosity and pH on the astringency of a model beverage containing whey protein isolate was investigated. Trained sensory panelists (n = 8) evaluated the viscosity and pH effects on astringency and basic tastes of whey protein beverages containing 6% wt/vol protein. Unlike what has been shown for alum and polyphenols, increasing viscosity (1.6 to 7.7 mPa.s) did not decrease the perception of astringency. In contrast, the pH of the whey protein solution had a major effect on astringency. A pH 6.8 whey protein beverage had a maximum astringency intensity of 1.2 (15-point scale), whereas that of a pH 3.4 beverage was 8.8 (15-point scale). Astringency decreased between pH 3.4 and 2.6, coinciding with an increase in sourness. Decreases in astringency corresponded to decreases in protein aggregation as observed by turbidity. We propose that astringency is related to interactions between positively charged whey proteins and negatively charged saliva proteins. As the pH decreased between 3.4 and 2.6, the negative charge on the saliva proteins decreased, causing the interactions with whey proteins to decrease.

  20. INVESTIGATION OF REDUCTION OF ABSORPTION OF RADIOACTIVE MATERIAL BY MEANS OF ASTRINGENTS (in German)

    SciTech Connect

    Lehrnbecher, W.

    1963-02-01

    An attempt was made to use the astringent properties of two substances, adrenalin and tannin, for reducing skin absorption of radioactive substances on female Wistar rats. The effect of 1/2% adrenalin emulsion and of a 2% tannin solution on the absorption of a BETA -emitting substance (Sr/sup 89/Cl/sub 2/ solution) was observed over three periods of 30, 60, and 90 min. A reduction of absorption was found after using adrenalin and tanning. The effect of adrenalin was small, particularly over prolonged periods of observation, and there was a marked reduction of absorption resulting from the use of tannin during allmore » periods of observation-. A method is described that permits an estimate of the reduction in skin absorption of BETA rays. (P.C.H.)« less

  1. Evidence for functional heterogeneity both between and within four sources of condensed tannin

    SciTech Connect

    Asquith, T.N.

    1985-01-01

    Condensed tannins are polymers of flavan-3-ols that are produced by many plants in a wide variety of tissues. The ability of these compounds to actively precipitate proteins has been linked to nutritional deficiencies in many animals. Four purified tannins (quebracho, wattle, pinto bean and sorghum) were compared to chemical assays and astringency towards (/sup 14/C)-BSA. Quebracho and wattle tannins were much less astringent and had longer chain lengths that sorghum or pinto bean tannins. Quebracho tannin had a very high affinity for salivary proline-rich glycoproteins (PRPs) and pinto bean tannin alone had a measurable affinity for soybean trypsin inhibitor. Thismore » suggests that tannin/protein interactions in vivo may be very specific. Protein bound carbohydrate enhanced the binding of PRPs to tanning and conferred specificity on the interactions. Carbohydrate also increases the solubility of protein/tanning complexes, which may aid the animal in eliminating the complexes. (/sup 125/I)-labeled condensed tannin was shown to retain the ability to discriminate between high and low affinity proteins. (/sup 125/I)-labeled phenols were isolated from livers and kidneys of rats fed (/sup 125/I)-labeled tannin. The techniques described in this thesis should be widely applicable to studying in vivo functions of condensed tannins.« less

  2. Interactions of Condensed Tannins with Saccharomyces cerevisiae Yeast Cells and Cell Walls: Tannin Location by Microscopy.

    PubMed

    Mekoue Nguela, Julie; Vernhet, Aude; Sieczkowski, Nathalie; Brillouet, Jean-Marc

    2015-09-02

    Interactions between grape tannins/red wine polyphenols and yeast cells/cell walls was previously studied within the framework of red wine aging and the use of yeast-derived products as an alternative to aging on lees. Results evidenced a quite different behavior between whole cells (biomass grown to elaborate yeast-derived products, inactivated yeast, and yeast inactivated after autolysis) and yeast cell walls (obtained from mechanical disruption of the biomass). Briefly, whole cells exhibited a high capacity to irreversibly adsorb grape and wine tannins, whereas only weak interactions were observed for cell walls. This last point was quite unexpected considering the literature and called into question the real role of cell walls in yeasts' ability to fix tannins. In the present work, tannin location after interactions between grape and wine tannins and yeast cells and cell walls was studied by means of transmission electron microscopy, light epifluorescence, and confocal microscopy. Microscopy observations evidenced that if tannins interact with cell walls, and especially cell wall mannoproteins, they also diffuse freely through the walls of dead cells to interact with their plasma membrane and cytoplasmic components.

  3. Predicting the composition of red wine blends using an array of multicomponent Peptide-based sensors.

    PubMed

    Ghanem, Eman; Hopfer, Helene; Navarro, Andrea; Ritzer, Maxwell S; Mahmood, Lina; Fredell, Morgan; Cubley, Ashley; Bolen, Jessica; Fattah, Rabia; Teasdale, Katherine; Lieu, Linh; Chua, Tedmund; Marini, Federico; Heymann, Hildegarde; Anslyn, Eric V

    2015-05-20

    Differential sensing using synthetic receptors as mimics of the mammalian senses of taste and smell is a powerful approach for the analysis of complex mixtures. Herein, we report on the effectiveness of a cross-reactive, supramolecular, peptide-based sensing array in differentiating and predicting the composition of red wine blends. Fifteen blends of Cabernet Sauvignon, Merlot and Cabernet Franc, in addition to the mono varietals, were used in this investigation. Linear Discriminant Analysis (LDA) showed a clear differentiation of blends based on tannin concentration and composition where certain mono varietals like Cabernet Sauvignon seemed to contribute less to the overall characteristics of the blend. Partial Least Squares (PLS) Regression and cross validation were used to build a predictive model for the responses of the receptors to eleven binary blends and the three mono varietals. The optimized model was later used to predict the percentage of each mono varietal in an independent test set composted of four tri-blends with a 15% average error. A partial least square regression model using the mouth-feel and taste descriptive sensory attributes of the wine blends revealed a strong correlation of the receptors to perceived astringency, which is indicative of selective binding to polyphenols in wine.

  4. Accumulation of uranium by immobilized persimmon tannin

    SciTech Connect

    Sakaguchi, Takashi; Nakajima, Akira

    1994-01-01

    We have discovered that the extracted juice of unripe astringent persimmon fruit, designated as kakishibu or shibuol, has an extremely high affinity for uranium. To develop efficient adsorbents for uranium, we tried to immobilize kakishibu (persimmon tannin) with various aldehydes and mineral acids. Persimmon tannin immobilized with glutaraldehyde can accumulate 1.71 g (14 mEq U) of uranium per gram of the adsorbent. The uranium accumulating capacity of this adsorbent is several times greater than that of commercially available chelating resins (2-3 mEq/g). Immobilized persimmon tannin has the most favorable features for uranium recovery; high selective adsorption ability, rapid adsorption rate,more » and applicability in both column and batch systems. The uranium retained on immobilized persimmon tannin can be quantitatively and easily eluted with a very dilute acid, and the adsorbent can thus be easily recycled in the adsorption-desorption process. Immobilized persimmon tannin also has a high affinity for thorium. 23 refs., 13 figs., 7 tabs.« less

  5. Ethylene-responsive transcription factors interact with promoters of ADH and PDC involved in persimmon (Diospyros kaki) fruit de-astringency

    PubMed Central

    Min, Ting; Yin, Xue-ren; Chen, Kun-song

    2012-01-01

    The persimmon fruit is a particularly good model for studying fruit response to hypoxia, in particular, the hypoxia-response ERF (HRE) genes. An anaerobic environment reduces fruit astringency by converting soluble condensed tannins (SCTs) into an insoluble form. Although the physiology of de-astringency has been widely studied, its molecular control is poorly understood. Both CO2 and ethylene treatments efficiently removed the astringency from ‘Mopan’ persimmon fruit, as indicated by a decrease in SCTs. Acetaldehyde, the putative agent for causing de-astringency, accumulated during these treatments, as did activities of the key enzymes of acetaldehyde synthesis, alcohol dehydrogenase (ADH), and pyruvate decarboxylase (PDC). Eight DkADH and DkPDC genes were isolated, and three candidates for a role in de-astringency, DkADH1, DkPDC1, and DkPDC2, were characterized by transcriptional analysis in different tissues. The significance of these specific isoforms was confirmed by principal component analysis. Transient expression in leaf tissue showed that DkPDC2 decreased SCTs. Interactions of six hypoxia-responsive ERF genes and target promoters were tested in transient assays. The results indicated that two hypoxia-responsive ERF genes, DkERF9 and DkERF10, were involved in separately regulating the DkPDC2 and DkADH1 promoters. It is proposed that a DkERF–DkADH/DkPDC cascade is involved in regulating persimmon de-astringency. PMID:23095993

  6. Evaluation of unsaturated alkanoic acid amides as maskers of epigallocatechin gallate astringency.

    PubMed

    Obst, Katja; Paetz, Susanne; Backes, Michael; Reichelt, Katharina V; Ley, Jakob P; Engel, Karl-Heinz

    2013-05-08

    Some foods, beverages, and food ingredients show characteristic long-lasting aftertastes. The sweet, lingering taste of high intensity sweeteners or the astringency of tea catechins are typical examples. Epigallocatechin-3-gallate (EGCG), the most abundant catechin in green tea, causes a long-lasting astringency and bitterness. These sensations are mostly perceived as aversive and are only accepted in a few foods (e.g., tea and red wine). For the evaluation of the aftertaste of such constituents over a certain period of time, Intensity Variation Descriptive Methodology (IVDM) was used. The approach allows the measurement of different descriptors in parallel in one panel session. IVDM was evaluated concerning the inter- and intraindividual differences of panelists for bitterness and astringency of EGCG. Subsequently, the test method was used as a screening tool for the identification of potential modality-selective masking compounds. In particular, the intensity of the astringency of EGCG (750 mg kg(-1)) could be significantly lowered by 18-33% during the time course by adding the trigeminal-active compound trans-pellitorine (2E,4E-decadienoic acid N-isobutyl amide 1, 5 mg kg(-1)) without significantly affecting bitterness perception. Further, structurally related compounds were evaluated on EGCG to gain evidence for possible structure-activity relationships. A more polar derivative of 1, (2S)-2-[[(2E,4E)-deca-2,4-dienoyl]amino]propanoic acid 9, was also able to reduce the astringency of EGCG similar to trans-pellitorine but without showing the strong tingling effect.

  7. Astringent compounds suppress taste responses in gerbil.

    PubMed

    Schiffman, S S; Suggs, M S; Simon, S A

    1992-11-06

    Astringent tastes are generally considered those that induce long-lasting puckering and drying sensations on the tongue and membranes of the oral cavity. Electrophysiological recordings were made here from the whole chorda tympani nerve in gerbil to understand the interactive effect of astringent-tasting molecules with a broad spectrum of tastants including mono- and divalent salts, bitter compounds, acids, and sweeteners. The astringent tasting compounds were tannic acid (24 mM at pH's 2.9 and 5.5), aluminum ammonium sulfate (30 mM), aluminum potassium sulfate (10 mM) and gallic acid (30 mM). Hydrochloric acid (1 mM, pH 2.9) was also tested to control for acidity, since aqueous solutions of astringent-tasting compounds are acidic. Adaptation of the tongue to tannic acid (24 mM) at both pH 2.9 and 5.5 markedly inhibited responses elicited by salts, acids, sweeteners, and bitter-tasting compounds. The degree of the inhibition at these two pH values is about the same which suggests that tannic acid itself (as opposed to acidity) may produce this inhibition. Chorda tympani responses to sweeteners were completely suppressed by tannic acid; responses to KCl, NH4Cl, and urea were the least suppressed. The aluminum salts also inhibited the chorda tympani responses to all stimuli tested. Gallic acid, which is weakly astringent, had minimal effects on the chorda tympani responses to the test compounds. These data suggest that both tannic acid and the aluminum salts inhibit a variety of transport pathways and receptors in taste cells for a broad spectrum of tastants. The inhibition of some of these pathways may contribute to the astringent taste sensation.

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

    PubMed

    Gonzalo-Diago, Ana; Dizy, Marta; Fernández-Zurbano, Purificación

    2013-09-18

    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.

  9. Salivary tannin-binding proteins are a pervasive strategy used by the folivorous/frugivorous black howler monkey.

    PubMed

    Espinosa-Gómez, Fabiola Carolina; Serio-Silva, Juan Carlos; Santiago-García, Juan Diego; Sandoval-Castro, Carlos Alfredo; Hernández-Salazar, Laura Teresa; Mejía-Varas, Fernando; Ojeda-Chávez, Javier; Chapman, Colin Austin

    2018-02-01

    Dietary tannins can affect protein digestion and absorption, be toxic, and influence food selection by being astringent and bitter tasting. Animals that usually ingest tannins may regularly secrete tannin-binding salivary proteins (TBSPs) to counteract the negative effects of tannins or TBSPs production can be induced by a tannin-rich diet. In the wild, many primates regularly eat a diet that contains tannin-rich leaves and unripe fruit and it has been speculated that they have the physiological ability to cope with dietary tannins; however, details of their strategy remains unclear. Our research details the salivary protein composition of wild and zoo-living black howler monkeys (Alouatta pigra) feeding on natural versus manufactured low-tannin diets, and examines differences in TBSPs, mainly proline-rich proteins (PRPs), to determine whether production of these proteins is dependent on the tannin content of their food. We measured the pH, flow rate, and concentration of total protein and trichloroacetic acid soluble proteins (an index of PRPs) in saliva. Howler monkeys produced slightly alkaline saliva that may aid in the binding interaction between tannin and salivary proteins. We used gel electrophoresis to describe the salivary protein profile and this analysis along with a tannin-binding assay allowed us to detect several TBSPs in all individuals. We found no differences in the characteristics of saliva between wild and zoo-living monkeys. Our results suggest that black howler monkeys always secrete TBSPs even when fed on foods low in tannins. This strategy of constantly using this salivary anti-tannin defense enables them to obtain nutrients from plants that sometimes contain high levels of tannins and may help immediately to overcome the astringent sensation of their food allowing howler monkeys to eat tanniferous plants. © 2018 Wiley Periodicals, Inc.

  10. Colorimetric Sensor Array for White Wine Tasting.

    PubMed

    Chung, Soo; Park, Tu San; Park, Soo Hyun; Kim, Joon Yong; Park, Seongmin; Son, Daesik; Bae, Young Min; Cho, Seong In

    2015-07-24

    A colorimetric sensor array was developed to characterize and quantify the taste of white wines. A charge-coupled device (CCD) camera captured images of the sensor array from 23 different white wine samples, and the change in the R, G, B color components from the control were analyzed by principal component analysis. Additionally, high performance liquid chromatography (HPLC) was used to analyze the chemical components of each wine sample responsible for its taste. A two-dimensional score plot was created with 23 data points. It revealed clusters created from the same type of grape, and trends of sweetness, sourness, and astringency were mapped. An artificial neural network model was developed to predict the degree of sweetness, sourness, and astringency of the white wines. The coefficients of determination (R2) for the HPLC results and the sweetness, sourness, and astringency were 0.96, 0.95, and 0.83, respectively. This research could provide a simple and low-cost but sensitive taste prediction system, and, by helping consumer selection, will be able to have a positive effect on the wine industry.

  11. Colorimetric Sensor Array for White Wine Tasting

    PubMed Central

    Chung, Soo; Park, Tu San; Park, Soo Hyun; Kim, Joon Yong; Park, Seongmin; Son, Daesik; Bae, Young Min; Cho, Seong In

    2015-01-01

    A colorimetric sensor array was developed to characterize and quantify the taste of white wines. A charge-coupled device (CCD) camera captured images of the sensor array from 23 different white wine samples, and the change in the R, G, B color components from the control were analyzed by principal component analysis. Additionally, high performance liquid chromatography (HPLC) was used to analyze the chemical components of each wine sample responsible for its taste. A two-dimensional score plot was created with 23 data points. It revealed clusters created from the same type of grape, and trends of sweetness, sourness, and astringency were mapped. An artificial neural network model was developed to predict the degree of sweetness, sourness, and astringency of the white wines. The coefficients of determination (R2) for the HPLC results and the sweetness, sourness, and astringency were 0.96, 0.95, and 0.83, respectively. This research could provide a simple and low-cost but sensitive taste prediction system, and, by helping consumer selection, will be able to have a positive effect on the wine industry. PMID:26213946

  12. Molecular Interaction Between Salivary Proteins and Food Tannins.

    PubMed

    Silva, Mafalda Santos; García-Estévez, Ignacio; Brandão, Elsa; Mateus, Nuno; de Freitas, Victor; Soares, Susana

    2017-08-09

    Polyphenols interaction with salivary proteins (SP) has been related with organoleptic features such as astringency. The aim of this work was to study the interaction between some human SP and tannins through two spectroscopic techniques, fluorescence quenching, and saturation transfer difference-nuclear magnetic resonance (STD-NMR). Generally, the results showed a significant interaction between SP and both condensed tannins and ellagitannins. Herein, STD-NMR proved to be a useful tool to map tannins' epitopes of binding, while fluorescence quenching allowed one to discriminate binding affinities. Ellagitannins showed the greatest binding constants values (K SV from 20.1 to 94.1 mM -1 ; K A from 0.7 to 8.3 mM -1 ) in comparison with procyanidins (K SV from 5.4 to 40.0 mM -1 ; K A from 1.1 to 2.7 mM -1 ). In fact, punicalagin was the tannin that demonstrated the highest affinity for all three SP. Regarding SP, P-B peptide was the one with higher affinity for ellagitannins. On the other hand, cystatins showed in general the lower K SV and K A values. In the case of condensed tannins, statherin was the SP with the highest affinity, contrasting with the other two SP. Altogether, these results are evidence that the distinct SP present in the oral cavity have different abilities to interact with food tannins class.

  13. Interactions between yeast lees and wine polyphenols during simulation of wine aging: I. Analysis of remnant polyphenolic compounds in the resulting wines.

    PubMed

    Mazauric, Jean-Paul; Salmon, Jean-Michel

    2005-07-13

    Wine aging on yeast lees is a traditional enological practice used during the manufacture of wines. This technique has increased in popularity in recent years for the aging of red wines. Although wine polyphenols interact with yeast lees to a limited extent, such interactions have a large effect on the reactivity toward oxygen of wine polyphenolic compounds and yeast lees. Various domains of the yeast cell wall are protected by wine polyphenols from the action of extracellular hydrolytic enzymatic activities. Polysaccharides released during autolysis are thought to exert a significant effect on the sensory qualities of wine. We studied the chemical composition of polyphenolic compounds remaining in solution or adsorbed on yeast lees after various contact times during the simulation of wine aging. The analysis of the remnant polyphenols in the wine indicated that wine polyphenols adsorption on yeast lees follows biphasic kinetics. An initial and rapid fixation is followed by a slow, constant, and saturating fixation that reaches its maximum after about 1 week. Only very few monomeric phenolic compounds remained adsorbed on yeast lees, and no preferential adsorption of low or high polymeric size tannins occurred. The remnant condensed tannins in the wine contained fewer epigallocatechin units than the initial tannins, indicating that polar condensed tannins were preferentially adsorbed on yeast lees. Conversely, the efficiency of anthocyanin adsorption on yeast lees was unrelated to its polarity.

  14. Characterization of Vitis vinifera L. Cv. Carménère grape and wine proanthocyanidins.

    PubMed

    Fernández, Katherina; Kennedy, James A; Agosin, Eduardo

    2007-05-02

    A formal compositional study of the proanthocyanidins of Vitis vinifera L. cv. Carménère was conducted in this work. We first characterized the polymeric proanthocyanidins of Carménère skins, seeds, and wines. In addition, the wine astringency was analyzed and compared with Cabernet Sauvignon. Although Carménère wines had a higher proanthocyanidin concentration and mean degree of polymerization than Cabernet Sauvignon wines, the former wines were perceived as less astringent. The low seed/skin proportion in Carménère wines as compared to other varieties, as evidenced by the reduced number of seeds per berry and the higher amount of epigallocatechin subunits of Carménère wine proanthocyanidins, could explain this apparent paradox.

  15. Characterization of taste-active fractions in red wine combining HPLC fractionation, sensory analysis and ultra performance liquid chromatography coupled with mass spectrometry detection.

    PubMed

    Sáenz-Navajas, María-Pilar; Ferreira, Vicente; Dizy, Marta; Fernández-Zurbano, Purificación

    2010-07-19

    Five Tempranillo wines exhibiting marked differences in taste and/or astringency were selected for the study. In each wine the non-volatile extract was obtained by freeze-drying and further liquid extraction in order to eliminate remaining volatile compounds. This extract was fractionated by semipreparative C18-reverse phase-high performance liquid chromatography (C18-RP-HPLC) into nine fractions which were freeze-dried, reconstituted with water and sensory assessed for taste attributes and astringency by a specifically trained sensory panel. Results have shown that wine bitterness and astringency cannot be easily related to the bitter and astringent character of the HPLC fractions, what can be due to the existence of perceptual and physicochemical interactions. While the bitter character of the bitterest fractions may be attributed to some flavonols (myricetin, quercetin and their glycosides) the development of a sensitive UPLC-MS method to quantify astringent compounds present in wines has made it possible to demonstrate that proanthocyanidins monomers, dimers, trimers and tetramers, both galloylated or non-galloylated are not relevant compounds for the perceived astringency of the fractions, while cis-aconitic acid, and secondarily vainillic, and syringic acids and ethyl syringate, are the most important molecules driving astringency in two of the fractions (F5 and F6). The identity of the chemicals responsible for the astringency of the third fraction could be assigned to some proanthocyanidins (higher than the tetramer) capable to precipitate with ovalbumin. 2010 Elsevier B.V. All rights reserved.

  16. Protein Binding and Astringent Taste of a Polymeric Procyanidin, 1,2,3,4,6-Penta-O-galloyl-β-D-glucopyranose, Castalagin and Grandinin

    PubMed Central

    Hofmann, Thomas; Glabasnia, Arne; Schwarz, Bernd; Wisman, Kimberly N.; Gangwer, Kelly A.; Hagerman, Ann E.

    2008-01-01

    The objective of the present investigation was to examine oral astringency and protein binding activity of four structurally well-defined tannins, namely procyanidin (epicatechin16(4→8)catechin), pentagalloyl glucose (1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose), castalagin, and grandinin, representing the three main structural categories of tannins, the proanthocyanidins, the gallotannins, and the ellagitannins. Astringency threshold and dose response were determined by the half-tongue test using a trained human panel. Protein binding stoichiometry and relative affinity were determined using radioiodinated bovine serum albumin in precipitation or competitive binding assays. Procyanidin and pentagalloyl glucose were perceived as highly astringent compounds and had relatively steep dose response curves but castalagin and grandinin had a lower mass threshold for detection. In vitro, procyanidin was the most effective protein precipitating agent, and grandinin the least. Increasing the temperature increased protein precipitation by the hydrolysable tannins, especially grandinin. All four polyphenols had higher relative affinity for proline-rich proteins than for bovine serum albumin. PMID:17147439

  17. Impact of condensed tannin size as individual and mixed polymers on bovine serum albumin precipitation.

    PubMed

    Harbertson, James F; Kilmister, Rachel L; Kelm, Mark A; Downey, Mark O

    2014-10-01

    Condensed tannins composed of epicatechin from monomer to octamer were isolated from cacao (Theobroma cacao, L.) seeds and added to bovine serum albumin (BSA) individually and combined as mixtures. When added to excess BSA the amount of tannin precipitated increased with tannin size. The amount of tannin required to precipitate BSA varied among the polymers with the trimer requiring the most to precipitate BSA (1000 μg) and octamer the least (50 μg). The efficacy of condensed tannins for protein precipitation increased with increased degree of polymerisation (or size) from trimers to octamers (monomers and dimers did not precipitate BSA), while mixtures of two sizes primarily had an additive effect. This study demonstrates that astringent perception is likely to increase with increasing polymer size. Further research to expand our understanding of astringent perception and its correlation with protein precipitation would benefit from sensory analysis of condensed tannins across a range of polymer sizes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Compositional and sensory characterization of red wine polymers.

    PubMed

    Wollmann, Nadine; Hofmann, Thomas

    2013-03-06

    After isolation from red wine by means of ultrafiltration and gel adsorption chromatography, the composition of the highly astringent tasting high-molecular weight polymers was analyzed by means of HPLC-MS/MS, HPLC-UV/vis, and ion chromatography after thiolytic, alkaline, and acidic depolymerization and, on the basis of the quantitative data obtained as well as model incubation experiments, key structural features of the red wine polymers were proposed. The structural backbone of the polymers seems to be comprised of a procyanidin chain with (-)-epicatechin, (+)-catechin, (-)-epicatechin-3-O-gallate units as extension and terminal units as well as (-)-epigallocatechin as extension units. In addition, acetaldehyde was shown to link different procyanidins at the A-ring via an 1,1-ethylene bridge and anthocyanins and pyranoanthocyanins were found to be linked to the procyanidin backbone via a C-C-linkage at position C(6) or C(8), respectively. Alkaline hydrolysis demonstrated the polymeric procyanidins to be esterified with various organic acids and phenolic acids, respectively. In addition, the major part of the polysaccharides present in the red wine polymeric fraction were found not to be covalently linked to procyanidins. Interestingly, sensory evaluation of individual fractions of the red wine polymers did not show any significant difference in the astringent threshold concentrations, nor in the astringency intensity in supra-threshold concentrations and demonstrated the mean degree of polymerization as well as the galloylation degree not to have an significant influence on the astringency perception.

  19. 21 CFR 347.12 - Astringent active ingredients.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Astringent active ingredients. 347.12 Section 347...) DRUGS FOR HUMAN USE SKIN PROTECTANT DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 347.12 Astringent active ingredients. The active ingredient of the product consists of any one of the...

  20. 21 CFR 346.18 - Astringent active ingredients.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Astringent active ingredients. 346.18 Section 346...) DRUGS FOR HUMAN USE ANORECTAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 346.18 Astringent active ingredients. The active ingredient of the product consists of any of the following when...

  1. 21 CFR 346.18 - Astringent active ingredients.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Astringent active ingredients. 346.18 Section 346...) DRUGS FOR HUMAN USE ANORECTAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 346.18 Astringent active ingredients. The active ingredient of the product consists of any of the following when...

  2. 21 CFR 346.18 - Astringent active ingredients.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 5 2013-04-01 2013-04-01 false Astringent active ingredients. 346.18 Section 346...) DRUGS FOR HUMAN USE ANORECTAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 346.18 Astringent active ingredients. The active ingredient of the product consists of any of the following when...

  3. 21 CFR 347.12 - Astringent active ingredients.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Astringent active ingredients. 347.12 Section 347...) DRUGS FOR HUMAN USE SKIN PROTECTANT DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 347.12 Astringent active ingredients. The active ingredient of the product consists of any one of the...

  4. 21 CFR 346.18 - Astringent active ingredients.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Astringent active ingredients. 346.18 Section 346...) DRUGS FOR HUMAN USE ANORECTAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 346.18 Astringent active ingredients. The active ingredient of the product consists of any of the following when...

  5. 21 CFR 346.18 - Astringent active ingredients.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Astringent active ingredients. 346.18 Section 346...) DRUGS FOR HUMAN USE ANORECTAL DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 346.18 Astringent active ingredients. The active ingredient of the product consists of any of the following when...

  6. 21 CFR 347.12 - Astringent active ingredients.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 5 2013-04-01 2013-04-01 false Astringent active ingredients. 347.12 Section 347...) DRUGS FOR HUMAN USE SKIN PROTECTANT DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 347.12 Astringent active ingredients. The active ingredient of the product consists of any one of the...

  7. 21 CFR 347.12 - Astringent active ingredients.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Astringent active ingredients. 347.12 Section 347...) DRUGS FOR HUMAN USE SKIN PROTECTANT DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients § 347.12 Astringent active ingredients. The active ingredient of the product consists of any one of the...

  8. Characterization of Phenolic Compounds in Wine Lees.

    PubMed

    Zhijing, Ye; Shavandi, Amin; Harrison, Roland; Bekhit, Alaa El-Din A

    2018-03-25

    The effect of vinification techniques on phenolic compounds and antioxidant activity of wine lees are poorly understood. The present study investigated the antioxidant activity of white and red wine lees generated at early fermentation and during aging. In this study, the total phenol content (TPC), total tannin content (TTC), mean degree of polymerization (mDP), and antioxidant activities of five white and eight red wine lees samples from different vinification backgrounds were determined. The results showed that vinification techniques had a significant ( p < 0.05) impact on total phenol and tannin content of the samples. White wine lees had high mDP content compared with red ones. Catechin (50-62%) and epicatechin contents were the predominant terminal units of polymeric proanthocyanidin extracted from examined samples. Epigallocatechin was the predominant extension unit of white wine lees, whereas epicatechin was the predominant compound in red wine marc. The ORAC (oxygen radical absorbance capacity) assay was strongly correlated with the DPPH (α, α-diphenyl-β-picrylhydrazyl) assay, and the results showed the strong antioxidant activities associated with red wine lees (PN > 35 mg Trolox/g FDM) (PN: Pinot noir lees; FDM: Freeze-dried Material). This study indicates that tannin is one of the major phenolic compounds available in wine lees that can be useful in human and animal health applications.

  9. Characterization of Phenolic Compounds in Wine Lees

    PubMed Central

    Zhijing, Ye; Shavandi, Amin; Harrison, Roland; Bekhit, Alaa El-Din A.

    2018-01-01

    The effect of vinification techniques on phenolic compounds and antioxidant activity of wine lees are poorly understood. The present study investigated the antioxidant activity of white and red wine lees generated at early fermentation and during aging. In this study, the total phenol content (TPC), total tannin content (TTC), mean degree of polymerization (mDP), and antioxidant activities of five white and eight red wine lees samples from different vinification backgrounds were determined. The results showed that vinification techniques had a significant (p < 0.05) impact on total phenol and tannin content of the samples. White wine lees had high mDP content compared with red ones. Catechin (50–62%) and epicatechin contents were the predominant terminal units of polymeric proanthocyanidin extracted from examined samples. Epigallocatechin was the predominant extension unit of white wine lees, whereas epicatechin was the predominant compound in red wine marc. The ORAC (oxygen radical absorbance capacity) assay was strongly correlated with the DPPH (α,α-diphenyl-β-picrylhydrazyl) assay, and the results showed the strong antioxidant activities associated with red wine lees (PN > 35 mg Trolox/g FDM) (PN: Pinot noir lees; FDM: Freeze-dried Material). This study indicates that tannin is one of the major phenolic compounds available in wine lees that can be useful in human and animal health applications. PMID:29587406

  10. Effect of wine inhibitors on free pineapple stem bromelain activity in a model wine system.

    PubMed

    Esti, Marco; Benucci, Ilaria; Liburdi, Katia; Garzillo, Anna Maria Vittoria

    2011-04-13

    The influence of potential inhibitors, naturally present in wine, on the activity of stem bromelain was investigated in order to evaluate the applicability of this enzyme for protein stabilization in white wine. Bromelain proteolytic activity was tested against a synthetic substrate (Bz-Phe-Val-Arg-pNA) in a model wine system after adding ethanol, sulfur dioxide (SO(2)), skin, seed, and gallic and ellagic tannins at the average range of their concentration in wine. All the inhibitors of stem bromelain activity tested turned out to be reversible. Ethanol was a competitive inhibitor with a rather limited effect. Gallic and ellagic tannins have no inhibitory effect on stem bromelain activity, while both seed and skin tannins were uncompetitive inhibitors. The strongest inhibition effect was revealed for sulfur dioxide, which was a mixed-type inhibitor for the enzyme activity. This study provides useful information relative to a future biotechnological application of stem bromelain in winemaking.

  11. Research observation: Hydrolyzable and condensed tannins in plants of the northwest

    USGS Publications Warehouse

    Gonzalez-Hernandez, M. P.; Karchesy, J.; Starkey, Edward E.

    2003-01-01

    Tannins are secondary metabolites that may influence feeding by mammals on plants. We analyzed hydrolyzable and condensed tannins in 30 plant species consumed by livestock and deer, as a preliminary attempt to study their possible implications on browsing and grazing in forest ecosystems. Heathers (Ericaceae) and plants of the Rose (Rosaceae) family had tannins, while forbs, grasses and shrubs other than the heathers did not show astringency properties. We found the highest tannin content of all the species in Rubus sp., with the highest value around 180 mg TAE/g dry weight in spring. Potentilla erecta, Alnus glutinosa and Quercus robur were next with 57 to 44 mg TAE/g dw. Total tannins in heathers ranged from 22 to 36 mg TAE/g dw. Levels of condensed tannins were higher than hydrolyzable for most of the species. Only Betula alba, Calluna vulgaris, Pteridium aquilinum and Vaccinium myrtillus had 100% hydrolyzable tannins. Tannin content of the species changed seasonally with highest values during the growing season, corresponding to late winter or early spring, depending on the species.

  12. Research observation: Hydrolyzable and condensed tannins in plants of northwest Spain forests

    USGS Publications Warehouse

    Gonzalez-Hernandez, M. P.; Karchesy, J.; Starkey, E.E.

    2003-01-01

    Tannins are secondary metabolites that may influence feeding by mammals on plants. We analyzed hydrolyzable and condensed tannins in 30 plant species consumed by livestock and deer, as a preliminary attempt to study their possible implications on browsing and grazing in forest ecosystems. Heathers (Ericaceae) and plants of the Rose (Rosaceae) family had tannins, while forbs, grasses and shrubs other than the heathers did not show astringency properties. We found the highest tannin content of all the species in Rubus sp., with the highest value around 180 mg TAE/g dry weight in spring. Potentilla erecta, Alnus glutinosa and Quercus robur were next with 57 to 44 mg TAE/g dw. Total tannins in heathers ranged from 22 to 36 mg TAE/g dw. Levels of condensed tannins were higher than hydrolyzable for most of the species. Only Betula alba, Calluna vulgaris, Pteridium aquilinum and Vaccinium myrtillus had 100% hydrolyzable tannins. Tannin content of the species changed seasonally with highest values during the growing season, corresponding to late winter or early spring, depending on the species.

  13. Application of insoluble fibers in the fining of wine phenolics.

    PubMed

    Guerrero, Raúl F; Smith, Paul; Bindon, Keren A

    2013-05-08

    The application of animal-derived proteins as wine fining agents has been subject to increased regulation in recent years. As an alternative to protein-based fining agents, insoluble plant-derived fibers have the capacity to adsorb red wine tannins. Changes in red wine tannin were analyzed following application of fibers derived from apple and grape and protein-based fining agents. Other changes in wine composition, namely, color, monomeric phenolics, metals, and turbidity, were also determined. Wine tannin was maximally reduced by application of an apple pomace fiber and a grape pomace fiber (G4), removing 42 and 38%, respectively. Potassium caseinate maximally removed 19% of wine tannin, although applied at a lower dose. Fibers reduced anthocyanins, total phenolics, and wine color density, but changes in wine hue were minor. Proteins and apple fiber selectively removed high molecular mass phenolics, whereas grape fibers removed those of both high and low molecular mass. The results show that insoluble fibers may be considered as alternative fining agents for red wines.

  14. Specific and sensitive enzyme-linked immunosorbent assays for analysis of residual allergenic food proteins in commercial bottled wine fined with egg white, milk, and nongrape-derived tannins.

    PubMed

    Rolland, Jennifer M; Apostolou, Effie; de Leon, Maria P; Stockley, Creina S; O'Hehir, Robyn E

    2008-01-23

    Regulations introduced by the Food Standards Australia New Zealand in December 2002 require all wine and wine product labels in Australia to identify the presence of a processing aid, additive or other ingredient, which is known to be a potential allergen. The objective of this study was to establish sensitive assays to detect and measure allergenic proteins from commonly used processing aids in final bottled wine. Sensitive and specific enzyme-linked immunosorbent assays (ELISA) were developed and established for the proteins casein, ovalbumin, and peanut. Lower limits of detection of these proteins were 8, 1, and 8 ng/mL, respectively. A panel of 153 commercially available bottled Australian wines were tested by these ELISA, and except for two red wines known to contain added whole eggs, residuals of these food allergens were not detected in any wine. These findings are consistent with a lack of residual potentially allergenic egg-, milk-, or nut-derived processing aids in final bottled wine produced in Australia according to good manufacturing practice at a concentration that could cause an adverse reaction in egg, milk, or peanut/tree-nut allergic adult consumers.

  15. Seed incorporation during vinification and its impact on chemical and organoleptic properties in Syzygium cumini wine.

    PubMed

    VenuGopal, K S; Anu-Appaiah, K A

    2017-12-15

    Syzgium cumini (Jamun) is an evergreen tropical tree, its various parts are known for many therapeutic properties. The present work represents the production of wines from jamun fruits using two different native isolates (Saccharomyces cerevisiae - KF551990 and Pichia gummiguttae - MCC 1273) and influence of jamun seeds on the physico-chemical parameters, chromatic properties, phenolic components and sensory attributes of wine. Wine produced was bottle aged for one year. On aging there was a reduction in bitterness and astringency. Aging lead to reduction in monomeric anthocyanin with an increase in co-pigmented and polymeric anthocynins thus affecting the wine color. Anthocyanin analysis in jamun wine indicated petunidin 3,5-diglucoside as the principal anthocyanin. PCA analysis of wine revealed association of young jamun wine with anthocyanin components. PLS analysis exhibited both positive and negative correlation between various attributes indicating sensory perception of jamun wine is affected by overall composition of the wine. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Metals in wine--impact on wine quality and health outcomes.

    PubMed

    Tariba, Blanka

    2011-12-01

    Metals in wine can originate from both natural and anthropogenic sources, and its concentration can be a significant parameter affecting consumption and conservation of wine. Since metallic ions have important role in oxide-reductive reactions resulting in wine browning, turbidity, cloudiness, and astringency, wine quality depends greatly on its metal composition. Moreover, metals in wine may affect human health. Consumption of wine may contribute to the daily dietary intake of essential metals (i.e., copper, iron, and zinc) but can also have potentially toxic effects if metal concentrations are not kept under allowable limits. Therefore, a strict analytical control of metal concentration is required during the whole process of wine production. This article presents a critical review of the existing literature regarding the measured metal concentration in wine, methods applied for their determination, and possible sources, as well as their impact on wine quality and human health. The main focus is set on aluminum, arsenic, cadmium, chromium, copper, iron, manganese, nickel, lead, and zinc, as these elements most often affect wine quality and human health.

  17. Cardiotonic action of two tannins

    PubMed Central

    Broadbent, J. L.

    1962-01-01

    A tannin isolated from Paullinia pinnata Linn., and tannic acid, have cardiotonic actions on the isolated perfused frog heart. Paullinia tannin is more firmly “fixed” than tannic acid. Tannin solutions contain peroxide, but the cardiotonic action is not dependent on this, since drugs believed to prevent peroxide formation, and sodium pyruvate which destroys peroxides, do not prevent the cardiotonic action. Maximal stimulation by tannin greatly reduces subsequent stimulation by ouabain. If calcium is omitted from the Ringer solution tannins cannot stimulate the heart. In this respect they differ from ouabain. However, the ouabain stimulation can be prevented by prior perfusion with tannin. It is suggested that the antagonism between tannin and ouabain is due to the former preventing ouabain from reaching its receptor sites, and that tannin stimulation is dependent on the formation of a calcium-tannin complex at the heart surface. In the isolated perfused mammalian heart preparation tannins increase diastolic tonus and coronary flow. PMID:13873207

  18. Calcium isotopes in wine

    NASA Astrophysics Data System (ADS)

    Holmden, C. E.

    2011-12-01

    Merlot grapes was -1.94%, which is lower than any of the bottled wines measured, thus far, whether white or red. The wine made from this juice yielded -1.16%, which points to fermentation being the principal source of isotopic variability found in bottled wine. The working hypothesis is that light isotopes of Ca are preferentially stripped from the juice during maceration, fermentation, and lees contact, by ion exchange sites on solid organic-matter comprising the skins and yeast and/or by Ca-tartrate precipitation. High quality wines (especially reds) tend to involve longer contact times between juice and skins in order to increase the extraction of color and phenolic compounds (tannins) from the grape skins, a practice that might also result in greater losses of light isotopes of Ca from the juice, thus explaining the isotopic pattern in bottled wine.

  19. The impact of wine components on fractionation of Cu and Fe in model wine systems: Macromolecules, phenolic and sulfur compounds.

    PubMed

    Kontoudakis, Nikolaos; Smith, Mark; Guo, Anque; Smith, Paul A; Scollary, Geoffrey R; Wilkes, Eric N; Clark, Andrew C

    2017-08-01

    A variety of techniques have been developed with the ability to measure different forms of metals in wine with the ultimate aim of providing a more accurate indicator of metal induced spoilage of wine. This study was conducted in order to identify which wine components influence the measurement of Cu and Fe in their fractionated and/or electrochemically active forms. The measurement techniques involved detection of labile Cu by stripping potentiometry and fractionation of Cu and Fe by sequential solid phase extraction, with detection by inductively coupled plasma-optical emission spectroscopy. The wine components assessed included those extracted from wine (red wine tannin, white wine protein, white wine polysaccharide, red wine polyphenol, white wine polyphenol), and commercially available monomeric compounds, including phenolic compounds and sulfur-containing compounds. For Cu, only hydrogen sulfide, which is known to induce the formation of Cu(I) sulfide, showed any appreciable influence on the fractionation and electrochemical detection of Cu. This form of Cu was also identified as the major component of red and white wines. For Fe, the fractionation was different for red versus white wine, and influenced significantly by extracted red wine polyphenol, (-)-epicatechin, gallic acid and tartaric acid. The wine components showed more influence on Fe at pH4.00 compared to pH3.25. These results enable a targeted use of these techniques in the assessment of metal-induced spoilage of wine. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Investigating Mixture Interactions of Astringent Stimuli Using the Isobole Approach

    PubMed Central

    Fleming, Erin E.; Ziegler, Gregory R.

    2016-01-01

    Abstract Astringents (alum, malic acid, tannic acid) representing 3 broad classes (multivalent salts, organic acids, and polyphenols) were characterized alone, and as 2- and 3-component mixtures using isoboles. In experiment 1, participants rated 7 attributes (“astringency,” the sub-qualities “drying,” “roughing,” and “puckering,” and the side tastes “bitterness,” “sourness,” and “sweetness”) using direct scaling. Quality specific power functions were calculated for each stimulus. In experiment 2, the same participants characterized 2- and 3-component mixtures. Multiple factor analysis (MFA) and hierarchical clustering on attribute ratings across stimuli indicate “astringency” is highly related to “bitterness” as well as “puckering,” and the subqualities “drying” and “roughing” are somewhat redundant. Moreover, power functions were used to calculate indices of interaction (I) for each attribute/mixture combination. For “astringency,” there was evidence of antagonism, regardless of the type of mixture. Conversely, for subqualities, the pattern of interaction depended on the mixture type. Alum/tannic acid and tannic acid/malic acid mixtures showed evidence of synergy for “drying” and “roughing”; alum/malic acid mixtures showed evidence of antagonism for “drying,” “roughing,” and “puckering.” Collectively, these data clarify some semantic ambiguity regarding astringency and its subqualities, as well as the nature of interactions of among different types of astringents. Present data are not inconsistent with the idea that astringency arises from multiple mechanisms, although it remains to be determined whether the synergy observed here might reflect simultaneous activation of these multiple mechanisms. PMID:27252355

  1. Dynamic sensory description of Rioja Alavesa red wines made by different winemaking practices by using Temporal Dominance of Sensations.

    PubMed

    Etaio, Iñaki; Meillon, Sophie; Pérez-Elortondo, Francisco J; Schlich, Pascal

    2016-08-01

    Although sensory description of wines in scientific literature is very large, there is an evident lack of studies describing wines from a dynamic approach. The objective of this study was to describe the evolution of the sensations perceived in red wines from Rioja Alavesa by using Temporal Dominance of Sensations (TDS) and also to compare wines made with the two winemaking procedures used in Rioja Alavesa: carbonic maceration (CM) and destemming (DS). Ten sensory attributes were evaluated in eight wines (four CM and four DS wines) in triplicate by a panel of 16 trained assessors. Red/black berry and woody aromas were dominant firstly, whereas heat, astringent, bitter and pungent sensations were dominant later. CM wines showed higher dominance for woody, spicy, pungent and acid sensations and lower dominance for red/black berry aroma and astringency than DS wines. This study is the first to describe Rioja wines from a dynamic approach and it also provides information about the dynamic sensory differences between wines made by CM or by DS. In this sense, this work shows the usefulness of TDS to describe and differentiate wines and to provide additional information to the conventional static descriptive analysis. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  2. White wine taste and mouthfeel as affected by juice extraction and processing.

    PubMed

    Gawel, Richard; Day, Martin; Van Sluyter, Steven C; Holt, Helen; Waters, Elizabeth J; Smith, Paul A

    2014-10-15

    The juice used to make white wine can be extracted using various physical processes that affect the amount and timing of contact of juice with skins. The influence of juice extraction processes on the mouthfeel and taste of white wine and their relationship to wine composition were determined. The amount and type of interaction of juice with skins affected both wine total phenolic concentration and phenolic composition. Wine pH strongly influenced perceived viscosity, astringency/drying, and acidity. Despite a 5-fold variation in total phenolics among wines, differences in bitter taste were small. Perceived viscosity was associated with higher phenolics but was not associated with either glycerol or polysaccharide concentration. Bitterness may be reduced by using juice extraction and handling processes that minimize phenolic concentration, but lowering phenolic concentration may also result in wines of lower perceived viscosity.

  3. Reducing astringency in persimmons through processing, an approach for increasing marketability (abstract)

    USDA-ARS?s Scientific Manuscript database

    Persimmons are an orange flesh fruit produced in temperate climates throughout the world. Varieties within the commercially most important species (Diospyros kaki) are divided into three astringency types- non-astringent, astringent, and pollination variant. In the U.S., California is the largest ...

  4. 21 CFR 347.12 - Astringent active ingredients.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Astringent active ingredients. 347.12 Section 347.12 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS FOR HUMAN USE SKIN PROTECTANT DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Active Ingredients...

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

    PubMed

    Sáenz-Navajas, María-Pilar; Campo, Eva; Avizcuri, José Miguel; Valentin, Dominique; Fernández-Zurbano, Purificación; Ferreira, Vicente

    2012-06-30

    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. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Enhanced antioxidant activity of polyolefin films integrated with grape tannins.

    PubMed

    Olejar, Kenneth J; Ray, Sudip; Kilmartin, Paul A

    2016-06-01

    A natural antioxidant derived from an agro-waste of the wine industry, grape tannin, was incorporated by melt blending into three different polyolefins (high-density polyethylene, linear low-density polyethylene and polypropylene) to introduce antioxidant functionality. Significant antioxidant activity was observed at 1% tannin inclusion in all polymer blends. The antioxidant activity was observed to increase steadily with a greater concentration of grape tannins, the highest increases being seen with polypropylene. The mechanical and thermal properties of the polymer films following antioxidant incorporation were minimally altered with up to 3% grape tannins. All of the polyolefin-grape tannin films successfully passed the leachability test following USP661 standard protocol. Superior antioxidant activity was established in polyolefin thin films by utilization of a bulk grape extract obtained from winery waste. Significant increases in antioxidant activity were seen with 1% extract inclusion. This not only demonstrates the potential for food packaging applications of the polyolefin blends, but also valorizes the agro-waste. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  7. Effects of tannins on fruit selection in three southern African frugivorous birds.

    PubMed

    Zungu, Manqoba M; Downs, Colleen T

    2015-02-01

    Tannins are common secondary compounds in plant material and are known for their ability to bind to protein which reduces nitrogen availability in the diet. In fruits, these compounds are responsible for their astringency which is thought to result in reduced food intake. In this study, the repellent effects of tannins were examined in three species of frugivorous birds: red-winged starlings Onychognathus morio, speckled mousebirds Colius striatus and Cape white-eyes Zosterops virens. Birds were fed artificial fruit diets containing varying levels of tannins in paired choice tests with the amount of food eaten by birds used to determine preference. Red-winged starlings were attracted to the control diet, indifferent to the medium tannin diet and deterred by the high tannin diet whereas speckled mousebirds and Cape white-eyes were not deterred at all concentrations. The discrepancy in the results was attributed to differences in taste sensitivity, tolerance levels and detoxification mechanisms of secondary compounds between species. Because fruit selection and ultimately fruit removal rates affect plant community composition, the disparity in the results suggests that frugivorous birds do not contribute equally to plant community dynamics. However, plant secondary compounds in fruits are diverse and their effects are similarly diverse and there is potential that different groups of secondary compounds generate disparate effects. Similar studies on other types of secondary compounds may thus contribute towards a broader understanding of the role of secondary compounds in mediating fruit-frugivore interactions. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Use of a flor velum yeast for modulating colour, ethanol and major aroma compound contents in red wine.

    PubMed

    Moreno, Juan; Moreno-García, Jaime; López-Muñoz, Beatriz; Mauricio, Juan Carlos; García-Martínez, Teresa

    2016-12-15

    The most important and negative effect of the global warming for winemakers in warm and sunny regions is the observed lag between industrial and phenolic grape ripeness, so only it is possible to obtain an acceptable colour when the ethanol content of wine is high. By contrast, the actual market trends are to low ethanol content wines. Flor yeast growing a short time under velum conditions, decreases the ethanol and volatile acidity contents, has a favorable effect on the colour and astringency and significantly changes the wine content in 1-propanol, isobutanol, acetaldehyde, 1,1-diethoxiethane and ethyl lactate. The Principal Component Analysis of six enological parameters or five aroma compounds allows to classify the wines subjected to different velum formation conditions. The obtained results in two tasting sessions suggest that the flor yeast helps to modulate the ethanol, astringency and colour and supports a new biotechnological perspective for red winemakers. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Relationships between harvest time and wine composition in Vitis vinifera L. cv. Cabernet Sauvignon 1. Grape and wine chemistry.

    PubMed

    Bindon, Keren; Varela, Cristian; Kennedy, James; Holt, Helen; Herderich, Markus

    2013-06-01

    The study aimed to quantify the effects of grape maturity on wine alcohol, phenolics, flavour compounds and polysaccharides in Vitis vinifera L. cv Cabernet Sauvignon. Grapes were harvested at juice soluble solids from 20 to 26 °Brix which corresponded to a range of wine ethanol concentrations between 12% and 15.5%. Grape anthocyanin and skin tannin concentration increased as ripening progressed, while seed tannin declined. In the corresponding wines, monomeric anthocyanin and wine tannin concentration increased with harvest date, consistent with an enhanced extraction of skin-derived phenolics. In wines, there was an observed increase in yeast-derived metabolites, including volatile esters, dimethyl sulfide, glycerol and mannoproteins with harvest date. Wine volatiles which were significantly influenced by harvest date were isobutyl methoxypyrazine, C(6) alcohols and hexyl acetate, all of which decreased as ripening progressed. The implications of harvest date for wine composition is discussed in terms of both grape composition and yeast metabolism. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Interactions between yeast lees and wine polyphenols during simulation of wine aging. II. Analysis of desorbed polyphenol compounds from yeast lees.

    PubMed

    Mazauric, Jean-Paul; Salmon, Jean-Michel

    2006-05-31

    In the first part of this work, the analysis of the polyphenolic compounds remaining in the wine after different contact times with yeast lees during simulation of red wine aging was undertaken. To achieve a more precise view of the wine polyphenols adsorbed on lees during red wine aging and to establish a clear balance between adsorbed and remnant polyphenol compounds, the specific analysis of the chemical composition of the adsorbed polyphenolic compounds (condensed tannins and anthocyanins) after their partial desorbtion from yeast lees by denaturation treatments was realized in the second part of the study. The total recovery of polyphenol compounds from yeast lees was not complete, since a rather important part of the initial wine colored polyphenols, especially those with a dominant blue color component, remained strongly adsorbed on yeast lees, as monitored by color tristimulus and reflectance spectra measurements. All anthocyanins were recovered at a rather high percentage (about 62%), and it was demonstrated that they were not adsorbed in relation with their sole polarity. Very few monomeric phenolic compounds were extracted from yeast lees. With the use of drastic denaturing treatments, the total recovery of condensed tannins reached 83%. Such tannins extracted from yeast lees exhibited very high polymeric size and a rather high percentage of galloylated residues by comparison with initial wine tannins, indicating that nonpolar tannins were preferentially desorbed from yeast lees by the extraction treatments.

  11. Analysis of the grape MYB R2R3 subfamily reveals expanded wine quality-related clades and conserved gene structure organization across Vitis and Arabidopsis genomes

    PubMed Central

    Matus, José Tomás; Aquea, Felipe; Arce-Johnson, Patricio

    2008-01-01

    Background The MYB superfamily constitutes the most abundant group of transcription factors described in plants. Members control processes such as epidermal cell differentiation, stomatal aperture, flavonoid synthesis, cold and drought tolerance and pathogen resistance. No genome-wide characterization of this family has been conducted in a woody species such as grapevine. In addition, previous analysis of the recently released grape genome sequence suggested expansion events of several gene families involved in wine quality. Results We describe and classify 108 members of the grape R2R3 MYB gene subfamily in terms of their genomic gene structures and similarity to their putative Arabidopsis thaliana orthologues. Seven gene models were derived and analyzed in terms of gene expression and their DNA binding domain structures. Despite low overall sequence homology in the C-terminus of all proteins, even in those with similar functions across Arabidopsis and Vitis, highly conserved motif sequences and exon lengths were found. The grape epidermal cell fate clade is expanded when compared with the Arabidopsis and rice MYB subfamilies. Two anthocyanin MYBA related clusters were identified in chromosomes 2 and 14, one of which includes the previously described grape colour locus. Tannin related loci were also detected with eight candidate homologues in chromosomes 4, 9 and 11. Conclusion This genome wide transcription factor analysis in Vitis suggests that clade-specific grape R2R3 MYB genes are expanded while other MYB genes could be well conserved compared to Arabidopsis. MYB gene abundance, homology and orientation within particular loci also suggests that expanded MYB clades conferring quality attributes of grapes and wines, such as colour and astringency, could possess redundant, overlapping and cooperative functions. PMID:18647406

  12. Wine tasting based on emotional responses: An expedite approach to distinguish between warm and cool climate dry red wine styles.

    PubMed

    Coste, Amaury; Sousa, Paulo; Malfeito-Ferreira, Manuel

    2018-04-01

    In this study, we improved an empirical tasting sheet including emotional responses and common sensory attributes. An Optimized Descriptive Profile (ODP) was run to characterize different red wines according to sensory descriptors used in the improved sheet. A total of 5 wines were evaluated by a Consumer Panel (CP) of 103 subjects (36 females, 67 males) using the improved sheet and a Check-All-That-Apply (CATA) list of 25 emotions. In the ODP, the panel identified the main discriminating sensory attributes as "Complexity", "Astringency" and "Duration of the wine fragrance". However, this analysis did not allow for differentiating very distinct dry red wine styles originating from warmer or cooler regions. On the contrary, Principal Component Analysis of emotional attributes demonstrated that these two wine styles could be easily distinguished. In particular, wine with a red-brick color, complex smell and aggressive mouthfeel consistent with those from cooler regions was less liked by the CP than a warm climate gold-awarded wine. Although receiving lower scores considering its color and smell, the former wine was regarded as the most "surprising" in the CATA. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Comparison of Aquitaine and Rioja Red Wines: Characterization of Their Phenolic Composition and Evolution from 2000 to 2013.

    PubMed

    Quaglieri, Cindy; Prieto-Perea, Noelia; Berrueta, Luis Angel; Gallo, Blanca; Rasines-Perea, Zurine; Jourdes, Michael; Teissedre, Pierre-Louis

    2017-01-24

    Wine chemical analysis was carried out on 194 commercial blended red wines produced by two major wine-growing areas-the Aquitaine (France) and Rioja (Spain) regions-in order to compare the wines of both regions. Anthocyanins and derived pigments, tannins and derivatives were identified and quantified by HPLC-DAD-ESI-MS/MS (high pressure liquid chromatography coupled to diode array detector and mass spectrometry using the electrospray ionization interface). Mean degree of polymerization (mDP) was determined. The influence of the wine-growing region and the predominance of the properties of some grape varieties used are confirmed by the significant differences observed between both regions. Rioja and Bordeaux "generic" (Bordeaux and Bordeaux-Supérieur appellations) red wines showed the highest anthocyanic content and the highest mDP, as these wines are in a majority made from Merlot (Bordeaux "generic") and Tempranillo (Rioja). On the contrary, Bordeaux "specific" regions (Blayais, Médoc, Graves, and Libournais) showed the red wines with the highest total phenolic content and tannin concentration, as the predominant grape variety used is Cabernet Sauvignon. A principal component analysis (PCA) and a hierarchical ascendant classification (HAC) suggesting patterns between the chemical parameters and the distribution of the red wines in three groups were proposed. The comparison of the two wine-growing areas also reveals some similarities between the various grape varieties used. A general effect of a progressive decrease in anthocyanins, anthocyanin-derived pigment and tannins is observed for older wines.

  14. Sensory representation of typicality of Cabernet franc wines related to phenolic composition: impact of ripening stage and maceration time.

    PubMed

    Cadot, Yves; Caillé, Soline; Samson, Alain; Barbeau, Gérard; Cheynier, Véronique

    2012-06-30

    Phenolics are responsible for important sensory properties of red wines, including colour, astringency, and possibly bitterness. From a technical viewpoint, the harvest date and the maceration duration are critical decisions for producing red wine with a distinctive style. But little is known about the evolution of phenolics and of their extractability during ripening to predict the composition of the wine and related sensory properties. The aim of this study was to understand the relationship between the sensory profile of the wines and (i) the ripening stage of the berries (harvest date) and (ii) the extraction time (maceration duration). Phenolic acids, flavonols, anthocyanins and proanthocyanidins of Vitis Vinifera var. Cabernet franc were measured in grapes and in wines from two stages of maturity and with two maceration durations. Phenolic composition was analysed by high performance liquid chromatography, after fractionation and thiolysis for proanthocyanidins. The distinctive style of wines was investigated by descriptive analysis (trained panel), Just About Right profiles and typicality assessment (wine expert panel). Relationships between phenolics and sensory attributes were established by multidimensional analysis, and phenolics were classified according to sensory data by ANOVA and PLS regressions. Astringency, bitterness, colour intensity and alcohol significantly increased with ripening and astringency and colour intensity increased with maceration time. Grape anthocyanins increased and thiolysis yield significantly decreased with ripening. In wine, proanthocyanidins increased, and mean degree of polymerisation and thiolysis yield decreased with longer extraction time. The high impact of harvest date on the sensory profiles could be due to changes in anthocyanin and sugar contents, but also to an evolution of proanthocyanidins. Moreover, proanthocyanidin composition was affected by maceration time as suggested by the decrease of thiolysis yield. Our

  15. Influence of aging conditions on the quality of red Sangiovese wine.

    PubMed

    Castellari, M; Piermattei, B; Arfelli, G; Amati, A

    2001-08-01

    A red Sangiovese wine was stored in barrels of different woods (oak and chestnut) and types (225-L "barriques" and 1000-L barrels) at 12 and 22 degrees C for 320 days to evaluate the effects of different aging conditions on wine quality. Chestnut barrels led to wines richer in phenolics, and which were more tannic, colored, and fruity. Oak barrels gave wines with more monomeric phenolics, but less astringent, with higher vanilla smell, and more harmonious. The type of barrel could be used as a parameter to regulate the extraction of wood components and the polymerization of monomeric phenolics. Storage at 22 degrees C favored the formation of polymerized phenolics and the increase of color density and color hue. The temperature produced less pronounced effects on aroma and taste, even if wines stored at 12 degrees C showed more harmony.

  16. Color stabilization of red wines. A chemical and colloidal approach.

    PubMed

    Alcalde-Eon, Cristina; García-Estévez, Ignacio; Puente, Victor; Rivas-Gonzalo, Julián C; Escribano-Bailón, M Teresa

    2014-07-23

    The effects of cold treatment and time on CIELAB color parameters and on anthocyanin and anthocyanin-derived pigments composition have been evaluated as has been the effectiveness of either an enological tannin or a mannoprotein (M) on their stabilization. With respect to color, hue (hab) was increased in the wines treated with both enological products. Furthermore, the color changes induced by cold treatment were lessened by the addition of these two enological products, although the protective effect was higher for the wines treated with M. The pigment analysis revealed higher percentages of anthocyanin-derived pigments in tannin and M-treated samples (in both cold treated and not) in relation to control ones. The addition of the enological tannin may favor the synthesis of anthocyanin-derived pigments, which are chemically more stable than native anthocyanins, whereas M seems to stabilize anthocyanin-derived pigments from a colloidal point of view, avoiding their aggregation and further precipitation.

  17. Folding of a salivary intrinsically disordered protein upon binding to tannins.

    PubMed

    Canon, Francis; Ballivian, Renaud; Chirot, Fabien; Antoine, Rodolphe; Sarni-Manchado, Pascale; Lemoine, Jérôme; Dugourd, Philippe

    2011-05-25

    We used ion mobility spectrometry to explore conformational adaptability of intrinsically disordered proteins bound to their targets in complex mixtures. We investigated the interactions between a human salivary proline-rich protein IB5 and a model of wine and tea tannin: epigallocatechin gallate (EgCG). Collisional cross sections of naked IB5 and IB5 complexed with N = 1-15 tannins were recorded. The data demonstrate that IB5 undergoes an unfolded to folded structural transition upon binding with EgCG.

  18. Botanical traceability of commercial tannins using the mineral profile and stable isotopes.

    PubMed

    Bertoldi, Daniela; Santato, Alessandro; Paolini, Mauro; Barbero, Alice; Camin, Federica; Nicolini, Giorgio; Larcher, Roberto

    2014-09-01

    Commercial tannins are natural polyphenolic compounds extracted from different plant tissues such as gall, the wood of different species and fruit. In the food industry they are mainly used as flavourings and food ingredients, whereas in winemaking they are classified as clarification agents for wine protein stabilisation, although colour stabilisation, metal removal, unpleasant thiol removal and rheological correction are also well-known and desired effects. Due to their particular technical properties and very different costs, the possibility of correct identification of the real botanical origin of tannins can be considered a primary target in oenology research and in fulfilling the technical and economic requirements of the wine industry. For some categories of tannins encouraging results have already been achieved by considering sugar or polyphenolic composition. For the first time this work verifies the possibility of determining the botanical origin of tannins on the basis of the mineral element profile and analysis of the (13) C/(12) C isotopic ratio. One hundred two commercial tannins originating from 10 different botanical sources (grapes, oak, gall, chestnut, fruit trees, quebracho, tea, acacia, officinal plants and tara) were analysed to determine 57 elements and the (13) C/(12) C isotopic ratio, using inductively coupled plasma mass spectrometry and isotope-ratio mass spectrometry, respectively. Forward stepwise discriminant analysis provided good discrimination between the 8 most abundant groups, with 100% correct re-classification. The model was then validated five times on subsets of 10% of the overall samples, randomly extracted, achieving satisfactory results. With a similar approach it was also possible to distinguish toasted and untoasted oak tannins as well as tannins from grape skin and grape seeds. Copyright © 2014 John Wiley & Sons, Ltd.

  19. Effect of flash release treatment on phenolic extraction and wine composition.

    PubMed

    Morel-Salmi, Cécile; Souquet, Jean-Marc; Bes, Magali; Cheynier, Véronique

    2006-06-14

    The flash release (FR) process, consisting of rapidly heating the grapes and then applying strong vacuum, has been proposed to increase the polyphenol content of red wines. Its impact on polyphenol extraction kinetics and on the polyphenol composition of red juice and wines was studied over two seasons on different grape varieties (Grenache, Mourvedre, Carignan). The FR process allows fast extraction of all phenolic compounds (hydroxycinnamic acids, flavonols, anthocyanins, catechins, proanthocyanidins) and can be used to produce polyphenol-enriched grape juices. However, the concentration of all polyphenols dramatically decreased throughout fermentation when pressing was achieved immediately after FR. The FR wines made with pomace maceration were also enriched in polyphenols compared to the corresponding control wines. Increasing the duration of high-temperature exposure in the FR treatment further increased extraction of phenolic compounds but also accelerated their conversion to derived species. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase, higher after FR than in the control, and even higher after longer heating. FR resulted in an increased tannin-to-anthocyanin ratio and an increased conversion of anthocyanins to tannin-anthocyanin adducts showing the same color properties as anthocyanins. The tannin-to-anthocyanin ratio was particularly low in the wine fermented in the liquid phase that also contained larger amounts of orange sulfite bleaching-resistant pigments.

  20. Soil Types Effect on Grape and Wine Composition in Helan Mountain Area of Ningxia

    PubMed Central

    Wang, Rui; Sun, Quan; Chang, Qingrui

    2015-01-01

    Different soil types can significantly affect the composition of wine grapes and the final wine product. In this study, the effects of soil types on the composition of Cabernet Sauvignon grapes and wine produced in the Helan Mountains were evaluated. Three different representative soil types—aeolian, sierozem and irrigation silting soil were studied. The compositions of grapes and wines were measured, and in addition, the weights of 100-berry samples were determined. The grapes that grown on the aeolian and sierozem soils matured sooner than those grown on the irrigation silting soil. The highest sugar content, total soluble solids content, sugar to acid ratio and anthocyanin content were found in the grapes that grown on the aeolian soil. The wine produced from this soil had improved chroma and tone and higher-quality phenols. The grapes grown on the sierozem soil had the highest total phenol and tannin contents, which affected the wine composition. The grapes grown on the irrigation silting soil had higher acidities, but the remaining indices were lower. In addition, the grapes grown on the aeolian soil resulted in wines with better chroma and aroma. The sierozem soil was beneficial for the formation of wine tannins and phenols and significantly affected the wine composition. The quality of the grapes from the irrigation silting soil was relatively low, resulting in lower-quality wine. PMID:25706126

  1. Soil types effect on grape and wine composition in Helan Mountain area of Ningxia.

    PubMed

    Wang, Rui; Sun, Quan; Chang, Qingrui

    2015-01-01

    Different soil types can significantly affect the composition of wine grapes and the final wine product. In this study, the effects of soil types on the composition of Cabernet Sauvignon grapes and wine produced in the Helan Mountains were evaluated. Three different representative soil types--aeolian, sierozem and irrigation silting soil were studied. The compositions of grapes and wines were measured, and in addition, the weights of 100-berry samples were determined. The grapes that grown on the aeolian and sierozem soils matured sooner than those grown on the irrigation silting soil. The highest sugar content, total soluble solids content, sugar to acid ratio and anthocyanin content were found in the grapes that grown on the aeolian soil. The wine produced from this soil had improved chroma and tone and higher-quality phenols. The grapes grown on the sierozem soil had the highest total phenol and tannin contents, which affected the wine composition. The grapes grown on the irrigation silting soil had higher acidities, but the remaining indices were lower. In addition, the grapes grown on the aeolian soil resulted in wines with better chroma and aroma. The sierozem soil was beneficial for the formation of wine tannins and phenols and significantly affected the wine composition. The quality of the grapes from the irrigation silting soil was relatively low, resulting in lower-quality wine.

  2. Quantitative reconstruction of the nonvolatile sensometabolome of a red wine.

    PubMed

    Hufnagel, Jan Carlos; Hofmann, Thomas

    2008-10-08

    The first comprehensive quantitative determination of 82 putative taste-active metabolites and mineral salts, the ranking of these compounds in their sensory impact based on dose-over-threshold (DoT) factors, followed by the confirmation of their sensory relevance by taste reconstruction and omission experiments enabled the decoding of the nonvolatile sensometabolome of a red wine. For the first time, the bitterness of the red wine could be demonstrated to be induced by subthreshold concentrations of phenolic acid ethyl esters and flavan-3-ols. Whereas the velvety astringent onset was imparted by three flavon-3-ol glucosides and dihydroflavon-3-ol rhamnosides, the puckering astringent offset was caused by a polymeric fraction exhibiting molecular masses above >5 kDa and was found to be amplified by the organic acids. The perceived sourness was imparted by l-tartaric acid, d-galacturonic acid, acetic acid, succinic acid, l-malic acid, and l-lactic acid and was slightly suppressed by the chlorides of potassium, magnesium, and ammonium, respectively. In addition, d-fructose and glycerol as well as subthreshold concentrations of glucose, 1,2-propandiol, and myo-inositol were found to be responsible for the sweetness, whereas the mouthfulness and body of the red wine were induced only by glycerol, 1,2-propandiol, and myo-inositol.

  3. Interactions between grape skin cell wall material and commercial enological tannins. Practical implications.

    PubMed

    Bautista-Ortín, Ana Belén; Cano-Lechuga, Mario; Ruiz-García, Yolanda; Gómez-Plaza, Encarna

    2014-01-01

    Commercial enological tannins were used to investigate the role that cell wall material plays in proanthocyanidin adsorption. Insoluble cell wall material, prepared from the skin of Vitis vinifera L. cv. Monastrell berries, was combined with solutions containing six different commercial enological tannins (proanthocyanidin-type tannins). Analysis of the proanthocyanidins in the solution, after fining with cell wall material, using phloroglucinolysis and size exclusion chromatography, provided quantitative and qualitative information on the non-adsorbed compounds. Cell wall material showed strong affinity for the proanthocyanidins, one of the commercial tannins being bound up to 61% in the experiment. Comparison of the molecular mass distribution of the commercial enological tannins in solution, before and after fining, suggested that cell walls affinity for proanthocyanidins was more related with the proanthocyanidin molecular mass than with their percentage of galloylation. These interactions may have some enological implications, especially as regards the time of commercial tannins addition to the must/wine. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Contribution of low molecular weight phenols to bitter taste and mouthfeel properties in red wines.

    PubMed

    Gonzalo-Diago, Ana; Dizy, Marta; Fernández-Zurbano, Purificación

    2014-07-01

    The aim of this study was to explore the relationship between low molecular weight compounds present in wines and their sensory contribution. Six young red wines were fractionated by gel permeation chromatography and subsequently each fraction obtained was separated from sugars and acids by solid phase extraction. Wines and both fractions were in-mouth evaluated by a trained sensory panel and UPLC-MS analyses were performed. The lack of ethanol and proanthocyanidins greatly increased the acidity perceived. The elimination of organic acids enabled the description of the samples, which were evaluated as bitter, persistent and slightly astringent. Coutaric acid and quercetin-3-O-rutinoside appear to be relevant astringent compounds in the absence of proanthocyanidins. Bitter taste was highly correlated with the in-mouth persistence. A significant predictive model for bitter taste was built by means of PLSR. Further research must be carried out to validate the sensory contribution of the compounds involved in bitterness and astringency and to verify the sensory interactions observed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Effect of fining on the colour and pigment composition of young red wines.

    PubMed

    González-Neves, Gustavo; Favre, Guzmán; Gil, Graciela

    2014-08-15

    This work aimed to evaluate the effect of four fining agents on the colour and pigment composition of red wines of Tannat. The wines were analysed 15 days after fining and immediately after separation of sediments and bottling. Colour was evaluated by spectrophotometry and polyphenols were analysed by spectrophotometry and HPLC-DAD. The colour intensity of wine was significantly decreased by bentonite and egg albumin. The most remarkable effects on wine phenolic composition were produced by bentonite and gelatin, which significantly decreased anthocyanin and tannin concentrations, respectively. Results show that each fining agent has very different impact on the wine attributes, and their effects depended as well on the composition of the clarified wine. The use of non-traditional agents of fining, as vegetable proteins, may have less impact on the colour and anthocyanin content of red wines. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Influence of Different Fermentation Strategies on the Phenolic Profile of Bilberry Wine (Vaccinium myrtillus L.).

    PubMed

    Behrends, Annika; Weber, Fabian

    2017-08-30

    Polyphenol rich and especially anthocyanin rich berries like bilberries (Vaccinium myrtillus L.) and derived products such as wine have enjoyed increasing popularity. During winemaking and aging, the phenolic profile undergoes distinct changes, a phenomenon that has been well investigated in grape wine but not in bilberry wine. The present study determined the influence of different fermentation strategies including various pre- and postfermentative heating and cooling concepts on the phenolic profile of bilberry wine. Besides significant differences in total anthocyanin and tannin concentrations, the different fermentation strategies resulted in distinguishable anthocyanin profiles. A very fast aging manifested by a rapid decrease in monomeric anthocyanins of up to 98% during a 12 week storage and a coincident formation of polymeric pigments and pyranoanthocyanins was observed. Several well-known processes associated with production and aging of wine were much more pronounced in bilberry wine compared to grape wine.

  7. Micro-oxygenation of red wine: techniques, applications, and outcomes.

    PubMed

    Schmidtke, Leigh M; Clark, Andrew C; Scollary, Geoff R

    2011-02-01

    Wine micro-oxygenation (MOX) is the controlled addition of oxygen to wine in a manner designed to ensure that complete mass transfer of molecular oxygen from gaseous to dissolved state occurs. MOX was initially developed to improve the body, structure, and fruitfulness in red wines with high concentrations of tannins and anthocyanins, by replicating the ingress of oxygen thought to arise from barrel maturation, but without the need for putting all wine to barrel. This review describes the operational parameters essential for the effective performance of the micro-oxidation process as well as the chemical and microbiological outcomes. The methodologies for introducing oxygen into the wine, the rates of oxygen addition, and their relationship to oxygen solubility in the wine matrix are examined. The review focuses on the techniques used for monitoring the MOX process, including sensory assessment, physicochemical properties, and the critical balance of the rate of oxygen addition in relation to maintaining the sulfur dioxide concentration. The chemistry of oxygen reactivity with wine components, the changes in wine composition that occur as a consequence of MOX, and the potential for wine spoilage if proper monitoring is not adopted are examined. Gaps in existing knowledge are addressed focusing on the limitations associated with the transfer of concepts from research trials in small volume tanks to commercial practice, and the dearth of kinetic data for the various chemical and physical processes that are claimed to occur during MOX.

  8. Polyphenols: factors influencing their sensory properties and their effects on food and beverage preferences.

    PubMed

    Lesschaeve, Isabelle; Noble, Ann C

    2005-01-01

    Bitterness and astringency are found in a variety of foods, including nuts, fruits, chocolate, tea, wine, and soymilk. In fruits and beverages, the taste of bitterness and the tactile sensation of astringency are elicited primarily by flavanol polymers (proanthocyanidins or condensed tannins). Variations in proanthocyanidin composition, such as polymer size, extent of galloylation, and formation of derivatives, affect both bitterness and astringency. In beverages, other factors also influence these sensations, including the pH and the levels of ethanol, sweetness, and viscosity. Similarly, foods eaten with beverages can influence astringency. For example, eating dark chocolate increases the astringency of red wine more than does milk chocolate. Individuals perceive astringency differently because of variations in salivary flow rates, and preferences for and acceptance of a product may vary tremendously among individuals; decreasing bitterness and/or astringency may not increase preference. Factors influencing bitterness, astringency, and individual preference decisions are discussed.

  9. Identification of Catechin, Syringic Acid, and Procyanidin B2 in Wine as Stimulants of Gastric Acid Secretion.

    PubMed

    Liszt, Kathrin Ingrid; Eder, Reinhard; Wendelin, Sylvia; Somoza, Veronika

    2015-09-09

    Organic acids of wine, in addition to ethanol, have been identified as stimulants of gastric acid secretion. This study characterized the influence of other wine compounds, particularly phenolic compounds, on proton secretion. Forty wine parameters were determined in four red wines and six white wines, including the contents of organic acids and phenolic compounds. The secretory activity of the wines was determined in a gastric cell culture model (HGT-1 cells) by means of a pH-sensitive fluorescent dye. Red wines stimulated proton secretion more than white wines. Lactic acid and the phenolic compounds syringic acid, catechin, and procyanidin B2 stimulated proton secretion and correlated with the pro-secretory effect of the wines. Addition of the phenolic compounds to the least active white wine sample enhanced its proton secretory effect by 65 ± 21% (p < 0.05). These results indicate that not only malic and lactic acid but also bitter and astringent tasting phenolic compounds in wine contribute to its stimulatory effect on gastric acid secretion.

  10. Phenolic composition and mouthfeel characteristics resulting from blending Chilean red wines.

    PubMed

    Cáceres-Mella, Alejandro; Peña-Neira, Alvaro; Avilés-Gálvez, Pamela; Medel-Marabolí, Marcela; Del Barrio-Galán, Rubén; López-Solís, Remigio; Canals, Joan Miquel

    2014-03-15

    The blending of wine is a common practice in winemaking to improve certain characteristics that are appreciated by consumers. The use of some cultivars may contribute phenolic compounds that modify certain characteristics in blended wines, particularly those related to mouthfeel. The aim of this work was to study the effect of Carménère, Merlot and Cabernet Franc on the phenolic composition, proanthocyanidin profile and mouthfeel characteristics of Cabernet Sauvignon blends. Significant differences in chemical composition were observed among the monovarietal wines. Separation using Sep-Pak C₁₈ cartridges revealed differences in the concentration but not in the proportion of various proanthocyanidins. Blending reduced polyphenol concentration differences among the various monovarietal wines. Although no major overall differences were observed after blending the monovarietal wines, this oenological practice produced clear differences in mouthfeel characteristics in such a way that the quality of the perceived astringency was different. This study showed that the use of a particular wine variety (Cabernet Sauvignon) in a higher proportion in wine blending produced blends that were less differentiable from the monovarietal wine, owing to a suppression effect, producing an apparent standardization of the wines regarding chemical composition. © 2013 Society of Chemical Industry.

  11. Characterization of taste-active compounds of various cherry wines and their correlation with sensory attributes.

    PubMed

    Niu, Yunwei; Zhang, Xiaoming; Xiao, Zuobing; Song, Shiqing; Jia, Chengsheng; Yu, Haiyan; Fang, Lingling; Xu, Chunhua

    2012-08-01

    Five cherry wines exhibiting marked differences in taste and mouthfeel were selected for the study. The taste and mouthfeel of cherry wines were described by four sensory terms as sour, sweet, bitter and astringent. Eight organic acids, seventeen amino acids, three sugars and tannic acid were determined by high performance liquid chromatography (HPLC). Five phenolic acids were determined by ultra performance liquid chromatography coupled with mass spectrometry (UPLC-MS). The relationship between these taste-active compounds, wine samples and sensory attributes was modeled by partial least squares regression (PLSR). The regression analysis indicated tartaric acid, methionine, proline, sucrose, glucose, fructose, asparagines, serine, glycine, threonine, phenylalanine, leucine, gallic acid, chlorogenic acid, vanillic acid, arginine and tannic acid made a great contribution to the characteristic taste or mouthfeel of cherry wines. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Application of ultrasound to improve lees ageing processes in red wines.

    PubMed

    Del Fresno, Juan Manuel; Loira, Iris; Morata, Antonio; González, Carmen; Suárez-Lepe, Jose Antonio; Cuerda, Rafael

    2018-09-30

    Ageing on lees (AOL) is a technique that increases volatile compounds, promotes colour stability, improves mouthfeel and reduces astringency in red wines. The main drawback is that it is a slow process. Several months are necessary to obtain perceptible effects in wines. Different authors have studied the application of new techniques to accelerate the AOL process. Ultrasound (US) has been used to improve different food industry processes; it could be interesting to accelerate the yeast autolysis during AOL. This work evaluates the use of the US technique together with AOL and oak chips for this purpose studying the effects of different oenological parameters of red wines. The results obtained indicate an increase of polysaccharides content when US is applied in wine AOL. In addition, total polyphenol index (TPI) and volatile acidity were not affected. However, this treatment increases the dissolved oxygen affecting the volatile compounds and total anthocyanins. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Phenolic content and antioxidant activity of Primitivo wine: comparison among winemaking technologies.

    PubMed

    Baiano, A; Terracone, C; Gambacorta, G; La Notte, E

    2009-04-01

    The aim of this study was to assess the influence of 9 winemaking technologies (traditional, delestage, saignée, delayed punching-down, addition of grape seed tannins, addition of ellagic-skin-seed tannins, heating of must-wine, cryo-maceration, and prolonged maceration) on the phenolic content and antioxidant activity of Primitivo musts and wines. Three methods for the determination of the antioxidant activity were compared: DPPH, beta-carotene bleaching assay, and ABTS. Oenological parameters and composition of the phenolic fraction of 1-y-aged wines was also determined. The addition of tannins allowed the increase of the phenolic content of musts and wines in a greater amount than the other technologies. The results concerning the antioxidant activity depended on the method applied. Concerning musts, the DPPH assay did not highlight great differences among technologies, whereas the addition of tannins allowed the obtainment of the highest antioxidant activity according to beta-carotene and ABTS assays. The wine aging determined an increase of the antioxidant activity, independently on the method applied. Wine obtained through traditional technology, saignée, and addition of tannins showed the highest antioxidant activities according to DPPH and beta-carotene. The highest correlation coefficients (0.961 and 0.932) were calculated between phenolic content and ABTS values of musts whereas the lowest values (0.413 and 0.517) were calculated between phenolic content and ABTS values of wines. Wines produced through traditional technology were the richest in anthocyanins. The addition of tannins allowed to obtain high content in monomeric anthocyanins, flavonoids, flavans reactive to vanillin, and coumaroylated malvidin and a low content in acetylated malvidin. Practical Applications: It is well known that a moderate consumption (equivalent to 2 glasses per day) of red wine is actually recommended since it appears associated with a decreased incidence of

  14. Taste thresholds and suprathreshold responses to tannin-rich plant extracts and quinine in a primate species (Microcebus murinus).

    PubMed

    Iaconelli, S; Simmen, B

    2002-11-01

    Theories of plant chemical defenses discriminate between quantitative digestibility reducers (e.g., tannins) and qualitative toxins (e.g., alkaloids). Since the differential effect on taste of these compounds is poorly known, we recorded ingestive responses of a primate species, Microcebus murinus, to four tannin-rich plant extracts and to quinine, by using the behavioral method of the "two-bottle test." The efficiency of tannic extracts at precipitating protein was measured with the blue BSA method. Inhibition taste thresholds for tannins added to a moderately sweet solution varied between 0.25 and 2 g/l. The threshold for quinine hydrochloride was 0.32 g/l. The profiles of the response/concentration curves established for these astringent and bitter substances were similar, with maximal inhibition of consumption occurring for near-threshold concentrations. The large amounts of quinine required to deter this small-bodied species from feeding were unexpected, given its unspecialized frugivorous/insectivorous diet. We propose that the taste responses of Microcebus to tannins have been shaped in relation to the widespread occurrence of efficient polyphenols in food plants, while low responsiveness to quinine reflects a low risk of ingesting toxic alkaloids when feeding on ripe fruits and insects.

  15. Ellagitannin content, volatile composition and sensory profile of wines from different countries matured in oak barrels subjected to different toasting methods.

    PubMed

    González-Centeno, M R; Chira, K; Teissedre, P-L

    2016-11-01

    Ellagitannins and aromatic compounds evolution in Cabernet Sauvignon wines macerated in oak barrels for a year was studied. Identical barrels with different toastings (medium toasting, medium toasting with watering, Noisette) were used in French, Italian and USA cellars. Ellagitannins increased by 84-96% with aging time, as did woody volatiles, by 86-91% in French wines and 23-35% in Italian wines, while fruity aroma compounds declined by 50-57% in the French and Italian wines over a 12-months period. Nevertheless, other behaviors and different kinetics rates for these compounds were observed depending on barrel toasting, wine matrix and their interactions. Perceived overall woody intensity was closely related to trans-whiskey lactone, guaiacol and vanillin, whereas astringency and bitterness were significantly linked to ellagitannins (p<0.05). This is the first study that evaluates the toasting effect on wines from different countries matured in the same oak barrels. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Assessing the Effect of Musical Congruency on Wine Tasting in a Live Performance Setting

    PubMed Central

    Wang, Qian (Janice)

    2015-01-01

    At a wine tasting event with live classical music, we assessed whether participants would agree that certain wine and music pairings were congruent. We also assessed the effect of musical congruency on the wine tasting experience. The participants were given two wines to taste and two pieces of music—one chosen to match each wine—were performed live. Half of the participants tasted the wines while listening to the putatively more congruent music, the rest tasted the wines while listening to the putatively less congruent music. The participants rated the wine–music match and assessed the fruitiness, acidity, tannins, richness, complexity, length, and pleasantness of the wines. The results revealed that the music chosen to be congruent with each wine was indeed rated as a better match than the other piece of music. Furthermore, the music playing in the background also had a significant effect on the perceived acidity and fruitiness of the wines. These findings therefore provide further support for the view that music can modify the wine drinking experience. However, the present results leave open the question of whether the crossmodal congruency between music and wine itself has any overarching influence on the wine drinking experience. PMID:27433313

  17. Potential food allergens in wine: double-blind, placebo-controlled trial and basophil activation analysis.

    PubMed

    Rolland, Jennifer M; Apostolou, Effie; Deckert, Kirsten; de Leon, Maria P; Douglass, Jo A; Glaspole, Ian N; Bailey, Michael; Stockley, Creina S; O'Hehir, Robyn E

    2006-09-01

    Recent Australian and international legislation requires labeling of wines made by using the potentially allergenic food proteins casein, milk, egg white, or isinglass (fish-derived) where "there is a detectable residual processing aid." We investigated whether wines fined using these proteins or non-grape-derived tannins (tree-nut derived) can provoke significant clinical allergic reactions (anaphylaxis) in patients with confirmed immunoglobulin E-mediated relevant food allergy. A double-blind, placebo-controlled trial was performed to determine whether allergic reactions followed consumption of Australian commercial wines fined using one or more of the legislation-targeted food proteins. In addition, allergenicity of a larger panel of these wines was evaluated by blood basophil activation. No anaphylaxis was induced by wine consumption. Three mild clinical reactions to protein-fined wine and two mild reactions to unfined wine occurred, but there was no statistically significant difference in reaction parameters between subject groups or between processing aids. No pattern of basophil activation correlated with wine type, processing aid, or subject group. Wines fined with egg white, isinglass, or non-grape-derived tannins present an extremely low risk of anaphylaxis to fish-, egg-, or peanut-allergic consumers. Although consumption of milk protein-fined wine did not induce anaphylaxis, there were insufficient subjects to determine statistically whether wines fined with milk proteins present a risk to the very rare milk-allergic consumers. In summary, the observed lack of anaphylaxis and basophil activation induced by wines made using the legislation-targeted food proteins according to good manufacturing practice suggests negligible residual food allergens in these wines.

  18. Tannins in plant-herbivore interactions.

    PubMed

    Barbehenn, Raymond V; Peter Constabel, C

    2011-09-01

    Tannins are the most abundant secondary metabolites made by plants, commonly ranging from 5% to 10% dry weight of tree leaves. Tannins can defend leaves against insect herbivores by deterrence and/or toxicity. Contrary to early theories, tannins have no effect on protein digestion in insect herbivores. By contrast, in vertebrate herbivores tannins can decrease protein digestion. Tannins are especially prone to oxidize in insects with high pH guts, forming semiquinone radicals and quinones, as well as other reactive oxygen species. Tannin toxicity in insects is thought to result from the production of high levels of reactive oxygen species. Tannin structure has an important effect on biochemical activity. Ellagitannins oxidize much more readily than do gallotannins, which are more oxidatively active than most condensed tannins. The ability of insects to tolerate ingested tannins comes from a variety of biochemical and physical defenses in their guts, including surfactants, high pH, antioxidants, and a protective peritrophic envelope that lines the midgut. Most work on the ecological roles of tannins has been correlative, e.g., searching for negative associations between tannins and insect performance. A greater emphasis on manipulative experiments that control tannin levels is required to make further progress on the defensive functions of tannins. Recent advances in the use of molecular methods has permitted the production of tannin-overproducing transgenic plants and a better understanding of tannin biosynthetic pathways. Many research areas remain in need of further work, including the effects of different tannin types on different types of insects (e.g., caterpillars, grasshoppers, sap-sucking insects). Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Talking About Wine

    ERIC Educational Resources Information Center

    Lehrer, Adrienne

    1975-01-01

    A structural analysis of the wine vocabulary used by wine experts is given. Experiments involving typical wine drinkers show that there is little consensus in how the words are applied to wine. Communication tasks show that the sender and receiver of messages about wine perform little better than chance. (Author/RM)

  20. Temporal Check-All-That-Apply Characterization of Syrah Wine.

    PubMed

    Baker, Allison K; Castura, John C; Ross, Carolyn F

    2016-06-01

    Temporal Check-All-That-Apply (TCATA) is a new dynamic sensory method for which analysis techniques are still being developed and optimized. In this study, TCATA methodology was applied for the evaluation of wine finish by trained panelists (n = 13) on Syrah wines with different ethanol concentrations (10.5% v/v and 15.5% v/v). Raw data were time standardized to create a percentage of finish duration, subsequently segmented into thirds (beginning, middle, and end) to capture panel perception. Results indicated the finish of the high ethanol treatments lasted longer (approximately 12 s longer) than the low ethanol treatment (P ≤ 0.05). Within each finish segment, Cochran's Q was conducted on each attribute and differences were detected amongst treatments (P ≤ 0.05). Pairwise tests showed the high ethanol treatments were more described by astringency, heat/ethanol burn, bitterness, dark fruit, and spices, whereas the low ethanol treatment was more characterized by sourness, red fruit, and green flavors (P ≤ 0.05). This study demonstrated techniques for dealing with the data generated by TCATA. Furthermore, this study further characterized the influence of ethanol on wine finish, and by extension wine quality, with implications to winemakers responsible for wine processing decisions involving alcohol management. © 2016 Institute of Food Technologists®

  1. Condensed tannins. Structure of the "phenolic scids"

    Treesearch

    Peter E. Laks; Richard W. Hemingway

    1987-01-01

    Conifer bark-derived condensed tannins can be used in formulating adhesives. Under some extraction conditions and during normal adhesive formulation, the tannin is exposed to strongly alkaline conditions. Alkaline rearrangement results in partial or total rearrangement of tannins of the procyanidin class to "phenolic acids" which have less phloroglucinol...

  2. Oligomeric hydrolyzable tannins from Monochaetum multiflorum.

    PubMed

    Isaza, José H; Ito, Hideyuki; Yoshida, Takashi

    2004-02-01

    Four hydrolyzable tannins, nobotanins Q, R, S, and T, were isolated from the aqueous acetone extract of the dried leaves of Monochaetum multiflorum (Melastomataceae), a plant indigenous to Colombia. Their dimeric and tetrameric structures were elucidated by spectral and chemical methods. Eight known hydrolyzable tannin monomers and eight ellagitannin oligomers characteristic of melastomataceous plants were also characterized as tannin constituents of the plant.

  3. A new methodology to obtain wine yeast strains overproducing mannoproteins.

    PubMed

    Quirós, Manuel; Gonzalez-Ramos, Daniel; Tabera, Laura; Gonzalez, Ramon

    2010-04-30

    Yeast mannoproteins are highly glycosylated proteins that are covalently bound to the beta-1,3-glucan present in the yeast cell wall. Among their outstanding enological properties, yeast mannoproteins contribute to several aspects of wine quality by protecting against protein haze, reducing astringency, retaining aroma compounds and stimulating growth of lactic-acid bacteria. The development of a non-recombinant method to obtain enological yeast strains overproducing mannoproteins would therefore be very useful. Our previous experience on the genetic determinants of the release of these molecules by Saccharomyces cerevisiae has allowed us to propose a new methodology to isolate and characterize wine yeast that overproduce mannoproteins. The described methodology is based on the resistance of the killer 9 toxin produced by Williopsis saturnus, a feature linked to an altered biogenesis of the yeast cell wall. Copyright 2010 Elsevier B.V. All rights reserved.

  4. Wine and heart health

    MedlinePlus

    Health and wine; Wine and heart disease; Preventing heart disease - wine; Preventing heart disease - alcohol ... more often just to lower your risk of heart disease. Heavier drinking can harm the heart and ...

  5. Low molecular-weight phenols in Tannat wines made by alternative winemaking procedures.

    PubMed

    Favre, Guzmán; Peña-Neira, Álvaro; Baldi, Cecilia; Hernández, Natalia; Traverso, Sofía; Gil, Graciela; González-Neves, Gustavo

    2014-09-01

    Low molecular weight phenols of Tannat red wines produced by Traditional Maceration (TM), Prefermentative Cold Maceration (PCM), Maceration Enzyme (ENZ) and grape-Seed Tannins additions (ST), were performed and discussed. Alternatives to TM increased wine phenolic contents but unequally, ST increased mainly smaller flavans-3-ol, PCM anthocyanins and ENZ proanthocyanidins (up to 2250 mg/L). However low molecular weight flavan-3-ols remained below 9 mg/L in all wines, showing that there is not necessarily a correspondence between wine richness in total tannins and flavan-3-ols contents at low molecular weight. PCM wines had particularly high concentrations of tyrosol and tryptophol, yeast metabolism derived compounds. The use of grape-seed enological tannins did not increase grape seed derived phenolic compounds such as gallic acid. Caftaric acid was found in concentrations much higher than those reported in other grape varieties. Wine phenolic content and composition was considerably affected by the winemaking procedures tested. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. A Novel Quantitative Prediction Approach for Astringency Level of Herbs Based on an Electronic Tongue

    PubMed Central

    Han, Xue; Jiang, Hong; Zhang, Dingkun; Zhang, Yingying; Xiong, Xi; Jiao, Jiaojiao; Xu, Runchun; Yang, Ming; Han, Li; Lin, Junzhi

    2017-01-01

    Background: The current astringency evaluation for herbs has become dissatisfied with the requirement of pharmaceutical process. It needed a new method to accurately assess astringency. Methods: First, quinine, sucrose, citric acid, sodium chloride, monosodium glutamate, and tannic acid (TA) were analyzed by electronic tongue (e-tongue) to determine the approximate region of astringency in partial least square (PLS) map. Second, different concentrations of TA were detected to define the standard curve of astringency. Meanwhile, coordinate-concentration relationship could be obtained by fitting the PLS abscissa of standard curve and corresponding concentration. Third, Chebulae Fructus (CF), Yuganzi throat tablets (YGZTT), and Sanlejiang oral liquid (SLJOL) were tested to define the region in PLS map. Finally, the astringent intensities of samples were calculated combining with the standard coordinate-concentration relationship and expressed by concentrations of TA. Then, Euclidean distance (Ed) analysis and human sensory test were processed to verify the results. Results: The fitting equation between concentration and abscissa of TA was Y = 0.00498 × e(−X/0.51035) + 0.10905 (r = 0.999). The astringency of 1, 0.1 mg/mL CF was predicted at 0.28, 0.12 mg/mL TA; 2, 0.2 mg/mL YGZTTs was predicted at 0.18, 0.11 mg/mL TA; 0.002, 0.0002 mg/mL SLJOL was predicted at 0.15, 0.10 mg/mL TA. The validation results showed that the predicted astringency of e-tongue was basically consistent to human sensory and was more accuracy than Ed analysis. Conclusion: The study indicated the established method was objective and feasible. It provided a new quantitative method for astringency of herbs. SUMMARY The astringency of Chebulae Fructus, Yuganzi throat tablets, and Sanlejiang oral liquid was predicted by electronic tongueEuclidean distance analysis and human sensory test verified the resultsA new strategy which was objective, simple, and sensitive to compare astringent intensity of

  7. Short-term effect of red wine (consumed during meals) on insulin requirement and glucose tolerance in diabetic patients.

    PubMed

    Gin, H; Morlat, P; Ragnaud, J M; Aubertin, J

    1992-04-01

    To determine the effect of wine on insulin requirement or glucose tolerance. Five men with insulin-treated diabetes and 10 men with non-insulin-treated diabetes ate the same lunch with the same volume of either water or red wine (2 glasses). Insulin requirement was determined with an artificial pancreas (Biostator). Glucose tolerance was evaluated from the postprandial glycemic level. There was no significant difference in insulin requirement determined with an artificial pancreas in the insulin-treated patients after the two meals (31.5 +/- 4.21 U with water and 31.8 +/- 4.3 U with wine). Glucose tolerance in the non-insulin-treated patients was lower after the meal with wine. Moderate prandial wine consumption has no adverse effect on the glycemic control of diabetic patients. Thus, it appears unnecessary to proscribe the consumption of red wine in moderation with meals to diabetic patients. Wine contains tannins and phytates that can explain its action.

  8. New insight into the unresolved HPLC broad peak of Cabernet Sauvignon grape seed polymeric tannins by combining CPC and Q-ToF approaches.

    PubMed

    Ma, Wen; Waffo-Téguo, Pierre; Alessandra Paissoni, Maria; Jourdes, Michäel; Teissedre, Pierre-Louis

    2018-05-30

    Polymeric tannins from grapes have always been reported as an unresolved broad peak in HPLC chromatograms, and this has severely limited their identification to date. This study aimed to disassemble this broad peak and explore the polymeric tannin molecules inside. By applying centrifugal partition chromatography (CPC), an efficient separation approach was developed to split the broad peak of grape seed tannins into fractions. Then, the fractions were analyzed by Q-ToF (quadrupole time-of-flight mass spectrometry) to determine the corresponding structures of the tannins. The results suggest that grape seed polymeric tannins were eluted consecutively according to their degree of polymerization (DP). Condensed tannins identified in wine grape seed have a range of DP and degree of galloylation (DG) up to 20 and 11, respectively. The molecular mass of the largest molecule detected was 6067. To our knowledge, this is the first report to offer an insight into the broad peak of polymeric tannins found with HPLC and to characterize the tannins with a DP up to 20 as shown by HRMS and MS/MS data. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Impacts of Grapevine Leafroll Disease on Fruit Yield and Grape and Wine Chemistry in a Wine Grape (Vitis vinifera L.) Cultivar.

    PubMed

    Alabi, Olufemi J; Casassa, L Federico; Gutha, Linga R; Larsen, Richard C; Henick-Kling, Thomas; Harbertson, James F; Naidu, Rayapati A

    2016-01-01

    Grapevine leafroll disease (GLD) is an economically important virus disease affecting wine grapes (Vitis vinifera L.), but little is known about its effect on wine chemistry and sensory composition of wines. In this study, impacts of GLD on fruit yield, berry quality and wine chemistry and sensory features were investigated in a red wine grape cultivar planted in a commercial vineyard. Own-rooted Merlot vines showing GLD symptoms and tested positive for Grapevine leafroll-associated virus 3 and adjacent non-symptomatic vines that tested negative for the virus were compared during three consecutive seasons. Number and total weight of clusters per vine were significantly less in symptomatic relative to non-symptomatic vines. In contrast to previous studies, a time-course analysis of juice from grapes harvested at different stages of berry development from symptomatic and non-symptomatic vines indicated more prominent negative impacts of GLD on total soluble solids (TSS) and berry skin anthocyanins than in juice pH and titratable acidity. Differences in TSS between grapes of symptomatic and non-symptomatic vines were more pronounced after the onset of véraison, with significantly lower concentrations of TSS in grapes from symptomatic vines throughout berry ripening until harvest. Wines made from grapes of GLD-affected vines had significantly lower alcohol, polymeric pigments, and anthocyanins compared to corresponding wines from grapes of non-symptomatic vines. Sensory descriptive analysis of 2010 wines indicated significant differences in color, aroma and astringency between wines made from grapes harvested from GLD-affected and unaffected vines. The impacts of GLD on yield and fruit and wine quality traits were variable between the seasons, with greater impacts observed during a cooler season, suggesting the influence of host plant × environment interactions on overall impacts of the disease.

  10. Impacts of Grapevine Leafroll Disease on Fruit Yield and Grape and Wine Chemistry in a Wine Grape (Vitis vinifera L.) Cultivar

    PubMed Central

    Gutha, Linga R.; Larsen, Richard C.; Henick-Kling, Thomas; Harbertson, James F.; Naidu, Rayapati A.

    2016-01-01

    Grapevine leafroll disease (GLD) is an economically important virus disease affecting wine grapes (Vitis vinifera L.), but little is known about its effect on wine chemistry and sensory composition of wines. In this study, impacts of GLD on fruit yield, berry quality and wine chemistry and sensory features were investigated in a red wine grape cultivar planted in a commercial vineyard. Own-rooted Merlot vines showing GLD symptoms and tested positive for Grapevine leafroll-associated virus 3 and adjacent non-symptomatic vines that tested negative for the virus were compared during three consecutive seasons. Number and total weight of clusters per vine were significantly less in symptomatic relative to non-symptomatic vines. In contrast to previous studies, a time-course analysis of juice from grapes harvested at different stages of berry development from symptomatic and non-symptomatic vines indicated more prominent negative impacts of GLD on total soluble solids (TSS) and berry skin anthocyanins than in juice pH and titratable acidity. Differences in TSS between grapes of symptomatic and non-symptomatic vines were more pronounced after the onset of véraison, with significantly lower concentrations of TSS in grapes from symptomatic vines throughout berry ripening until harvest. Wines made from grapes of GLD-affected vines had significantly lower alcohol, polymeric pigments, and anthocyanins compared to corresponding wines from grapes of non-symptomatic vines. Sensory descriptive analysis of 2010 wines indicated significant differences in color, aroma and astringency between wines made from grapes harvested from GLD-affected and unaffected vines. The impacts of GLD on yield and fruit and wine quality traits were variable between the seasons, with greater impacts observed during a cooler season, suggesting the influence of host plant × environment interactions on overall impacts of the disease. PMID:26919614

  11. Interactions of tea tannins and condensed tannins with proteins.

    PubMed

    Frazier, Richard A; Deaville, Eddie R; Green, Rebecca J; Stringano, Elisabetta; Willoughby, Ian; Plant, John; Mueller-Harvey, Irene

    2010-01-20

    Binding parameters for the interactions of four types of tannins: tea catechins, grape seed proanthocyanidins, mimosa 5-deoxy proanthocyanidins, and sorghum procyanidins (mDP=17), with gelatin and bovine serum albumin (BSA) have been determined from isothermal titration calorimetry data. Equilibrium binding constants determined for the interaction with gelatin were in the range 10(4) to 10(6) M(-1) and in the order: sorghum procyanidins > grape seed proanthocyanidins > mimosa 5-deoxy proanthocyanidins > tea catechins. Interaction with BSA was generally weaker, with equilibrium binding constants of < or =10(3)M(-1) for grape seed proanthocyanidins, mimosa 5-deoxy proanthocyanidins and tea catechins, and 10(4)M(-1) for the sorghum procyanidins. In all cases the interactions with proteins were exothermic and involved multiple binding sites on the protein. The data are discussed in relation to the structures and the known nutritional effects of the condensed tannins.

  12. Identification and characterization of microRNAs from Chinese pollination constant non-astringent persimmon using high-throughput sequencing.

    PubMed

    Luo, Yujie; Zhang, Xiaona; Luo, Zhengrong; Zhang, Qinglin; Liu, Jihong

    2015-01-21

    microRNAs (miRNAs) have been shown to play key roles in regulating gene expression at post-transcriptional level, but miRNAs associated with natural deastringency of Chinese pollination-constant nonastringent persimmon (CPCNA) have never been identified. In this study, two small RNA libraries established using 'Eshi No. 1' persimmon (Diospyros kaki Thunb.; CPCNA) fruits collected at 15 and 20 weeks after flowering (WAF) were sequenced through Solexa platform in order to identify miRNAs involved in deastringency of persimmon. A total of 6,258,487 and 7,634,169 reads were generated for the libraries at 15 and 20 WAF, respectively. Based on sequence similarity and hairpin structure prediction, 236 known miRNAs belonging to 65 miRNA families and 33 novel miRNAs were identified using persimmon transcriptome data. Sixty one of the characterized miRNAs exhibited pronounced difference in the expression levels between 15 and 20 WAF, 17 up-regulated and 44 down-regulated. Expression profiles of 12 conserved and 10 novel miRNAs were validated by stem loop qRT-PCR. A total of 198 target genes were predicted for the differentially expressed miRNAs, including several genes that have been reported to be implicated in proanthocyanidins (PAs, or called tannin) accumulation. In addition, two transcription factors, a GRF and a bHLH, were experimentally confirmed as the targets of dka-miR396 and dka-miR395, respectively. Taken together, the present data unraveled several important miRNAs in persimmon. Among them, miR395p-3p and miR858b may regulate bHLH and MYB, respectively, which are influenced by SPL under the control of miR156j-5p and in turn regulate the structural genes involved in PA biosynthesis. In addition, dka-miR396g and miR2911a may regulate their target genes associated with glucosylation and insolubilization of tannin precursors. All of these miRNAs might play key roles in the regulation of (de)astringency in persimmon fruits under normal development conditions.

  13. Protein Binding Capacity of Different Forages Tannin

    NASA Astrophysics Data System (ADS)

    Yusiati, L. M.; Kurniawati, A.; Hanim, C.; Anas, M. A.

    2018-02-01

    Eight forages of tannin sources(Leucaena leucocephala, Arachis hypogaea, Mimosa pudica, Morus alba L, Swietenia mahagoni, Manihot esculenta, Gliricidia sepium, and Bauhinia purpurea)were evaluated their tannin content and protein binding capacity. The protein binding capacity of tannin were determined using precipitation of bovine serum albumin (BSA). Swietenia mahagonihas higest total tannin level and condensed tannin (CT) compared with other forages (P<0.01). The Leucaena leucocephala has highest hydrolysable tannin (HT) level (P<0.01). The total and condensed tannin content of Swietenia mahagoni were 11.928±0.04 mg/100 mg and 9.241±0.02mg/100mg dry matter (DM) of leaves. The hydrolysable tannin content of Leucaena leucocephala was 5.338±0.03 mg/100 mg DM of leaves. Binding capacity was highest in Swietenia mahagoni and Leucaena leucocephala compared to the other forages (P<0.01). The optimum binding of BSA to tannin in Leucaena leucocephala and Swietenia mahagoniwere1.181±0.44 and 1.217±0.60mg/mg dry matter of leaves. The present study reports that Swietenia mahagoni has highest of tannin content and Leucaena leucocephala and Swietenia mahagoni capacity of protein binding.

  14. Effect of a grapevine shoot waste extract on red wine aromatic properties.

    PubMed

    Ruiz-Moreno, María J; Raposo, Rafaela; Puertas, Belén; Cuevas, Francisco J; Chinnici, Fabio; Moreno-Rojas, José M; Cantos-Villar, Emma

    2018-04-26

    The use of a grapevine shoot extract (VIN) is being studied as an alternative to sulfur dioxide (SO 2 ). VIN stabilizes anthocyanins and preserves polyphenolic compounds, and thus improves chromatic wine properties. In the current work, selected aroma compounds (esters, C13-norisoprenoids, oxidation and vine shoot related compounds), sensory analysis and the olfactometric profile were determined in the wines treated with VIN at two concentrations. Treatment with VIN hardly modified the content of esters and oxidation-related compounds in the wines. However, the high β-damascenone and isoeugenol content, and the increase in astringency at tasting in VIN wines were noteworthy, as were some odorant zones. All above were established as VIN markers after the chemometric data analysis. These date revealed that only the lowest dose tested may be recommended as a suitable alternative to SO 2 . Although some aromatic properties of these wines may change, these changes are not considered to affect negatively to the quality of the wines. These results are useful for wineries, which face to uncover aroma-related processes in the challenge of producing SO 2 free wines without detriment of its sensory properties. This article is protected by copyright. All rights reserved.

  15. Effect of different enological practices on skin and seed proanthocyanidins in three varietal wines.

    PubMed

    Busse-Valverde, Naiara; Gómez-Plaza, Encarna; López-Roca, Jose M; Gil-Muñoz, Rocio; Fernández-Fernández, Jose I; Bautista-Ortín, Ana B

    2010-11-10

    Proanthocyanidins are important for wine quality since they participate in astringency, bitterness and color. Given the localization of proanthocyanidins in the berry (skin and seeds), different methods have been developed that help to modulate the release of these phenolic compounds. In this study, the effect of two low prefermentative temperature techniques (cold soak and must freezing with dry ice) and the use of macerating enzymes has been studied during the vinification of three different varietal wines (Monastrell, Syrah and Cabernet Sauvignon) to assess their influence on wine proanthocyanidin concentration and composition. Syrah wines showed the lowest proanthocyanidin content, together with the lowest mDP and the highest percentage of galloylation in its proanthocyanidins. Monastrell and Cabernet Sauvignon wines showed similar proanthocyanidin concentration. The application of the low temperature prefermentative maceration (cold soak) was the most effective treatment, increasing the proanthocyanidin concentration in Monastrell and Cabernet Sauvignon wines although neither of the treatments had any effect on Syrah wines. As regards the effect of the different treatments on the proanthocyanidin composition, the results seem to indicate that the observed increases were mainly due to an increase in seed proanthocyanidins, even in the case of cold soak treatments, which occur in the absence of ethanol, suggesting that ethanol is not so crucial in the extraction of seed proanthocyanidins.

  16. Variations in oxygen and ellagitannins, and organoleptic properties of red wine aged in French oak barrels classified by a near infrared system.

    PubMed

    Michel, Julien; Albertin, Warren; Jourdes, Michael; Le Floch, Alexandra; Giordanengo, Thomas; Mourey, Nicolas; Teissedre, Pierre-Louis

    2016-08-01

    During wine aging in barrels, antioxidant molecules from wood, such as ellagitannins, are solubilized and react with wine molecules and oxygen. However, their concentrations are highly variable. Oxygen is an important factor, as it plays a role in wine parameters and organoleptic perceptions. Five barrel modalities were used; three polyphenol indices (IP), classified using the NIRS procedure, and three grain qualities. Barrels were equipped with windows to measure the oxygen using luminescence technology. The ellagitannin concentrations in the wine and its organoleptic properties were monitored. Oxygen concentrations decreased quickly during the first 8days of aging and this phenomenon was significantly more marked in barrels with a higher IP and medium grain. The ellagitannin concentrations were believed to be correlated with wood classification and oxygen consumption. Furthermore, the organoleptic properties were significantly impacted, as the wine with the lowest ellagitannin level was described as less astringent, bitter, woody, and smoky/toasty. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. The influence of cation exchange treatment on the final characteristics of red wines.

    PubMed

    Lasanta, Cristina; Caro, Ildefonso; Pérez, Luis

    2013-06-01

    Ion exchange technology has been applied to adjust the pH of red wine and improve its tartaric and oxidative stability. Ion exchange appears to be a useful technique to achieve these objectives. Regarding the effect of ion exchange on organoleptic characteristics and the quality of the obtained wines, a slight decrease in both anthocyanin and tannin contents was observed along with a small drop in the aromatic content. However, the treated wines had lower hue and higher colour intensity and gave better punctuations in the sensory evaluation. These results confirm that ion exchange is an interesting technique for application in red winemaking. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Tears of Wine

    ERIC Educational Resources Information Center

    Gugliotti, Marcos

    2004-01-01

    The unique occurrence of the upward motion of a thin film of wine, and its formation into drops inside the wall of a wine glass is explained. Evaporation of alcohol generates a surface tension gradient, moving the film of wine upwards on the internal sides of a wine glass, where it collects and forms into drops or tears.

  19. Salivary protein levels as a predictor of perceived astringency in model systems and solid foods.

    PubMed

    Fleming, Erin E; Ziegler, Gregory R; Hayes, John E

    2016-09-01

    Salivary protein difference value (SP D-value) is a quantitative measure of salivary protein replenishment, which reportedly relates to individual differences in perceived astringency. This in vitro measure is calculated as the difference in total salivary protein before (S1) and after (S2) stimulation with tannic acid, with a greater absolute value (S2-S1) indicating less protein replenishment. Others report that this measure predicts perceived astringency and liking of liquid model systems and beverages containing added polyphenols. Whether this relationship generalizes to astringent compounds other than polyphenols, or to solid foods is unknown. Here, the associations between SP D-values and perceived astringency and overall liking/disliking for alum and tannic acid (experiment 1) as well as solid chocolate-flavored compound coating with added tannic acid or grape seed extract (GSE) (experiment 2) were examined. In both experiments, participants (n=84 and 81, respectively) indicated perceived intensity of astringency, bitterness, sweetness, and sourness, and degree of liking of either aqueous solutions, or solid chocolate-flavored compound coating with added astringents. Data were analyzed via linear regression, and as discrete groups for comparison to prior work. Three discrete groups were formed based on first and third quartile splits of the SP D-value distribution: low (LR), medium (MR), and high responding (HR) individuals. In experiment 1, significantly higher mean astringency ratings were observed for the HR as compared to the LR/MR groups for alum and tannic acid, confirming and extending prior work. In experiment 2, significantly higher mean astringency ratings were also observed for HR as compared to LR groups in solid chocolate-flavored compound containing added tannic acid or GSE. Significant differences in liking were found between HR and LR groups for alum and tannic acid in water, but no significant differences in liking were observed for

  20. Salivary protein levels as a predictor of perceived astringency in model systems and solid foods

    PubMed Central

    Fleming, Erin E.; Ziegler, Gregory R.; Hayes, John E.

    2016-01-01

    Salivary protein difference value (SP D-value) is a quantitative measure of salivary protein replenishment, which reportedly relates to individual differences in perceived astringency. This in vitro measure is calculated as the difference in total salivary protein before (S1) and after (S2) stimulation with tannic acid, with a greater absolute value (S2-S1) indicating less protein replenishment. Others report this measure predicts perceived astringency and liking of liquid model systems and beverages containing added polyphenols. Whether this relationship generalizes to astringent compounds other than polyphenols, or to solid foods is unknown. Here, the associations between SP D-values and perceived astringency and overall liking/disliking for alum and tannic acid (experiment 1) as well as solid chocolate-flavored compound coating with added tannic acid or grape seed extract (GSE) (experiment 2) were examined. In both experiments, participants (n=84 and 81, respectively) indicated perceived intensity of astringency, bitterness, sweetness, and sourness, and degree of liking of either aqueous solutions, or solid chocolate-flavored compound coating with added astringents. Data were analyzed via linear regression, and as discrete groups for comparison to prior work. Three discrete groups were formed based on first and third quartile splits of the SP D-value distribution: low (LR), medium (MR), and high responding (HR) individuals. In experiment 1, significantly higher mean astringency ratings were observed for the HR as compared to the LR/MR groups for alum and tannic acid, confirming and extending prior work. In experiment 2, significantly higher mean astringency ratings were also observed for HR as compared to LR groups in solid chocolate-flavored compound containing added tannic acid or GSE. Significant differences in liking were found between HR and LR groups for alum and tannic acid in water, but no significant differences in liking were observed for chocolate

  1. Phenolic contents and antioxidant activities of major Australian red wines throughout the winemaking process.

    PubMed

    Ginjom, Irine R; D'Arcy, Bruce R; Caffin, Nola A; Gidley, Michael J

    2010-09-22

    Three Australian red wine types (Shiraz, Cabernet Sauvignon, and Merlot) were analyzed for antioxidant activity and a range of phenolic component contents using various spectral methods. More than half of the total phenolic compounds were tannins, whereas monomeric anthocyanins and flavonols were present in much lesser amounts (<10%). The evolution of phenolic contents and the respective antioxidant activities in wine samples from all stages of winemaking showed progressive changes toward those of commercial wines. The antioxidant activity of the wines in DPPH and ABTS assays was positively correlated with total phenolic contents and tannins. Comparisons of the three wine varieties based on their individual phenolic component groups and antioxidant activities showed limited differences between the different varieties. However, when all of the variables were combined in a principal component analysis, variety differentiation was observed. The three varieties of red wines all contained similar and high concentrations of antioxidants despite differences in grape variety/maturity and winemaking process, suggesting that related health benefits would accrue from all of the red wines studied.

  2. Oral astringent stimuli alter the enamel pellicle's ultrastructure as revealed by electron microscopy.

    PubMed

    Rehage, Melanie; Delius, Judith; Hofmann, Thomas; Hannig, Matthias

    2017-08-01

    This electron microscopic study aimed at investigating effects of oral astringent stimuli on the enamel pellicle's morphology. Pellicles were formed in situ within 30min on bovine enamel slabs, fixed to individuals' upper jaw splints. The pellicle-coated specimens were immersed in vitro in seven diverse astringent solutions and subsequently analyzed by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, as well as transmission electron microscopy (TEM). Four biocompatible astringents, namely the polyphenol epigallocatechin gallate, the metal salt iron(III) sulfate, the basic protein lysozyme, and the aminopolysaccharide chitosan, were additionally applied in situ. After rinsing the oral cavity with these compounds, the pellicle's ultrastructure was imaged by SEM and TEM, respectively. Untreated pellicle samples served as controls. Exposure to polyphenols and lysozyme induced particularly thicker and electron-denser pellicles in comparison to the control pellicle with similar characteristics in vitro and in situ. In contrast, acidic chitosan and metal salt solutions, respectively, revealed minor pellicle alterations. The incorporation of Fe and Al into the pellicles treated with the corresponding inorganic salts was verified by EDX analysis. Astringent-induced pellicle modifications were for the first time visualized by TEM. The ultrastructural alterations of the dental pellicle may partly explain the tooth-roughening effect caused by oral astringent stimuli. Astringents might modify the pellicle's protective properties against dental erosion, attrition, as well as bacterial adhesion, and by this means may influence tooth health. The findings may thus be particularly relevant for preventive dentistry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Formation and Accumulation of Acetaldehyde and Strecker Aldehydes during Red Wine Oxidation.

    PubMed

    Bueno, Mónica; Marrufo-Curtido, Almudena; Carrascón, Vanesa; Fernández-Zurbano, Purificación; Escudero, Ana; Ferreira, Vicente

    2018-01-01

    The main aim of the present work is to study the accumulation of acetaldehyde and Strecker aldehydes (isobutyraldehyde, 2-methylbutanal, isovaleraldehyde, methional, phenylacetaldehyde) during the oxidation of red wines, and to relate the patterns of accumulation to the wine chemical composition. For that, eight different wines, extensively chemically characterized, were subjected at 25°C to three different controlled O 2 exposure conditions: low (10 mg L -1 ) and medium or high (the stoichiometrically required amount to oxidize all wine total SO 2 plus 18 or 32 mg L -1 , respectively). Levels of volatile aldehydes and carbonyls were then determined and processed by different statistical techniques. Results showed that young wines (<2 years-old bottled wines) hardly accumulate any acetaldehyde regardless of the O 2 consumed. In contrast, aged wines (>3 years-old bottled wines) accumulated acetaldehyde while their content in SO 2 was not null, and the aged wine containing lowest polyphenols accumulated it throughout the whole process. Models suggest that the ability of a wine to accumulate acetaldehyde is positively related to its content in combined SO 2 , in epigallocatechin and to the mean degree of polymerization, and negatively to its content in Aldehyde Reactive Polyphenols (ARPs) which, attending to our models, are anthocyanins and small tannins. The accumulation of Strecker aldehydes is directly proportional to the wine content in the amino acid precursor, being the proportionality factor much higher for aged wines, except for phenylacetaldehyde, for which the opposite pattern was observed. Models suggest that non-aromatic Strecker aldehydes share with acetaldehyde a strong affinity toward ARPs and that the specific pattern of phenylacetaldehyde is likely due to a much reduced reactivity toward ARPs, to the possibility that diacetyl induces Strecker degradation of phenyl alanine and to the potential higher reactivity of this amino acid to some quinones

  4. Formation and Accumulation of Acetaldehyde and Strecker Aldehydes during Red Wine Oxidation

    PubMed Central

    Bueno, Mónica; Marrufo-Curtido, Almudena; Carrascón, Vanesa; Fernández-Zurbano, Purificación; Escudero, Ana; Ferreira, Vicente

    2018-01-01

    The main aim of the present work is to study the accumulation of acetaldehyde and Strecker aldehydes (isobutyraldehyde, 2-methylbutanal, isovaleraldehyde, methional, phenylacetaldehyde) during the oxidation of red wines, and to relate the patterns of accumulation to the wine chemical composition. For that, eight different wines, extensively chemically characterized, were subjected at 25°C to three different controlled O2 exposure conditions: low (10 mg L−1) and medium or high (the stoichiometrically required amount to oxidize all wine total SO2 plus 18 or 32 mg L−1, respectively). Levels of volatile aldehydes and carbonyls were then determined and processed by different statistical techniques. Results showed that young wines (<2 years-old bottled wines) hardly accumulate any acetaldehyde regardless of the O2 consumed. In contrast, aged wines (>3 years-old bottled wines) accumulated acetaldehyde while their content in SO2 was not null, and the aged wine containing lowest polyphenols accumulated it throughout the whole process. Models suggest that the ability of a wine to accumulate acetaldehyde is positively related to its content in combined SO2, in epigallocatechin and to the mean degree of polymerization, and negatively to its content in Aldehyde Reactive Polyphenols (ARPs) which, attending to our models, are anthocyanins and small tannins. The accumulation of Strecker aldehydes is directly proportional to the wine content in the amino acid precursor, being the proportionality factor much higher for aged wines, except for phenylacetaldehyde, for which the opposite pattern was observed. Models suggest that non-aromatic Strecker aldehydes share with acetaldehyde a strong affinity toward ARPs and that the specific pattern of phenylacetaldehyde is likely due to a much reduced reactivity toward ARPs, to the possibility that diacetyl induces Strecker degradation of phenyl alanine and to the potential higher reactivity of this amino acid to some quinones derived

  5. Formation and accumulation of acetaldehyde and Strecker aldehydes during red wine oxidation

    NASA Astrophysics Data System (ADS)

    Bueno, Mónica; Marrufo-Curtido, Almudena; Carrascón, Vanesa; Fernández-Zurbano, Purificación; Escudero, Ana; Ferreira, Vicente

    2018-02-01

    The main aim of the present work is to study the accumulation of acetaldehyde and Strecker aldehydes (isobutyraldehyde, 2-methylbutanal, isovaleraldehyde, methional, phenylacetaldehyde) during the oxidation of red wines, and to relate the patterns of accumulation to the wine chemical composition. For that, eight different wines, extensively chemically characterized, were subjected at 25°C to three different controlled O2 exposure conditions: low (10 mg L-1) and medium or high (the stoichiometrically required amount to oxidize all wine total SO2 plus 18 or 32 mg L-1, respectively). Levels of volatile aldehydes and carbonyls were then determined and processed by different statistical techniques. Results showed that young wines (<2 years-old bottled wines) hardly accumulate any acetaldehyde regardless of the O2 consumed. In contrast, aged wines (>3 years-old bottled wines) accumulated acetaldehyde while their content in SO2 was not null, and the aged wine containing lowest polyphenols accumulated it throughout the whole process. Models suggest that the ability of a wine to accumulate acetaldehyde is positively related to its content in combined SO2, in epigallocatechin and to the mean degree of polymerization, and negatively to its content in Aldehyde Reactive Polyphenols (ARPs) which, attending to our models, are anthocyanins and small tannins. The accumulation of Strecker aldehydes is directly proportional to the wine content in the amino acid precursor, being the proportionality factor much higher for aged wines, except for phenylacetaldehyde, for which the opposite pattern was observed. Models suggest that non-aromatic Strecker aldehydes share with acetaldehyde a strong affinity towards ARPs and that the specific pattern of phenylacetaldehyde is likely due to a much reduced reactivity towards ARPs, to the possibility that diacetyl induces Strecker degradation of phenyl alanine and to the potential higher reactivity of this amino acid to some quinones derived from

  6. Factors affecting skin tannin extractability in ripening grapes.

    PubMed

    Bindon, Keren A; Madani, S Hadi; Pendleton, Phillip; Smith, Paul A; Kennedy, James A

    2014-02-05

    The acetone-extractable (70% v/v) skin tannin content of Vitis vinifera L. cv. Cabernet Sauvignon grapes was found to increase during late-stage ripening. Conversely, skin tannin content determined following ethanol extraction (10, 20, and 50% v/v) did not consistently reflect this trend. The results indicated that a fraction of tannin became less extractable in aqueous ethanol during ripening. Skin cell walls were observed to become more porous during ripening, which may facilitate the sequestering of tannin as an adsorbed fraction within cell walls. For ethanol extracts, tannin molecular mass increased with advancing ripeness, even when extractable tannin content was constant, but this effect was negligible in acetone extracts. Reconstitution experiments with isolated skin tannin and cell wall material indicated that the selectivity of tannin adsorption by cell walls changed as tannin concentration increased. Tannin concentration, tannin molecular mass, and cell wall porosity are discussed as factors that may influence skin tannin extractability.

  7. Association between modification of phenolic profiling and development of wine color during alcohol fermentation.

    PubMed

    Li, Si-Yu; Liu, Pei-Tong; Pan, Qiu-Hong; Shi, Ying; Duan, Chang-Qing

    2015-04-01

    To solve the problem of wine color instability in western China, different additives (the maceration enzymes Vinozym G and Ex-color, yeasts VR5 and Red Star, and commercial tannins) were added during alcoholic fermentation of Syrah (Vitis vinifera L.). The phenolic profile and color characteristics of wine were examined using high performance liquid chromatography mass spectrometry and CIELAB, respectively. The results showed that the combination of the enzyme Ex-color with the Red Star yeast eased the release of non-anthocyanins from grape berries into wine, whereas the use of enzyme Vinozym G and VR5 yeast enhanced the concentration of anthocyanins and achieved a higher red hue (a* value) and a lower yellow hue (b* value) in the wine. The addition of commercial tannins greatly promoted the level of gallic acid in the wine and led to a relatively higher concentration of anthocyanins. Partial least-squares regression analysis was used to find out the major phenolics, which were in close relation with color parameters; principal component analysis was used to evaluate the contribution of different winemaking techniques to wine color. The combination of these 2 analytic methods indicated that Vinozym G and VR5 yeast together with commercial tannins should be an appropriate combination to enhance the stability of wine color during alcohol fermentation, which was related to a significant increase in cyanidin-3-O-(6-O-acetyl)-glucoside, cyanidin-3-O-(6-O-coumaryl)-glucoside, trans-peonidin-3-O-(6-O-coumaryl)-glucoside, trans-malvidin-3-O-(6-O-coumaryl)-glucoside, and malvidin-3-O-(6-O-acetyl)-glucoside-pyruvic acid, all of which played an important role in stabilizing wine color. © 2015 Institute of Food Technologists®

  8. Use of Multi-Intake Temporal Dominance of Sensations (TDS) to Evaluate the Influence of Cheese on Wine Perception.

    PubMed

    Galmarini, Mara V; Loiseau, Anne-Laure; Visalli, Michel; Schlich, Pascal

    2016-10-01

    Though the gastronomic sector recommends certain wine-cheese associations, there is little sensory evidence on how cheese influences the perception of wine. It was the aim of this study to dynamically characterize 4 wines as they would be perceived when consumed with and without cheese. The tasting protocol was based on multi-intake temporal dominance of sensations (TDS) coupled with hedonic rating. In the 1st session, 31 French wine and cheese consumers evaluated the wines (Pacherenc, Sancerre, Bourgogne, and Madiran) over 3 consecutive sips. In the following sessions, they performed the same task, but eating small portions of cheese (Epoisses, Comté, Roquefort, Crottin de Chavignol) between sips. All cheeses were tasted with all wines over 4 sessions. TDS data were mainly analyzed in terms of each attribute's duration of dominance by analysis of variance, multivariate analysis of variance, and canonical variate analysis. Results showed that cheese consumption had an impact (P < 0.1) on dominance duration of attributes and on preference for most wines. For example, in Madiran, all cheeses reduced dominance duration (P < 0.01) of astringency and sourness and increased duration of red fruit aroma. Although the number of consumers was small to make extended general conclusions on wine's preference, significant changes were observed before and after cheese intake. © 2016 Institute of Food Technologists®.

  9. 27 CFR 27.42 - Wines.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... TREASURY ALCOHOL IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER Tax On Imported Distilled Spirits, Wines, and Beer Wines § 27.42 Wines. All wines (including imitation, substandard, or artificial wine, and...

  10. 27 CFR 27.42 - Wines.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... TREASURY ALCOHOL IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER Tax On Imported Distilled Spirits, Wines, and Beer Wines § 27.42 Wines. All wines (including imitation, substandard, or artificial wine, and...

  11. 27 CFR 27.42 - Wines.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER Tax On Imported Distilled Spirits, Wines, and Beer Wines § 27.42 Wines. All wines (including imitation, substandard, or artificial wine, and...

  12. 27 CFR 27.42 - Wines.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER Tax On Imported Distilled Spirits, Wines, and Beer Wines § 27.42 Wines. All wines (including imitation, substandard, or artificial wine, and...

  13. Variability in tannin content, chemistry and activity in a diverse group of tannin containing sorghum cultivars.

    PubMed

    Kaufman, Rhett C; Herald, Thomas J; Bean, Scott R; Wilson, Jeff D; Tuinstra, Mitch R

    2013-03-30

    Tannins are large polyphenolic polymers and are known to bind proteins, limiting their digestibility, but are also excellent antioxidants. Numerous studies investigating the functional properties of sorghum tannin have been conducted by comparing grain samples from different sorghum lines without considering the other intrinsic characteristics of the grain. The purpose of this study was to remove the confounding intrinsic factors present in the endosperm so the effect of the tannins could be evaluated utilizing a unique decortication/reconstitution procedure. The tannin content of the 14 cultivars tested ranged from 2.3 to 67.2 catechin equivalents. The bran fractions were studied for their impact on protein binding and antioxidant capacity. Protein digestibility by pepsin ranged from 8% to 58% at the highest tannin level addition. Protein binding ranged from 3.11 to 16.33 g blue bovine serum albumin kg⁻¹ bran. Antioxidant capacity ranged from 81.33 to 1122.54 µmol Trolox equivalents g⁻¹ bran. High-performance size-exclusion chromatography detailed molecular size distributions of the tannin polymers and relationship to tannin functionality. The tannin content and composition play a significant role in determining tannin functionality. These differences will allow for selections of high-tannin sorghums with consideration of the biological activities of the tannins. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

  14. Influence of the temperature and oxygen exposure in red Port wine: A kinetic approach.

    PubMed

    Oliveira, Carla Maria; Barros, António S; Silva Ferreira, António César; Silva, Artur M S

    2015-09-01

    Although phenolics are recognized to be related with health benefits by limiting lipid oxidation, in wine, they are the primary substrates for oxidation resulting in the quinone by-products with the participation of transition metal ions. Nevertheless, high quality Port wines require a period of aging in either bottle or barrels. During this time, a modification of sensory properties of wines such as the decrease of astringency or the stabilization of color is recognized to phenolic compounds, mainly attributed to anthocyanins and derived pigments. The present work aims to illustrate the oxidation of red Port wine based on its phenolic composition by the effect of both thermal and oxygen exposures. A kinetic approach toanthocyanins degradation was also achieved. For this purpose a forced red Port wine aging protocol was performed at four different storage temperatures, respectively, 20, 30, 35 and 40°C, and two adjusted oxygen saturation levels, no oxygen addition (treatment I), and oxygen addition (treatment II). Three hydroxycinnamic esters, three hydroxycinnamic acids, three hydroxybenzoic acids, two flavan-3-ols, and six anthocyanins were quantitated weekly during 63days, along with oxygen consumption. The most relevant phenolic oxidation markers were anthocyanins and catechin-type flavonoids, which had the highest decreases during the thermal and oxidative red Port wine process. Both temperature and oxygen treatments affected the rate of phenolic degradation. In addition, temperature seems to influence mostly the phenolics kinetic degradation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Development of a fractionation method for the detection and identification of oak ellagitannins in red wines.

    PubMed

    García-Estévez, Ignacio; Escribano-Bailón, M Teresa; Rivas-Gonzalo, Julián C; Alcalde-Eon, Cristina

    2010-02-15

    During maturation and ageing in oak barrels wines improve their organoleptic properties. Ellagitannins can be released from wood to the wine and be involved in oxidation reactions and seem to influence the astringency and colour properties of the wine. Nevertheless, the ellagitannins levels are lower than those of other wine constituents and, consequently, they are not easily detected. This study has developed a two-step fractionation method consisting of a solid phase extraction in C-18 Sep-Pak cartridges followed by size exclusion chromatography in hand-packed Sephadex LH-20 minicolumn for the detection of oak ellagitannins in different types of wines. An HPLC method has also been developed which allows the separation of compounds with the same m/z ratios, facilitating the ellagitannin identification by means of the mass spectrometric analyses. The main oak ellagitannins (grandinin, vescalagin, roburin E and castalagin) were isolated, detected separately and identified in a spiked wine and in three real ones, proving the usefulness of the fractionation method. Copyright 2009 Elsevier B.V. All rights reserved.

  16. Sorption of polyphenolics (tannins) to natural soils

    USDA-ARS?s Scientific Manuscript database

    Tannins enter soil systems via rainfall through the leaf canopy, leaf litter decomposition, and root exudation and decomposition. For tannins released into soils, the relative importance of sorption to soil; chemical reactions with soil minerals; and biological decomposition is unknown. Determinin...

  17. Role of thin-layer chromatography in ascertaining Kashaya Rasa (astringent taste) in medicinal plants on the concept of Samana and Vichitra Pratyayarabdha principles of Ayurveda

    PubMed Central

    Kolhe, Rasika H.; Acharya, Rabinarayan; Shukla, Vinay J.

    2014-01-01

    Background: Pharmacodynamics, in Ayurveda has been described in terms of Rasadipanchaka. Rasa, on one side indicates the Bhautika composition of the drug and on the other side predicts the action. Different analytical techniques, pharmaceutical processes are being used in Ayurveda for the purpose of standardization of raw drugs. Aim: In this study an attempt has been made to apply chromatographic technique in determination of Kashaya (astringent) Rasa (taste). Materials and Methods: Two important Kashaya dominant drugs Kulattha (Dolichos biflorus Linn.) and Kanchanara (Bauhinia variegata Linn.), falling under Vichitra and Samana Pratyayarabdha category respectively, were subjected to physicochemical parameters and qualitative tests followed by High-Performance Thin-Layer Chromatography (HPTLC). In light of chromatographic fingerprinting; sample preparation protocol is modified to incorporate taste threshold in correlation. Column chromatography is used for first-level discrimination technique followed by HPTLC. Kashaya Rasa Dominant Zone (KsRDZ) was separated and subjected to TLC fingerprinting. The KsRDZ fraction was designated as Botanical Reference Material (BRM) in further analysis. Results: Ash value, Alcohol and water soluble extract value were more in B variegata as compared to D biflorus. Presence of tannin in both the samples was confirmed through qualitative test. The KsRDZ fraction separated at Rf 0.46 and 0.48 for Kulattha and Kanchanara respectively. Conclusion: The results showed that the planner chromatography technique seems very useful when BRM hypothesis was adjunct to method that explains the categorization according to traditional Rasa domain classification method. PMID:25558164

  18. Exogenously applied abscisic acid to Yan73 (V. vinifera) grapes enhances phenolic content and antioxidant capacity of its wine.

    PubMed

    Xi, Zhu-Mei; Meng, Jiang-Fei; Huo, Shan-Shan; Luan, Li-Ying; Ma, Li-Na; Zhang, Zhen-Wen

    2013-06-01

    Yan73 is a 'teinturier' red wine variety cultivated in China and widely used in winemaking to strengthen red wine colour. The objective of this study was to evaluate the effect of exogenous abscisic acid (ABA) applied to the grapevine cluster on the antioxidant capacity and phenolic content of the wine made from Yan73. Two hundred mg/l ABA was applied on Yan73 grapevine cluster during veraison. As they mature, these ABA-treated and untreated grape berries were transformed into wines, respectively, and the phenolic content and antioxidant capacity of these wines were compared. The results showed that phenolic content (total phenolics, tannins, flavonoids and anthocyanins) and antioxidant capacity were higher in the wine produced with ABA-treated Yan73 grapes than those in the wine from untreated grapes. Compared to Cabernet Sauvignon wine, Yan73 wine had higher phenolic content and stronger antioxidant capacity. These strongly suggest that exogenously applied ABA to Yan73 grapes can enhance phenolic content and antioxidant capacity of its wine, and Yan73 wine has the higher utilization value and potential for development.

  19. Chestnut astringent skin extract, an alpha-amylase inhibitor, retards carbohydrate absorption in rats and humans.

    PubMed

    Tsujita, Takahiro; Takaku, Takeshi; Suzuki, Tsuneo

    2008-02-01

    Inhibitors of carbohydrate-hydrolyzing enzyme play an important role to control postprandial blood glucose levels. In this paper, we investigated the effect of an ethanol extract from chestnut astringent skin (CAS) on alpha-amylase. Chestnut astringent skin extract strongly inhibited human and porcine pancreatic alpha-amylase. We also investigated the effect of CAS extract on carbohydrate absorption in rats and humans. Oral administration of CAS extract to normal rats fed corn starch (2 g/kg body weight), significantly suppressed the increase of blood glucose levels after starch loading in a dose-dependent manner. The effective dose of CAS extract required to achieve 20 and 40% suppression of the rise in blood glucose level was estimated to be 40 and 155 mg/kg body weight, respectively. Chestnut astringent skin extract also suppressed the rise in plasma insulin level and the fall in plasma non-esterified fatty acid level. In the type 2 diabetic rat model, CAS extract significantly suppressed the rise in blood glucose level after starch loading in a dose-dependent manner. Chestnut astringent skin extract also suppressed the rise in plasma glucose level after boiled rice loading in a dose-dependent manner in humans. The amount of CAS extract required to achieve 11 and 23% suppression in the rise in plasma glucose level was 300 and 600 mg/person, respectively. These results suggest that CAS extract retards absorption of carbohydrate and reduces post-prandial hyperglycemia.

  20. Spectroscopy analysis of phenolic and sugar patterns in a food grade chestnut tannin.

    PubMed

    Ricci, A; Lagel, M-C; Parpinello, G P; Pizzi, A; Kilmartin, P A; Versari, A

    2016-07-15

    Tannin of chestnut (Castanea sativa Mill.) wood, commonly used in winemaking was characterised with a spectroscopy qualitative approach that revealed its phenolic composition: several vibrational diagnostic bands assigned using the Attenuated Total Reflectance-Infrared Spectroscopy, and fragmentation patterns obtained using the Laser-Desorption-Ionization Time-of-Flight technique evidenced polygalloylglucose, e.g. castalagin/vescalagin-like structures as the most representative molecules, together with sugar moieties. The implication of these findings on winemaking application and the potential influence of the chemical structure on the sensory properties of wine are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Sensory characteristics changes of red Grenache wines submitted to different oxygen exposures pre and post bottling.

    PubMed

    Caillé, Soline; Samson, Alain; Wirth, Jérémie; Diéval, Jean-Baptiste; Vidal, Stéphane; Cheynier, Véronique

    2010-02-15

    It is widely accepted that oxygen contributes to wine development by impacting its colour, aromatic bouquet, and mouth-feel properties. The wine industry can now also take advantage of engineered solutions to deliver known amounts of oxygen into bottles through the closures. This study was aimed at monitoring the influence of oxygen pick-up, before (micro-oxygenation, Mox) and after (nano-oxygenation) bottling, on wine sensory evolution. Red Grenache wines were prepared either by flash release (FR) or traditional soaking (Trad) and with or without Mox during elevage (FR+noMox, FR+Mox, Trad+noMox, Trad+Mox). The rate of nano oxygenation was controlled by combining consistent oxygen transfer rate (OTR) closures and different oxygen controlled storage conditions. Wine sensory characteristics were analyzed by sensory profile, at bottling (T0) and after 5 and 10 months of ageing, by a panel of trained judges. Effects of winemaking techniques and OTR were analyzed by multivariate analysis (principal component analysis and agglomerative hierarchical clustering) and analysis of variance. Results showed that, at bottling, Trad wines were perceived more animal and FR wines more bitter and astringent. Mox wines showed more orange shade. At 5 and 10 months, visual and olfactory differences were observed according to the OTR levels: modalities with higher oxygen ingress were darker and fruitier but also perceived significantly less animal than modalities with lower oxygen. Along the 10 months of ageing, the influence of OTR became more important as shown by increased significance levels of the observed differences. As the mouth-feel properties of the wines were mainly dictated by winemaking techniques, OTR had only little impact on "in mouth" attributes. Copyright 2009 Elsevier B.V. All rights reserved.

  2. Effect of wine inhibitors on the proteolytic activity of papain from Carica papaya L. latex.

    PubMed

    Benucci, Ilaria; Esti, Marco; Liburdi, Katia

    2015-01-01

    The influence of potential inhibitors naturally present in wine on the proteolytic activity of papain from Carica papaya latex was investigated to evaluate its applicability in white wine protein haze stabilization. Enzymatic activity was tested against a synthetic tripeptide chromogenic substrate in wine-like acidic medium that consisted of tartaric buffer (pH 3.2) supplemented with ethanol, free sulfur dioxide (SO2 ), grape skin and seed tannins within the average ranges of concentrations that are typical in wine. The diagnosis of inhibition type, performed with the graphical method, demonstrated that all of tested wine constituents were reversible inhibitors of papain. The strongest inhibition was exerted by free SO2 , which acted as a mixed-type inhibitor, similar to grape skin and seed tannins. Finally, when tested in table white wines, the catalytic activity of papain, even when if it was ascribable to the hyperbolic behavior of Michaelis-Menten equation, was determined to be strongly affected by free SO2 and total phenol level. © 2014 American Institute of Chemical Engineers.

  3. Garnacha Tintorera-based sweet wines: chromatic properties and global phenolic composition by means of UV-Vis spectrophotometry.

    PubMed

    Figueiredo-González, M; Cancho-Grande, B; Simal-Gándara, J

    2013-09-01

    Valdeorras (the N.W. corner of Spain) wants to promote the production and marketing of new sweet wines. The present work represents the first study on sweet wines manufactured with red grapes Vitis vinifera L. Garnacha Tintorera, a teinturier cultivar. Two different red sweet wines were elaborated: the first one was made with dried grapes; Vitis vinifera L. Garnacha Tintorera has excellent potential to produce wines from raisined grapes; the second one, a fortified sweet wine aged in oak barrels. Different red Garnacha Tintorera-based wines (a dry base wine, GBW; a naturally sweet wine, GNSW; and a fortified sweet wine, GFSW) were characterized. Chromatic characteristics and phenolic compounds were established by spectrophotometric methods in order to assess the technology of Garnacha Tintorera-based sweet wines. High molecular weight brown polymers, produced during the grape drying process and isolated from sweet wines by the dialysis process, were responsible for the brown colour of sweet wines. As a consequence, yellowness of sweet wines was also higher which was confirmed by colorimetric indexes. With respect to phenolic content, GFSW presented the lowest content because the maceration-alcoholic fermentation was stopped through the addition of alcohol before the diffusion of red pigments from skins to must was complete. GNSW presented the highest phenolic content due to the concentration effect resulting from evaporation of water from the grapes. Anthocyanins of sweet wines were polymerised in great extent. The percentage of polymerised tannins was sufficient to guarantee the aging process of sweet wines. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Effect of cluster thinning and prohexadione calcium applications on phenolic composition and sensory properties of red wines.

    PubMed

    Avizcuri-Inac, José-Miguel; Gonzalo-Diago, Ana; Sanz-Asensio, Jesús; Martínez-Soria, María-Teresa; López-Alonso, Miguel; Dizy-Soto, Marta; Echávarri-Granado, José-Federico; Vaquero-Fernández, Luis; Fernández-Zurbano, Purificación

    2013-02-06

    The overall objective of this study was to investigate the effect of manual cluster thinning (CT) and the application of the growth regulator Prohexadione calcium (ProCa) on the phenolic composition and the sensory profile of Tempranillo and Grenache wines produced from treated vines in La Rioja (Spain). ProCa was applied at preblooming and CT was carried out at veraison in two consecutive years. Different physicochemical parameters and analyses of phenolic compounds were carried out in control, CT and ProCa grapes and wines and wine sensory was performed. Thinning treatments decreased crop yield, besides ProCa application reduced berry size, and berry weight. Color and phenolic composition of Grenache and Tempranillo wines in general were affected by thinning treatments, with an increase in anthocyanin, flavanol and flavonol concentrations. In sensory analysis, wines obtained from thinned vines presented higher values for several aromatic (e.g., white and yellow fruits, fresh flowers) and taste attributes (i.e., astringency, bitternes, persistence). CT and ProCa treatments resulted in an improvement in wine quality. In general, similar results in phenolic composition, sensory properties and quality of wines were obtained by manual and chemical cluster thinning. ProCa as a growth regulator may be an option for a quality vitiviniculture.

  5. Hydrolyzable tannin analysis in food.

    PubMed

    Arapitsas, Panagiotis

    2012-12-01

    The discovery of plant polyphenols in food is perhaps one of the biggest breakthroughs in modern food science. Plant polyphenols are known for their role in food quality and safety, since they contribute significantly to taste, flavour, colour, stability etc., while they are increasingly recognised as important factors in long-term health, contributing towards reducing the risk of chronic disease. Almost 200years ago, hydrolyzable tannins (HTs) were the first group of plant polyphenols subjected to analytical chemical research. Despite the lack of commercially available standards, food analysis research offers a wealth of papers dealing with extraction optimisation, identification and quantification of HTs. The object of this review is to summarise analytical chemistry applications and the tools currently used for the analysis of HTs in food. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Polyphenols-enriched Chardonnay white wine and sparkling Pinot Noir red wine identically prevent early atherosclerosis in hamsters.

    PubMed

    Auger, Cyril; Rouanet, Jean-Max; Vanderlinde, Regina; Bornet, Aurélie; Décordé, Kelly; Lequeux, Nadine; Cristol, Jean-Paul; Teissedre, Pierre-Louis

    2005-12-14

    The effects of a white wine enriched with polyphenols (PEWW) from Chardonnay grapes and of a sparkling red wine (SRW) from Pinot Noir and Chardonnay grapes were studied for the first time on early atherosclerosis in hamsters. Animals were fed an atherogenic diet for 12 weeks. They received by force-feeding PEWW, SRW, ethanol 12% (ETH), or water as control (mimicking a moderate consumption of approximately 2 red wine glasses per meal for a 70 kg human). Plasma cholesterol concentrations were lower in groups that consumed PEWW and SRW accompanied by an increase in the ratio apo A-1/apo B. Liver-specific activities of superoxide dismutase and catalase were significantly increased by PEWW (38 and 16%, respectively) and by SRW (48 and 15%, respectively). PEWW and ETH significantly increased plasma antioxidant capacity and vitamin A concentrations. Aortic fatty streak area (AFSA) was significantly strongly reduced in the groups receiving PEWW (85%) and SRW (89%) in comparison with the control. AFSA was reduced by ethanol to a lesser extent (58%). These data suggest that tannins from the phenolics-enriched white wine induce a protective effect against early atherosclerosis comparable to that produced by sparkling red wine containing tanins and anthocyanins and dissociated from the antioxidant action of these compounds.

  7. Measuring protection of aromatic wine thiols from oxidation by competitive reactions vs wine preservatives with ortho-quinones.

    PubMed

    Nikolantonaki, Maria; Magiatis, Prokopios; Waterhouse, Andrew L

    2014-11-15

    Quinones are central intermediates in wine oxidation that can degrade the quality of wine by reactions with varietal thiols, such as 3-sulfanylhexanol, decreasing desirable aroma. Protection by wine preservatives (sulphur dioxide, glutathione, ascorbic acid and model tannin, phloroglucinol) was assessed by competitive sacrificial reactions with 4-methyl-1,2-benzoquinone, quantifying products and ratios by HPLC-UV-MS. Regioselectivity was assessed by product isolation and identification by NMR spectroscopy. Nucleophilic addition reactions compete with two electron reduction of quinones by sulphur dioxide or ascorbic acid, and both routes serve as effective quenching pathways, but minor secondary products from coupled redox reactions between the products and reactants are also observed. The wine preservatives were all highly reactive and thus all very protective against 3-sulfanylhexanol loss to the quinone, but showed only additive antioxidant effects. Confirmation of these reaction rates and pathways in wine is needed to assess the actual protective action of each tested preservative. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Effect of micro-oxygenation on sensory characteristics and consumer preference of Cabernet Sauvignon wine.

    PubMed

    Parpinello, Giuseppina Paola; Plumejeau, François; Maury, Chantal; Versari, Andrea

    2012-04-01

    The main objective of this study was to improve the structure of a Cabernet Sauvignon red wine in a short period of time by micro-oxygenation (MOX) at high rates (25 and 50 mL L(-1) month(-1) ), the effects of which were evaluated based on sensory characteristics and consumer preference. Sensory data were analysed by principal component analysis, discriminant analysis and ordinal logistic regression (OLR). MOX led to significant differences in the colour, colour stability and phenolic compounds of wine. Sensory characteristics also changed through MOX treatment, and wine experts were able to discriminate between MOX-treated and untreated samples, with olfactory intensity, complexity, astringency and roundness being the main discriminating characteristics. Ordinal logistic regression enabled identification of the sensory characteristics that drove consumer preference. MOX at high rates improved the sensory characteristics of wine and may therefore be considered a valid technique for obtaining structured wines in a short period of time, i.e. within just a few months after the vintage. The results highlight the need for (i) careful selection of the MOX dosage rate and duration (the 25 mL L(-1) month(-1) dose for 6 days provided the best result) and (ii) continuous monitoring of the MOX treatment. Copyright © 2011 Society of Chemical Industry.

  9. Analysis of polymeric phenolics in red wines using different techniques combined with gel permeation chromatography fractionation.

    PubMed

    Guadalupe, Zenaida; Soldevilla, Alberto; Sáenz-Navajas, María-Pilar; Ayestarán, Belén

    2006-04-21

    A multiple-step analytical method was developed to improve the analysis of polymeric phenolics in red wines. With a common initial step based on the fractionation of wine phenolics by gel permeation chromatography (GPC), different analytical techniques were used: high-performance liquid chromatography-diode array detection (HPLC-DAD), HPLC-mass spectrometry (MS), capillary zone electrophoresis (CZE) and spectrophotometry. This method proved to be valid for analyzing different families of phenolic compounds, such as monomeric phenolics and their derivatives, polymeric pigments and proanthocyanidins. The analytical characteristics of fractionation by GPC were studied and the method was fully validated, yielding satisfactory statistical results. GPC fractionation substantially improved the analysis of polymeric pigments by CZE, in terms of response, repeatability and reproducibility. It also represented an improvement in the traditional vanillin assay used for proanthocyanidin (PA) quantification. Astringent proanthocyanidins were also analyzed using a simple combined method that allowed these compounds, for which only general indexes were available, to be quantified.

  10. 27 CFR 24.215 - Wine or wine products not for beverage use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Wine or wine products not... AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.215 Wine or wine products not for beverage use. (a) General. Wine, or wine products made from wine...

  11. Wine and endothelial function.

    PubMed

    Caimi, G; Carollo, C; Lo Presti, R

    2003-01-01

    In recent years many studies have focused on the well-known relationship between wine consumption and cardiovascular risk. Wine exerts its protective effects through various changes in lipoprotein profile, coagulation and fibrinolytic cascades, platelet aggregation, oxidative mechanisms and endothelial function. The last has earned more attention for its implications in atherogenesis. Endothelium regulates vascular tone by a delicate balancing among vasorelaxing (nitric oxide [NO]) and vasoconstrincting (endothelins) factors produced by endothelium in response to various stimuli. In rat models, wine and other grape derivatives exerted an endothelium-dependent vasorelaxing capacity especially associated with the NO-stimulating activity of their polyphenol components. In experimental conditions, reservatrol (a stilbene polyphenol) protected hearts and kidneys from ischemia-reperfusion injury through antioxidant activity and upregulation of NO production. Wine polyphenols are also able to induce the expression of genes involved in the NO pathway within the arterial wall. The effects of wine on endothelial function in humans are not yet clearly understood. A favorable action of red wine or dealcoholized wine extract or purple grape juice on endothelial function has been observed by several authors, but discrimination between ethanol and polyphenol effects is controversial. It is, however likely that regular and prolonged moderate wine drinking positively affects endothelial function. The beneficial effects of wine on cardiovascular health are greater if wine is associated with a healthy diet. The most recent nutritional and epidemiologic studies show that the ideal diet closely resembles the Mediterranean diet.

  12. Towards high resolution ^1H NMR spectra of tannin colloidal aggregates

    NASA Astrophysics Data System (ADS)

    Mirabel, M.; Glories, Y.; Pianet, I.; Dufourc, E. J.

    1999-10-01

    The time dependent colloidal formation of tannins in hydro-alcoholic medium has been studied by 1H-NMR. Line broadening observed with time can be cancelled by making use of magic angle sample spinning (MASS) thus yielding sharp lines that allow structural studies. We used as an example catechin, a constitutive monomer of Bordeaux young red wine tannins. Chemical shift variations of polyphenol protons allow monitoring the time course of aggregation. La formation de tanins colloïdaux au cours du temps, en milieu hydroalcoolique, a été suivie par RMN-^1H. Un élargissement marqué des résonances est observé et peut être supprimé par la rotation de l'échantillon à l'angle magique ce qui ouvre tout un champ d'études structurales sur ces composés colloïdaux. L'exemple proposé est celui de la catéchine, monomère constitutif de tannins présents en grande quantité dans les vins rouges jeunes de Bordeaux. Des variations du déplacement chimique de certains protons polyphénoliques permettent de suivre l'évolution temporelle de l'agrégation.

  13. Interaction of gut microflora with tannins in feeds

    NASA Astrophysics Data System (ADS)

    Goel, Gunjan; Puniya, A. K.; Aguilar, C. N.; Singh, Kishan

    2005-11-01

    Tannins (hydrolyzable and condensed) are water-soluble polyphenolic compounds that exert antinutritional effects on ruminants by forming complexes with dietary proteins. They limit nitrogen supply to animals, besides inhibiting the growth and activity of ruminal microflora. However, some gastrointestinal microbes are able to break tannin-protein complexes while preferentially degrading hydrolyzable tannins (HTs). Streptococcus gallolyticus, Lonepinella koalarum and Selenomonas ruminantium are the dominant bacterial species that have the ability to degrade HTs. These tanninolytic microorganisms possess tannin-degrading ability and have developed certain mechanisms to tolerate tannins in feeds. Hence, selection of efficient tanninolytic microbes and transinoculation among animals for long-term benefits become areas of intensive interest. Here, we review the effects of tannins on ruminants, the existence and significance of tannin-degrading microorganisms in diverse groups of animals and the mechanisms that tannin-degrading microorganisms have developed to counter the toxic effects of tannin.

  14. Interaction of gut microflora with tannins in feeds.

    PubMed

    Goel, Gunjan; Puniya, A K; Aguilar, C N; Singh, Kishan

    2005-11-01

    Tannins (hydrolyzable and condensed) are water-soluble polyphenolic compounds that exert antinutritional effects on ruminants by forming complexes with dietary proteins. They limit nitrogen supply to animals, besides inhibiting the growth and activity of ruminal microflora. However, some gastrointestinal microbes are able to break tannin-protein complexes while preferentially degrading hydrolyzable tannins (HTs). Streptococcus gallolyticus, Lonepinella koalarum and Selenomonas ruminantium are the dominant bacterial species that have the ability to degrade HTs. These tanninolytic microorganisms possess tannin-degrading ability and have developed certain mechanisms to tolerate tannins in feeds. Hence, selection of efficient tanninolytic microbes and transinoculation among animals for long-term benefits become areas of intensive interest. Here, we review the effects of tannins on ruminants, the existence and significance of tannin-degrading microorganisms in diverse groups of animals and the mechanisms that tannin-degrading microorganisms have developed to counter the toxic effects of tannin.

  15. Maceration with stems contact fermentation: effect on proanthocyanidins compounds and color in Primitivo red wines.

    PubMed

    Suriano, Serafino; Alba, Vittorio; Tarricone, Luigi; Di Gennaro, Domenico

    2015-06-15

    Three Primitivo (Vitis vinifera, cv.) red wines were microvinified by means of different winemaking technologies: no stem-contact fermentation destemming 100% of grapes (D100); stem-contact fermentation destemming 75%, 50% of grapes (D75-D50) respectively. The objectives of this work were to improve proanthocyanidins content in wine, to monitor the relationships between anthocyanins/tannins and to detect the effects on the polymerization state of polyphenols after 12 months storage of wines. D100 showed higher anthocyanins content but lower color intensity and phenolic compounds content with respect to the theses D75 and D50, the last two showing lower anthocyanins content due their partial adsorption by grape stems during the fermentation. D75 gave the best results in terms of anthocyanins/color intensity balance and showed a better wine tannin component with respect to D50. Moreover after 12 months storage D50 reached a more advanced and stable polymerization state of colored pigments than the other wines. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Sensory descriptors, hedonic perception and consumer’s attitudes to Sangiovese red wine deriving from organically and conventionally grown grapes

    PubMed Central

    Pagliarini, Ella; Laureati, Monica; Gaeta, Davide

    2013-01-01

    In recent years, produce obtained from organic farming methods (i.e., a system that minimizes pollution and avoids the use of synthetic fertilizers and pesticides) has rapidly increased in developed countries. This may be explained by the fact that organic food meets the standard requirements for quality and healthiness. Among organic products, wine has greatly attracted the interest of the consumers. In the present study, trained assessors and regular wine consumers were respectively required to identify the sensory properties (e.g., odor, taste, flavor, and mouthfeel sensations) and to evaluate the hedonic dimension of red wines deriving from organically and conventionally grown grapes. Results showed differences related mainly to taste (sour and bitter) and mouthfeel (astringent) sensations, with odor and flavor playing a minor role. However, these differences did not influence liking, as organic and conventional wines were hedonically comparable. Interestingly, 61% of respondents would be willing to pay more for organically produced wines, which suggests that environmentally sustainable practices related to wine quality have good market prospects. PMID:24348447

  17. Partial shading of Cabernet Sauvignon and Shiraz vines altered wine color and mouthfeel attributes, but increased exposure had little impact.

    PubMed

    Joscelyne, Venetia L; Downey, Mark O; Mazza, Marica; Bastian, Susan E P

    2007-12-26

    Few studies have investigated the impact of vine shading on the sensory attributes of the resultant wine. This study examines the effects of canopy exposure levels on phenolic composition plus aroma, flavor, and mouthfeel aspects in wine. Wines were made from Cabernet Sauvignon and Shiraz grapes (Vitis vinifera L.) subjected to different levels of canopy exposure in a commercial vineyard in the Sunraysia region, Victoria, Australia. Canopy exposure treatments included control (standard vineyard practice), exposed (achieved with a foliage wire 600 mm above the top cordon), highly exposed (using a foliage wire with leaf plucking in the fruit zone), and shaded treatment (using 70% shade-cloth). Spectral and descriptive analyses showed that levels of anthocyanins, other phenolics, and perceived astringency were lower in wines made from shaded fruit; however, the reverse was generally not observed in wines of exposed and highly exposed fruit. Descriptive analysis also showed wines from the shaded fruit were different from other treatments for a number of flavor and aroma characters. These findings have implications for vineyard management practices.

  18. Sensory descriptors, hedonic perception and consumer's attitudes to Sangiovese red wine deriving from organically and conventionally grown grapes.

    PubMed

    Pagliarini, Ella; Laureati, Monica; Gaeta, Davide

    2013-01-01

    In recent years, produce obtained from organic farming methods (i.e., a system that minimizes pollution and avoids the use of synthetic fertilizers and pesticides) has rapidly increased in developed countries. This may be explained by the fact that organic food meets the standard requirements for quality and healthiness. Among organic products, wine has greatly attracted the interest of the consumers. In the present study, trained assessors and regular wine consumers were respectively required to identify the sensory properties (e.g., odor, taste, flavor, and mouthfeel sensations) and to evaluate the hedonic dimension of red wines deriving from organically and conventionally grown grapes. Results showed differences related mainly to taste (sour and bitter) and mouthfeel (astringent) sensations, with odor and flavor playing a minor role. However, these differences did not influence liking, as organic and conventional wines were hedonically comparable. Interestingly, 61% of respondents would be willing to pay more for organically produced wines, which suggests that environmentally sustainable practices related to wine quality have good market prospects.

  19. Check-All-That-Apply (CATA), Sorting, and Polarized Sensory Positioning (PSP) with Astringent Stimuli

    PubMed Central

    Fleming, Erin E.; Ziegler, Gregory R.; Hayes, John E.

    2015-01-01

    Multiple rapid sensory profiling techniques have been developed as more efficient alternatives to traditional sensory descriptive analysis. Here, we compare the results of three rapid sensory profiling techniques – check-all-that-apply (CATA), sorting, and polarized sensory positioning (PSP) – using a diverse range of astringent stimuli. These rapid methods differ in their theoretical basis, implementation, and data analyses, and the relative advantages and limitations are largely unexplored. Additionally, we were interested in using these methods to compare varied astringent stimuli, as these compounds are difficult to characterize using traditional descriptive analysis due to high fatigue and potential carry-over. In the CATA experiment, subjects (n=41) were asked to rate the overall intensity of each stimulus as well as to endorse any relevant terms (from a list of 13) which characterized the sample. In the sorting experiment, subjects (n=30) assigned intensity-matched stimuli into groups 1-on-1 with the experimenter. In the PSP experiment, (n=41) subjects first sampled and took notes on three blind references (‘poles’) before rating each stimulus for its similarity to each of the 3 poles. Two-dimensional perceptual maps from correspondence analysis (CATA), multidimensional scaling (sorting), and multiple factor analysis (PSP) were remarkably similar, with normalized RV coefficients indicating significantly similar plots, regardless of method. Agglomerative hierarchical clustering of all data sets using Ward’s minimum variance as the linkage criteria showed the clusters of astringent stimuli were approximately based on the respective class of astringent agent. Based on the descriptive CATA data, it appears these differences may be due to the presence of side tastes such as bitterness and sourness, rather than astringent sub-qualities per se. Although all three methods are considered ‘rapid,’ our prior experience with sorting suggests it is best

  20. Trends in wine microbiology.

    PubMed

    Ramón, D

    1997-12-01

    During the last few years many winemakers have started to use pure Saccharomyces cerevisiae strains, frequently isolated from their own geographical regions, to produce wines of more reproductable quality. This microbiological simplification has opened the way for the genetic modification of wine yeast strains. This review concerns the application of molecular techniques in oenology, not only from the point of view of the construction of recombinant strains but also for the study of the population dynamics of wine fermentations.

  1. Effect of micro-oxygenation on color and anthocyanin-related compounds of wines with different phenolic contents.

    PubMed

    Cano-López, Marta; Pardo-Mínguez, Francisco; Schmauch, Gregory; Saucier, Cedric; Teissedre, Pierre-Louis; López-Roca, Jose María; Gómez-Plaza, Encarna

    2008-07-23

    Several factors may affect the results obtained when micro-oxygenation is applied to red wines, the most important being the moment of application, the doses of oxygen, and the wine phenolic characteristics. In this study, three red wines, made from Vitis vinifera var. Monastrell (2005 vintage) and with different phenolic characteristics, were micro-oxygenated to determine as to how this technique affected the formation of new pigments in the wines and their chromatic characteristics. The results indicated that the different wines were differently affected by micro-oxygenation. In general, the micro-oxygenated wines had a higher percentage of new anthocyanin-derived pigments, being that this formation is more favored in the wines with the highest total phenol content. These compounds, in turn, significantly increased the wine color intensity. The wine with the lowest phenolic content was less influenced by micro-oxygenation, and the observed evolution in the degree of polymerization of tannins suggested that it might have suffered overoxygenation.

  2. Volatile and sensory profiling of Shiraz wine in response to alcohol management: comparison of harvest timing versus technological approaches.

    PubMed

    Longo, Rocco; Blackman, John W; Antalick, Guillaume; Torley, Peter J; Rogiers, Suzy Y; Schmidtke, Leigh M

    2018-07-01

    The aim of this study was to compare the volatile and sensory profiles of Australian Shiraz red wines produced by several methods to achieve alcohol concentrations of 10.5 and 13.5% v/v. These levels were considerably lower contents than the commercial wine (16-17% v/v) that was produced from this vineyard site. Wines were produced by: (i) harvest timing (19.3, 24 and 29.3 Brix); (ii) blending equal proportions of early harvest (19.3 Brix) and late harvest wines (29.3 Brix); and (iii) dealcoholization using reverse osmosis followed by a membrane contactor. Dealcoholization caused a significant loss of volatile compounds, particularly esters, while the blending treatment had an averaging effect on most analytes. Sensory descriptive analysis of treatments with 10.5% v/v alcohol showed that the perception of the herbaceous attribute was more intense in the early harvest wines in comparison to the dealcoholized wines, while those of dark fruit, raisin/prune, astringency and alcohol were lower. No sensory differences were found amongst the 13.5% v/v wines, except for alcohol. Sensory and compositional data were modelled by means of Common Dimension (ComDim) multi-block analysis and indicated which chemical components are important to the perceived wine sensory properties. Insights from this study will provide knowledge that may be applied to control or moderate both unripe sensory attributes in addition to a deficiency of ripe fruit aromas or mouthfeel characteristics in reduced-alcohol red wines. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Synthesis and stable isotope dilution assay of ethanethiol and diethyl disulfide in wine using solid phase microextraction. Effect of aging on their levels in wine.

    PubMed

    Belancic Majcenovic, Andrea; Schneider, Rémi; Lepoutre, Jean-Paul; Lempereur, Valérie; Baumes, Raymond

    2002-11-06

    Ethanethiol and diethyl disulfide (DEDS) most often occurred at levels above their olfactive threshold in wines with nauseous sulfur-linked smells. As ethanethiol is very oxidizable and chemically reactive, a stable isotopic dilution analysis of both ethanethiol and its disulfide in wines using solid phase microextraction and GC-MS was developed. The latter involved the determination of the proportion of DEDS formed by oxidation of the thiol during the analysis conditions, which was obtained by the use of two differently labeled disulfide standards. An original synthesis of labeled ethanethiol standards in conditions minimizing oxidation was developed, and the corresponding labeled diethyl disulfides were obtained from these thiols. This analytical method was used to follow the levels of these sulfur compounds during aging in a young red wine spiked with ethanethiol and added with enological tannins, with or without oxygen addition. The total levels of these two sulfur compounds were shown to decrease steadily after 60 days of aging, up to 83%. The effect of oxygen sped this decrease, but the effect of enological tannins was very slight. Residual ethanethiol was detected in its disulfide form from approximately 36% in the nonoxygenated wines to 69% in the oxygenated samples.

  4. Systematic identification of yeast proteins extracted into model wine during aging on the yeast lees.

    PubMed

    Rowe, Jeffrey D; Harbertson, James F; Osborne, James P; Freitag, Michael; Lim, Juyun; Bakalinsky, Alan T

    2010-02-24

    Total protein and protein-associated mannan concentrations were measured, and individual proteins were identified during extraction into model wines over 9 months of aging on the yeast lees following completion of fermentations by seven wine strains of Saccharomyces cerevisiae. In aged wines, protein-associated mannan increased about 6-fold (+/-66%), while total protein only increased 2-fold (+/-20%), which resulted in a significantly greater protein-associated mannan/total protein ratio for three strains. A total of 219 proteins were identified among all wine samples taken over the entire time course. Of the 17 "long-lived" proteins detected in all 9 month samples, 13 were cell wall mannoproteins, and four were glycolytic enzymes. Most cytosolic proteins were not detected after 6 months. Native mannosylated yeast invertase was assayed for binding to wine tannin and was found to have a 10-fold lower affinity than nonglycosylated bovine serum albumin. Enrichment of mannoproteins in the aged model wines implies greater solution stability than other yeast proteins and the possibility that their contributions to wine quality may persist long after bottling.

  5. 27 CFR 27.42 - Wines.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Wines. 27.42 Section 27.42... TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER Tax On Imported Distilled Spirits, Wines, and Beer Wines § 27.42 Wines. All wines (including imitation, substandard, or artificial wine, and...

  6. Multifunctional porous solids derived from tannins

    NASA Astrophysics Data System (ADS)

    Celzard, Alain; Fierro, Vanessa; Pizzi, Antonio; Zhao, Weigang

    2013-03-01

    Tannins are extremely valuable, non toxic, wood extractives combining reactivity towards aldehydes, low cost, natural origin and easy handling. When polymerized in the presence of suitable chemicals including blowing agent, ultra lightweight rigid tannin-based foams are obtained. If pyrolyzed under inert gas, reticulated carbon foams having the same pore structure and the same density are obtained. The most remarkable features of tannin-based foams are the following: mechanical resistance similar to, or higher than, that of commercial phenolic foams, tuneable pore size and permeability, infusibility, very low thermal conductivity, cheapness, ecological character, high resistance to flame and to chemicals. Carbon foams have even better properties and are also electrically conducting. Consequently, various applications are suggested for organic foams: cores of sandwich composite panels, sound and shock absorbers and thermal insulators, whereas carbon foams can be used as porous electrodes, filters for molten metals and corrosive chemicals, catalyst supports and adsorbents.

  7. Fate of tannins in Corsican pine litter.

    PubMed

    Nierop, Klaas G J; Verstraten, Jacobus M

    2006-12-01

    Tannins are ubiquitous in higher plants and also in litter and soils where they affect many biogeochemical processes. Despite this well-recognized role, their fate in litter and mineral soils is hardly known, as often only trace amounts, if any, are measured. In this study, we conducted an incubation experiment with Corsican pine litter to which known amounts of tannic acid (TA) or condensed tannins (CTs) from Corsican pine were added. Using Folin-Ciocalteu as a measure for total phenolics and HCl-butanol as an assay specific for CTs, acetone/water extractable phenolics and tannins decreased with time towards very low levels. Application of thermally assisted hydrolysis and methylation to litter before and after acetone/water extraction revealed that TA concentration decreased. By contrast, CTs remained to a great extent in the litter and could not be extracted suggesting that they were tightly bound.

  8. Co-occurrence of tannin and tannin-less vacuoles in sensitive plants.

    PubMed

    Fleurat-Lessard, Pierrette; Béré, Emile; Lallemand, Magali; Dédaldéchamp, Fabienne; Roblin, Gabriel

    2016-05-01

    Vacuoles of different types frequently coexist in the same plant cell, but the duality of the tannin/tannin-less vacuoles observed in Mimosa pudica L. is rare. In this plant, which is characterized by highly motile leaves, the development and original features of the double vacuolar compartment were detailed in primary pulvini from the young to the mature leaf stage. In young pulvini, the differentiation of tannin vacuoles first occurred in the epidermis and progressively spread toward the inner cortex. In motor cells of nonmotile pulvini, tannin deposits first lined the membranes of small vacuole profiles and then formed opaque clusters that joined together to form a large tannin vacuole (TV), the proportion of which in the cell was approximately 45%. At this stage, transparent vacuole profiles were rare and small, but as the parenchyma cells enlarged, these profiles coalesced to form a transparent vacuole with a convexity toward the larger-sized tannin vacuole. When leaf motility began to occur, the two vacuole types reached the same relative proportion (approximately 30%). Finally, in mature cells displaying maximum motility, the large transparent colloidal vacuole (CV) showed a relative proportion increasing to approximately 50%. At this stage, the proportion of the tannin vacuole, occurring in the vicinity of the nucleus, decreased to approximately 10%. The presence of the condensed type of tannins (proanthocyanidins) was proven by detecting their fluorescence under UV light and by specific chemical staining. This dual vacuolar profile was also observed in nonmotile parts of M. pudica (e.g., the petiole and the stem). Additional observations of leaflet pulvini showing more or less rapid movements showed that this double vacuolar structure was present in certain plants (Mimosa spegazzinii and Desmodium gyrans), but absent in others (Albizzia julibrissin, Biophytum sensitivum, and Cassia fasciculata). Taken together, these observations strongly suggest that a

  9. Persimmon breeding in Japan for pollination-constant non-astringent (PCNA) type with marker-assisted selection

    PubMed Central

    Sato, Akihiko; Yamada, Masahiko

    2016-01-01

    Oriental persimmon (Diospyros kaki) originated in Eastern Asia, and many indigenous cultivars have been developed in China, Japan, and Korea. These cultivars are classified into four groups based on their natural astringency loss on the tree and seed formation: pollination-constant non-astringent (PCNA), pollination-variant non-astringent (PVNA), pollination-constant astringent (PCA), and pollination-variant astringent (PVA). PCNA is the most desirable type because the fruit can be eaten without any postharvest treatment; therefore, one of the goals of our persimmon breeding programs is to release superior PCNA cultivars. The PCNA genotype is recessive to the other three non-PCNA genotypes, and PCNA-type F1 offspring are obtained exclusively from crosses among PCNA genotypes. Moreover, the number of superior PCNA cross-parents have been limited. In the late 1980s, inbreeding depression became obvious, especially in terms of fruit size, tree vigor, and productivity. To mitigate the inbreeding, a backcross program using PCNA [(non-PCNA × PCNA) × PCNA] was started in 1990. This process, however, was inefficient because only 15% of the offspring were PCNA, and all offspring had to be grown to the fruiting stage. Therefore, molecular markers linked to the PCNA locus were developed for discriminating PCNA offspring. A molecular marker linked to Chinese PCNA has also been developed. PMID:27069391

  10. Persimmon breeding in Japan for pollination-constant non-astringent (PCNA) type with marker-assisted selection.

    PubMed

    Sato, Akihiko; Yamada, Masahiko

    2016-01-01

    Oriental persimmon (Diospyros kaki) originated in Eastern Asia, and many indigenous cultivars have been developed in China, Japan, and Korea. These cultivars are classified into four groups based on their natural astringency loss on the tree and seed formation: pollination-constant non-astringent (PCNA), pollination-variant non-astringent (PVNA), pollination-constant astringent (PCA), and pollination-variant astringent (PVA). PCNA is the most desirable type because the fruit can be eaten without any postharvest treatment; therefore, one of the goals of our persimmon breeding programs is to release superior PCNA cultivars. The PCNA genotype is recessive to the other three non-PCNA genotypes, and PCNA-type F1 offspring are obtained exclusively from crosses among PCNA genotypes. Moreover, the number of superior PCNA cross-parents have been limited. In the late 1980s, inbreeding depression became obvious, especially in terms of fruit size, tree vigor, and productivity. To mitigate the inbreeding, a backcross program using PCNA [(non-PCNA × PCNA) × PCNA] was started in 1990. This process, however, was inefficient because only 15% of the offspring were PCNA, and all offspring had to be grown to the fruiting stage. Therefore, molecular markers linked to the PCNA locus were developed for discriminating PCNA offspring. A molecular marker linked to Chinese PCNA has also been developed.

  11. Port-wine stain

    MedlinePlus

    ... Laser therapy is most successful in removing port-wine stains. It is the only method that can destroy the tiny blood vessels in the skin without causing much damage to the skin. The exact type ... on the person's age, skin type, and particular port-wine stain.

  12. Interaction between Wine Phenolic Acids and Salivary Proteins by Saturation-Transfer Difference Nuclear Magnetic Resonance Spectroscopy (STD-NMR) and Molecular Dynamics Simulations.

    PubMed

    Ferrer-Gallego, Raúl; Hernández-Hierro, José Miguel; Brás, Natércia F; Vale, Nuno; Gomes, Paula; Mateus, Nuno; de Freitas, Victor; Heredia, Francisco J; Escribano-Bailón, María Teresa

    2017-08-09

    The interaction between phenolic compounds and salivary proteins is highly related to the astringency perception. Recently, it has been proven the existence of synergisms on the perceived astringency when phenolic acids were tested as mixtures in comparison to individual compounds, maintaining constant the total amount of the stimulus. The interactions between wine phenolic acids and the peptide fragment IB7 12 have been studied by saturation-transfer difference (STD) NMR spectroscopy. This technique provided the dissociation constants and the percentage of interaction between both individual and mixtures of hydroxybenzoic and hydroxycinnamic acids and the model peptide. It is noteworthy that hydroxybenzoic acids showed higher affinity for the peptide than hydroxycinnamic acids. To obtain further insights into the mechanisms of interaction, molecular dynamics simulations have been performed. Results obtained not only showed the ability of these compounds to interact with salivary proteins but also may justify the synergistic effect observed in previous sensory studies.

  13. Powdered hide model for vegetable tanning II. hydrolyzable tannin

    USDA-ARS?s Scientific Manuscript database

    Vegetable tannages employ both condensed and hydrolyzable tannins. As part of our exploration of tanning mechanisms, we reported last year on interactions of the condensed tannin, quebracho, with powdered hide. In this study, the interactions of chestnut extract, a hydrolyzable tannin, with powdere...

  14. Association between taste receptor (TAS) genes and the perception of wine characteristics.

    PubMed

    Carrai, Maura; Campa, Daniele; Vodicka, Pavel; Flamini, Riccardo; Martelli, Irene; Slyskova, Jana; Jiraskova, Katerina; Rejhova, Alexandra; Vodenkova, Sona; Canzian, Federico; Bertelli, Alberto; Dalla Vedova, Antonio; Bavaresco, Luigi; Vodickova, Ludmila; Barale, Roberto

    2017-08-23

    Several studies have suggested a possible relationship between polymorphic variants of the taste receptors genes and the acceptance, liking and intake of food and beverages. In the last decade investigators have attempted to link the individual ability to taste 6-n-propylthiouracil (PROP) and the sensations, such as astringency and bitterness, elicited by wine or its components, but with contradictory results. We have used the genotype instead of the phenotype (responsiveness to PROP or other tastants), to test the possible relation between genetic variability and the perception of wine characteristic in 528 subjects from Italy and the Czech Republic. We observed several interesting associations, among which the association between several TAS2R38 gene single nucleotide polymorphisms (P = 0.002) and the TAS2R16-rs6466849 polymorphism with wine sourness P = 0.0003). These associations were consistent in both populations, even though the country of origin was an important factor in the two models, thus indicating therefore that genetics alongside cultural factors also play a significant role in the individual liking of wine.

  15. Effect of Saccharomyces strains on the quality of red wines aged on lees.

    PubMed

    Loira, I; Vejarano, R; Morata, A; Ricardo-da-Silva, J M; Laureano, O; González, M C; Suárez-Lepe, J A

    2013-08-15

    Ageing on lees involves ageing the wine in contact with yeast cells after fermentation. If combined with the addition of oak chips, it can soften the wood flavour and increase the aromatic complexity of wine. The aim of the present work is to optimise both ageing techniques through selection of an adequate Saccharomyces cerevisiae strain. The study lasted 6 months and content of polysaccharides, anthocyanins, proanthocyanidins, volatile compounds, colour parameters and sensory analysis, were periodically evaluated. Among the strains tested, G37 showed the highest release of polysaccharides (24.4±5.5 mg l(-1)). Vanillin, syringaldehyde and furfuryl alcohol increased with ageing time in 7VA2 treatment. The wine aged with CTPL14 strain presented fewer monomeric and oligomeric proanthocyanidins (12.4±0.6 and 83.4±8.3 mg l(-1), respectively), and showed the lowest astringency and bitterness sensations. Results show an improvement in the sensory profile of the red wine aged with a combination of these two techniques. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Role of protein concentration and protein-saliva interactions in the astringency of whey proteins at low pH.

    PubMed

    Kelly, M; Vardhanabhuti, B; Luck, P; Drake, M A; Osborne, J; Foegeding, E A

    2010-05-01

    Whey protein beverages are adjusted to pH <4.5 to enhance clarity and stability, but this pH level is also associated with increased astringency. The goal of this investigation was to determine the effects of protein concentration on astringency and interactions between whey and salivary proteins. Whey protein beverages containing 0.25 to 13% (wt/wt) beta-lactoglobulin and 0.017% (wt/wt) sucralose at pH 2.6 to 4.2 were examined using descriptive sensory analysis. Controls were similar pH phosphate buffers at phosphate concentrations equivalent to the amount of phosphoric acid required to adjust the pH of the protein solution. Changes in astringency with protein concentration depended on pH. At pH 3.5, astringency significantly increased with protein concentration from 0.25 to 4% (wt/wt) and then remained constant from 4 to 13% (wt/wt). Conversely, at pH 2.6, astringency decreased with an increase in protein concentration [0.5-10% (wt/wt)]. This suggests a complex relationship that includes pH and buffering capacity of the beverages. Furthermore, saliva flow rates increased with increasing protein concentrations, showing that the physiological conditions in the mouth change with protein concentration. Maximum turbidity of whey protein-saliva mixtures was observed between pH 4.6 and 5.2. Both sensory evaluation and in vitro study of interactions between beta-LG and saliva indicate that astringency of whey proteins is a complex process determined by the extent of aggregation occurring in the mouth, which depends on the whey protein beverage pH and buffering capacity in addition to saliva flow rate. Copyright 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  17. Impact of concentration of ellagitannins in oak wood on their levels and organoleptic influence in red wine.

    PubMed

    Michel, Julien; Jourdes, Michael; Silva, Maria A; Giordanengo, Thomas; Mourey, Nicolas; Teissedre, Pierre-Louis

    2011-05-25

    Some wood substances such as ellagitannins can be extracted during wine aging in oak barrels. The level of these hydrolyzable tannins in wine depends of some parameters of oak wood. Their impact on the organoleptic perception of red wine is poorly known. In our research, oak staves were classified in three different groups according to their level of ellagitannins estimated by NIRS (near infrared spectroscopy) online procedure (Oakscan). First, the ellagitannin level and composition were determine for each classified stave and an excellent correlation between the NIRS classification (low, medium and high potential level of ellagitannin) and the ellagitannin content estimated by HPLC-UV was found. Each different group of NIRS classified staves was then added to red wine during its aging in a stainless tank, and the extraction and evolution of the ellagitannins were monitored. A good correlation between the NIRS classification and the concentration of ellagitannins in red wine aging in contact with the classified staves was observed. The influence of levels of ellagitannins on the resulting wine perception was estimated by a trained judge's panel, and it reveals that the level of ellagitannins in wine has an impact on the roundness and amplitude of the red wine.

  18. Activity, purification, and analysis of condensed tannins

    USDA-ARS?s Scientific Manuscript database

    As a class of plant polyphenolic compounds contained in some forages (i.e., sanfoin, big trefoil, birdfoot trefoil), condensed tannins (CTs), also referred to as proanthocyanidins (PAs), exhibit a variety of biological effects on ruminants and on the dairy farm nitrogen cycle. Interest in CTs stems ...

  19. Science Study Aids 5: Tannin - Nature's Filter.

    ERIC Educational Resources Information Center

    Boeschen, John; Randall, John M.

    This publication is the fifth in a series of seven supplementary investigative materials for use in secondary science classes providing up-to-date research-related investigations. This unit is structured for grade levels 9 through 12. It is concerned with the removal of heavy divalent metals from water with the use of tannin-containing…

  20. Modulation of in vitro rumen biohydrogenation by Cistus ladanifer tannins compared with other tannin sources.

    PubMed

    Costa, Mónica; Alves, Susana P; Cabo, Ângelo; Guerreiro, Olinda; Stilwell, George; Dentinho, Maria T; Bessa, Rui Jb

    2017-01-01

    Tannins are polyphenolic compounds able to modify the ruminal biohydrogenation (BH) of unsaturated fatty acids, but their activity may vary among different tannin sources. The effect of rockrose (Cistus ladanifer) on BH has never been compared with other more common tannin sources. Tannin extracts (100 g kg -1 substrate dry matter) from chestnut (CH), quebracho (QB), grape seed (GS) and rockrose (CL) were incubated in vitro for 6 h with ruminal fluid using as substrate a feed containing 60 g kg -1 of sunflower oil. A control treatment with no added tannins was also included. Compared with the control, GS and CL, but not CH and QB, increased (P < 0.05) the disappearance of c9,c12-18:2 with a consequent larger production of c9,t11-18:2 and t11-18:1. However, no differences among treatments (P > 0.05) were observed for the disappearance of c9-18:1 and c9,c12,c15-18:3. The production of 18:0 was not different (P > 0.05) among treatments, although its proportion in the total BH products was lower (P < 0.05) for GS than for the other treatments. Condensed tannins from GS and, to a lesser extent, from CL stimulate the first steps of BH, without a clear inhibition of 18:0 production. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  1. Inoculation of tannin-degrading bacteria into novel hosts increases performance on tannin-rich diets.

    PubMed

    Kohl, Kevin D; Stengel, Ashley; Dearing, M Denise

    2016-06-01

    It has been hypothesized that herbivores host tannin-degrading bacteria (TDB) to overcome the toxic challenges posed by plant tannins. While TDB have been isolated from the guts of numerous mammals, their functional significance to their hosts has never been explicitly tested. We introduced TDB into lab rats, which do not host TDB, and measured host performance on tannin-rich diets. We first isolated three species of TDB, Escherichia coli, Bacillus subtilis and Enterococcus faecalis, from the guts of the desert woodrat (Neotoma lepida), which regularly feeds on tannin-rich plants. Then, we inoculated isolated TDB, as well as full woodrat microbial communities into laboratory rats. A control group was inoculated with sterilized woodrat faeces. Recipient lab rats were fed increasing concentrations of tannic acid, and we monitored tannic acid intake, body mass and liver damage as measured by serum alanine aminotransferase activity. Lab rats given TDB as isolates or full communities exhibited increased tannic acid intake, higher maintenance of body mass and lower indicators of liver damage compared with control animals. These differences were maintained when the trial was repeated after 6 weeks of feeding on tannin-free diets. Our results are the first to demonstrate that TDB significantly increase host performance on tannin-rich diets. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  2. Tannins and Tannin-Related Derivatives Enhance the (Pseudo-)Halogenating Activity of Lactoperoxidase.

    PubMed

    Gau, Jana; Prévost, Martine; Van Antwerpen, Pierre; Sarosi, Menyhárt-Botond; Rodewald, Steffen; Arnhold, Jürgen; Flemmig, Jörg

    2017-05-26

    Several hydrolyzable tannins, proanthocyanidins, tannin derivatives, and a tannin-rich plant extract of tormentil rhizome were tested for their potential to regenerate the (pseudo-)halogenating activity, i.e., the oxidation of SCN - to hypothiocyanite - OSCN, of lactoperoxidase (LPO) after hydrogen peroxide-mediated enzyme inactivation. Measurements were performed using 5-thio-2-nitrobenzoic acid in the presence of tannins and related substances in order to determine kinetic parameters and to trace the LPO-mediated - OSCN formation. The results were combined with docking studies and molecular orbital analysis. The - OSCN-regenerating effect of tannin derivatives relates well with their binding properties toward LPO as well as their occupied molecular orbitals. Especially simple compounds like ellagic acid or methyl gallate and the complex plant extract were found as potent enzyme-regenerating compounds. As the (pseudo-)halogenating activity of LPO contributes to the maintenance of oral bacterial homeostasis, the results provide new insights into the antibacterial mode of action of tannins and related compounds. Furthermore, chemical properties of the tested compounds that are important for efficient enzyme-substrate interaction and regeneration of the - OSCN formation by LPO were identified.

  3. Biodegradability of tannin-containing wastewater from leather industry.

    PubMed

    He, Qiang; Yao, Kai; Sun, Danhong; Shi, Bi

    2007-08-01

    Tannins occur commonly in the wastewaters from forestry, plant medicine, paper and leather industries. The treatment of this kind of wastewaters, including settling and biodegradation, is usually difficult because tannins are highly soluble in water and would inhibit the growth of microorganisms in activated sludge. The objective of this study is to investigate biodegradability of tannin-containing wastewaters, so as to characterize the pollution properties of such wastewaters and provide a reference for their biological treatment in wastewater treatment plants. The research was typified by using the wastewater collected from vegetable tanning process in leather industry. A model was developed to describe the activated sludge process, and the biodegradation kinetics of vegetable tanning wastewater (VET wastewater) was studied. It was found that the biodegradability of tannin-containing wastewater varies heavily with the content of tannins in wastewater. The biodegradation of VET wastewater with tannin content around 4,900 mg/l occurred inefficiently due to the inhibition of tannins to the activated sludge process, and only 34.7% of biodegradation extent was reached in 14 days of incubation. The optimal biodegradability of VET wastewater was observed when its tannin content was diluted to 490 mg/l, where the COD and tannin removals reached 51.3% and 45.1% respectively in 6 days. Hence, it is suggested that a proper control of tannin content is necessary to achieve an effective biodegradation of tannin-containing wastewaters in wastewater treatment plants.

  4. Tannin-assisted aggregation of natively unfolded proteins

    NASA Astrophysics Data System (ADS)

    Zanchi, D.; Narayanan, T.; Hagenmuller, D.; Baron, A.; Guyot, S.; Cabane, B.; Bouhallab, S.

    2008-06-01

    Tannin-protein interactions are essentially physical: hydrophobic and hydrogen-bond-mediated. We explored the tannin-assisted protein aggregation on the case of β-casein, which is a natively unfolded protein known for its ability to form micellar aggregates. We used several tannins with specified length. Our SAXS results show that small tannins increase the number of proteins per micelle, but keeping their size constant. It leads to a tannin-assisted compactization of micelles. Larger tannins, with linear dimensions greater than the crown width of micelles, lead to the aggregation of micelles by a bridging effect. Experimental results can be understood within a model where tannins are treated as effective enhancers of hydrophobic attraction between specific sites in proteins.

  5. Non-targeted glycosidic profiling of international wines using neutral loss-high resolution mass spectrometry.

    PubMed

    Barnaba, C; Dellacassa, E; Nicolini, G; Nardin, T; Serra, M; Larcher, R

    2018-07-06

    Many metabolites naturally occur as glycosides, since sugar moieties can be crucial for their biological activity and increase their water solubility. In the plant kingdom they may occur as glycosides or sugar esters, depending on precursor chemical structure, and in wine they have traditionally attracted attention due to their organoleptic properties, such as astringency and bitterness, and because they affect the colour and aroma of wines. A new approach directed at detailed description of glycosides in a large selection of monovarietal wines (8 samples each of Pinot Blanc, Muller Thurgau, Riesling, Traminer, Merlot, Pinot Noir and Cabernet Sauvignon) was developed by combining high performance liquid chromatography with high resolution tandem mass spectrometry. Analytical separation was performed on an Accucore™ Polar Premium LC column, while mass analysis was performed in negative ion mode with an non-targeted screening approach, using a Full MS/AIF/NL dd-MS 2 experiment at a resolving power of 140,000 FWHM. Over 280 glycoside-like compounds were detected, of which 133 (including low-molecular weight phenols, flavonoids and monoterpenols) were tentatively identified in the form of pentose (6), deoxyhexose (17), hexose (73), hexose-pentose (16), hexose-deoxyhexose (7), dihexose (5) and hexose ester (9) derivatives. It was not possible to univocally define the corresponding chemical structure for the remaining 149 glycosides. Non-parametric statistical analysis showed it was possible to well characterise the glycosylated profile of all red and Traminer wines, while the identified glycosides were almost entirely lacking in Pinot Blanc, Riesling and Muller Thurgau wines. Also Tukey's Honestly Significant Difference test (p < 0.05) and Principal Component Analysis confirmed that it was possible to almost entirely distinguish the selected red wines from each other according to their glycosylated profile. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. 27 CFR 27.59 - Wines.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... TREASURY ALCOHOL IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER General Requirements Marking and Labeling of Wines and Beer § 27.59 Wines. All imported wines containing not less than 7 percent and not...

  7. 27 CFR 27.59 - Wines.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... TREASURY ALCOHOL IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER General Requirements Marking and Labeling of Wines and Beer § 27.59 Wines. All imported wines containing not less than 7 percent and not...

  8. 27 CFR 27.59 - Wines.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER General Requirements Marking and Labeling of Wines and Beer § 27.59 Wines. All imported wines containing not less than 7 percent and not...

  9. 27 CFR 27.59 - Wines.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER General Requirements Marking and Labeling of Wines and Beer § 27.59 Wines. All imported wines containing not less than 7 percent and not...

  10. Responses of primate taste cortex neurons to the astringent tastant tannic acid.

    PubMed

    Critchley, H D; Rolls, E T

    1996-04-01

    In order to advance knowledge of the neural control of feeding, we investigated the cortical representation of the taste of tannic acid, which produces the taste of astringency. It is a dietary component of biological importance particularly to arboreal primates. Recordings were made from 74 taste responsive neurons in the orbitofrontal cortex. Single neurons were found that were tuned to respond to 0.001 M tannic acid, and represented a subpopulation of neurons that was distinct from neurons responsive to the tastes of glucose (sweet), NaCl (salty), HCl (sour), quinine (bitter) and monosodium glutamate (umami). In addition, across the population of 74 neurons, tannic acid was as well represented as the tastes of NaCl, HCl quinine or monosodium glutamate. Multidimensional scaling analysis of the neuronal responses to the tastants indicates that tannic acid lies outside the boundaries of the four conventional taste qualities (sweet, sour, bitter and salty). Taken together these data indicate that the astringent taste of tannic acid should be considered as a taste quality, which receives a separate representation from sweet, salt, bitter and sour in the primate cortical taste areas.

  11. Preliminary Reconnaissance of West Astringent Creek Thermal Area, Yellowstone National Park

    NASA Astrophysics Data System (ADS)

    Fairley, J. P., Jr.; Villegas, G.; Aunan, M. M.; Lindsey, C.; Sorensen, A.; Larson, P. B.

    2016-12-01

    The West Astringent Creek Thermal Area (WACTA) is one of the newest thermal areas in Yellowstone National Park (YNP). Thermal activity in the headwaters region of Astringent Creek, on the southeast edge of Sour Creek Dome, was rst noted in 1985; subsequent developments included the appearance of a high-temperature (104C) hydrothermal fumarole (which later metamorphosed into a mud volcano) and an area of tree-kill due to rising ground temperatures [Hutchinson, 1996]. We conducted a preliminary exploration of the hydrothermal area through visual evaluation of the spatial extent, location of the features, and nature of the hydrothermal area. 16 features were chosen based upon the following criteria: 1) initial appearance, 2) location in the thermal area, 3) location with respect to each other, and 4) accessibility. From these features we collected in-situ temperature and pH, as well as aqueous samples for geochemical analysis of cations, and deuterium and oxygen isotopes. With the information collected we will make a brief description of the thermal area and present a basis to conduct future research to obtain an amplified characterization of the WACTA.

  12. Vine vigor components and its variability - relationship to wine composition

    NASA Astrophysics Data System (ADS)

    Lafontaine, Magali; Tittmann, Susanne; Stoll, Manfred

    2015-04-01

    It was pointed out that a high spatial variability for canopy size and yield would exist within a vineyard but a high temporal stability over the years was observed. Furthermore, a greater variability in grape phenolics than in sugars and pH was detected within a vineyard. But the link between remote sensing indices and quality parameters of grapes is still unclear. Indeed, though in red grape varieties anthocyanins content was spatially negatively correlated to vigor parameters, it seemed that yield, Normalized Difference Vegetation Index (NDVI) and Plant Cell Density (PCD) indices were poorly correlated. Moreover, the link to quality parameters of wines remains uncertain. It was shown that more vigorous vines would lead to wines with less tannins while anthocyanins in wines would be highest when the vines were balanced but the question is if vine size or architecture, yield or nitrogen assimilation would play major contribution to those differences. The general scope of our project was to provide further knowledge on the relationship between vigor parameters and wine composition and relate these to the information gained by remote sensing. Variability in a 0.15 ha vineyard of Pinot noir planted in 2003 and grafted on SO4 rootstock at Geisenheim (Germany) was followed. Vine vigor was assessed manually for each of the 400 vines (cane number, pruning weight, trunk diameter) together with yield parameters (number of bunches per vine, crop yield). Leaf composition was assessed with a hand-held optical sensor (Multiplex3® [Mx3] (Force-A, Orsay, France) based on chlorophyll fluorescence screening providing information on leaf chlorophyll (SFR_G) and nitrogen (NBI_G) content. A micro-scale winemaking of single vines with a 3 factorial design on yield (L low, M middle, H high), SFRG (L, M, H) and canopy size (pruning weight, trunk diameter) (L, M, H) was performed for 2013 and 2014 to completely reflect variability. Wine tannin concentration represented the highest

  13. The kinetics of oxygen and SO2 consumption by red wines. What do they tell about oxidation mechanisms and about changes in wine composition?

    PubMed

    Carrascón, Vanesa; Vallverdú-Queralt, Anna; Meudec, Emmanuelle; Sommerer, Nicolas; Fernandez-Zurbano, Purificación; Ferreira, Vicente

    2018-02-15

    This work seeks to understand the kinetics of O 2 and SO 2 consumption of air-saturated red wine as a function of its chemical composition, and to describe the chemical changes suffered during the process in relation to the kinetics. Oxygen Consumption Rates (OCRs) are faster with higher copper and epigallocatechin contents and with higher absorbance at 620nm and slower with higher levels of gallic acid and catechin terminal units in tannins. Acetaldehyde Reactive Polyphenols (ARPs) may be key elements determining OCRs. It is confirmed that SO 2 is poorly consumed in the first saturation. Phenylalanine, methionine and maybe, cysteine, seem to be consumed instead. A low SO 2 consumption is favoured by low levels of SO 2 , by a low availability of free SO 2 caused by a high anthocyanin/tannin ratio, and by a polyphenolic profile poor in epigallocatechin and rich in catechin-rich tannins. Wines consuming SO 2 efficiently consume more epigallocatechin, prodelphinidins and procyanidins. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Chemical and sensory characterisation of Sangiovese red wines: comparison between biodynamic and organic management.

    PubMed

    Parpinello, Giuseppina Paola; Rombolà, Adamo Domenico; Simoni, Marco; Versari, Andrea

    2015-01-15

    The effects of biodynamic production practices on composition and sensory attributes of Sangiovese wines were examined for 2 years (2009 and 2010) in a vineyard that was converted from organic (ORG) to biodynamic (BDN) viticulture. During the first year (2009), the BDN wines were characterised by low alcohol strength, colour intensity, total polyphenols, monomeric anthocyanins and catechin. Conversely, the second year BDN wines differed from the organic wines in terms of total polyphenols and phenolic compounds, including polymeric pigments, co-pigmentation, tannins and iron-reactive polyphenols. The effect of management practices, harvest and their interaction was analysed for each compound. Positive interaction was observed for total acidity, volatile acidity, cyanidin-3-glucoside, protocatechuic acid, (+)-catechin, quercetin and trans-resveratrol. ORG wine initially showed a more complex aroma profile; however, the differences were almost indistinguishable during the second year. Trained panellists highlighted differences in colour intensity between ORG and BDN wines although no preference was found by consumers. The concentrations of ochratoxin A and biogenic amines were far below the health-hazardous threshold. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Preharvest methyl jasmonate and postharvest UVC treatments: increasing stilbenes in wine.

    PubMed

    Fernández-Marín, María Isabel; Puertas, Belén; Guerrero, Raúl F; García-Parrilla, María Carmen; Cantos-Villar, Emma

    2014-03-01

    Stilbene-enriched wine is considered to be an interesting new food product with added value due to its potential health-promoting properties. Stilbene concentration in grape is highly variable and rather scarce. However, it can be increased by stress treatments. For this reason, numerous pre- and postharvest grape treatments, and some combinations of them, have been tested to maximize stilbene content in grapes. In the present manuscript, Syrah grapes were treated with (i) methyl jasmonate (MEJA), (ii) ultraviolet light (UVC), and (iii) methyl jasmonate and ultraviolet light (MEJA-UVC) and compared with untreated grapes. Afterward, winemaking was developed. Wine achieved by combination of both treatments (MEJA-UVC) contained significantly higher stilbene concentration (trans-resveratrol and piceatannol) than its respective control (2.5-fold). Wine quality was improved in color-related parameters (color intensity, L*, a*, b*, ΔE*, anthocyanins, and tannin). Moreover, MEJA-UVC wines obtained the highest score in sensorial analysis. To the best of our knowledge, this is the first time that pre- and postharvest treatments are combined to increase stilbenes in wine. The effect of treatment combination (methyl jasmonate and UVC light) on grape and wine was evaluated. Our results highlight the positive effect of the treatments in stilbene content, color parameters, and sensorial analysis. Moreover, added-value by-products were achieved. © 2014 Institute of Food Technologists®

  16. A Metabolomic Approach to the Study of Wine Micro-Oxygenation

    PubMed Central

    Arapitsas, Panagiotis; Scholz, Matthias; Vrhovsek, Urska; Di Blasi, Stefano; Biondi Bartolini, Alessandra; Masuero, Domenico; Perenzoni, Daniele; Rigo, Adelio; Mattivi, Fulvio

    2012-01-01

    Wine micro-oxygenation is a globally used treatment and its effects were studied here by analysing by untargeted LC-MS the wine metabolomic fingerprint. Eight different procedural variations, marked by the addition of oxygen (four levels) and iron (two levels) were applied to Sangiovese wine, before and after malolactic fermentation. Data analysis using supervised and unsupervised multivariate methods highlighted some known candidate biomarkers, together with a number of metabolites which had never previously been considered as possible biomarkers for wine micro-oxygenation. Various pigments and tannins were identified among the known candidate biomarkers. Additional new information was obtained suggesting a correlation between oxygen doses and metal contents and changes in the concentration of primary metabolites such as arginine, proline, tryptophan and raffinose, and secondary metabolites such as succinic acid and xanthine. Based on these findings, new hypotheses regarding the formation and reactivity of wine pigment during micro-oxygenation have been proposed. This experiment highlights the feasibility of using unbiased, untargeted metabolomic fingerprinting to improve our understanding of wine chemistry. PMID:22662221

  17. Matrix-calibrated LC-MS/MS quantitation and sensory evaluation of oak Ellagitannins and their transformation products in red wines.

    PubMed

    Stark, Timo; Wollmann, Nadine; Wenker, Kerstin; Lösch, Sofie; Glabasnia, Arne; Hofmann, Thomas

    2010-05-26

    Aimed at investigating the concentrations and taste contribution of the oak-derived ellagitannins castalagin and vescalagin as well as their transformation products acutissimin A/B, epiacutissimin A/B, and beta-1-O-ethylvescalagin in red wine, a highly sensitive and accurate quantification method was developed on the basis of LC-MS/MS-MRM analysis with matrix calibration. Method validation showed good recovery rates ranging from 102.4 +/- 5.9% (vescalagin) to 113.7 +/- 15.2% (epiacutissimin A). In oak-matured wines, castalagin was found as the predominant ellagitannin, followed by beta-1-O-ethylvescalagin, whereas the flavano-C-ellagitannins (epi)acutissimin A/B were present in significantly lower amounts. In contrast to the high threshold concentration levels (600-1000 micromol/L) and the puckering astringent orosensation induced by flavan-3-ols, all of the ellagitannin derivatives were found to induce a smooth and velvety astringent oral sensation at rather low threshold concentrations ranging from 0.9 to 2.8 micromol/L. Dose/activity considerations demonstrated that, among all the ellagitannins investigated, castalagin exclusively exceeded its threshold concentration in various oak-matured wine samples.

  18. Port-Wine Stains

    MedlinePlus

    ... or surgery. Port-wine stains can also develop grape-like growths of small blood vessels called vascular ... another part of themselves — like their height or eye color. It's also important, emotionally, for kids to ...

  19. 27 CFR 24.218 - Other wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Other wine. 24.218 Section... THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.218 Other wine. (a) General. Other than standard wine not included in other sections in this subpart are considered other wine. Those...

  20. 27 CFR 4.27 - Vintage wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Vintage wine. 4.27 Section... THE TREASURY LIQUORS LABELING AND ADVERTISING OF WINE Standards of Identity for Wine § 4.27 Vintage wine. (a) General. Vintage wine is wine labeled with the year of harvest of the grapes and made in...

  1. Yeast's balancing act between ethanol and glycerol production in low-alcohol wines.

    PubMed

    Goold, Hugh D; Kroukamp, Heinrich; Williams, Thomas C; Paulsen, Ian T; Varela, Cristian; Pretorius, Isak S

    2017-03-01

    Alcohol is fundamental to the character of wine, yet too much can put a wine off-balance. A wine is regarded to be well balanced if its alcoholic strength, acidity, sweetness, fruitiness and tannin structure complement each other so that no single component dominates on the palate. Balancing a wine's positive fruit flavours with the optimal absolute and relative concentration of alcohol can be surprisingly difficult. Over the past three decades, consumers have increasingly demanded wine with richer and riper fruit flavour profiles. In response, grape and wine producers have extended harvest times to increase grape maturity and enhance the degree of fruit flavours and colour intensity. However, a higher degree of grape maturity results in increased grape sugar concentration, which in turn results in wines with elevated alcohol concentration. On average, the alcohol strength of red wines from many warm wine-producing regions globally rose by about 2% (v/v) during this period. Notwithstanding that many of these 'full-bodied, fruit-forward' wines are well balanced and sought after, there is also a significant consumer market segment that seeks lighter styles with less ethanol-derived 'hotness' on the palate. Consumer-focussed wine producers are developing and implementing several strategies in the vineyard and winery to reduce the alcohol concentration in wines produced from well-ripened grapes. In this context, Saccharomyces cerevisiae wine yeasts have proven to be a pivotal strategy to reduce ethanol formation during the fermentation of grape musts with high sugar content (> 240 g l -1 ). One of the approaches has been to develop 'low-alcohol' yeast strains which work by redirecting their carbon metabolism away from ethanol production to other metabolites, such as glycerol. This article reviews the current challenges of producing glycerol at the expense of ethanol. It also casts new light on yeast strain development programmes which, bolstered by synthetic

  2. Tannins from Acacia mearnsii De Wild. Bark: Tannin Determination and Biological Activities.

    PubMed

    Ogawa, Sosuke; Yazaki, Yoshikazu

    2018-04-05

    The bark of Acacia mearnsii De Wild. (black wattle) contains significant amounts of water-soluble components acalled "wattle tannin". Following the discovery of its strong antioxidant activity, a wattle tannin dietary supplement has been developed and as part of developing new dietary supplements, a literature search was conducted using the SciFinder data base for " Acacia species and their biological activities". An analysis of the references found indicated that the name of Acacia nilotica had been changed to Vachellia nilotica , even though the name of the genus Acacia originated from its original name. This review briefly describes why and how the name of A. nilotica changed. Tannin has been analyzed using the Stiasny method when the tannin is used to make adhesives and the hide-powder method is used when the tannin is to be used for leather tanning. A simple UV method is also able to be used to estimate the values for both adhesives and leather tanning applications. The tannin content in bark can also be estimated using NIR and NMR. Tannin content estimations using pyrolysis/GC, electrospray mass spectrometry and quantitative 31 P-NMR analyses have also been described. Tannins consists mostly of polyflavanoids and all the compounds isolated have been updated. Antioxidant activities of the tannin relating to anti-tumor properties, the viability of human neuroblastoma SH-SY5Y cells and also anti-hypertensive effects have been studied. The antioxidant activity of proanthocyanidins was found to be higher than that of flavan-3-ol monomers. A total of fourteen papers and two patents reported the antimicrobial activities of wattle tannin. Bacteria were more susceptible to the tannins than the fungal strains tested. Several bacteria were inhibited by the extract from A. mearnsii bark. The growth inhibition mechanisms of E. coli were investigated. An interaction between extracts from A. mearnsii bark and antibiotics has also been studied. The extracts from A. mearnsii

  3. [Review in the studies on tannins activity of cancer prevention and anticancer].

    PubMed

    Li, Haixia; Wang, Zhao; Liu, Yanze

    2003-06-01

    This paper reviewed the biological activities of tannins in cancer prevention and anticancer, and mainly discussed related mechanisms. The results suggest that tannins, whether total tannins or pure tannin compound, have remarkable activity in cancer prevention and anticancer. It has wealthy foreground for developing new cancer prevention agents and/or new anticancer drugs screening among tannin compounds.

  4. Aging effect on the pigment composition and color of Vitis vinifera L. Cv. Tannat wines. Contribution of the main pigment families to wine color.

    PubMed

    Boido, Eduardo; Alcalde-Eon, Cristina; Carrau, Francisco; Dellacassa, Eduardo; Rivas-Gonzalo, Julian C

    2006-09-06

    Red wines made from Vitis vinifera L. cv. Tannat grapes are known to possess high contents of tannins and intense color, features that are responsible for the originality of these wines. This work aimed to study the evolution of the pigment composition and CIELAB color parameters as Tannat wines become older, as well as to establish the contribution to wine color of the main pigment families. Tannat wines produced in Uruguay from grapes of the same vineyard in six consecutive vintages (1998-2003) and Tannat grapes of the 2003 harvest were analyzed by means of HPLC-DAD-MS and UV-vis spectrometric techniques. The correlations between the different pigment families and the CIELAB parameters revealed the importance of the variations of the percentage, found in anthocyanins and flavanol-anthocyanin acetaldehyde-mediated condensation products (decrease) and pyranoanthocyanins and direct condensation products (increase), in the modification of the color from purple-red hues to more orange-red ones. The color suffered qualitative rather than quantitative changes, that is, the hue (h*ab) increased, whereas the chroma (C*ab) and lightness (L) did not show a defined trend with time.

  5. Green synthesis of silver nanoparticles using tannins

    NASA Astrophysics Data System (ADS)

    Raja, Pandian Bothi; Rahim, Afidah Abdul; Qureshi, Ahmad Kaleem; Awang, Khalijah

    2014-09-01

    Colloidal silver nanoparticles were prepared by rapid green synthesis using different tannin sources as reducing agent viz. chestnut (CN), mangrove (MG) and quebracho (QB). The aqueous silver ions when exposed to CN, MG and QB tannins were reduced which resulted in formation of silver nanoparticles. The resultant silver nanoparticles were characterized using UV-Visible, X-ray diffraction (XRD), scanning electron microscopy (SEM/EDX), and transmission electron microscopy (TEM) techniques. Furthermore, the possible mechanism of nanoparticles synthesis was also derived using FT-IR analysis. Spectroscopy analysis revealed that the synthesized nanoparticles were within 30 to 75 nm in size, while XRD results showed that nanoparticles formed were crystalline with face centered cubic geometry.

  6. Wine and Maths: Mathematical Solutions to Wine-Inspired Problems

    ERIC Educational Resources Information Center

    Cadeddu, L.; Cauli, A.

    2018-01-01

    We deal with an application of partial differential equations to the correct definition of a wine cellar. We present some historical details about this problem. We also discuss how to build or renew a wine cellar, creating ideal conditions for the ageing process and improving the quality of wines. Our goal is to calculate the optimal depth…

  7. Cytotoxic hydrolyzable tannins from Balanophora japonica.

    PubMed

    Jiang, Zhi-Hong; Wen, Xiao-Yun; Tanaka, Takashi; Wu, Shao-Yu; Liu, Zhongqiu; Iwata, Hiromi; Hirose, Yoko; Wu, Shuguang; Kouno, Isao

    2008-04-01

    Four hydrolyzable tannins named balanophotannins D-G ( 1- 4) were isolated from the aerial parts of the parasitic plant Balanophora japonica. Their structures were characterized on the basis of spectroscopic and chemical evidence. Balanophotannins D-G contain an oxidized hexahydroxydiphenoyl (HHDP) group. The absolute configurations of balanophotannins D ( 1) and F ( 3) were determined via the PGME method. Balanophotannin E ( 2) showed cytotoxicity to Hep G2 cancer cells with an IC 50 value of 4.22 microM.

  8. Interactions between whey proteins and salivary proteins as related to astringency of whey protein beverages at low pH.

    PubMed

    Ye, A; Streicher, C; Singh, H

    2011-12-01

    Whey protein beverages have been shown to be astringent at low pH. In the present study, the interactions between model whey proteins (β-lactoglobulin and lactoferrin) and human saliva in the pH range from 7 to 2 were investigated using particle size, turbidity, and ζ-potential measurements and sodium dodecyl sulfate-PAGE. The correlation between the sensory results of astringency and the physicochemical data was discussed. Strong interactions between β-lactoglobulin and salivary proteins led to an increase in the particle size and turbidity of mixtures of both unheated and heated β-lactoglobulin and human saliva at pH ∼3.4. However, the large particle size and high turbidity that occurred at pH 2.0 were the result of aggregation of human salivary proteins. The intense astringency in whey protein beverages may result from these increases in particle size and turbidity at these pH values and from the aggregation and precipitation of human salivary proteins alone at pH <3.0. The involvement of salivary proteins in the interaction is a key factor in the perception of astringency in whey protein beverages. At any pH, the increases in particle size and turbidity were much smaller in mixtures of lactoferrin and saliva, which suggests that aggregation and precipitation may not be the only mechanism linked to the perception of astringency in whey protein. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. Wine yeasts for the future.

    PubMed

    Fleet, Graham H

    2008-11-01

    International competition within the wine market, consumer demands for newer styles of wines and increasing concerns about the environmental sustainability of wine production are providing new challenges for innovation in wine fermentation. Within the total production chain, the alcoholic fermentation of grape juice by yeasts is a key process where winemakers can creatively engineer wine character and value through better yeast management and, thereby, strategically tailor wines to a changing market. This review considers the importance of yeast ecology and yeast metabolic reactions in determining wine quality, and then discusses new directions for exploiting yeasts in wine fermentation. It covers criteria for selecting and developing new commercial strains, the possibilities of using yeasts other than those in the genus of Saccharomyces, the prospects for mixed culture fermentations and explores the possibilities for high cell density, continuous fermentations.

  10. Recovery of uranium from seawater by immobilized tannin

    SciTech Connect

    Sakaguchi, T.; Nakajima, A.

    1987-06-01

    Tannin compounds having multiple adjacent hydroxy groups have an extremely high affinity for uranium. To prevent the leaching of tannins into water and to improve the adsorbing characteristics of these compounds, the authors tried to immobilize tannins. The immobilized tannin has the most favorable features for uranium recovery; high selective adsorption ability to uranium, rapid adsorption rate, and applicability in both column and batch systems. The immobilized tannin can recover uranium from natural seawater with high efficiency. About 2530 ..mu..g uranium is adsorbed per gram of this adsorbent within 22 h. Depending on the concentration in seawater, an enrichment ofmore » up to 766,000-fold within the adsorbent is possible. Almost all uranium adsorbed is easily desorbed with a very dilute acid. Thus, the immobilized tannin can be used repeatedly in the adsorption-desorption process.« less

  11. Grape seed and apple tannins: emulsifying and antioxidant properties.

    PubMed

    Figueroa-Espinoza, Maria Cruz; Zafimahova, Andrea; Alvarado, Pedro G Maldonado; Dubreucq, Eric; Poncet-Legrand, Céline

    2015-07-01

    Tannins are natural antioxidants found in plant-based foods and beverages, whose amphiphilic nature could be useful to both stabilize emulsions and protect unsaturated lipids from oxidation. In this paper, the use of tannins as antioxidant emulsifiers was studied. The main parameters influencing the stability of emulsions (i.e. tannins structure and concentration, aqueous phase pH, and ionic strength) were identified and optimized. Oil in water emulsions stabilized with tannins were compared with those stabilized with two commercial emulsifying agents, poly(vinyl alcohol) (PVA) and polyoxyethylene hydrogenated castor oil. In optimized conditions, the condensed tannins allowed to obtain a stability equivalent to that of PVA. Tannins presented good antioxidant activity in oil in water emulsion, as measured by the conjugated autoxidizable triene (CAT) assay. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. [Study on the kinetic fluorimetric determination of tannins in tea].

    PubMed

    Feng, Su-ling; Tang, Jun-ming; Fan, Jing

    2003-04-01

    A simple and highly sensitive kinetic fluorimetric method is proposed for the determination of trace tannins, based on the activation of tannins on the oxidation of pyronine Y by hydrogen peroxide catalyzed by Cu(II) ion. The effects of some experimental conditions were investigated and discussed in detail. The fixed reaction time procedure was used to determine the fluorescence intensity of the system. The calibration curve of tannin was linear in the range of 0.06-0.96 mg.L-1, and the detection limit for tannin was 0.032 mg.L-1. The relative standard deviation for the measurement of 0.32 mg.L-1 tannin (n = 11) was 2.3%. The proposed method has been successfully applied to the determination of tannins in tea. The results obtained were compared with those provided by the Folin-Ciocalteu method.

  13. Influence of closure, phenolic levels and microoxygenation on Cabernet Sauvignon wine composition after 5 years' bottle storage.

    PubMed

    Han, Guomin; Ugliano, Maurizio; Currie, Bruce; Vidal, Stéphane; Diéval, Jean-Baptiste; Waterhouse, Andrew L

    2015-01-01

    Wine aging is generally limited by the amount of oxidation, which is dependent on the amount of oxygen entering via the closure. Cabernet Sauvignon wine is well known for its high concentration of tannin, making it an ideal red wine for aging. The impact of closure type after 5 years' bottle aging has been investigated on a 2007 Cabernet Sauvignon red wine, treated with or without polyvinylpolypyrrolidone (PVPP) and micro-oxygenation (Mox). Two oxygen transfer rate (OTR) conditions (16 and 5 µg per day) into 375 mL bottles were obtained by using different synthetic stoppers. Color was evaluated by UV-visible spectrophotometry, carbonyls by 2,4-dinitrophenylhydrazine derivatization, phenolics by high-performance liquid chromatography and sulfur dioxide by the aspiration method. Closure type strongly influenced color parameters involving SO2 bleaching and some phenolics, particularly quercetin, were affected, but there was little effect on carbonyls other than acetaldehyde. PVPP treatment afforded wines with the lowest levels of phenolics and color density, but highest acetaldehyde. Few effects of Mox could be detected. Closure OTR strongly affects sulfur dioxide levels - the primary antioxidant in wine - in aged wine, but phenolic levels substantially alter the secondary reactions of oxidative aging. © 2014 Society of Chemical Industry.

  14. Selective determination of aluminum bound with tannin in tea infusion.

    PubMed

    Erdemoğlu, Sema B; Güçer, Seref

    2005-08-01

    In this study, an analytical method for indirect measurement of Al bound with tannin in tea infusion was studied. This method utilizes the ability of the tannins to precipitate with protein. Separation conditions were investigated using model solutions. This method is uncomplicated, inexpensive and suitable for real samples. About 34% of the total Al in brew extracted from commercially available teas was bound to condensed and hydrolyzable tannins.

  15. Fun with Singing Wine Glasses

    ERIC Educational Resources Information Center

    Boone, Christine; Galloway, Melodie; Ruiz, Michael J.

    2018-01-01

    A fun activity is presented using singing wine glasses for introductory physics students. Students tune a white wine glass and a red wine glass to as many semitones as possible by filling the glasses with the appropriate amounts of water. A smart phone app is used to measure the frequencies of equal-temperament tones. Then plots of frequency…

  16. Tears of Wine

    NASA Astrophysics Data System (ADS)

    Rathore, Prerana; Sharma, Vivek

    `Tears of wine' refer to the rows of wine-drops that spontaneously emerge within a glass of strong wine. Evaporation-driven Marangoni flows near the meniscus of water-alcohol mixtures drive liquid upward forming a thin liquid film, and a rim or ridge forms near the moving contact line. Eventually the rim undergoes an instability forming drops, that roll back into bulk reservoir forming so called tears or legs of wine. Most studies in literature argue the evaporation of more volatile, lower surface tension component (alcohol) results in a concentration-dependent surface tension gradient that drives the climbing flow within the thin film. Though it is well-known that evaporative cooling can create temperature gradients that could provide additional contribution to the climbing flows, the role of thermocapillary flows is less well-understood. Furthermore, the patterns, flows and instabilities that occur near the rim, and determine the size and periodicity of tears, are not well-studied. Using experiments and theory, we visualize and analyze the formation and growth of tears of wine. The sliding drops, released from the rim towards the bulk reservoir, show oscillations and a cascade of fascinating flows that are analyzed for the first time.

  17. Wine and maths: mathematical solutions to wine-inspired problems

    NASA Astrophysics Data System (ADS)

    Cadeddu, L.; Cauli, A.

    2018-04-01

    We deal with an application of partial differential equations to the correct definition of a wine cellar. We present some historical details about this problem. We also discuss how to build or renew a wine cellar, creating ideal conditions for the ageing process and improving the quality of wines. Our goal is to calculate the optimal depth z0 of a wine cellar in order to attenuate the periodic temperature fluctuations. What follows is a kind of survey of wine-related and optimization problems which have been solved by means of powerful math tools.

  18. Tannin structural elucidation and quantitative ³¹P NMR analysis. 2. Hydrolyzable tannins and proanthocyanidins.

    PubMed

    Melone, Federica; Saladino, Raffaele; Lange, Heiko; Crestini, Claudia

    2013-10-02

    An unprecedented analytical method that allows simultaneous structural and quantitative characterization of all functional groups present in tannins is reported. In situ labeling of all labile H groups (aliphatic and phenolic hydroxyls and carboxylic acids) with a phosphorus-containing reagent (Cl-TMDP) followed by quantitative ³¹P NMR acquisition constitutes a novel fast and reliable analytical tool for the analysis of tannins and proanthocyanidins with significant implications for the fields of food and feed analyses, tannery, and the development of natural polyphenolics containing products.

  19. Peel effects on phenolic composition, antioxidant activity, and making of pomegranate juice and wine.

    PubMed

    Wasila, Humaira; Li, Xuan; Liu, Linwei; Ahmad, Imran; Ahmad, Sajjad

    2013-08-01

    Pomegranate peel was used in juicing to find out its effects on the juice products' (storable juice and wine) sensory property, polyphenols composition, and antioxidant ability. Macroporous resin was used to purify the polyphenols, and 6 different in vitro assays were used to comprehensively determine the antioxidant activity of each. The results showed that juicing with peel made the juice bitter and astringent, but contributed better sensory quality to wine. Peel contributed higher total polyphenols and flavonoids, but lower anthocyanins to the juice products, and caused the phenolics content to fluctuate more dramatically during making wine than the storable juice. Polyphenols purified from the juice products containing peel showed higher total reducing ability and 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid radical elimination abilities, but their clearance activity of hydroxyl radicals was not positive, and their superoxide anion radical elimination ability showed no significant difference when compared to polyphenols purified from juice products without peel. © 2013 Institute of Food Technologists®

  20. Ruminal biohydrogenation as affected by tannins in vitro.

    PubMed

    Vasta, Valentina; Makkar, Harinder P S; Mele, Marcello; Priolo, Alessandro

    2009-07-01

    The aim of the present work was to study the effects of tannins from carob (CT; Ceratonia siliqua), acacia leaves (AT; Acacia cyanophylla) and quebracho (QT; Schinopsis lorentzii) on ruminal biohydrogenation in vitro. The tannins extracted from CT, AT and QT were incubated for 12 h in glass syringes in cow buffered ruminal fluid (BRF) with hay or hay plus concentrate as a substrate. Within each feed, three concentrations of tannins were used (0.0, 0.6 and 1.0 mg/ml BRF). The branched-chain volatile fatty acids, the branched-chain fatty acids and the microbial protein concentration were reduced (P < 0.05) by tannins. In the tannin-containing fermenters, vaccenic acid was accumulated (+23 %, P < 0.01) while stearic acid was reduced ( - 16 %, P < 0.0005). The concentration of total conjugated linoleic acid (CLA) isomers in the BRF was not affected by tannins. The assay on linoleic acid isomerase (LA-I) showed that the enzyme activity (nmol CLA produced/min per mg protein) was unaffected by the inclusion of tannins in the fermenters. However, the CLA produced by LA-I (nmol/ml per min) was lower in the presence of tannins. These results suggest that tannins reduce ruminal biohydrogenation through the inhibition of the activity of ruminal micro-organisms.

  1. Tannins occurring in the toxic Brazilian plant Thiloa glaucocarpa.

    PubMed

    Itakura, Y; Habermehl, G; Mebs, D

    1987-01-01

    Four tannins were isolated from dried leaves of Thiloa glaucocarpa, which is one of the plants causing poisoning of cattle in Brazil. These four tannins were determined from spectrometric and chemical evidence to be the ellagic C-glucosyl tannins vescalagin, castalagin, stachyurin and casuarinin. The main components, vescalagin and castalagin, are also known as constituents of oak (Quercus spp.), the toxicity of which for cattle is supposed to be due to tannins. Suggestions concerning the resemblance of the symptoms of poisoning by Thiloa glaucocarpa and by oak are supported by the presence of the constituents in both plants.

  2. CHANGES IN QUALITY AND COMPOSITION PRODUCED IN WINE BY COBALT-60 GAMMA IRRADIATION

    SciTech Connect

    Singleton, V.L.

    1963-06-01

    Glass-bottled red port, white port, dry red table wine, and dry white table wine purged with nitrogen and airsaturated dry sherry material were irradiated with and sensory evaluation showed considerable changes after irradiation. The bottle glass changed from colorless to greenish-brown. The wines were under a small positive pressure when opened, both white and red wines were bleached, and odor and flavor were changed. Analytical results showed no changes in extract, ethanol, volatile esters, or volatile acid, but a slight increase in pH and decrease in total acidity upon irradiation. Changes in spectral absorption were great; absorbance diminished at everymore » wavelength, but not proportionately. All untreated wines showed a maximum at 265 to 85 m mu and a shoulder at about 320 m mu , and the red wines the typical maximum near 520 m mu , which was much decreased by irradiation. The absorbance at 320 m mu was greatly decreased and the shoulder disappeared, leaving only the residual absorption from the more intense but less affected peak at 265 to 85 m mu (absorption at these wavelengths is attributed largely to their content of flavonoid, polyphenolic substances). No appreciable change in the tannin (total polyphenolic) constant was seen, but paper chromatographic studies showed definite qualitative and quantitative changes in polyphenols The oxidation- reduction potential was greatly lowered by irradiation, and volatile substances reacting as aldehydes were produced in considerable amounts, confirming that definite, selective, and specific compositional changes are produced in wine by gamma irradiation at feasible dose levels. With wines flavor-rated by experienced judges with reference to standard wine types, large changes were produced by 500,000 and 1,000,000 rad. Grape aroma rating was significantly decreased in all cases by the higher levels of irradiation. A radiation-induced flavor seemed similar, regardless of the type of wine irradiated. Descriptive

  3. Electronic Nose For Measuring Wine Evolution In Wine Cellars

    NASA Astrophysics Data System (ADS)

    Lozano, J.; Santos, J. P.; Horrillo, M. C.; Cabellos, J. M.; Arroyo, T.

    2009-05-01

    An electronic nose installed in a wine cellar for measuring the wine evolution is presented in this paper. The system extract the aroma directly from the tanks where wine is stored and carry the volatile compounds to the sensors cell. A tin oxide multisensor, prepared with RF sputtering onto an alumina substrate and doped with chromium and indium, is used. The whole system is fully automated and controlled by computer and can be supervised by internet. Linear techniques like principal component analysis (PCA) and nonlinear ones like probabilistic neural networks (PNN) are used for pattern recognition. Results show that system can detect the evolution of two different wines along 9 months stored in tanks. This system could be trained to detect off-odours of wine and warn the wine expert to correct it as soon as possible, improving the final quality of wine.

  4. [Eulogy of wine?].

    PubMed

    Godfroid, I O

    1997-12-20

    In the literature the beneficial effects on health of drinking alcoholic beverages, especially red wine, is becoming increasingly more evident. We report an objective analysis of the advantages and the dangers of such a tendency. It appears that the daily consumption of red wine at moderate doses (200-400 ml a day) has real prophylactic effects. These are particularly marked in the prevention of coronary heart disease (CHD), but also for a possible cancer chemopreventive activity, in the prevention of type II diabetes, of ischemic stroke, of osteoporosis in older women, and of Alzheimer's disease. But, inasmuch as the consumption of alcoholic beverages always involves a potential danger (organic diseases, risk of dependence, alcoholism), from a medical point of view eulogy to wine is ethically indefensible. Similar effects may be obtained from a diet rich in fruits and fresh vegetables.

  5. Influence of wood barrels classified by NIRS on the ellagitannin content/composition and on the organoleptic properties of wine.

    PubMed

    Michel, Julien; Jourdes, Michael; Le Floch, Alexandra; Giordanengo, Thomas; Mourey, Nicolas; Teissedre, Pierre-Louis

    2013-11-20

    Ellagitannins are extracted from oak wood during wine aging in oak barrels. This research is based on the NIRS (Oakscan) oak wood classification according to their index polyphenolic (IP) (between 21.07 and 70.15). Their level in wood is very variable (between 5.95 and 32.91 mg/g dry wood) and influenced their concentration in red wine (between 2.30 and 32.56 mg/L after 24 months of aging) and thus their impact on wine organoleptic properties. The results show a good correlation between the NIRS classification and the chemical analysis (HPLC-UV-MS and acidic hydrolysis procedure) and with the wood ellagitannin level, the ellagitannin extraction kinetic, and the ellagitannins evolution in red wine (Cabernet Sauvignon). Moreover, a correlation between the NIRS classification and the increasing intensity of some wood aromas (woody, spicy, vanilla, and smoked/toasted), flavors (bitterness and astringency), and a decreasing intensity of fruitiness was also observed.

  6. Specific phenolic compounds and sensory properties of a new dealcoholized red wine with pomegranate (Punica granatum L.) extract.

    PubMed

    Tárrega, Maria Amparo; Varela, Paula; Fromentin, Emilie; Feuillère, Nicolas; Issaly, Nicolas; Roller, Marc; Sanz-Buenhombre, Marisa; Villanueva, Sonia; Moro, Carlos; Guadarrama, Alberto; Fiszman, Susana

    2014-09-01

    The pomegranate (Punica granatum L.) fruit has a long history of human consumption and possesses notable antioxidant and cardiovascular properties. This work evaluated the feasibility to provide a new functional beverage based on a dealcoholized red wine matrix supplemented by a pomegranate extract. The potential bioactive compounds in the pomegranate extract, punicalagin A and B and ellagic acid, were analyzed during the downstream process in order to evaluate the functional dose in the final beverage. The addition of pomegranate extract to the dealcoholized red wine resulted in a product with more intense yeast odor, acidity, yeast flavor, and astringency and with a less intense berry flavor. Consumer acceptance of the product was also investigated and the results revealed the existence of a niche of consumers willing to consume dealcoholized wine enriched with pomegranate extract. After tasting, 50% and 40% of those consumers initially interested by this product concept declared to be interested to purchase the control sample and the functional beverage, respectively. The daily consumption of two servings of 250 mL of this new pomegranate-enriched dealcoholized wine provides 82 mg of total ellagitannins, corresponding to the sum of punicalagin A and B and ellagic acid. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  7. Relationship between Menthiafolic Acid and Wine Lactone in Wine.

    PubMed

    Giaccio, Joanne; Curtin, Chris D; Sefton, Mark A; Taylor, Dennis K

    2015-09-23

    Menthiafolic acid (6-hydroxy-2,6-dimethylocta-2,7-dienoic acid, 2a) was quantified by GC-MS in 28 white wines, 4 Shiraz wines, and for the first time in 6 white grape juice samples. Menthiafolic acid was detected in all but one of the wine samples at concentrations ranging from 26 to 342 μg/L and in the juice samples from 16 to 236 μg/L. Various model fermentation experiments showed that some menthiafolic acid in wine could be generated from the grape-derived menthiafolic acid glucose ester (2b) during alcoholic and malolactic fermentation. Samples containing high concentrations of menthiafolic acid were also analyzed by enantioselective GC-MS and were shown to contain this compound in predominantly the (S)-configuration. Enantioselective analysis of wine lactone (1) in one of these samples, a four-year-old Chardonnay wine showed, for the first time, the presence of the 3R,3aR,7aS isomer of wine lactone (1b), which is the enantiomer of the form previously reported as the sole isomer present in young wine samples. The weakly odorous 3R,3aR,7aS 1b form comprised 69% of the total wine lactone in the sample. On the basis of the enantioselectivity of the hydrolytic conversion of menthiafolic acid to wine lactone at pH 3.0 determined previously and the relative proportions of (R)- and (S)-menthiafolic acid in the Chardonnay wine, the predicted ratio of wine lactone enantiomers that would be formed from hydrolysis at ambient temperature of the menthiafolic acid present in this wine was close to the ratio measured, which was consistent with menthiafolic acid being the major or sole precursor to wine lactone in this sample.

  8. Reaction of Acetaldehyde with Wine Flavonoids in the Presence of Sulfur Dioxide.

    PubMed

    Sheridan, Marlena K; Elias, Ryan J

    2016-11-16

    Acetaldehyde is responsible for many of the beneficial changes that occur in red wine as a result of oxidation. Ethylidene bridges are formed between flavonoids upon their reaction with acetaldehyde, which can contribute to improvements in color stability and SO 2 -resistant pigments. In the present study, the reactions between acetaldehyde and various flavonoids (catechin, tannins from grape seed extract, and malvidin-3-glucoside) were examined in a model wine system. Lower pH conditions were seen to significantly increase the rate of reaction with acetaldehyde, whereas dissolved oxygen did not affect the rate. In systems containing SO 2 , the rate of reaction of acetaldehyde with catechin was slowed but was not prevented until SO 2 was in great excess. Significant improvements in color stability were also observed after treatment with acetaldehyde, despite the presence of equimolar SO 2 . These results demonstrate that acetaldehyde is reactive in its sulfonate form, which is contrary to widely held assumptions. In addition, the products of the reaction of flavonoids with acetaldehyde were characterized using MALDI-TOF MS in this study. Ethyl-bridged catechin nonamers were observed, as well as anthocyanin and pyranoanthocyanin derivatives of catechin and tannin oligomers. The results of this work illustrate the significance of acetaldehyde reactions in forming stable pigments in wine and the reactivity of acetaldehyde from its sulfonate form.

  9. 27 CFR 27.59 - Wines.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Wines. 27.59 Section 27.59... TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER General Requirements Marking and Labeling of Wines and Beer § 27.59 Wines. All imported wines containing not less than 7 percent and not...

  10. A Laboratory Classroom Where ?Wining? Is Encouraged

    ERIC Educational Resources Information Center

    Gibbs, Hope

    2004-01-01

    A wine analysis for most is: take a sip, and either like it or don't. Not so for the students taking wine analysis courses at California Polytechnic State University in San Luis Obispo, California. In the college's new Wine Analysis Laboratory, students learn how to run chemical analyses of wines and compare chemical profiles of wines. Professor…

  11. 27 CFR 24.218 - Other wine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... wines considered to be other wine include: (1) Wine made with sugar, water, or sugar and water beyond... kinds of fruit. (3) Wine made with sugar other than pure dry sugar, liquid pure sugar, and invert sugar.... Other wine will have a basic character derived from the primary winemaking material. If sugar is used to...

  12. 27 CFR 24.218 - Other wine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... wines considered to be other wine include: (1) Wine made with sugar, water, or sugar and water beyond... kinds of fruit. (3) Wine made with sugar other than pure dry sugar, liquid pure sugar, and invert sugar.... Other wine will have a basic character derived from the primary winemaking material. If sugar is used to...

  13. 27 CFR 24.218 - Other wine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... wines considered to be other wine include: (1) Wine made with sugar, water, or sugar and water beyond... kinds of fruit. (3) Wine made with sugar other than pure dry sugar, liquid pure sugar, and invert sugar.... Other wine will have a basic character derived from the primary winemaking material. If sugar is used to...

  14. 27 CFR 24.218 - Other wine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... wines considered to be other wine include: (1) Wine made with sugar, water, or sugar and water beyond... kinds of fruit. (3) Wine made with sugar other than pure dry sugar, liquid pure sugar, and invert sugar.... Other wine will have a basic character derived from the primary winemaking material. If sugar is used to...

  15. 27 CFR 24.292 - Exported wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Exported wine. 24.292....292 Exported wine. (a) General. Wine may be removed from a bonded wine premises without payment of tax... wine for export will be in accordance with the procedures in part 28 of this chapter. (b) Return of...

  16. Biosynthesis and subcellular distribution of hydrolyzable tannins.

    PubMed

    Grundhöfer, P; Niemetz, R; Schilling, G; Gross, G G

    2001-07-01

    Pathways to complex gallotannins have been elucidated by enzyme studies, indicating that beta-glucogallin is required as principal acyl donor. Evidence for the in vitro oxidation of pentagalloylglucose, the pivotal metabolite in this sequence, to ellagitannins, is presented. Immunohistochemical studies with antibodies raised against pentagalloylglucose and the galloyltransferase catalyzing the formation of this ester revealed that leaf mesophyll cell walls were a typical site of origin and deposition of hydrolyzable tannins. Seasonal changes of these compounds were studied with extracts from cell walls and intracellular space of oak leaves.

  17. Reconstitution of the flavor signature of Dornfelder red wine on the basis of the natural concentrations of its key aroma and taste compounds.

    PubMed

    Frank, Stephanie; Wollmann, Nadine; Schieberle, Peter; Hofmann, Thomas

    2011-08-24

    By application of aroma extract dilution analysis (AEDA) on the volatile fraction isolated from a Dornfelder red wine, 31 odor-active compounds were identified by means of HRGC-MS and comparison with reference compounds. A total of 27 odorants, judged with high FD factors by means of AEDA, was quantitated by means of stable isotope dilution assays, and acetaldehyde was determined enzymatically. In addition, 36 taste-active compounds were analyzed by means of HPLC-UV, HPLC-MS/MS, and ion chromatography. The quantitative data obtained for the identified aroma and taste compounds enabled for the first time the reconstruction of the overall flavor of the red wine. Sensory evaluation of both the aroma and taste profiles of the authentic red wine and the recombinate revealed that Dornfelder red wine was closely mimicked. Moreover, it was demonstrated that the high molecular weight fraction of red wine is essential for its astringent taste impression. By comparison of the overall odor of the aroma recombinate in ethanol with that of the total flavor recombinate containing all tastants, it was shown for the first time that the nonvolatile tastants had a strong influence on the intensity of certain aroma qualities.

  18. Manure total nitrogen flux from condensed tannin fed beef cattle

    USDA-ARS?s Scientific Manuscript database

    A study was conducted to determine the effects of three levels of condensed tannins fed to 27 beef feedyard steers on total nitrogen (N) flux from manure. Condensed tannins were fed at rates of 0, 0.5, and 1 percent of the daily ration on a dry matter basis. Manure and urine were collected over two ...

  19. SEPARATION OF THORIUM FROM RARE EARTHS WITH TANNIN (in Russian)

    SciTech Connect

    Vlodavets, N.I.

    1959-03-01

    Thorium is quantitatively precipitated with tannin in a 0.005 N solution of nitric or hydrochloric acid. This permits its separation from trivalent rare earths, which are not precipitated with tannin in such relatively weak acid solutions. The accuracy of the determinations is as usual at the gravimetric determinations of macroquantities of elements. (auth)

  20. Flavanoid biocides: Wood preservatives based on condensed tannins

    Treesearch

    Peter Laks; Peggy A. McKaig; Richard W. Hemingway

    1988-01-01

    The condensed tannins are natural wood preservatives found in high concentrations in the bark and wood of some tree species. Condensed tannin-containing bark extracts from loblolly pine (Pinus taeda) were evaluated as wood preservatives using standard methods. Bark extracts by themselves did not cause any reduction in weight loss of pressure-treated...

  1. Formaldehyde condensation products of model phenols for conifer bark tannins

    Treesearch

    Richard W. Hemingway; Gerald W. McGraw

    1978-01-01

    Gel permeation chromatography of the condensation products of phenols and formaldehyde proved effective in understanding the reactions of condensed tannins with formaldehyde. Rates of condensation of phloroglucinols, resorcinols, catechols, (+)catechins, and (-)epicatechin were examined to determine if methylol-tannins from southern pine bark could be prepared as resin...

  2. Formaldehyde condensation products of model phenols for conifer bark tannins

    Treesearch

    R.W. Hemingway; G.W. McGraw

    1978-01-01

    Gel permeation chromatograpy of the condensation products of phenols and formaldehyde proved effective in understanding the reactions of condensed tannins with formaldehyde. Rates of condensation of phloroglucinols, resorcinols, catechols, (+)catechin, and (-)epicatechin were examined to determine if methylol-tannins from southern pine bark could be prepared as resin...

  3. Constituent and induced tannin accumulations in roots of loblolly pines

    Treesearch

    Charles H. Walkinshaw

    1999-01-01

    Loblolly pine (Pinus taeda L [L.]) has become the most important source of wood fiber in the Southern United States. This tree is an excellent competitor and recovers well from a variety of adverse conditions. The author presents a histological study of tannin in pine roots to measure tannin abundance as a primary trait to evaluate root health at the...

  4. Assisting Wine Growers

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This video documents efforts at NASA Ames Research Center to assist wine growers in the Napa valley in their fight against a root parasite which is destroying millions of dollars worth of grape crops. NASA researchers are using airborne scanners and remote sensing equipment to detect the parasite before it becomes entrenched, so that growers can treat the harvest to resist infestation.

  5. 27 CFR 24.213 - Heavy bodied blending wine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Production of Other Than Standard Wine § 24.213 Heavy bodied blending wine. Heavy bodied blending wine is wine made for blending purposes from grapes or other fruit without...

  6. 27 CFR 24.213 - Heavy bodied blending wine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.213 Heavy bodied blending wine. Heavy bodied blending wine is wine made for blending purposes from grapes or other fruit without...

  7. 27 CFR 24.213 - Heavy bodied blending wine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.213 Heavy bodied blending wine. Heavy bodied blending wine is wine made for blending purposes from grapes or other fruit without...

  8. 27 CFR 24.213 - Heavy bodied blending wine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Production of Other Than Standard Wine § 24.213 Heavy bodied blending wine. Heavy bodied blending wine is wine made for blending purposes from grapes or other fruit without...

  9. Wine phenolic compounds influence the production of volatile phenols by wine-related lactic acid bacteria.

    PubMed

    Silva, I; Campos, F M; Hogg, T; Couto, J A

    2011-08-01

    To evaluate the effect of wine phenolic compounds on the production of volatile phenols (4-vinylphenol [4VP] and 4-ethylphenol [4EP]) from the metabolism of p-coumaric acid by lactic acid bacteria (LAB). Lactobacillus plantarum, Lactobacillus collinoides and Pediococcus pentosaceus were grown in MRS medium supplemented with p-coumaric acid, in the presence of different phenolic compounds: nonflavonoids (hydroxycinnamic and benzoic acids) and flavonoids (flavonols and flavanols). The inducibility of the enzymes involved in the p-coumaric acid metabolism was studied in resting cells. The hydroxycinnamic acids tested stimulated the capacity of LAB to synthesize volatile phenols. Growth in the presence of hydroxycinnamic acids, especially caffeic acid, induced the production of 4VP by resting cells. The hydroxybenzoic acids did not significantly affect the behaviour of the studied strains. Some of the flavonoids showed an effect on the production of volatile phenols, although strongly dependent on the bacterial species. Relatively high concentrations (1 g l(-1) ) of tannins inhibited the synthesis of 4VP by Lact. plantarum. Hydroxycinnamic acids were the main compounds stimulating the production of volatile phenols by LAB. The results suggest that caffeic and ferulic acids induce the synthesis of the cinnamate decarboxylase involved in the metabolism of p-coumaric acid. On the other hand, tannins exert an inhibitory effect. This study highlights the capacity of LAB to produce volatile phenols and that this activity is markedly influenced by the phenolic composition of the medium. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  10. Extraction of oak volatiles and ellagitannins compounds and sensory profile of wine aged with French winewoods subjected to different toasting methods: behaviour during storage.

    PubMed

    Chira, Kleopatra; Teissedre, Pierre-Louis

    2013-09-01

    In Merlot wines the evolution of volatile and non-volatile (ellagitannins) compounds extracted from winewoods while being macerated for 12 months was studied. Seven types of winewoods subjected to different toasting methods were used. Different rates of extraction, depending mainly on wood compounds origin (toasting or naturally present in wood) and on the watering process during toasting, were observed, which were reflected in sensory differences. Globally, volatile phenols together with aldehydes, phenols and lactones showed an increase with increasing maceration time. Ellagitannins were extracted faster during the first 3 months; after 6 months an important decrease was observed. Wines with winewoods subjected to watering during toasting were lower in ellagitannins concentrations and demonstrated the greatest decrease of these compounds during maceration. Astringency and bitterness intensified with increasing ellagitannins. Lactones induced positive sweetness sensations, whereas furanic and guaiacol compounds influenced bitterness and astringency. Spicy and vanilla descriptors were related to eugenol, vanillin and other odorous chemicals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Microchip electrophoresis for wine analysis.

    PubMed

    Gomez, Federico J V; Silva, M Fernanda

    2016-12-01

    The present critical review provides a summary of representative articles describing the analysis of wine by microchip electrophoresis. Special emphasis has been given to those compounds able to provide background information to achieve the differentiation of wines according to botanical origin, provenance, vintage and quality or assure wine authentication. This review focuses on capillary electrophoresis (CE) microchips dedicated to the analysis of wine covering all the contributions concerning this area. The most relevant compounds in wine analysis such as phenols, organic acids, inorganic species, aldehydes, sugars, alcohols, and neuroactive amines were considered. Moreover, a special section is dedicated to the potential of CE microchip for wine classification. Indeed, potential directions for the future are discussed.

  12. Wine fermentation microbiome: a landscape from different Portuguese wine appellations

    PubMed Central

    Pinto, Cátia; Pinho, Diogo; Cardoso, Remy; Custódio, Valéria; Fernandes, Joana; Sousa, Susana; Pinheiro, Miguel; Egas, Conceição; Gomes, Ana C.

    2015-01-01

    Grapes and wine musts harbor a complex microbiome, which plays a crucial role in wine fermentation as it impacts on wine flavour and, consequently, on its final quality and value. Unveiling the microbiome and its dynamics, and understanding the ecological factors that explain such biodiversity, has been a challenge to oenology. In this work, we tackle this using a metagenomics approach to describe the natural microbial communities, both fungal and bacterial microorganisms, associated with spontaneous wine fermentations. For this, the wine microbiome, from six Portuguese wine appellations, was fully characterized as regards to three stages of fermentation – Initial Musts (IM), and Start and End of alcoholic fermentations (SF and EF, respectively). The wine fermentation process revealed a higher impact on fungal populations when compared with bacterial communities, and the fermentation evolution clearly caused a loss of the environmental microorganisms. Furthermore, significant differences (p < 0.05) were found in the fungal populations between IM, SF, and EF, and in the bacterial population between IM and SF. Fungal communities were characterized by either the presence of environmental microorganisms and phytopathogens in the IM, or yeasts associated with alcoholic fermentations in wine must samples as Saccharomyces and non-Saccharomyces yeasts (as Lachancea, Metschnikowia, Hanseniaspora, Hyphopichia, Sporothrix, Candida, and Schizosaccharomyces). Among bacterial communities, the most abundant family was Enterobacteriaceae; though families of species associated with the production of lactic acid (Lactobacillaceae, Leuconostocaceae) and acetic acid (Acetobacteriaceae) were also detected. Interestingly, a biogeographical correlation for both fungal and bacterial communities was identified between wine appellations at IM suggesting that each wine region contains specific and embedded microbial communities which may contribute to the uniqueness of regional wines. PMID

  13. Wine fermentation microbiome: a landscape from different Portuguese wine appellations.

    PubMed

    Pinto, Cátia; Pinho, Diogo; Cardoso, Remy; Custódio, Valéria; Fernandes, Joana; Sousa, Susana; Pinheiro, Miguel; Egas, Conceição; Gomes, Ana C

    2015-01-01

    Grapes and wine musts harbor a complex microbiome, which plays a crucial role in wine fermentation as it impacts on wine flavour and, consequently, on its final quality and value. Unveiling the microbiome and its dynamics, and understanding the ecological factors that explain such biodiversity, has been a challenge to oenology. In this work, we tackle this using a metagenomics approach to describe the natural microbial communities, both fungal and bacterial microorganisms, associated with spontaneous wine fermentations. For this, the wine microbiome, from six Portuguese wine appellations, was fully characterized as regards to three stages of fermentation - Initial Musts (IM), and Start and End of alcoholic fermentations (SF and EF, respectively). The wine fermentation process revealed a higher impact on fungal populations when compared with bacterial communities, and the fermentation evolution clearly caused a loss of the environmental microorganisms. Furthermore, significant differences (p < 0.05) were found in the fungal populations between IM, SF, and EF, and in the bacterial population between IM and SF. Fungal communities were characterized by either the presence of environmental microorganisms and phytopathogens in the IM, or yeasts associated with alcoholic fermentations in wine must samples as Saccharomyces and non-Saccharomyces yeasts (as Lachancea, Metschnikowia, Hanseniaspora, Hyphopichia, Sporothrix, Candida, and Schizosaccharomyces). Among bacterial communities, the most abundant family was Enterobacteriaceae; though families of species associated with the production of lactic acid (Lactobacillaceae, Leuconostocaceae) and acetic acid (Acetobacteriaceae) were also detected. Interestingly, a biogeographical correlation for both fungal and bacterial communities was identified between wine appellations at IM suggesting that each wine region contains specific and embedded microbial communities which may contribute to the uniqueness of regional wines.

  14. Effects of different tannin-rich extracts and rapeseed tannin monomers on methane formation and microbial protein synthesis in vitro.

    PubMed

    Wischer, G; Boguhn, J; Steingaß, H; Schollenberger, M; Rodehutscord, M

    2013-11-01

    Tannins, polyphenolic compounds found in plants, are known to complex with proteins of feed and rumen bacteria. This group of substances has the potential to reduce methane production either with or without negative effects on digestibility and microbial yield. In the first step of this study, 10 tannin-rich extracts from chestnut, mimosa, myrabolan, quebracho, sumach, tara, valonea, oak, cocoa and grape seed, and four rapeseed tannin monomers (pelargonidin, catechin, cyanidin and sinapinic acid) were used in a series of in vitro trials using the Hohenheim gas test, with grass silage as substrate. The objective was to screen the potential of various tannin-rich extracts to reduce methane production without a significant effect on total gas production (GP). Supplementation with pelargonidin and cyanidin did not reduce methane production; however, catechin and sinapinic acid reduced methane production without altering GP. All tannin-rich extracts, except for tara extract, significantly reduced methane production by 8% to 28% without altering GP. On the basis of these results, five tannin-rich extracts were selected and further investigated in a second step using a Rusitec system. Each tannin-rich extract (1.5 g) was supplemented to grass silage (15 g). In this experiment, nutrient degradation, microbial protein synthesis and volatile fatty acid production were used as additional response criteria. Chestnut extract caused the greatest reduction in methane production followed by valonea, grape seed and sumach, whereas myrabolan extract did not reduce methane production. Whereas chestnut extract reduced acetate production by 19%, supplementation with grape seed or myrabolan extract increased acetate production. However, degradation of fibre fractions was reduced in all tannin treatments. Degradation of dry matter and organic matter was also reduced by tannin supplementation, and no differences were found between the tannin-rich extracts. CP degradation and ammonia

  15. Electrochemical removal of tannins from aqueous solutions

    SciTech Connect

    Buso, A.; Balbo, L.; Giomo, M.

    2000-02-01

    The application of electrochemical methods to remove tannins from wastewater was investigated. Gallotannic acid was used as the reference substance. Electrochemical experiments were performed using platinum electrodes. Macroscale potentiostatic or galvanostatic electrolyses were carried out with sodium sulfate or sodium chloride as supporting electrolytes, to analyze direct and indirect oxidation processes. Operating variables such as pH and chloride concentration were considered to determine their influence on the efficiency and energy consumption of the process. The simulation of a pilot plant was carried out with a mathematical model, the parameters of which were determined by fitting of experimental profiles. The resultsmore » of a preliminary investigation on the oxidation-coagulation process using sacrificial electrodes are also reported.« less

  16. Alcohol, wine and platelet function.

    PubMed

    Ruf, Jean-Claude

    2004-01-01

    Epidemiological studies have demonstrated an inverse correlation between moderate wine and alcohol consumption and morbidity and mortality from coronary heart disease. The protective effect has been associated with an increase in the plasma level of HDL cholesterol, as it is well recognized that plasma HDL is inversely correlated with CHD. In addition, it has become evident that blood platelets contribute to the rate of development of atherosclerosis and CHD through several mechanisms. In recent studies it has been shown that the level of HDL cholesterol can explain only 50% of the protective effect of alcoholic beverages; the other 50% may be partly related to a decrease in platelet activity. This anti-platelet activity of wine is explained by ethanol but also by the polyphenolic components with which red wines are richly endowed. Several studies carried out on humans and animals have shown that wine phenolics could exert their effects by reducing prostanoid synthesis from arachidonate. In addition, it has been suggested that wine phenolics could reduce platelet activity mediated by nitric oxide. Moreover, wine phenolics increase vitamin E levels while decreasing the oxidation of platelets submitted to oxidative stress. However, a rebound phenomenon of hyperaggregability is observed after an acute alcohol consumption which is not observed with wine consumption. This protection afforded by wine has been duplicated in animals with grape phenolics added to alcohol. The rebound phenomenon may explain ischemic strokes or sudden deaths known to occur after episodes of drunkenness. It appears that wine, and wine phenolics in particular, could have a more significant inhibitory effect on platelet aggregation and could explain, in part, the hypothesis that red wine is more protective against atherosclerosis and coronary heart disease.

  17. Wine Expertise Predicts Taste Phenotype

    PubMed Central

    Hayes, John E; Pickering, Gary J

    2011-01-01

    Taste phenotypes have long been studied in relation to alcohol intake, dependence, and family history, with contradictory findings. However, on balance – with appropriate caveats about populations tested, outcomes measured and psychophysical methods used – an association between variation in taste responsiveness and some alcohol behaviors is supported. Recent work suggests super-tasting (operationalized via propylthiouracil (PROP) bitterness) not only associates with heightened response but also with more acute discrimination between stimuli. Here, we explore relationships between food and beverage adventurousness and taste phenotype. A convenience sample of wine drinkers (n=330) were recruited in Ontario and phenotyped for PROP bitterness via filter paper disk. They also filled out a short questionnaire regarding willingness to try new foods, alcoholic beverages and wines as well as level of wine involvement, which was used to classify them as a wine expert (n=110) or wine consumer (n=220). In univariate logisitic models, food adventurousness predicted trying new wines and beverages but not expertise. Likewise, wine expertise predicted willingness to try new wines and beverages but not foods. In separate multivariate logistic models, willingness to try new wines and beverages was predicted by expertise and food adventurousness but not PROP. However, mean PROP bitterness was higher among wine experts than wine consumers, and the conditional distribution functions differed between experts and consumers. In contrast, PROP means and distributions did not differ with food adventurousness. These data suggest individuals may self-select for specific professions based on sensory ability (i.e., an active gene-environment correlation) but phenotype does not explain willingness to try new stimuli. PMID:22888174

  18. Wine Expertise Predicts Taste Phenotype.

    PubMed

    Hayes, John E; Pickering, Gary J

    2012-03-01

    Taste phenotypes have long been studied in relation to alcohol intake, dependence, and family history, with contradictory findings. However, on balance - with appropriate caveats about populations tested, outcomes measured and psychophysical methods used - an association between variation in taste responsiveness and some alcohol behaviors is supported. Recent work suggests super-tasting (operationalized via propylthiouracil (PROP) bitterness) not only associates with heightened response but also with more acute discrimination between stimuli. Here, we explore relationships between food and beverage adventurousness and taste phenotype. A convenience sample of wine drinkers (n=330) were recruited in Ontario and phenotyped for PROP bitterness via filter paper disk. They also filled out a short questionnaire regarding willingness to try new foods, alcoholic beverages and wines as well as level of wine involvement, which was used to classify them as a wine expert (n=110) or wine consumer (n=220). In univariate logisitic models, food adventurousness predicted trying new wines and beverages but not expertise. Likewise, wine expertise predicted willingness to try new wines and beverages but not foods. In separate multivariate logistic models, willingness to try new wines and beverages was predicted by expertise and food adventurousness but not PROP. However, mean PROP bitterness was higher among wine experts than wine consumers, and the conditional distribution functions differed between experts and consumers. In contrast, PROP means and distributions did not differ with food adventurousness. These data suggest individuals may self-select for specific professions based on sensory ability (i.e., an active gene-environment correlation) but phenotype does not explain willingness to try new stimuli.

  19. 27 CFR 24.294 - Destruction of wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Destruction of wine. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Removal, Return and Receipt of Wine Removals Without Payment of Tax § 24.294 Destruction of wine. (a) General. Wine on bonded wine premises may be destroyed on or off wine...

  20. Impact of Increasing Levels of Oxygen Consumption on the Evolution of Color, Phenolic, and Volatile Compounds of Nebbiolo Wines.

    PubMed

    Petrozziello, Maurizio; Torchio, Fabrizio; Piano, Federico; Giacosa, Simone; Ugliano, Maurizio; Bosso, Antonella; Rolle, Luca

    2018-01-01

    Since the end of the last century, many works have been carried out to verify the effect of controlled oxygen intake on the chemical and organoleptic characteristics of red wines. In spite of the large number of studies on this subject, oxygen remains a cutting-edge research topic in oenology. Oxygen consumption leads to complex and not univocal changes in wine composition, sometimes positive such as color stabilization, softening of mouthfeel, increase of aroma complexity. However, the variability of these effects, which depend both on the oxygenation conditions and the composition of the wine, require more efforts in this research field to effectively manage wine oxygen exposure. The present study is focused on the evolution of the chemical composition of four different Nebbiolo wines, each of them added with 4 different doses of oxygen (7, 14, 21, and 28 mg/L total intake) during the first month of storage. In this perspective, the evolution over time of wine color and polyphenols was studied. Acetaldehyde, glyceraldehyde and glyoxylic acid were quantified by HPLC. These compounds can play a role in wine aging creating condensed colored and stable products involving anthocyanins with or without tannins. Moreover, some volatile aldehydes correlated with oxidized olfactory notes, including methional and (E)-2-alkenals, have been quantified by GC-MS. Overall, during storage a decrease of color intensity, total and free anthocyanins and an increase in polymeric pigments (in particular the contribution to the red color of pigments not-bleachable by SO 2 or dTAT%) and some minor aldehydes was observed. Nevertheless, the differences in color parameters between the samples with different doses of oxygen were modest. These evidences were in contrast with an evident and detectable increase of free acetaldehyde content at increasing doses of oxygen measured after 60 days of storage. The effect of oxygen on color and production of SO 2 non-bleachable pigments during aging

  1. Impact of Increasing Levels of Oxygen Consumption on the Evolution of Color, Phenolic, and Volatile Compounds of Nebbiolo Wines

    PubMed Central

    Petrozziello, Maurizio; Torchio, Fabrizio; Piano, Federico; Giacosa, Simone; Ugliano, Maurizio; Bosso, Antonella; Rolle, Luca

    2018-01-01

    Since the end of the last century, many works have been carried out to verify the effect of controlled oxygen intake on the chemical and organoleptic characteristics of red wines. In spite of the large number of studies on this subject, oxygen remains a cutting-edge research topic in oenology. Oxygen consumption leads to complex and not univocal changes in wine composition, sometimes positive such as color stabilization, softening of mouthfeel, increase of aroma complexity. However, the variability of these effects, which depend both on the oxygenation conditions and the composition of the wine, require more efforts in this research field to effectively manage wine oxygen exposure. The present study is focused on the evolution of the chemical composition of four different Nebbiolo wines, each of them added with 4 different doses of oxygen (7, 14, 21, and 28 mg/L total intake) during the first month of storage. In this perspective, the evolution over time of wine color and polyphenols was studied. Acetaldehyde, glyceraldehyde and glyoxylic acid were quantified by HPLC. These compounds can play a role in wine aging creating condensed colored and stable products involving anthocyanins with or without tannins. Moreover, some volatile aldehydes correlated with oxidized olfactory notes, including methional and (E)-2-alkenals, have been quantified by GC-MS. Overall, during storage a decrease of color intensity, total and free anthocyanins and an increase in polymeric pigments (in particular the contribution to the red color of pigments not-bleachable by SO2 or dTAT%) and some minor aldehydes was observed. Nevertheless, the differences in color parameters between the samples with different doses of oxygen were modest. These evidences were in contrast with an evident and detectable increase of free acetaldehyde content at increasing doses of oxygen measured after 60 days of storage. The effect of oxygen on color and production of SO2 non-bleachable pigments during aging

  2. Impact of increasing levels of oxygen consumption on the evolution of color, phenolic and volatile compounds of Nebbiolo wines

    NASA Astrophysics Data System (ADS)

    Petrozziello, Maurizio; Torchio, Fabrizio; Piano, Federico; Giacosa, Simone; Ugliano, Maurizio; Bosso, Antonella; Rolle, Luca

    2018-04-01

    Since the end of the last century, many works have been carried out to verify the effect of controlled oxygen intake on the chemical and organoleptic characteristics of red wines. In spite of the large number of studies on this subject, oxygen remains a cutting-edge research topic in oenology. Oxygen consumption leads to complex and not univocal changes in wine composition, sometimes positive such as color stabilization, softening of mouthfeel, increase of aroma complexity. However, the variability of these effects, which depend both on the oxygenation conditions and the composition of the wine, require more efforts in this research field to effectively manage wine oxygen exposure. The present study is focused on the evolution of the chemical composition of four different Nebbiolo wines, each of them added with 4 different doses of oxygen (7, 14, 21, and 28 mg/L total intake) during the first month of storage. In this perspective, the evolution over time of wine color and polyphenols was studied. Acetaldehyde, glyceraldehyde and glyoxylic acid were quantified by HPLC. These compounds can play a role in wine aging creating condensed colored and stable products involving anthocyanins with or without tannins. Moreover, some volatile aldehydes correlated with oxidized olfactory notes, including methional and (E)-2-alkenals, have been quantified by GC-MS. Overall, during storage a decrease of color intensity, total and free anthocyanins and an increase in polymeric pigments (in particular the contribution to the red color of pigments not-bleachable by SO2 or dTAT%) and some minor aldehydes was observed. Nevertheless, the differences in color parameters between the samples with different doses of oxygen were modest. These evidences were in contrast with an evident and detectable increase of free acetaldehyde content at increasing doses of oxygen measured after 60 days of storage. The effect of oxygen on color and production of SO2 non-bleachable pigments during ageing

  3. Use of whole grain and refined flour from tannin and non-tannin sorghum (Sorghum bicolor (L.) Moench) varieties in frybread.

    PubMed

    Rose, Devin J; Williams, Emily; Mkandawire, Nyambe L; Weller, Curtis L; Jackson, David S

    2014-07-01

    Frybreads were prepared using wheat flour and wheat-sorghum composite flours (refined and whole grain; white, tannin-free and red, tannin-containing) at 0, 25, 50, and 75% sorghum flour. Hardness, volume, specific volume, color, and oil uptake were determined. Frybreads made with refined white, tannin-free sorghum were also evaluated in a sensory panel. Substitution of sorghum flour for wheat flour reduced the volume and increased the darkness of the fried dough pieces compared with wheat flour controls. Oil absorption was unaffected when using white, tannin-free sorghum. When using red, tannin-containing sorghum, oil absorption increased for refined flour and decreased for whole grain flour, suggesting that a component only present in the whole grain tannin-containing Sorghum--perhaps tannins themselves--may decrease oil uptake. Panelists rated frybreads containing up to 50% white, tannin-free sorghum flour as not significantly different from control frybreads made with refined wheat flour.

  4. In vitro assay to estimate tea astringency via observing flotation of artificial oil bodies sheltered by caleosin fused with histatin 3.

    PubMed

    Shih, Yu-En; Lin, Yu-Chih; Chung, Tse-Yu; Liu, Mei-Chun; Chen, Guan-Heng; Wu, Chia-Chang; Tzen, Jason T C

    2017-10-01

    Astringency, a sensory characteristic of food and beverages rich in polyphenols, mainly results from the formation of complexes between polyphenols and salivary proteins, causing a reduction of the lubricating properties of saliva. To develop an in vitro assay to estimate the astringency of oolong tea infusion, artificial oil bodies were constituted with sesame oil sheltered by a modified caleosin fused with histatin 3, one of the human salivary small peptides. Aggregation of artificial oil bodies was induced when they were mixed with oolong tea infusion or its major polyphenolic compound, (-)-epigallocatechin gallate (EGCG) of 100μM as observed in light microscopy. The aggregated artificial oil bodies gradually floated on top of the solution and formed a visible milky layer whose thickness was in proportion to the concentrations of tea infusion. This assay system was applied to test four different oolong tea infusions with sensory astringency corresponding to their EGCG contents. The result showed that relative astringency of the four tea infusions was correlated to the thickness of floated artificial oil bodies, and could be estimated according to the standard curve generated by simultaneously observing a serial dilution of the tea infusion with the highest astringency. Copyright © 2016. Published by Elsevier B.V.

  5. The health benefits of wine.

    PubMed

    German, J B; Walzem, R L

    2000-01-01

    Epidemiologic studies from numerous disparate populations reveal that individuals with the habit of daily moderate wine consumption enjoy significant reductions in all-cause and particularly cardiovascular mortality when compared with individuals who abstain or who drink alcohol to excess. Researchers are working to explain this observation in molecular and nutritional terms. Moderate ethanol intake from any type of beverage improves lipoprotein metabolism and lowers cardiovascular mortality risk. The question now is whether wine, particularly red wine with its abundant content of phenolic acids and polyphenols, confers additional health benefits. Discovering the nutritional properties of wine is a challenging task, which requires that the biological actions and bioavailability of the >200 individual phenolic compounds be documented and interpreted within the societal factors that stratify wine consumption and the myriad effects of alcohol alone. Further challenge arises because the health benefits of wine address the prevention of slowly developing diseases for which validated biomarkers are rare. Thus, although the benefits of the polyphenols from fruits and vegetables are increasingly accepted, consensus on wine is developing more slowly. Scientific research has demonstrated that the molecules present in grapes and in wine alter cellular metabolism and signaling, which is consistent mechanistically with reducing arterial disease. Future research must address specific mechanisms both of alcohol and of polyphenolic action and develop biomarkers of their role in disease prevention in individuals.

  6. Cardioprotective abilities of white wine.

    PubMed

    Cui, Jianhua; Tosaki, Arpad; Cordis, Gerald A; Bertelli, Alberto A E; Bertelli, Aldo; Maulik, Nilanjana; Das, Dipak K

    2002-05-01

    To study if white wines, like red wine, can also protect the heart from ischemia reperfusion injury, ethanol-free extracts of three different white wines (WW1, WW2 and WW3) (100 mg/100 g body weight) were given orally to Sprague Dawley rats (200 g body weight) for three weeks. Control rats were given water only for the same period of time. After three weeks, rats were anesthetized and sacrificed, and the hearts excised for the preparation of isolated working rat heart. All hearts were subjected to 30 min global ischemia followed by two hours of reperfusion. The results demonstrated that among the three different white wines, only WW2 showed cardioprotection as evidenced by improved post-ischemic ventricular recovery compared to control. The amount of malonaldehyde production in white wine-fed rat hearts were lower compared to that found in control hearts indicating reduced formation of the reactive oxygen species. In vitro studies using chemiluminescence technique revealed that these white wines scavenged both superoxide anions and hydroxyl radicals. The results of our study demonstrated that only WW2 white wine provided cardioprotection as evidenced by the improved the post-ischemic contractile recovery and reduced myocardial infarct size. The cardioprotective effect of this white wine may be attributed, at least in part, from its ability to function as an in vivo antioxidant.

  7. Tasting Wine: A Learning Experience

    ERIC Educational Resources Information Center

    King, Tanya J.; Donaldson, Jilleen A.; Harry, Emma

    2012-01-01

    This paper describes a field trip by senior undergraduate anthropology students to a local winery, where they participated in a wine-tasting class with winery staff. In response to explicit hints from a wine-tasting facilitator, and more subtle cues from the cultural capital embedded in their surroundings and the winery staff, the students…

  8. Influence of bottle storage time on colour, phenolic composition and sensory properties of sweet red wines.

    PubMed

    Marquez, Ana; Serratosa, Maria P; Merida, Julieta

    2014-03-01

    Changes in colour and phenolic composition in sweet red wines made from Merlot, Syrah and Tempranillo grapes were studied in order to assess the influence of bottle storage over a period of 12months. For this purpose, wine colour parameters, sensory analysis and concentrations of monomeric anthocyanins, pyranoanthocyanins, methylmethine-mediated condensation adducts, flavan3-ol derivatives and flavonols were measured. Hue increased and red colours decreased with the storage time, particularly over the first 3months. The concentrations of low molecular weight flavan-3-ol derivatives decreased with time due to the effect of their conversion into tannins of high molecular weight. In addition, the glycosylated flavonols decreased through hydrolysis to give the corresponding aglycones. Overall, the concentration of phenolic compounds decreased markedly with storage time, whereas the antioxidant activity in the wines remained constant throughout. A panel of expert tasters judged the colour, aroma and flavour of all initial and final wines to be acceptable. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Tannins from Canarium album with potent antioxidant activity.

    PubMed

    Zhang, Liang-liang; Lin, Yi-ming

    2008-05-01

    The contents of total phenolics and extractable condensed tannins in the leaves, twigs and stem bark of Canarium album were determined. The structural heterogeneity of condensed tannins from stem bark was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and nuclear magnetic resonance (NMR) analyses. The results show the predominance of signals representative of procyanidins and prodelphinidins. In addition, epicatechin and epigallocatechin polymers with galloylated procyanidin or prodelphinidin were also observed. The tannins were screened for their potential antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) model systems. Tannins extracted from leaves, twigs and stem bark all showed a very good DPPH radical scavenging activity and ferric reducing power.

  10. Tannins from Canarium album with potent antioxidant activity*

    PubMed Central

    Zhang, Liang-liang; Lin, Yi-ming

    2008-01-01

    The contents of total phenolics and extractable condensed tannins in the leaves, twigs and stem bark of Canarium album were determined. The structural heterogeneity of condensed tannins from stem bark was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and nuclear magnetic resonance (NMR) analyses. The results show the predominance of signals representative of procyanidins and prodelphinidins. In addition, epicatechin and epigallocatechin polymers with galloylated procyanidin or prodelphinidin were also observed. The tannins were screened for their potential antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) model systems. Tannins extracted from leaves, twigs and stem bark all showed a very good DPPH radical scavenging activity and ferric reducing power. PMID:18500781

  11. 27 CFR 19.534 - Withdrawals of spirits for use in production of nonbeverage wine and nonbeverage wine products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... use in production of nonbeverage wine and nonbeverage wine products. 19.534 Section 19.534 Alcohol... Withdrawals of spirits for use in production of nonbeverage wine and nonbeverage wine products. Spirits... bonded wine cellar for use in the production of nonbeverage wine and nonbeverage wine products. (Sec. 455...

  12. Increased mannoprotein content in wines produced by Saccharomyces kudriavzevii×Saccharomyces cerevisiae hybrids.

    PubMed

    Pérez-Través, Laura; Querol, Amparo; Pérez-Torrado, Roberto

    2016-11-21

    Several wine quality aspects are influenced by yeast mannoproteins on account of aroma compounds retention, lactic-acid bacterial growth stimulation, protection against protein haze and astringency reduction. Thus selecting a yeast strain that produces high levels of mannoproteins is important for the winemaking industry. In this work, we observed increased levels of mannoproteins in S. cerevisiae×S. kudriavzevii hybrids, compared to the S. cerevisiae strain, in wine fermentations. Furthermore, the expression of a key gene related to mannoproteins biosynthesis, PMT1, increased in the S. cerevisiae×S. kudriavzevii hybrid. We showed that artificially constructed S. cerevisiae×S. kudriavzevii hybrids also increased the levels of mannoproteins. This work demonstrates that either natural or artificial S. cerevisiae×S. kudriavzevii hybrids present mannoprotein overproducing capacity under winemaking conditions, a desirable physiological feature for this industry. These results suggest that genome interaction in hybrids generates a physiological environment that enhances the release of mannoproteins. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Sealing and anti-corrosive action of tannin rust converters

    SciTech Connect

    Gust, J.; Bobrowicz, J.

    1993-01-01

    A possibility of the application of mercury porosimetry in the investigation on porosity in corrosion products of the carbon steel along with the degree of sealing by the use of tannin rust converters is presented. The effect of the atmospheric humidity on the rust conversion including the time of that conversion on the degree of rust sealing is discussed. The results of the corrosion investigation of carbon steel covered with a layer of the rust converted with tannin-containing agents are presented.

  14. Hydrolyzable and condensed tannins resistance in Clostridium perfringens.

    PubMed

    Redondo, L M; Dominguez, J E; Rabinovitz, B C; Redondo, E A; Fernández Miyakawa, M E

    2015-08-01

    Tannins added in the diet are being used to improve nutrition and health in farm animals as an alternative to antibiotic growth promoters and to control enteric clostridial diseases. However, the capacity of Clostridium perfringens to develop resistance under the selective pressure of tannins is unknown. The purpose of this study was to determine if C. perfringens possess the ability to develop resistance against tannins in comparison with antimicrobial agents. Susceptibility for 7 AGPs (antimicrobial growth promoters), 9 therapeutic antimicrobials and 2 tannin based extracts was determined for 30 C. perfringens strains isolated from poultry and cattle. Two susceptible strains were selected and cultured in presence of sub-inhibitory concentrations of tannins and AGPs for resistant sub-populations selection. Tannin resistance of C. perfringens isolates from both animal species revealed no statistically significant differences in MICs (minimum inhibitory concentration). Poultry isolates showed higher MICs to several AGPs compared with cattle isolates. All isolates were susceptible to the therapeutic antimicrobials tested, but avian isolates showed a significantly lower susceptibility to these antimicrobials which was highly correlated with an increased resistance to bacitracin and others AGPs. In-vitro selection of resistant clones suggests that C. perfringens was unable to develop resistance against tannins at least compared to AGPs like bacitracin and avilamycin. Avian origin strains, which were previously exposed to antibiotics showed higher resistance, compared to cattle origin strains. These results suggest that the evolution of resistance against tannins in C. perfringens would be more difficult and slower than to the determined AGPs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Rapid screening of tannase producing microbes by using natural tannin

    PubMed Central

    Jana, Arijit; Maity, Chiranjit; Halder, Suman Kumar; Pati, Bikas Ranjan; Mondal, Keshab Chandra; Mohapatra, Pradeep Kumar Das

    2012-01-01

    Use of natural tannin in the screening of tannase producing microbes is really promising. The present work describes about the possibility and integrity of the newly formulated method over the previously reported methods. Tannin isolated from Terminalia belerica Roxb. (Bahera) was used to differentiate between tanninolytic and nontanninolytic microbes. The method is simple, sensitive and superior for the rapid screening and isolation of tannase-producing microbes. PMID:24031931

  16. Rapid screening of tannase producing microbes by using natural tannin.

    PubMed

    Jana, Arijit; Maity, Chiranjit; Halder, Suman Kumar; Pati, Bikas Ranjan; Mondal, Keshab Chandra; Mohapatra, Pradeep Kumar Das

    2012-07-01

    Use of natural tannin in the screening of tannase producing microbes is really promising. The present work describes about the possibility and integrity of the newly formulated method over the previously reported methods. Tannin isolated from Terminalia belerica Roxb. (Bahera) was used to differentiate between tanninolytic and nontanninolytic microbes. The method is simple, sensitive and superior for the rapid screening and isolation of tannase-producing microbes.

  17. Effect of tannins on the in vitro growth of Clostridium perfringens.

    PubMed

    Elizondo, Ana M; Mercado, Elsa C; Rabinovitz, Bettina C; Fernandez-Miyakawa, Mariano E

    2010-10-26

    Vegetable tannins are water-soluble polyphenolic compounds of varying molecular weights that occur abundantly in nature. The diet of many free-ranging wild animals contains significant amounts of tannins. Also, commercial tannins are used in animal industry as food additives to improve animal performance. In order to further determine the capacity of tannins to inhibit the development of intestinal diseases produced by Clostridium pefringens, we evaluated here the effect of tannins from quebracho, chestnut or combinations of both on C. perfringens and their toxins. The C. perfringens (types A, B, C, D and E) growth obtained from the intestine of healthy and diseased animals was reduced in a dose-dependent manner in the presence of quebracho tannins, chestnut tannins, combinations of both or a commercial formula based in these tannins. Although the minimal inhibitory concentration of both tannins varied between isolates, no statistically significant differences were observed between isolates from healthy or sick animals. Comparative analysis showed that the concentrations of quebracho tannin inhibiting the growth of C. perfringens were higher than chestnut tannin. In fact, antibacterial effect of quebracho tannin was increased up to 20 times with the addition of 25% of chestnut tannin and 85 times with 75% of chestnut tannin. Antibacterial activity of the commercial product was up to ~50 times higher than quebracho tannin alone. Quebracho tannin showed partial bactericidal activity, whereas chestnut tannin activity was stronger. Both tannins were able to reduce the alpha toxin lecithinase activity and epsilon toxin cytotoxicity in MDCK cells. These results suggest that tannin-supplemented diet could be useful to prevent some clostridial diseases. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review.

    PubMed

    Delimont, Nicole M; Rosenkranz, Sara K; Haub, Mark D; Lindshield, Brian L

    2017-01-01

    Tannins are often cited for antinutritional effects, including chelation of non-heme iron. Despite this, studies exploring non-heme iron bioavailability inhibition with long-term consumption have reported mixed results. Salivary proline-rich proteins (PRPs) may mediate tannin-antinutritional effects on non-heme iron bioavailability. To review evidence regarding biochemical binding mechanisms and affinity states between PRPs and tannins, as well as effects of PRPs on non-heme iron bioavailability with tannin consumption in vivo. Narrative systematic review and meta-analysis. Common themes in biochemical modeling and affinity studies were collated for summary and synthesis; data were extracted from in vivo experiments for meta-analysis. Thirty-two studies were included in analysis. Common themes that positively influenced tannin-PRP binding included specificity of tannin-PRP binding, PRP and tannin stereochemistry. Hydrolyzable tannins have different affinities than condensed tannins when binding to PRPs. In vivo, hepatic iron stores and non-heme iron absorption are not significantly affected by tannin consumption ( d  = -0.64-1.84; -2.7-0.13 respectively), and PRP expression may increase non-heme iron bioavailability with tannin consumption. In vitro modeling suggests that tannins favor PRP binding over iron chelation throughout digestion. Hydrolyzable tannins are not representative of tannin impact on non-heme iron bioavailability in food tannins because of their unique structural properties and PRP affinities. With tannin consumption, PRP production is increased, and may be an initial line of defense against tannin-non-heme iron chelation in vivo . More research is needed to compare competitive binding of tannin-PRP to tannin-non-heme iron complexes, and elucidate PRPs' role in adaption to non-heme iron bioavailability in vivo.

  19. Hydrolyzable tannins of tamaricaceous plants. V. Structures of monomeric-trimeric tannins and cytotoxicity of macrocyclic-type tannins isolated from Tamarix nilotica (1).

    PubMed

    Orabi, Mohamed A A; Taniguchi, Shoko; Sakagami, Hiroshi; Yoshimura, Morio; Yoshida, Takashi; Hatano, Tsutomu

    2013-05-24

    Three new ellagitannin monomers, nilotinins M5-M7 (1-3), a dimer, nilotinin D10 (4), and a trimer, nilotinin T1 (5), together with three known dimers, hirtellin D (7) and tamarixinins B (8) and C (9), and a trimer, hirtellin T2 (6), were isolated from Tamarix nilotica dried leaves. The structures of the tannins were elucidated by intensive spectroscopic methods and chemical conversions into known tannins. The new trimer (5) is a unique macrocyclic type whose monomeric units are linked together by an isodehydrodigalloyl and two dehydrodigalloyl moieties. Additionally, dimeric and trimeric macrocyclic-type tannins isolated from T. nilotica in this study were assessed for possible cytotoxic activity against four human tumor cell lines. Tumor-selective cytotoxicities of the tested compounds were higher than those of synthetic and natural potent cytotoxic compounds, including polyphenols, and comparable with those of 5-fluorouracil and melphalan.

  20. Resveratrol, Wine, and Atherosclerosis

    PubMed Central

    Prasad, Kailash

    2012-01-01

    This review emphasizes the effects of resveratrol on factors involved in the mechanism of atherosclerosis and risk factors for atherosclerosis. The effects of wine and resveratrol on atherosclerosis are also discussed. Resveratrol is a potent antioxidant and an anti-inflammatory agent. It reduces the expression of cell adhesion molecules, monocyte colony stimulating factors, matrix metalloproteinases, and growth factors; and inhibits platelet aggregation and vascular smooth muscle cell proliferation. It reduces the serum levels of total cholesterol, triglycerides (TG), and raises high-density lipoprotein cholesterol, inhibits expression of C-reactive protein and lowers the levels of advanced glycation end products and its receptor in the vascular tissue. It lowers the risk factors for plaque rupture. Epidemiological data show that moderate consumption of alcohol has an inverse association with carotid atherosclerosis while high consumption has a positive association with carotid atherosclerosis. Wine reduces the extent of atherosclerosis in animal model. The antiatherosclerotic effect of wine is mainly due to it resveratrol content. Resveratrol reduces the extent of atherosclerosis in animal model of atherosclerosis (apolipoprotein [Apo] E-deficient and Apo E−/−/low-density lipoprotein receptor-deficient mice and macrophage). In rabbit model of atherosclerosis, both reduction and acceleration of atherosclerosis have been reported with resveratrol. There are no data for regression and slowing of progression of atherosclerosis. Robust clinical trials for suppression of atherosclerosis are lacking. In conclusion, resveratrol has potential but experimental studies in depth and robust clinical trials are lacking for this agent to be of any value in the primary and secondary prevention of coronary and peripheral artery disease. PMID:23450206

  1. Ancient Egyptian herbal wines

    PubMed Central

    McGovern, Patrick E.; Mirzoian, Armen; Hall, Gretchen R.

    2009-01-01

    Chemical analyses of ancient organics absorbed into pottery jars from the beginning of advanced ancient Egyptian culture, ca. 3150 B.C., and continuing for millennia have revealed that a range of natural products—specifically, herbs and tree resins—were dispensed by grape wine. These findings provide chemical evidence for ancient Egyptian organic medicinal remedies, previously only ambiguously documented in medical papyri dating back to ca. 1850 B.C. They illustrate how humans around the world, probably for millions of years, have exploited their natural environments for effective plant remedies, whose active compounds have recently begun to be isolated by modern analytical techniques. PMID:19365069

  2. 27 CFR 24.210 - Classes of wine other than standard wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... fermentation wine, produced as provided in § 24.212; (b) Heavy bodied blending wine, produced as provided in...; (f) Vinegar stock, produced as provided in § 24.217; and (g) Wines other than those in classes listed...

  3. Effect of Condensed Tannins on Bacterial Diversity and Metabolic Activity in the Rat Gastrointestinal Tract

    PubMed Central

    Smith, Alexandra H.; Mackie, Roderick I.

    2004-01-01

    The effect of dietary condensed tannins (proanthocyanidins) on rat fecal bacterial populations was ascertained in order to determine whether the proportion on tannin-resistant bacteria increased and if there was a change in the predominant bacterial populations. After 3 weeks of tannin diets the proportion of tannin-resistant bacteria increased significantly (P < 0.05) from 0.3% ± 5.5% to 25.3% ± 8.3% with a 0.7% tannin diet and to 47.2% ± 5.1% with a 2% tannin diet. The proportion of tannin-resistant bacteria returned to preexposure levels in the absence of dietary tannins. A shift in bacterial populations was confirmed by molecular fingerprinting of fecal bacterial populations by denaturing gradient gel electrophoresis (DGGE). Posttreatment samples were generally still distinguishable from controls after 3.5 weeks. Sequence analysis of DGGE bands and characterization of tannin-resistant isolates indicated that tannins selected for Enterobacteriaceae and Bacteroides species. Dot blot quantification confirmed that these gram-negative bacterial groups predominated in the presence of dietary tannins and that there was a corresponding decrease in the gram-positive Clostridium leptum group and other groups. Metabolic fingerprint patterns revealed that functional activities of culturable fecal bacteria were affected by the presence of tannins. Condensed tannins of Acacia angustissima altered fecal bacterial populations in the rat gastrointestinal tract, resulting in a shift in the predominant bacteria towards tannin-resistant gram-negative Enterobacteriaceae and Bacteroides species. PMID:14766594

  4. Investigation of the effect of gelatine, egg albumin and cross-flow microfiltration on the phenolic composition of Pinotage wine.

    PubMed

    Oberholster, A; Carstens, L M; du Toit, W J

    2013-06-01

    The effect of fining and cross-flow microfiltration on the phenolic composition of red wine was investigated. Both gelatine (G) and egg albumin (EA) fining decreased the mean degree of polymerisation (mDP) of tannin significantly by 26.4% and 25.2%, respectively, compared to the control (C). Cross-flow microfiltration (CF) also decreased the mDP significantly by 25%. Thus, the fining agents and cross-flow microfiltration selectively removed the highly polymerised phenols. After 3.5 months of bottle ageing, differences between the different treatments and the control decreased. CF had the most significant effect on the flavan-3-ol and polymeric phenol (tannin) content of the wines compared to the control followed by G fining. CF and EA treatments significantly decreased the total pigment content compared to C. CF was also the only treatment that could be distinguished from the other treatments by sensory analysis. All treatments improved clarity of the wines with cross-flow microfiltration having the largest effect. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Presence of tannins in sorghum grains is conditioned by different natural alleles of Tannin1

    PubMed Central

    Wu, Yuye; Li, Xianran; Xiang, Wenwen; Zhu, Chengsong; Lin, Zhongwei; Wu, Yun; Li, Jiarui; Pandravada, Satchidanand; Ridder, Dustan D.; Bai, Guihua; Wang, Ming L.; Trick, Harold N.; Bean, Scott R.; Tuinstra, Mitchell R.; Tesso, Tesfaye T.; Yu, Jianming

    2012-01-01

    Sorghum, an ancient old-world cereal grass, is the dietary staple of over 500 million people in more than 30 countries in the tropics and semitropics. Its C4 photosynthesis, drought resistance, wide adaptation, and high nutritional value hold the promise to alleviate hunger in Africa. Not present in other major cereals, such as rice, wheat, and maize, condensed tannins (proanthocyanidins) in the pigmented testa of some sorghum cultivars have been implicated in reducing protein digestibility but recently have been shown to promote human health because of their high antioxidant capacity and ability to fight obesity through reduced digestion. Combining quantitative trait locus mapping, meta-quantitative trait locus fine-mapping, and association mapping, we showed that the nucleotide polymorphisms in the Tan1 gene, coding a WD40 protein, control the tannin biosynthesis in sorghum. A 1-bp G deletion in the coding region, causing a frame shift and a premature stop codon, led to a nonfunctional allele, tan1-a. Likewise, a different 10-bp insertion resulted in a second nonfunctional allele, tan1-b. Transforming the sorghum Tan1 ORF into a nontannin Arabidopsis mutant restored the tannin phenotype. In addition, reduction in nucleotide diversity from wild sorghum accessions to landraces and cultivars was found at the region that codes the highly conserved WD40 repeat domains and the C-terminal region of the protein. Genetic research in crops, coupled with nutritional and medical research, could open the possibility of producing different levels and combinations of phenolic compounds to promote human health. PMID:22699509

  6. Wines in contact with oak wood: the impact of the variety (Carménère and Cabernet Sauvignon), format (barrels, chips and staves) and aging time on the phenolic composition.

    PubMed

    Laqui-Estaña, Jaime; López-Solís, Remigio; Peña-Neira, Álvaro; Medel-Marabolí, Marcela; Obreque-Slier, Elías

    2018-06-13

    This study characterized the flavonoid and non-flavonoid phenolic composition of Carménère and Cabernet Sauvignon wines that were in contact with barrels, chips and staves during a 12-month aging period. The wines were evaluated by spectrophotometric (for total phenols, anthocyanins and tannins, colorant intensity, hue, CIElab parameters and fractionation into mono-, oligo- and polymer of proanthocyanidins) and HPLC-DAD analyses (for ellagitannins, gallotannins, anthocyanins and low molecular weight phenols). Wines in contact with oak wood presented a strong enrichment with non-flavonoid compounds, such as caffeic, gallic, ellagic acids and ellagitannins. Wines in contact with staves stood out for the increased presence of total phenols, vanillic acid and higher color intensity, while wines aged in contact with chips showed large contents of proanthocyanidin gallates. Wines aged in barrels exhibited high contents of ellagitannins and ethyl gallates. The effect of wood on the phenolic composition was mostly associated to the original and intrinsic characteristics of each grape variety. Extraction of phenolic compounds from oak wood during wine aging is closely related to the wood format, grape variety (Carménère or Cabernet Sauvignon) and aging time. The final effect of wood on wine would be related not just to the transference of polyphenols from wood but also to structural modifications of grape polyphenols. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. Tree resistance to Lymantria dispar caterpillars: importance and limitations of foliar tannin composition.

    PubMed

    Barbehenn, Raymond V; Jaros, Adam; Lee, Grace; Mozola, Cara; Weir, Quentin; Salminen, Juha-Pekka

    2009-04-01

    The ability of foliar tannins to increase plant resistance to herbivores is potentially determined by the composition of the tannins; hydrolyzable tannins are much more active as prooxidants in the guts of caterpillars than are condensed tannins. By manipulating the tannin compositions of two contrasting tree species, this work examined: (1) whether increased levels of hydrolyzable tannins increase the resistance of red oak (Quercus rubra L.), a tree with low resistance that produces mainly condensed tannins, and (2) whether increased levels of condensed tannins decrease the resistance of sugar maple (Acer saccharum Marsh.), a tree with relatively high resistance that produces high levels of hydrolyzable tannins. As expected, when Lymantria dispar L. caterpillars ingested oak leaves coated with hydrolyzable tannins, levels of hydrolyzable tannin oxidation increased in their midgut contents. However, increased tannin oxidation had no significant impact on oxidative stress in the surrounding midgut tissues. Although growth efficiencies were decreased by hydrolyzable tannins, growth rates remained unchanged, suggesting that additional hydrolyzable tannins are not sufficient to increase the resistance of oak. In larvae on condensed tannin-coated maple, no antioxidant effects were observed in the midgut, and levels of tannin oxidation remained high. Consequently, neither oxidative stress in midgut tissues nor larval performance were significantly affected by high levels of condensed tannins. Post hoc comparisons of physiological mechanisms related to tree resistance revealed that maple produced not only higher levels of oxidative stress in the midgut lumen and midgut tissues of L. dispar, but also decreased protein utilization efficiency compared with oak. Our results suggest that high levels of hydrolyzable tannins are important for producing oxidative stress, but increased tree resistance to caterpillars may require additional factors, such as those that produce

  8. Effect of five enological practices and of the general phenolic composition on fermentation-related aroma compounds in Mencia young red wines.

    PubMed

    Añón, Ana; López, Jorge F; Hernando, Diego; Orriols, Ignacio; Revilla, Eugenio; Losada, Manuel M

    2014-04-01

    The effects of five technological procedures and of the contents of total anthocyanins and condensed tannins on 19 fermentation-related aroma compounds of young red Mencia wines were studied. Multifactor ANOVA revealed that levels of those volatiles changed significantly over the length of storage in bottles and, to a lesser extent, due to other technological factors considered; total anthocyanins and condensed tannins also changed significantly as a result of the five practices assayed. Five aroma compounds possessed an odour activity value >1 in all wines, and another four in some wines. Linear correlation among volatile compounds and general phenolic composition revealed that total anthocyanins were highly related to 14 different aroma compounds. Multifactor ANOVA, considering the content of total anthocyanins as a sixth random factor, revealed that this parameter affected significantly the contents of ethyl lactate, ethyl isovalerate, 1-pentanol and ethyl octanoate. Thus, the aroma of young red Mencia wines may be affected by levels of total anthocyanins. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. [Wine and heart].

    PubMed

    Rayo Llerena, I; Marín Huerta, E

    1998-06-01

    Many epidemiological studies have shown that moderate alcohol intake, from 10 to 30 g of ethanol a day, decreases cardiovascular mortality from atherosclerotic ischaemic heart disease and ischaemic stroke as compared to non-drinkers. This beneficial effect outweighs the risks of alcohol consumption in subgroups of people with a higher risk of atherosclerosis: the elderly, people with coronary risk factors and patients with previous coronary events. It has not been demonstrated that alcohol intake, even in moderate amounts, is beneficial for the general population, in particular, men under the age of 40 and women under 50, because it raises mortality due to other causes, especially injury, cirrhosis of the liver and some types of cancer, thereby outweighing the benefits for coronary artery disease. Thus, alcohol consumption should not be recommended as a prophylaxis for the general population. Guidelines on alcohol drinking habits--whether to continue, to start, to modify or to stop--must be given on an individual basis, taking into account the relative risks and benefits for each patient. The benefits of moderate alcohol consumption on the cardiovascular system seem to be exerted fundamentally through its effects on plasma lipoproteins, principally by raising high density lipoprotein (HDL) cholesterol and to a lesser degree, by decreasing low density lipoprotein (LDL) cholesterol. It appears to exert additional beneficial effects on the heart by decreasing platelet aggregability and by bringing about changes in the clotting-fibrinolysis system. Although there has been some debate about the relative superiority of different types of alcoholic beverages (wine, beer or hard liquor), and to a greater extent, about different types of wine, there is no current evidence of any kind of beneficial effect from other components of the beverage besides ethanol. Thus, it does not seem appropriate to recommend any particular type of alcoholic drink, except for sociocultural

  10. Molecular Approach to the Synergistic Effect on Astringency Elicited by Mixtures of Flavanols.

    PubMed

    Ramos-Pineda, Alba María; García-Estévez, Ignacio; Brás, Natércia F; Martín Del Valle, Eva M; Dueñas, Montserrat; Escribano Bailón, María Teresa

    2017-08-09

    The interactions between salivary proteins and wine flavanols (catechin, epicatechin, and mixtures thereof) have been studied by HPLC-DAD, isothermal titration microcalorimetry, and molecular dynamics simulations. Chromatographic results suggest that the presence of these flavanol mixtures could facilitate the formation of precipitates to the detriment of soluble aggregates. Comparison between the thermodynamic parameters obtained showed remarkably higher negative values of ΔG in the system containing the mixture of both flavanols in comparison to the systems containing individual flavanols, indicating a more favorable scenario in the mixing system. Also, the apparent binding constants were higher in this system. Furthermore, molecular dynamics simulations suggested a faster and greater cooperative binding of catechin and epicatechin to IB7 14 peptides when both types of flavanols are present simultaneously in solution.

  11. 27 CFR 24.311 - Taxpaid wine record.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Taxpaid wine record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.311 Taxpaid wine record. A proprietor who has taxpaid United States or foreign wine on taxpaid wine premises or on taxpaid wine bottling house...

  12. 27 CFR 24.256 - Bottle aging wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bottle aging wine. 24.256... OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine Bottling, Packing, and Labeling of Wine § 24.256 Bottle aging wine. Wine bottled or packed and stored for the purpose of aging need...

  13. 27 CFR 24.212 - High fermentation wine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.212 High fermentation wine. High fermentation wine is wine made with the addition of sugar within the limitations prescribed... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false High fermentation wine. 24...

  14. 27 CFR 24.212 - High fermentation wine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Production of Other Than Standard Wine § 24.212 High fermentation wine. High fermentation wine is wine made with the addition of sugar within the limitations prescribed... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false High fermentation wine. 24...

  15. 27 CFR 24.212 - High fermentation wine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., DEPARTMENT OF THE TREASURY ALCOHOL WINE Production of Other Than Standard Wine § 24.212 High fermentation wine. High fermentation wine is wine made with the addition of sugar within the limitations prescribed... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false High fermentation wine. 24...

  16. 27 CFR 24.212 - High fermentation wine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.212 High fermentation wine. High fermentation wine is wine made with the addition of sugar within the limitations prescribed... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false High fermentation wine. 24...

  17. 27 CFR 24.212 - High fermentation wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false High fermentation wine. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.212 High fermentation wine. High fermentation wine is wine made with the addition of sugar within the limitations prescribed...

  18. 27 CFR 24.213 - Heavy bodied blending wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Heavy bodied blending wine..., DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Other Than Standard Wine § 24.213 Heavy bodied blending wine. Heavy bodied blending wine is wine made for blending purposes from grapes or other fruit without...

  19. Wine, women, suspiciousness and advertising.

    PubMed

    Kohn, P M; Smart, R G

    1987-03-01

    Women college students (N = 66) viewed videotapes of a soap opera episode and a rock music program, ostensibly to evaluate the appeal of such material to college women. Different versions of the videotape included zero, three or nine wine commercials. Refreshments, including white wine, were available to the subjects. Suspiciousness about the experiment was evaluated through an open-ended questionnaire, responses to which were independently content-analyzed by two scorers. Major findings were as follows: Women exposed to nine wine commercials consumed more wine than those exposed to three. Twelve women were judged suspicious about the experiment, but none showed continued specific awareness of the study's true purpose. The differential consumption patterns of women in the three-wine-commercial and nine-wine-commercial conditions were exaggerated among suspicious women. These findings, in light of previous observations, suggest opposite reactions to soft-sell versus hard-sell persuasive appeals by men and women, notably ones predisposed to be suspicious about the purpose of experiments.

  20. Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel

    SciTech Connect

    Talib, Nur Atiqah Abu; Zakaria, Sarani; Hua, Chia Chin

    Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm.more » Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy.« less

  1. Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel

    NASA Astrophysics Data System (ADS)

    Talib, Nur Atiqah Abu; Zakaria, Sarani; Hua, Chia Chin; Othman, Norinsan Kamil

    2014-09-01

    Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm. Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy.

  2. A simple method to separate red wine nonpolymeric and polymeric phenols by solid-phase extraction.

    PubMed

    Pinelo, Manuel; Laurie, V Felipe; Waterhouse, Andrew L

    2006-04-19

    Simple polyphenols and tannins differ in the way that they contribute to the organoleptic profile of wine and their effects on human health. Very few straightforward techniques to separate red wine nonpolymeric phenols from the polymeric fraction are available in the literature. In general, they are complex, time-consuming, and generate large amounts of waste. In this procedure, the separation of these compounds was achieved using C18 cartridges, three solvents with different elution strengths, and pH adjustments of the experimental matrices. Two full factorial 2(3) experimental designs were performed to find the optimal critical variables and their values, allowing for the maximization of tannin recovery and separation efficiency (SE). Nonpolymeric phenols such as phenolic acids, monomers, and oligomers of flavonol and flavan-3-ols and anthocyanins were removed from the column by means of an aqueous solvent followed by ethyl acetate. The polymeric fraction was then eluted with a combination of methanol/acetone/water. The best results were attained with 1 mL of wine sample, a 10% methanol/water solution (first eluant), ethyl acetate (second eluant), and 66% acetone/water as the polymeric phenols-eluting solution (third eluant), obtaining a SE of ca. 90%. Trials with this method on fruit juices also showed high separation efficiency. Hence, this solid-phase extraction method has been shown to be a simple and efficient alternative for the separation of nonpolymeric phenolic fractions and the polymeric ones, and this method could have important applications to sample purification prior to biological testing due to the nonspecific binding of polymeric phenolics to nearly all enzymes and receptor sites.

  3. Performance of purified grape pomace as a fining agent to reduce the levels of some contaminants from wine.

    PubMed

    Jiménez-Martínez, María Dolores; Gil-Muñoz, Rocío; Gómez-Plaza, Encarna; Bautista-Ortín, Ana Belén

    2018-03-30

    The quality of red wine depends on the absence of compounds which may affect its safety and/or stability such as ochratoxin A, biogenic amines and some metals and trace compounds. The presence of ochratoxin A in musts and wines is due to fungal contamination of the grapes and has been classified as a possible human carcinogen. Biogenic amines are formed by the microbiological descarboxylation of the corresponding amino acid precursors during the fermentation or aging and storage, and, at high concentrations, they may induce adverse reactions in sensitive people. Trace elements may have both a nutritional and a toxic effect on health, but also can cause turbidity and stability problems. Their presence is affected mainly by natural factors such as soil mineral content and direct contact with tank surfaces and metallic tubing during winemaking. One of the best options to remove these compounds when present in excess in wine is fining. However, some fining agents commonly used may themselves present problems related with their allergenic properties or with their propensity to increase the protein content, which can cause turbidity problems. In an attempt to avoid such these problems, purified grape pomace was tested as a fining alternative since it has been seen to have a high capacity to reduce the astringency, turbidity and also the ochratoxin A content. The main aim of this work, therefore, was to study if this material can limit the presence of ochratoxin A, biogenic amines and metals and some trace elements in a Monastrell red wine, thus increasing the value and safety of this product.

  4. Evaluation of tannins interactions in grape (Vitis vinifera L.) skins.

    PubMed

    Rustioni, Laura; Fiori, Simone; Failla, Osvaldo

    2014-09-15

    Tannins have a central role in grapevine berries both for their physiological and enological implications. In the skin tissue they can be in vacuolar solution, or associated to the cell walls through weak or strong physicochemical interactions. The present work aims to separate vacuolar, non-covalently and covalently bonded tannins fractions. A specific extraction procedure was developed. A first extraction in ethanol at low temperature allowed the quantification of vacuolar tannins. An urea treatment followed by an ethanol extraction at room temperature was able to separate non-covalently bonded compounds. Finally an acid catalysis was used to break down proanthocyanidin covalent bonds. The method was validated on ripe grape samples of three cultivars, on berries developed in two sun exposure conditions. The Ethephon treatment effect was also evaluated. Beside the method development, a preliminary evaluation of the cultivar, exposition and Ethephon treatment effects are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Polyphenolic profile as a useful tool to identify the wood used in wine aging.

    PubMed

    Sanz, Miriam; Fernández de Simón, Brígida; Cadahía, Estrella; Esteruelas, Enrique; Muñoz, Angel Ma; Hernández, Ma Teresa; Estrella, Isabel

    2012-06-30

    Although oak wood is the main material used in cooperage, other species are being considered as possible sources of wood for the production of wines and their derived products. In this work we have compared the phenolic composition of acacia (Robinia pseudoacacia), chestnut (Castanea sativa), cherry (Prunus avium) and ash (Fraxinus excelsior and F. americana) heartwoods, by using HPLC-DAD/ESI-MS/MS (some of these data have been showed in previous paper), as well as the changes that toasting intensity at cooperage produce in each polyphenolic profile. Before toasting, each wood shows a different and specific polyphenolic profile, with both qualitative and quantitative differences among them. Toasting notably changed these profiles, in general, proportionally to toasting intensity and led to a minor differentiation among species in toasted woods, although we also found phenolic markers in toasted woods. Thus, methyl syringate, benzoic acid, methyl vanillate, p-hydroxybenzoic acid, 3,4,5-trimethylphenol and p-coumaric acid, condensed tannins of the procyanidin type, and the flavonoids naringenin, aromadendrin, isosakuranetin and taxifolin will be a good tool to identify cherry wood. In acacia wood the chemical markers will be the aldehydes gallic and β-resorcylic and two not fully identified hydroxycinnamic compounds, condensed tannins of the prorobinetin type, and when using untoasted wood, dihydrorobinetin, and in toasted acacia wood, robinetin. In untoasted ash wood, the presence of secoiridoids, phenylethanoid glycosides, or di and oligolignols will be a good tool, especially oleuropein, ligstroside and olivil, together verbascoside and isoverbascoside in F. excelsior, and oleoside in F. americana. In toasted ash wood, tyrosol, syringaresinol, cyclolovil, verbascoside and olivil, could be used to identify the botanical origin. In addition, in ash wood, seasoned and toasted, neither hydrolysable nor condensed tannins were detected. Lastly, in chestnut wood, gallic

  6. 40 CFR 721.10666 - Quaternary ammonium compounds, bis(fattyalkyl) dimethyl, salts with tannins (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...(fattyalkyl) dimethyl, salts with tannins (generic). 721.10666 Section 721.10666 Protection of Environment..., bis(fattyalkyl) dimethyl, salts with tannins (generic). (a) Chemical substance and significant new... compounds, bis(fattyalkyl) dimethyl, salts with tannins (PMN P-12-437) is subject to reporting under this...

  7. 40 CFR 721.10666 - Quaternary ammonium compounds, bis(fattyalkyl) dimethyl, salts with tannins (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...(fattyalkyl) dimethyl, salts with tannins (generic). 721.10666 Section 721.10666 Protection of Environment..., bis(fattyalkyl) dimethyl, salts with tannins (generic). (a) Chemical substance and significant new... compounds, bis(fattyalkyl) dimethyl, salts with tannins (PMN P-12-437) is subject to reporting under this...

  8. The role of condensed tannins in animal production: advances, limitations and future directions

    USDA-ARS?s Scientific Manuscript database

    Tannins represent one of the most abundant polyphenolic compounds in plants, second only to lignin. Tannins exist as a multitude of chemically unique entities in nature. The most commonly occurring tannins are typically divided into two major classes based on chemical structure: hydrolysable or cond...

  9. Influence of polysaccharides on wine protein aggregation.

    PubMed

    Jaeckels, Nadine; Meier, Miriam; Dietrich, Helmut; Will, Frank; Decker, Heinz; Fronk, Petra

    2016-06-01

    Polysaccharides are the major high-molecular weight components of wines. In contrast, proteins occur only in small amounts in wine, but contribute to haze formation. The detailed mechanism of aggregation of these proteins, especially in combination with other wine components, remains unclear. This study demonstrates the different aggregation behavior between a buffer and a model wine system by dynamic light scattering. Arabinogalactan-protein, for example, shows an increased aggregation in the model wine system, while in the buffer system a reducing effect is observed. Thus, we could show the importance to examine the behavior of wine additives under conditions close to reality, instead of simpler buffer systems. Additional experiments on melting points of wine proteins reveal that only some isoforms of thaumatin-like proteins and chitinases are involved in haze formation. We can confirm interactions between polysaccharides and proteins, but none of these polysaccharides is able to prevent haze in wine. Copyright © 2016. Published by Elsevier Ltd.

  10. 27 CFR 24.77 - Experimental wine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Experimental wine. (a) General. Any scientific university, college of learning, or institution of scientific research may, without payment of tax, produce, receive, blend, treat, and store wine for experimental or...

  11. 27 CFR 24.77 - Experimental wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Experimental wine. (a) General. Any scientific university, college of learning, or institution of scientific research may, without payment of tax, produce, receive, blend, treat, and store wine for experimental or...

  12. Synchronous fluorescence spectroscopy for analysis of wine and wine distillates

    NASA Astrophysics Data System (ADS)

    Andreeva, Ya.; Borisova, E.; Genova, Ts.; Zhelyazkova, Al.; Avramov, L.

    2015-01-01

    Wine and brandies are multicomponent systems and conventional fluorescence techniques, relying on recording of single emission or excitation spectra, are often insufficient. In such cases synchronous fluorescence spectra can be used for revealing the potential of the fluorescence techniques. The technique is based on simultaneously scanning of the excitation and emission wavelength with constant difference (Δλ) maintained between them. In this study the measurements were made using FluoroLog3 spectrofluorimeter (HORIBA Jobin Yvon, France) and collected for excitation and emission in the wavelength region 220 - 700 nm using wavelength interval Δλ from 10 to 100 nm in 10 nm steps. This research includes the results obtained for brandy and red wine samples. Fluorescence analysis takes advantage in the presence of natural fluorophores in wines and brandies, such as gallic, vanillic, p-coumaric, syringic, ferulic acid, umbelliferone, scopoletin and etc. Applying of synchronous fluorescence spectroscopy for analysis of these types of alcohols allows us to estimate the quality of wines and also to detect adulteration of brandies like adding of a caramel to wine distillates for imitating the quality of the original product aged in oak casks.

  13. Geochemistry and Minerality of Wine

    NASA Astrophysics Data System (ADS)

    Oze, C.; Horton, T. W.; Beaman, M.

    2010-12-01

    Kaolinite (Al2Si2O5(OH)4) and gibbsite (Al(OH)3) are capable of forming in a variety of environments including anthropogenic solutions such as wine. Here, we evaluate the geochemistry of twelve white wines in order to assess the potential relationship between kaolinite/gibbsite saturation and minerality, a common wine descriptor used to express the rock and/or soil character in the aromas and flavors of wines. Aluminum and Si concentrations ranged from 228-1,281 µg L-1 and 6,583-19,746 µg L-1, respectively, where Si and Al are the only elements to demonstrate positive covariance with minerality scores. Sulfur levels varied from 25,013-167,383 µg L-1 and show the strongest negative covariance with minerality scores. However, like all of the elements studied (Al, Si, Na, Mg, S, K, Ca, and Fe), these trends were not significantly different than random at the 95% confidence level. In contrast, the relative degrees of gibbsite/kaolinite saturation display strong positive covariance with minerality scores and these trends are not random at the greater than 95% confidence level. Overall, our tasters were able to accurately assess the degree of gibbsite/kaolinite saturation amongst the twelve wines based on the objective of assessing minerality. Although the wines were undersaturated with respect to gibbsite/kaolinite, geochemical modeling reveals that increasing the wines’ pHs from ~3.3 to 4.1-4.6 (which is achievable on the palate where saliva has a pH of 7.4) results in gibbsite/kaolinite oversaturation. By considering that minerality is a function of gibbsite/kaolinite saturation and decreasing S, the origin of minerality’s taste and chemical origin in wine with known physical standards becomes increasingly crystalline.

  14. Proton-beam technique dates fine wine

    NASA Astrophysics Data System (ADS)

    Dumé, Belle

    2008-10-01

    Nuclear physicists in France have invented a way to authenticate the vintage of rare wine without needing a sommelier's keen nose or even a corkscrew. The technique, which involves firing high-energy protons at wine bottles, can determine how old the bottles are and even where they come from. The new method could help unmask counterfeit wines - a growing problem in the fine-wine industry, where a bottle can sell for thousands of Euros.

  15. Associations among Wine Grape Microbiome, Metabolome, and Fermentation Behavior Suggest Microbial Contribution to Regional Wine Characteristics.

    PubMed

    Bokulich, Nicholas A; Collins, Thomas S; Masarweh, Chad; Allen, Greg; Heymann, Hildegarde; Ebeler, Susan E; Mills, David A

    2016-06-14

    Regionally distinct wine characteristics (terroir) are an important aspect of wine production and consumer appreciation. Microbial activity is an integral part of wine production, and grape and wine microbiota present regionally defined patterns associated with vineyard and climatic conditions, but the degree to which these microbial patterns associate with the chemical composition of wine is unclear. Through a longitudinal survey of over 200 commercial wine fermentations, we demonstrate that both grape microbiota and wine metabolite profiles distinguish viticultural area designations and individual vineyards within Napa and Sonoma Counties, California. Associations among wine microbiota and fermentation characteristics suggest new links between microbiota, fermentation performance, and wine properties. The bacterial and fungal consortia of wine fermentations, composed from vineyard and winery sources, correlate with the chemical composition of the finished wines and predict metabolite abundances in finished wines using machine learning models. The use of postharvest microbiota as an early predictor of wine chemical composition is unprecedented and potentially poses a new paradigm for quality control of agricultural products. These findings add further evidence that microbial activity is associated with wine terroir Wine production is a multi-billion-dollar global industry for which microbial control and wine chemical composition are crucial aspects of quality. Terroir is an important feature of consumer appreciation and wine culture, but the many factors that contribute to terroir are nebulous. We show that grape and wine microbiota exhibit regional patterns that correlate with wine chemical composition, suggesting that the grape microbiome may influence terroir In addition to enriching our understanding of how growing region and wine properties interact, this may provide further economic incentive for agricultural and enological practices that maintain regional

  16. Effect of cultivar and variety on phenolic compounds and antioxidant activity of cherry wine.

    PubMed

    Xiao, Zuobing; Fang, Lingling; Niu, Yunwei; Yu, Haiyan

    2015-11-01

    To compare the influence of cultivar and variety on the phenolic compounds and antioxidant activity (AA) of cherry wines, total phenolic (TP), total flavonoid (TF), total anthocyanin (TA), total tannin (TT), five individual phenolic acids, and AA were determined. An ultra-performance liquid chromatography tandem mass spectrometry (HPLC-DAD/ESI-MS) method was developed for the determination of gallic acid (GAE), p-hydroxybenzoic acid (PHB), chlorogenic acid (CHL), vanillic acid (VAN), and caffeic acid (CAF). A principal component analysis (PCA) and a cluster analysis (CA) were used to analyze differences related to cultivar and variety. The TP, TF, TA, TT, and AA of samples sourced from the Shandong province of China were higher than those from the Jiangsu province. The PCA and CA results showed that phenolic compounds in cherry wines were closely related to cultivar and variety and that cultivar had more influence on the phenolic compounds of cherry wines than variety. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. The Essentials of Proper Wine Service.

    ERIC Educational Resources Information Center

    Manago, Gary H.

    This instructional unit was designed to assist the food services instructor and/or the restaurant manager in training students and/or staff in the proper procedure for serving wines to guests. The lesson plans included in this unit focus on: (1) the different types of wine glasses and their uses; (2) the parts of a wine glass; (3) the proper…

  18. 27 CFR 31.232 - Wine bottling.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... The decanting of wine by caterers or other retail dealers for table or room service, banquets, and... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Wine bottling. 31.232... OF THE TREASURY LIQUORS ALCOHOL BEVERAGE DEALERS Miscellaneous § 31.232 Wine bottling. Each person...

  19. Comparison of fortified, sfursat, and passito wines produced from fresh and dehydrated grapes of aromatic black cv. Moscato nero (Vitis vinifera L.).

    PubMed

    Ossola, Carolina; Giacosa, Simone; Torchio, Fabrizio; Río Segade, Susana; Caudana, Alberto; Cagnasso, Enzo; Gerbi, Vincenzo; Rolle, Luca

    2017-08-01

    Moscato nero d'Acqui is an Italian aromatic black winegrape variety characterized by a low content of anthocyanins (mostly tri-substituted), a satisfactory content of high molecular mass tannins, and a fair amount of terpenes. The grapes were subjected to a postharvest dehydration process under controlled thermohygrometric conditions (16-18°C, 55-70 RH%, 0.6m/s air speed) with the aim to produce three different special wine types (fortified, sfursat, and passito) from fresh, partially dehydrated (27°Brix), and withered (36°Brix) grapes, respectively. Chemical traits of produced grapes and wines were then evaluated through spectrophotometric, HPLC, and GC-MS methods. Increased contents of skin phenolic compounds and reduced extractable contents of seed phenolic compounds were observed as dehydration progressed. Few significant differences were found in the anthocyanin profile of grapes, although the relative abundance of coumaroylated anthocyanins was higher in dehydrated grapes. The predominant free volatile compound found in grapes was geraniol, which decreased with increasing water loss, whereas the contents of major glycosylated volatile compounds increased even above the concentration effect. The changes in the phenolic composition among wines agreed with those among grape skins. Fortified wines were chromatically unsatisfactory probably due to the low content of total anthocyanins, whereas sfursat and passito wines meet good chromatic characteristics as a result of the concentration effect during grape dehydration. Fortified and sfursat wines had free aroma profiles richer in 2-phenylethanol and citronellol, whereas passito wines were mainly composed of 2-phenylethanol and 2-phenylethyl acetate, citronellol being the predominant terpenol in all the wine types studied. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Changes in Wine Ethanol Content Due to Evaporation from Wine Glasses and Implications for Sensory Analysis.

    PubMed

    Wollan, David; Pham, Duc-Truc; Wilkinson, Kerry Leigh

    2016-10-12

    The relative proportion of water and ethanol present in alcoholic beverages can significantly influence the perception of wine sensory attributes. This study therefore investigated changes in wine ethanol concentration due to evaporation from wine glasses. The ethanol content of commercial wines exposed to ambient conditions while in wine glasses was monitored over time. No change in wine ethanol content was observed where glasses were covered with plastic lids, but where glasses were not covered, evaporation had a significant impact on wine ethanol content, with losses from 0.9 to 1.9% alcohol by volume observed for wines that received direct exposure to airflow for 2 h. Evaporation also resulted in decreases in the concentration of some fermentation volatiles (determined by gas chromatography-mass spectrometry) and a perceptible change in wine aroma. The rate of ethanol loss was strongly influenced by exposure to airflow (i.e., from the laboratory air-conditioning unit), together with certain glass shape and wine parameters; glass headspace in particular. This is the first study to demonstrate the significant potential for ethanol evaporation from wine in wine glasses. Research findings have important implications for the technical evaluation of wine sensory properties; in particular, informal sensory trials and wine show judging, where the use of covers on wine glasses is not standard practice.

  1. Vascular effects of wine polyphenols.

    PubMed

    Dell'Agli, Mario; Buscialà, Alessandra; Bosisio, Enrica

    2004-09-01

    Moderate consumption of red wine has been putatively associated with lowering the risk of developing coronary heart disease. This beneficial effect is mainly attributed to the occurrence of polyphenol compounds such as anthocyanosides (ACs), catechins, proanthocyanidins (PAs), stilbenes and other phenolics in red wine. This review focuses on the vascular effects of red wine polyphenols (RWPs), with emphasis on anthocyanosides and proanthocyanidins. From in vitro studies, the effect of red wine polyphenols on the vascular tone is thought to be due to short- and long-term mechanisms. NO-mediated vasorelaxation represents the short-term response to wine polyphenols, which exert the effect by increasing the influx of extracellular Ca(2+), and the mobilization of intracellular Ca(2+) in endothelial cells. Polyphenolic compounds may also have long-term properties, as they increase endothelial NO synthase expression acting on the promoter activity. In addition, they decrease the expression of adhesion molecules and growth factors, involved in migration and proliferation of vascular smooth muscle cells. Moreover, they inhibit platelet aggregation. However, a paucity of data as regards the bioavailability and metabolism of these compounds in human studies is a limiting factor to proving their efficacy in vivo.

  2. Remarkable proanthocyanidin adsorption properties of monastrell pomace cell wall material highlight its potential use as an alternative fining agent in red wine production.

    PubMed

    Bautista-Ortín, Ana Belén; Ruiz-García, Yolanda; Marín, Fátima; Molero, Noelia; Apolinar-Valiente, Rafael; Gómez-Plaza, Encarna

    2015-01-21

    The existence of interactions between the polysaccharides of vegetal cell walls and proanthocyanins makes this cell wall material an interesting option for its use as a fining agent to reduce the level of proanthocyanins in wines. Pomace wastes from the winery are widely available and a source of cell wall material, and the identification of varieties whose pomace cell walls present high proanthocyanin binding capacity and of processing methods that could enhance their adsorption properties could be of great interest. This study compared the proanthocyanin adsorption properties of pomace cell wall material from three different grape varieties (Monastrell, Cabernet Sauvignon, and Syrah), and the results were compared with those obtained using fresh grape cell walls. Also, the effect of the vinification method has been studied. Analysis of the proanthocyanidins in the solution after reaction with the cell wall material, using phloroglucinolysis and size exclusion chromatography, provided quantitative and qualitative information on the adsorbed and nonadsorbed compounds. A highlight of this study was the observation that Monastrell pomace cell wall material showed a strong affinity for proanthocyanidins, with values similar to that obtained for fresh grapes cell walls, and a preferential binding of high molecular mass proanthocyanidins, so these pomace cell walls could be used in wines to reduce astringency. The use of maceration enzymes during vinification had little effect on the retention capacity of the pomace cell walls obtained from this vinification, although an increase in the retention of low molecular mass proanthocyanidins was observed, and this might have implications for wine sensory properties.

  3. Fast atom bombardment mass spectrometry of condensed tannin sulfonate derivatives

    Treesearch

    J.J. Karchesy; L.Y. Foo; Richard W. Hemingway; E. Barofsky; D.F. Barofsky

    1989-01-01

    Condensed tannin sulfonate derivatives were studied by fast atom bombardment mass spectrometry (FAB-MS) to assess the feasibility of using this technique for determining molecular weight and structural information about these compounds. Both positive- and negative-ion spectra provided useful data with regard to molecular weight, cation species present, and presence of...

  4. Condensed tannins: Quinone methide intermediates in procyanidin synthesis

    Treesearch

    Richard W. Hemingway; L. Y. Foo

    1983-01-01

    Proanthocyanidins (condensed tanruns) are widely distributed in plants and are found in sufficiently high concentration in some tree barks to encourage their industrial utilization. These polymers consist of flavanoid units linked through the C-4 of the pyran ring to the C-6 or C-8 carbons of the aromatic A-ring. Recent advances in the chemistry of condensed tannins...

  5. Genetics and Biochemistry of Zero-Tannin Lentils.

    PubMed

    Mirali, Mahla; Purves, Randy W; Stonehouse, Rob; Song, Rui; Bett, Kirstin; Vandenberg, Albert

    2016-01-01

    The zero-tannin trait in lentil is controlled by a single recessive gene (tan) that results in a phenotype characterized by green stems, white flowers, and thin, transparent, or translucent seed coats. Genes that result in zero-tannin characteristics are useful for studies of seed coat pigmentation and biochemical characters because they have altered pigmentation. In this study, one of the major groups of plant pigments, phenolic compounds, was compared among zero-tannin and normal phenotypes and genotypes of lentil. Biochemical data were obtained by liquid chromatography-mass spectrometry (LC-MS). Genomic sequencing was used to identify a candidate gene for the tan locus. Phenolic compound profiling revealed that myricetin, dihydromyricetin, flavan-3-ols, and proanthocyanidins are only detected in normal lentil phenotypes and not in zero-tannin types. The molecular analysis showed that the tan gene encodes a bHLH transcription factor, homologous to the A gene in pea. The results of this study suggest that tan as a bHLH transcription factor interacts with the regulatory genes in the biochemical pathway of phenolic compounds starting from flavonoid-3',5'-hydroxylase (F3'5'H) and dihydroflavonol reductase (DFR).

  6. Accumulation of hydrolyzable tannins by Aleurites fordii callus culture.

    PubMed

    Taniguchi, Shoko; Uechi, Kyoko; Kato, Reiko; Ito, Hideyuki; Hatano, Tsutomu; Yazaki, Kazufumi; Yoshida, Takashi

    2002-12-01

    A callus culture of Aleurites fordii Hemsley (Euphorbiaceae) producing five galloylglucoses and an ellagitannin, geraniin, was established. The production of pentagalloylglucose was remarkably enhanced under light irradiation compared with that in the dark. Cell growth and tannin production were also greatly affected by changing the concentrations and composition of nitrogen sources.

  7. α-Glucosidase inhibitory hydrolyzable tannins from Eugenia jambolana seeds.

    PubMed

    Omar, Raed; Li, Liya; Yuan, Tao; Seeram, Navindra P

    2012-08-24

    Three new hydrolyzable tannins including two gallotannins, jamutannins A (1) and B (2), and an ellagitannin, iso-oenothein C (3), along with eight known phenolic compounds were isolated from the seeds of Eugenia jambolana fruit. The structures were elucidated on the basis of spectroscopic data analysis. All compounds isolated were evaluated for α-glucosidase inhibitory effects compared to the clinical drug acarbose.

  8. The susceptibility of soil enzymes to inhibition by leaf litter tannins is dependent on the tannin chemistry, enzyme class and vegetation history.

    PubMed

    Triebwasser, Daniella J; Tharayil, Nishanth; Preston, Caroline M; Gerard, Patrick D

    2012-12-01

    By inhibiting soil enzymes, tannins play an important role in soil carbon (C) and nitrogen (N) mineralization. The role of tannin chemistry in this inhibitory process, in conjunction with enzyme classes and isoforms, is less well understood. Here, we compared the inhibition efficiencies of mixed tannins (MTs, mostly limited to angiosperms) and condensed tannins (CTs, produced mostly by gymnosperms) against the potential activity of β-glucosidase (BG), N-acetyl-glucosaminidase (NAG), and peroxidase in two soils that differed in their vegetation histories. Compared with CTs, MTs exhibited 50% more inhibition of almond (Prunus dulcis) BG activity and greater inhibition of the potential NAG activity in the gymnosperm-acclimatized soils. CTs exhibited lower BG inhibition in the angiosperm-acclimated soils, whereas both types of tannins exhibited higher peroxidase inhibition in the angiosperm soils than in gymnosperm soils. At all of the tested tannin concentrations, irrespective of the tannin type and site history, the potential peroxidase activity was inhibited two-fold more than the hydrolase activity and was positively associated with the redox-buffering efficiency of tannins. Our finding that the inhibitory activities and mechanisms of MTs and CTs are dependent on the vegetative history and enzyme class is novel and furthers our understanding of the role of tannins and soil isoenzymes in decomposition. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  9. Changes in the structural composition and reactivity of Acer rubrum leaf litter tannins exposed to warming and altered precipitation: climatic stress-induced tannins are more reactive.

    PubMed

    Tharayil, Nishanth; Suseela, Vidya; Triebwasser, Daniella J; Preston, Caroline M; Gerard, Patrick D; Dukes, Jeffrey S

    2011-07-01

    • Climate change could increase the frequency with which plants experience abiotic stresses, leading to changes in their metabolic pathways. These stresses may induce the production of compounds that are structurally and biologically different from constitutive compounds. • We studied how warming and altered precipitation affected the composition, structure, and biological reactivity of leaf litter tannins in Acer rubrum at the Boston-Area Climate Experiment, in Massachusetts, USA. • Warmer and drier climatic conditions led to higher concentrations of protective compounds, including flavonoids and cutin. The abundance and structure of leaf tannins also responded consistently to climatic treatments. Drought and warming in combination doubled the concentration of total tannins, which reached 30% of leaf-litter DW. This treatment also produced condensed tannins with lower polymerization and a greater proportion of procyanidin units, which in turn reduced sequestration of tannins by litter fiber. Furthermore, because of the structural flexibility of these tannins, litter from this treatment exhibited five times more enzyme (β-glucosidase) complexation capacity on a per-weight basis. Warmer and wetter conditions decreased the amount of foliar condensed tannins. • Our finding that warming and drought result in the production of highly reactive tannins is novel, and highly relevant to climate change research as these tannins, by immobilizing microbial enzymes, could slow litter decomposition and thus carbon and nutrient cycling in a warmer, drier world. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  10. Tannins: current knowledge of food sources, intake, bioavailability and biological effects.

    PubMed

    Serrano, José; Puupponen-Pimiä, Riitta; Dauer, Andreas; Aura, Anna-Marja; Saura-Calixto, Fulgencio

    2009-09-01

    Tannins are a unique group of phenolic metabolites with molecular weights between 500 and 30 000 Da, which are widely distributed in almost all plant foods and beverages. Proanthocyanidins and hydrolysable tannins are the two major groups of these bioactive compounds, but complex tannins containing structural elements of both groups and specific tannins in marine brown algae have also been described. Most literature data on food tannins refer only to oligomeric compounds that are extracted with aqueous-organic solvents, but a significant number of non-extractable tannins are usually not mentioned in the literature. The biological effects of tannins usually depend on their grade of polymerisation and solubility. Highly polymerised tannins exhibit low bioaccessibility in the small intestine and low fermentability by colonic microflora. This review summarises a new approach to analysis of extractable and non-extractable tannins, major food sources, and effects of storage and processing on tannin content and bioavailability. Biological properties such as antioxidant, antimicrobial and antiviral effects are also described. In addition, the role of tannins in diabetes mellitus has been discussed.

  11. The influence of condensed tannin structure on rate of microbial mineralization and reactivity to chemical assays.

    PubMed

    Norris, Charlotte E; Preston, Caroline M; Hogg, Karen E; Titus, Brian D

    2011-03-01

    We examined how tannin structure influences reactivity in tannin assays and carbon and nitrogen mineralization. Condensed tannins from the foliage of ten tree and shrub species and from pecan shells (Carya illinoensis) had different proportions of: (a) epicatechin (cis) and catechin (trans) isomers, (b) procyanidin (PC) and prodelphinidin (PD) monomers, and (c) different chain lengths. The response of each tannin to several widely used tannin assays was determined. Although there was some variation in response to proanthocyanidin (butanol/HCl) and Folin Ciocalteu assays, we did not deduce any predictable relationship between tannin structure and response to either assay. There was little variation in protein precipitation among the different tannins. To assess biological activity, six of the tannins were incubated with forest humus for 22 days. We determined that, while PC-based tannins remained at least partly extractable for the duration of the incubation, tannins with a high proportion of PD subunits rapidly became unextractable from soil. There was a positive correlation between net nitrogen mineralization and cis chemical structure. Carbon mineralization was enhanced initially by the addition of tannins to humus, but after 22 days, a negative correlation between the proportion of cis subunits and respiration was determined. Overall, we were not able to demonstrate consistent effects of structure on either microbial mineralization or reactivity to chemical assays; such relationships remain elusive.

  12. Raman spectroscopy of white wines.

    PubMed

    Martin, Coralie; Bruneel, Jean-Luc; Guyon, François; Médina, Bernard; Jourdes, Michael; Teissedre, Pierre-Louis; Guillaume, François

    2015-08-15

    The feasibility of exploiting Raman scattering to analyze white wines has been investigated using 3 different wavelengths of the incoming laser radiation in the near-UV (325 nm), visible (532 nm) and near infrared (785 nm). To help in the interpretation of the Raman spectra, the absorption properties in the UV-visible range of two wine samples as well as their laser induced fluorescence have also been investigated. Thanks to the strong intensity enhancement of the Raman scattered light due to electronic resonance with 325 nm laser excitation, hydroxycinnamic acids may be detected and analyzed selectively. Fructose and glucose may also be easily detected below ca. 1000 cm(-1). This feasibility study demonstrates the potential of the Raman spectroscopic technique for the analysis of white wines. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Fun with singing wine glasses

    NASA Astrophysics Data System (ADS)

    Boone, Christine; Galloway, Melodie; Ruiz, Michael J.

    2018-05-01

    A fun activity is presented using singing wine glasses for introductory physics students. Students tune a white wine glass and a red wine glass to as many semitones as possible by filling the glasses with the appropriate amounts of water. A smart phone app is used to measure the frequencies of equal-temperament tones. Then plots of frequency against water volume percent are made using a spreadsheet. Students can also play combinations of pitches with several glasses. A video (Ruiz 2018 Video: Singing glasses http://mjtruiz.com/ped/wineglasses/) is provided which includes an excerpt of a beautiful piece written for singing glasses and choir: Stars by Latvian composer Ēriks Ešenvalds.

  14. Tannin structural elucidation and quantitative ³¹P NMR analysis. 1. Model compounds.

    PubMed

    Melone, Federica; Saladino, Raffaele; Lange, Heiko; Crestini, Claudia

    2013-10-02

    Tannins and flavonoids are secondary metabolites of plants that display a wide array of biological activities. This peculiarity is related to the inhibition of extracellular enzymes that occurs through the complexation of peptides by tannins. Not only the nature of these interactions, but more fundamentally also the structure of these heterogeneous polyphenolic molecules are not completely clear. This first paper describes the development of a new analytical method for the structural characterization of tannins on the basis of tannin model compounds employing an in situ labeling of all labile H groups (aliphatic OH, phenolic OH, and carboxylic acids) with a phosphorus reagent. The ³¹P NMR analysis of ³¹P-labeled samples allowed the unprecedented quantitative and qualitative structural characterization of hydrolyzable tannins, proanthocyanidins, and catechin tannin model compounds, forming the foundations for the quantitative structural elucidation of a variety of actual tannin samples described in part 2 of this series.

  15. Analysis of supercooling activity of tannin-related polyphenols.

    PubMed

    Kuwabara, Chikako; Wang, Donghui; Endoh, Keita; Fukushi, Yukiharu; Arakawa, Keita; Fujikawa, Seizo

    2013-08-01

    Based on the discovery of novel supercooling-promoting hydrolyzable gallotannins from deep supercooling xylem parenchyma cells (XPCs) in Katsura tree (see Wang et al. (2012) [38]), supercooling capability of a wide variety of tannin-related polyphenols (TRPs) was examined in order to find more effective supercooling-promoting substances for their applications. The TRPs examined were single compounds including six kinds of hydrolyzable tannins, 11 kinds of catechin derivatives, two kinds of structural analogs of catechin and six kinds of phenolcarboxylic acid derivatives, 11 kinds of polyphenol mixtures and five kinds of crude plant tannin extracts. The effects of these TRPs on freezing were examined by droplet freezing assays using various solutions containing different kinds of identified ice nucleators such as the ice nucleation bacterium (INB) Erwinia ananas, the INB Xanthomonas campestris, silver iodide and phloroglucinol as well as a solution containing only unintentionally included unidentified airborne ice nucleators. Among the 41 kinds of TRPs examined, all of the hydrolyzable tannins, catechin derivatives, polyphenol mixtures and crude plant tannin extracts as well as a few structural analogs of catechin and phenolcarboxylic acid derivatives exhibited supercooling-promoting activity (SCA) with significant differences (p>0.05) from at least one of the solutions containing different kinds of ice nucleators. It should be noted that there were no TRPs exhibiting ice nucleation-enhancing activity (INA) in all solutions containing identified ice nucleators, whereas there were many TRPs exhibiting INA with significant differences in solutions containing unidentified ice nucleators alone. An emulsion freezing assay confirmed that these TRPs did not essentially affect homogeneous ice nucleation temperatures. It is thought that not only SCA but also INA in the TRPs are produced by interactions with heterogeneous ice nucleators, not by direct interaction with water

  16. Phenotypic and Phylogenetic Characterization of Ruminal Tannin-Tolerant Bacteria

    PubMed Central

    Nelson, Karen E.; Thonney, Michael L.; Woolston, Tina K.; Zinder, Stephen H.; Pell, Alice N.

    1998-01-01

    The 16S rRNA sequences and selected phenotypic characteristics were determined for six recently isolated bacteria that can tolerate high levels of hydrolyzable and condensed tannins. Bacteria were isolated from the ruminal contents of animals in different geographic locations, including Sardinian sheep (Ovis aries), Honduran and Colombian goats (Capra hircus), white-tail deer (Odocoileus virginianus) from upstate New York, and Rocky Mountain elk (Cervus elaphus nelsoni) from Oregon. Nearly complete sequences of the small-subunit rRNA genes, which were obtained by PCR amplification, cloning, and sequencing, were used for phylogenetic characterization. Comparisons of the 16S rRNA of the six isolates showed that four of the isolates were members of the genus Streptococcus and were most closely related to ruminal strains of Streptococcus bovis and the recently described organism Streptococcus gallolyticus. One of the other isolates, a gram-positive rod, clustered with the clostridia in the low-G+C-content group of gram-positive bacteria. The sixth isolate, a gram-negative rod, was a member of the family Enterobacteriaceae in the gamma subdivision of the class Proteobacteria. None of the 16S rRNA sequences of the tannin-tolerant bacteria examined was identical to the sequence of any previously described microorganism or to the sequence of any of the other organisms examined in this study. Three phylogenetically distinct groups of ruminal bacteria were isolated from four species of ruminants in Europe, North America, and South America. The presence of tannin-tolerant bacteria is not restricted by climate, geography, or host animal, although attempts to isolate tannin-tolerant bacteria from cows on low-tannin diets failed. PMID:9758806

  17. Phenotypic and phylogenetic characterization of ruminal tannin-tolerant bacteria.

    PubMed

    Nelson, K E; Thonney, M L; Woolston, T K; Zinder, S H; Pell, A N

    1998-10-01

    The 16S rRNA sequences and selected phenotypic characteristics were determined for six recently isolated bacteria that can tolerate high levels of hydrolyzable and condensed tannins. Bacteria were isolated from the ruminal contents of animals in different geographic locations, including Sardinian sheep (Ovis aries), Honduran and Colombian goats (Capra hircus), white-tail deer (Odocoileus virginianus) from upstate New York, and Rocky Mountain elk (Cervus elaphus nelsoni) from Oregon. Nearly complete sequences of the small-subunit rRNA genes, which were obtained by PCR amplification, cloning, and sequencing, were used for phylogenetic characterization. Comparisons of the 16S rRNA of the six isolates showed that four of the isolates were members of the genus Streptococcus and were most closely related to ruminal strains of Streptococcus bovis and the recently described organism Streptococcus gallolyticus. One of the other isolates, a gram-positive rod, clustered with the clostridia in the low-G+C-content group of gram-positive bacteria. The sixth isolate, a gram-negative rod, was a member of the family Enterobacteriaceae in the gamma subdivision of the class Proteobacteria. None of the 16S rRNA sequences of the tannin-tolerant bacteria examined was identical to the sequence of any previously described microorganism or to the sequence of any of the other organisms examined in this study. Three phylogenetically distinct groups of ruminal bacteria were isolated from four species of ruminants in Europe, North America, and South America. The presence of tannin-tolerant bacteria is not restricted by climate, geography, or host animal, although attempts to isolate tannin-tolerant bacteria from cows on low-tannin diets failed.

  18. Wine polyphenols: potential agents in neuroprotection.

    PubMed

    Basli, Abdelkader; Soulet, Stéphanie; Chaher, Nassima; Mérillon, Jean-Michel; Chibane, Mohamed; Monti, Jean-Pierre; Richard, Tristan

    2012-01-01

    There are numerous studies indicating that a moderate consumption of red wine provides certain health benefits, such as the protection against neurodegenerative diseases. This protective effect is most likely due to the presence of phenolic compounds in wine. Wine polyphenolic compounds are well known for the antioxidant properties. Oxidative stress is involved in many forms of cellular and molecular deterioration. This damage can lead to cell death and various neurodegenerative disorders, such as Parkinson's or Alzheimer's diseases. Extensive investigations have been undertaken to determine the neuroprotective effects of wine-related polyphenols. In this review we present the neuroprotective abilities of the major classes of wine-related polyphenols.

  19. Wine Polyphenols: Potential Agents in Neuroprotection

    PubMed Central

    Basli, Abdelkader; Soulet, Stéphanie; Chaher, Nassima; Mérillon, Jean-Michel; Chibane, Mohamed; Monti, Jean-Pierre; Richard, Tristan

    2012-01-01

    There are numerous studies indicating that a moderate consumption of red wine provides certain health benefits, such as the protection against neurodegenerative diseases. This protective effect is most likely due to the presence of phenolic compounds in wine. Wine polyphenolic compounds are well known for the antioxidant properties. Oxidative stress is involved in many forms of cellular and molecular deterioration. This damage can lead to cell death and various neurodegenerative disorders, such as Parkinson's or Alzheimer's diseases. Extensive investigations have been undertaken to determine the neuroprotective effects of wine-related polyphenols. In this review we present the neuroprotective abilities of the major classes of wine-related polyphenols. PMID:22829964

  20. Tannins and related polyphenols of melastomataceous plants. VIII. Nobotanins L, M and N, trimeric hydrolyzable tannins from Tibouchina semidecandra.

    PubMed

    Yoshida, T; Nakata, F; Okuda, T

    1999-06-01

    Three hydrolyzable tannins, nobotannins L, M and N, were isolated from the water-soluble portion of the leaf extract of Tibouchina semidecandra, and their trimeric structures were elucidated from spectral and chemical evidence. Nobotanins L and N exist as equilibrium mixtures of four anomers due to the presence of two unacylated anomeric centers.

  1. Associations among Wine Grape Microbiome, Metabolome, and Fermentation Behavior Suggest Microbial Contribution to Regional Wine Characteristics

    PubMed Central

    Bokulich, Nicholas A.; Collins, Thomas S.; Masarweh, Chad; Allen, Greg; Heymann, Hildegarde; Ebeler, Susan E.

    2016-01-01

    ABSTRACT Regionally distinct wine characteristics (terroir) are an important aspect of wine production and consumer appreciation. Microbial activity is an integral part of wine production, and grape and wine microbiota present regionally defined patterns associated with vineyard and climatic conditions, but the degree to which these microbial patterns associate with the chemical composition of wine is unclear. Through a longitudinal survey of over 200 commercial wine fermentations, we demonstrate that both grape microbiota and wine metabolite profiles distinguish viticultural area designations and individual vineyards within Napa and Sonoma Counties, California. Associations among wine microbiota and fermentation characteristics suggest new links between microbiota, fermentation performance, and wine properties. The bacterial and fungal consortia of wine fermentations, composed from vineyard and winery sources, correlate with the chemical composition of the finished wines and predict metabolite abundances in finished wines using machine learning models. The use of postharvest microbiota as an early predictor of wine chemical composition is unprecedented and potentially poses a new paradigm for quality control of agricultural products. These findings add further evidence that microbial activity is associated with wine terroir. PMID:27302757

  2. Implementation of an Enzyme Linked Immunosorbent Assay for the Quantification of Allergenic Egg Residues in Red Wines Using Commercially Available Antibodies

    PubMed Central

    Koestel, Carole; Simonin, Céline; Belcher, Sandrine

    2016-01-01

    Abstract Since the early 2000s, labeling of potentially allergenic food components to protect people who suffer from food allergies is compulsory in numerous industrialized countries. In Europe, milk and egg components used during the winemaking process must be indicated on the label since July 1, 2012. Several ELISA procedures have been developed to detect allergenic residues in wines. However, the complexity of the wine matrix can inhibit the immunoenzymatic reaction. The aim of this study was to implement an ELISA assay for the detection of ovalbumin in red wines using commercially available antibodies. The specificity of the acquired antibodies and the absence of cross reactivity were assessed by immunoblotting and ELISA. An ELISA assay with a LOD of 14.2 μg/L and a LOQ of 56.4 μg/L of ovalbumin in aqueous solution was obtained. Differences in ELISA signals were observed when analyzing various fining agents, although reproducible conformation of the antigen could be reached for the comparison of ovalbumin and Ovicolle. The differences between samples in terms of pH could be leveled but the inhibition of the ELISA signal, positively correlated to the tannin content of the wines, could not be suppressed. Thus, standard curves of ovalbumin in several wines were obtained by relative quantification. The control steps and the difficulties encountered presented in this study should be considered by anybody working toward the development of ELISA assays for the detection of allergenic residues in complex food matrices. PMID:27356183

  3. Pre-fermentative cold maceration, saignée, and various thermal treatments as options for modulating volatile aroma and phenol profiles of red wine.

    PubMed

    Lukić, Igor; Budić-Leto, Irena; Bubola, Marijan; Damijanić, Kristijan; Staver, Mario

    2017-06-01

    The effects of six maceration treatments on volatile aroma and phenol composition of Teran red wine were studied: standard maceration (control C), cold pre-fermentation maceration (CPM), saignée (S), pre-fermentation heating with extended maceration (PHT) or juice fermentation (PHP), and post-fermentation heating (POH). PHP wine contained the highest amounts of esters, fatty acids and anthocyanins, and the lowest content of other phenols. Alternative treatments decreased higher alcohols in relation to control C. CPM treatment lowered the extraction of seed tannins, exhibited the highest acetaldehyde, ethyl acetate and C 6 -compounds levels, and had increased ester levels in relation to control C. POH wine contained the highest concentration of total phenols, flavonoids, monomeric, oligomeric and polymeric flavanols, and color intensity and hue. S and PHT wines contained lower amount of total phenols, but higher than in C and CPM wines. The calculated Odor Activity Values were used to establish significant differences between the treatments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. A tannin-blocking agent does not modify the preference of sheep towards tannin-containing plants.

    PubMed

    Hernández-Orduño, G; Torres-Acosta, J F J; Sandoval-Castro, C A; Capetillo-Leal, C M; Aguilar-Caballero, A J; Alonso-Díaz, M A

    2015-06-01

    Sheep have been suggested to use their senses to perceive plant properties and associate their intake with consequences after ingestion. However, sheep with browsing experience do not seem to select against tannin-rich browsing materials in cafeteria trials. Thus, the objective of the present study was to evaluate the relationship between the chemical composition, selectivity index (SI), preference and intake rate (IR) of tannin-containing forage trees offered to sheep in cafeteria experiments. Four trees were selected for their condensed tannin content and their varying biological activities. Havardia albicans (high biological activity), Leucaena leucocephala (medium biological activity), Acacia gaumeri (low biological activity) and Brosimum alicastrum (very low biological activity) were used in this study. Ten hair sheep (23.7kg±1.43LW) with eight months of browsing experience in native vegetation were used in this study. Polyethylene glycol (PEG 3600MW) was administered to five sheep during all experiments. In experiment 1, fresh foliage from all trees was offered ad libitum for 4h. In experiment 2, B. alicastrum was withdrawn and the preference was determined again. The forage preference in experiment 1 was A. gaumeri (14.77gDM/kgLW)>B. alicastrum (11.77gDM/kgLW)>H. albicans (3.71gDM/kgLW)=L. leucocephala (1.87gDM/kgLW) (P<0.05). The preference in experiment 2 was A. gaumeri>H. albicans=L. leucocephala. PEG administration had no effect on the preference or IR. The intake rate seemed to have been affected by the plant density. Moreover, fiber compounds were found to be better predictors of DM intake than polyphenolic compounds at levels typically found in the evaluated forages. It was concluded that tannins and PEG did not modify the preferences of sheep in cafeteria trials. Thus, tannins are not involved in the preference regulation of animals with browsing experience. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. 27 CFR 4.71 - Standard wine containers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Standard wine containers..., DEPARTMENT OF THE TREASURY LIQUORS LABELING AND ADVERTISING OF WINE Standards of Fill for Wine § 4.71 Standard wine containers. (a) A standard wine container shall be made, formed and filled to meet the...

  6. 27 CFR 26.97 - Marking containers of wine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Marking containers of wine... Liquors and Articles in Puerto Rico Wine § 26.97 Marking containers of wine. Containers of wine of Puerto... winemaker, the serial number of the container, the kind and taxable grade of the wine, the gallon content...

  7. 27 CFR 24.307 - Nonbeverage wine record.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Nonbeverage wine record..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.307 Nonbeverage wine record. A proprietor who produces nonbeverage wine or wine products shall maintain a record by transaction date of such...

  8. 27 CFR 24.302 - Effervescent wine record.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Effervescent wine record..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.302 Effervescent wine record. A proprietor who produces or receives sparkling wine or artificially carbonated wine in bond shall maintain records...

  9. Wine Chemical Composition and Radical Scavenging Activity of Some Cabernet Franc Clones.

    PubMed

    Popovic-Djordjevic, Jelena; Pejin, Boris; Dramicanin, Aleksandra; Jovic, Sonja; Vujovic, Dragan; Zunic, Dragoljub; Ristic, Renata

    2017-01-01

    Three clones of Cabernet Franc (Nos. 02, 010 and 012) were selected in the last phase of clonal selection in Serbia. Wines made from each clone were assessed for quality parameters and taste during five consecutive vintages (2008-2012) and compared to the standard. The wine quality was determined based on the following parameters: alcohol, total extract, anthocyanins, tannins, pH, titratable acidity, volatile acidity, aldehydes, esters and reducing sugars, relative density, ash, colour, tonality, and tasting score. In the last year of the study, grapes and wines of Cabernet Franc clones and a standard were subjected to a chemical analysis of their phenolic composition, resveratrol and radical scavenging activity. In the last year of the study, grapes and wines of Cabernet Franc clones and a standard were subjected to a chemical analysis of their phenolic composition, resveratrol and radical scavenging activity. Chemical analyses of grapes and wines along with sensory and radical scavenging activity evaluations were done according to the standard procedures. The wines of the clone No. 010 showed some superior properties compared to the other two clones and the standard; in five-year period the average concentration of anthocyanins (179±3.8 mg/L) and polyphenolics (1.85±0.02 g/L) was significantly higher than in wines of clones and the standard, (168-173 mg/L and 1.63-1.74 g/L for anthocyanins and phenolics, respectively). Furthermore, the same clone had a higher alcohol content (13.97±0.03%) in each year of the study, which indicated that it ripened faster than other clones (13.06-13.08 %) and compared to the standard (13.04±0.07%). This finding suggested that the clone No. 010 could possibly have a significant economic impact and further increase popularity of Cabernet Franc in a cooler climate viticultural region. It was also found to have the highest contents of aldehydes (488±1.54 mg/L) and esters (322±0.71 mg/L) compared to aldehydes (452-467 mg/L) and

  10. Sulfites and the wine metabolome.

    PubMed

    Roullier-Gall, Chloé; Hemmler, Daniel; Gonsior, Michael; Li, Yan; Nikolantonaki, Maria; Aron, Alissa; Coelho, Christian; Gougeon, Régis D; Schmitt-Kopplin, Philippe

    2017-12-15

    In a context of societal concern about food preservation, the reduction of sulfite input plays a major role in the wine industry. To improve the understanding of the chemistry involved in the SO 2 protection, a series of bottle aged Chardonnay wines made from the same must, but with different concentrations of SO 2 added at pressing were analyzed by ultrahigh resolution mass spectrometry (FT-ICR-MS) and excitation emission matrix fluorescence (EEMF). Metabolic fingerprints from FT-ICR-MS data could discriminate wines according to the added concentration to the must but they also revealed chemistry-related differences according to the type of stopper, providing a wine metabolomics picture of the impact of distinct stopping strategies. Spearman rank correlation was applied to link the statistically modeled EEMF components (parallel factor analysis (PARAFAC)) and the exact mass information from FT-ICR-MS, and thus revealing the extent of sulfur-containing compounds which could show some correlation with fluorescence fingerprints. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Exploitation of dietary tannins to improve rumen metabolism and ruminant nutrition.

    PubMed

    Patra, Amlan K; Saxena, Jyotisna

    2011-01-15

    Tannins (hydrolysable and condensed tannin) are polyphenolic polymers of relatively high molecular weight with the capacity to form complexes mainly with proteins due to the presence of a large number of phenolic hydroxyl groups. They are widely distributed in nutritionally important forage trees, shrubs and legumes, cereals and grains, which are considered as anti-nutritional compounds due to their adverse effects on intake and animal performance. However, tannins have been recognised to modulate rumen fermentation favourably such as reducing protein degradation in the rumen, prevention of bloat, inhibition of methanogenesis and increasing conjugated linoleic acid concentrations in ruminant-derived foods. The inclusion of tannins in diets has been shown to improve body weight and wool growth, milk yields and reproductive performance. However, the beneficial effects on rumen modulation and animal performance have not been consistently observed. This review discusses the effects of tannins on nitrogen metabolism in the rumen and intestine, and microbial populations (bacteria, protozoa, fungi and archaea), metabolism of tannins, microbial tolerance mechanisms to tannins, inhibition of methanogenesis, ruminal biohydrogenation processes and performance of animals. The discrepancies of responses of tannins among different studies are attributed to the different chemical structures (degree of polymerisation, procyanidins to propdelphinidins, stereochemistry and C-C bonding) and concentrations of tannins, and type of diets. An establishment of structure-activity relationship would be required to explain differences among studies and obtain consistent beneficial tannin effects. Copyright © 2010 Society of Chemical Industry.

  12. Microbial Contribution to Wine Aroma and Its Intended Use for Wine Quality Improvement.

    PubMed

    Belda, Ignacio; Ruiz, Javier; Esteban-Fernández, Adelaida; Navascués, Eva; Marquina, Domingo; Santos, Antonio; Moreno-Arribas, M Victoria

    2017-01-24

    Wine is a complex matrix that includes components with different chemical natures, the volatile compounds being responsible for wine aroma quality. The microbial ecosystem of grapes and wine, including Saccharomyces and non- Saccharomyces yeasts, as well as lactic acid bacteria, is considered by winemakers and oenologists as a decisive factor influencing wine aroma and consumer's preferences. The challenges and opportunities emanating from the contribution of wine microbiome to the production of high quality wines are astounding. This review focuses on the current knowledge about the impact of microorganisms in wine aroma and flavour, and the biochemical reactions and pathways in which they participate, therefore contributing to both the quality and acceptability of wine. In this context, an overview of genetic and transcriptional studies to explain and interpret these effects is included, and new directions are proposed. It also considers the contribution of human oral microbiota to wine aroma conversion and perception during wine consumption. The potential use of wine yeasts and lactic acid bacteria as biological tools to enhance wine quality and the advent of promising advice allowed by pioneering -omics technologies on wine research are also discussed.

  13. Coriariin M, a trimeric hydrolysable tannin with dehydrodigalloyl and valoneoyl groups as linking units, and accompanying dimeric hydrolysable tannins from Coriaria japonica.

    PubMed

    Shimozu, Yuuki; Hirai, Takayasu; Hatano, Tsutomu

    2018-07-01

    Three oligomeric hydrolysable tannins, coriariins K, L, and M, which were previously undescribed, together with five known hydrolysable tannins were isolated from dried leaves of Coriaria japonica. Their structures were determined based on 1D and 2D NMR spectroscopy, HR-ESI-MS, and ECD spectroscopy experiments. Among the isolated compounds, coriariin M has a unique trimer structure where both dehydrodigalloyl and valoneoyl group linkages were found between the hydrolysable tannin monomers. Dimeric hydrolysable tannins coriariins K and L, having a dehydrodigalloyl group as the linking unit, were structurally related to coriariin A, the main hydrolysable tannin of this plant species. Additionally, the complexation of the eight hydrolysable tannins isolated in this study with bovine serum albumin (BSA) to form water-soluble macromolecules was analyzed using native polyacrylamide gel electrophoresis (PAGE). A comparison of the behaviors of the oligomeric hydrolysable tannins suggested the participation of the hexahydroxydiphenoyl group and the importance of the molecular sizes of the hydrolysable tannins in the formation of macromolecules. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. A glass of red wine to keep vascular disease at bay, but what about pemphigus vulgaris?

    PubMed

    Caldarola, Giacomo; Feliciani, Claudio

    2011-03-01

    Pemphigus vulgaris is a rare autoimmune blistering disease, involving the skin and mucous epithelia, which is characterized by flaccid blisters and erosions. It is caused by the presence of autoantibodies directed against desmoglein, a glycoprotein that plays a critical role in cell-cell attachment. Upon a predisposing genetic background, different agents have been shown to act as triggers for the pathogenesis of pemphigus. The most evident association is with drug intake, while the role of diet is often underestimated. The aim of this article is to review the possible role of tannins, a group of phenolic metabolites that are widely distributed in almost all plant foods and beverages, particularly red wine, as a trigger for pemphigus vulgaris.

  15. Effect of commercial mannoprotein addition on polysaccharide, polyphenolic, and color composition in red wines.

    PubMed

    Guadalupe, Zenaida; Ayestarán, Belén

    2008-10-08

    Commercially available mannoprotein preparations were tested in Tempranillo winemaking to determine their influence on polysaccharide, polyphenolic, and color composition. No effect was found in the content of grape arabinogalactans, homogalacturonans, and type II rhamnogalacturonans. In contrast, mannoprotein-treated samples showed considerably higher values of high-molecular-weight mannoproteins (bMP) than controls from the beginning of alcoholic fermentation, although these differences diminished as vinification progressed. The bMP decrease observed in the mannoprotein-treated samples coincided with a substantial reduction in their proanthocyanidin content and wine stable color, suggesting a precipitation of the coaggregates mannoprotein-tannin and mannoprotein-pigment. Contrary to what is widely described, these results revealed that at the studied conditions, mannoproteins did not act as stabilizing colloids. Mannoprotein addition did not modify the content and composition of either monomeric anthocyanins or other monomeric phenolics, and it did not affect monomeric anthocyanin color.

  16. Structural and biochemical changes induced by pulsed electric field treatments on Cabernet Sauvignon grape berry skins: impact on cell wall total tannins and polysaccharides.

    PubMed

    Cholet, Céline; Delsart, Cristèle; Petrel, Mélina; Gontier, Etienne; Grimi, Nabil; L'hyvernay, Annie; Ghidossi, Remy; Vorobiev, Eugène; Mietton-Peuchot, Martine; Gény, Laurence

    2014-04-02

    Pulsed electric field (PEF) treatment is an emerging technology that is arousing increasing interest in vinification processes for its ability to enhance polyphenol extraction performance. The aim of this study was to investigate the effects of PEF treatment on grape skin histocytological structures and on the organization of skin cell wall polysaccharides and tannins, which, until now, have been little investigated. This study relates to the effects of two PEF treatments on harvested Cabernet Sauvignon berries: PEF1 (medium strength (4 kV/cm); short duration (1 ms)) and PEF2 (low intensity (0.7 kV/cm); longer duration (200 ms)). Histocytological observations and the study of levels of polysaccharidic fractions and total amounts of tannins allowed differentiation between the two treatments. Whereas PEF1 had little effect on the polyphenol structure and pectic fraction, PEF2 profoundly modified the organization of skin cell walls. Depending on the PEF parameters, cell wall structure was differently affected, providing variable performance in terms of polyphenol extraction and wine quality.

  17. Performance and characterization of a new tannin-based coagulant

    NASA Astrophysics Data System (ADS)

    Beltrán-Heredia, J.; Sánchez-Martín, J.; Gómez-Muñoz, C.

    2012-09-01

    Diethanolamine and formaldehyde were employed to cationize tannins from black wattle. This novel coagulant called CDF was functionally characterized in removing sodium dodecylbenzene sulfonate (anionic surfactant) and Palatine Fast Black WAN (azoic dye). Refined tannin-derived commercial coagulants exhibited similar efficiency, while CDF presented higher coagulant ability than alum, a usual coagulant agent. Low doses of CDF (ca. 100 mg L-1) were able to remove more than 70 % of surfactant and more than 85 % of dye (initial pollutant concentration of ca. 100 mg L-1) and it presented no temperature affection and worked at a relatively wide pH range. Surfactant and dye removal responded to the classical coagulant-and-adsorption models, such as Frumkin-Fowler-Guggenheim or Gu and Zhu in the case of surfactant, and Langmuir and Freundlich in the case of dye.

  18. 27 CFR 24.301 - Bulk still wine record.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... The bulk still wine record will contain the following: (a) The volume produced by fermentation in wine... fermentation, amelioration, sweetening, addition of spirits, blending; (d) The volume of wine used and produced...

  19. 27 CFR 24.301 - Bulk still wine record.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... The bulk still wine record will contain the following: (a) The volume produced by fermentation in wine... fermentation, amelioration, sweetening, addition of spirits, blending; (d) The volume of wine used and produced...

  20. 27 CFR 24.301 - Bulk still wine record.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... The bulk still wine record will contain the following: (a) The volume produced by fermentation in wine... fermentation, amelioration, sweetening, addition of spirits, blending; (d) The volume of wine used and produced...

  1. 27 CFR 24.301 - Bulk still wine record.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... The bulk still wine record will contain the following: (a) The volume produced by fermentation in wine... fermentation, amelioration, sweetening, addition of spirits, blending; (d) The volume of wine used and produced...

  2. 27 CFR 24.301 - Bulk still wine record.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... The bulk still wine record will contain the following: (a) The volume produced by fermentation in wine... fermentation, amelioration, sweetening, addition of spirits, blending; (d) The volume of wine used and produced...

  3. Condensed tannin-resorcinol adducts in laminating adhesives

    Treesearch

    Richard W. Hemingway; Roland E. Kreibich

    1985-01-01

    A condensed tannin-resorcinol adduct made by co-reaction of an extract from southern pine bark with resorcinol at a 2 to 1 weight ratio was used to prepare a laminating resin in which the entire amount of resorcinol normally used was replaced by this adduct. The resin was formulated into a room temperature setting adhesive that meets the basic criteria of product...

  4. Proanthocyanidins and hydrolysable tannins: occurrence, dietary intake and pharmacological effects.

    PubMed

    Smeriglio, Antonella; Barreca, Davide; Bellocco, Ersilia; Trombetta, Domenico

    2017-06-01

    Tannins are a heterogeneous group of high MW, water-soluble, polyphenolic compounds, naturally present in cereals, leguminous seeds and, predominantly, in many fruits and vegetables, where they provide protection against a wide range of biotic and abiotic stressors. Tannins exert several pharmacological effects, including antioxidant and free radical scavenging activity as well as antimicrobial, anti-cancer, anti-nutritional and cardio-protective properties. They also seem to exert beneficial effects on metabolic disorders and prevent the onset of several oxidative stress-related diseases. Although the bioavailability and pharmacokinetic data for these phytochemicals are still sparse, gut absorption of these compounds seems to be inversely correlated with the degree of polymerization. Further studies are mandatory to better clarify how these molecules and their metabolites are able to cross the intestinal barrier in order to exert their biological properties. This review summarizes the current literature on tannins, focusing on the main, recently proposed mechanisms of action that underlie their pharmacological and disease-prevention properties, as well as their bioavailability, safety and toxicology. This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc. © 2016 The British Pharmacological Society.

  5. Anti-inflammatory Hydrolyzable Tannins from Myricaria bracteata.

    PubMed

    Liu, Jia-Bao; Ding, Ya-Si; Zhang, Ying; Chen, Jia-Bao; Cui, Bao-Song; Bai, Jin-Ye; Lin, Ming-Bao; Hou, Qi; Zhang, Pei-Cheng; Li, Shuai

    2015-05-22

    Twelve hydrolyzable tannins were obtained from the twigs of Myricaria bracteata, including two new hellinoyl-type dimers, bracteatinins D1 (1) and D2 (2); a new hellinoyl-type trimer, bracteatinin T1 (3); two known monomers, nilotinin M4 (4) and 1,3-di-O-galloyl-4,6-O-(aS)-hexahydroxydiphenoyl-β-d-glucose (5); six known dimers, tamarixinin A (6), nilotinin D8 (7), hirtellins A (10), B (9), and E (8), and isohirtellin C (11); and a known trimer, hirtellin T3 (12). The structures of the tannins were elucidated by spectroscopic data analysis and comparisons to known tannins. All compounds were evaluated as free radical scavengers using 1,1-diphenyl-2-picrylhydrazyl and hydroxy radicals and compared to the activity of BHT and Trolox. Compound 6 showed a significant anti-inflammatory effect on croton oil-induced ear edema in mice (200 mg/kg, inhibition rate 69.8%) and on collagen-induced arthritis in DBA/1 mice (20 mg/kg, inhibition rate 46.0% at day 57).

  6. Biomolecular Interactions of Tannin Isolated from Oenothera gigas with Liposomes.

    PubMed

    Sekowski, Szymon; Ionov, Maksim; Dubis, Alina; Mavlyanov, Saidmukhtar; Bryszewska, Maria; Zamaraeva, Maria

    2016-04-01

    We have examined the interaction between hydrolysable tannin 1-O-galloyl-4,6-hexahydroxydiphenoyl-β-D-glucose (OGβDG) with neutral liposomes as a model of cell membranes composed of three lipids: lecithin, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) at different mass ratios. OGβDG in the concentration range 0.5-15 µg/ml (0.4-12 µM) strongly interacts with liposomal membranes by changing their structure, surface charge and fluidity. Used OGβDG molecules decrease and increase the rigidity of hydrophilic surface and hydrophobic parts of liposomes, respectively. At higher concentrations of tannin (>15 µM), liposomes are aggregated. Fourier Transform Infra-Red (FTIR) analysis showed that mainly -OH groups from OGβDG and also PO(2-) groups from phospholipids are responsible for the interaction. Obtained data indicate the importance of membrane lipid composition in interactions between tannins and cells.

  7. Proanthocyanidins and hydrolysable tannins: occurrence, dietary intake and pharmacological effects

    PubMed Central

    Smeriglio, Antonella; Bellocco, Ersilia; Trombetta, Domenico

    2016-01-01

    Tannins are a heterogeneous group of high MW, water‐soluble, polyphenolic compounds, naturally present in cereals, leguminous seeds and, predominantly, in many fruits and vegetables, where they provide protection against a wide range of biotic and abiotic stressors. Tannins exert several pharmacological effects, including antioxidant and free radical scavenging activity as well as antimicrobial, anti‐cancer, anti‐nutritional and cardio‐protective properties. They also seem to exert beneficial effects on metabolic disorders and prevent the onset of several oxidative stress‐related diseases. Although the bioavailability and pharmacokinetic data for these phytochemicals are still sparse, gut absorption of these compounds seems to be inversely correlated with the degree of polymerization. Further studies are mandatory to better clarify how these molecules and their metabolites are able to cross the intestinal barrier in order to exert their biological properties. This review summarizes the current literature on tannins, focusing on the main, recently proposed mechanisms of action that underlie their pharmacological and disease‐prevention properties, as well as their bioavailability, safety and toxicology. Linked Articles This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc PMID:27646690

  8. Tannins and Bacitracin Differentially Modulate Gut Microbiota of Broiler Chickens

    PubMed Central

    Pin Viso, Natalia Daniela; Farber, Marisa Diana

    2018-01-01

    Antibiotic growth promoters have been used for decades in poultry farming as a tool to maintain bird health and improve growth performance. Global concern about the recurrent emergence and spreading of antimicrobial resistance is challenging the livestock producers to search for alternatives to feed added antibiotics. The use of phytogenic compounds appears as a feasible option due to their ability to emulate the bioactive properties of antibiotics. However, detailed description about the effects of in-feed antibiotics and alternative natural products on chicken intestinal microbiota is lacking. High-throughput sequencing of 16S rRNA gene was used to study composition of cecal microbiota in broiler chickens supplemented with either bacitracin or a blend of chestnut and quebracho tannins over a 30-day grow-out period. Both tannins and bacitracin had a significant impact on diversity of cecal microbiota. Bacitracin consistently decreased Bifidobacterium while other bacterial groups were affected only at certain times. Tannins-fed chickens showed a drastic decrease in genus Bacteroides while certain members of order Clostridiales mainly belonging to the families Ruminococcaceae and Lachnospiraceae were increased. Different members of these groups have been associated with an improvement of intestinal health and feed efficiency in poultry, suggesting that these bacteria could be associated with productive performance of birds. PMID:29682522

  9. [Optimization of extraction process for tannins from Geranium orientali-tibeticum by supercritical CO2 method].

    PubMed

    Xie, Song; Tong, Zhi-Ping; Tan, Rui; Liu, Xiao-Zhen

    2014-08-01

    In order to optimize extraction process conditions of tannins from Geranium orientali-tibeticum by supercritical CO2, the content of tannins was determined by phosphomolybdium tungsten acid-casein reaction, with extraction pressure, extraction temper- ature and extraction time as factors, the content of tannins from extract of G. orientali-tibeticum as index, technology conditions were optimized by orthogonal test. Optimum technology conditions were as follows: extraction pressure was 25 MPa, extraction temperature was 50 °C, extracted 1.5 h. The content of tannins in extract was 12.91 mg x g(-1), extract rate was 3.67%. The method established could be used for assay the contents of tannin in G. orientali-tibeticum. The circulated extraction was an effective extraction process that was stable and feasible, and that provides a way of the extraction process conditions of tannin from G. orientali-tibeticum.

  10. Contributions to the phytochemical study of Bidens tripartitae herba from Romania. I. Tannins.

    PubMed

    Zagnat, M; Cheptea, Corina; Spac, A F

    2013-01-01

    To analyze qualitatively and quantitatively tannins in the native plant, collected during the whole vegetation period from different areas of the country, and in its different organs (flower, stem, leaf). For quantitative analysis, the plant product was extracted by repeated maceration (3 days) with 80% methanol. Proanthocyanidins in the extract were quantified by spectrophotometric methods. condensed tannins were present while hydrolyzed tannins were absent. Chromatographic analysis showed that tannins spectrum is similar in all plant organs and in plants collected at different times throughout the vegetation period. The differences are only quantitative. The maximum amount of tannins was found during the flowering stage (10.32%). In terms of tannin content, flowering is the best time to collect. However, collection throughout the whole vegetation period is acceptable.

  11. Characteristics of traditional Chinese shanlan wine fermentation.

    PubMed

    Yang, Dongsheng; Luo, Xianqun; Wang, Xinguang

    2014-02-01

    Shanlan rice wine is made by a unique method by removing the saccharified liquid from wine mash constantly since it appeared during saccharification and fermentation. The objective of this study is to find the advantages of this technique of wine making by analyzing data of shanlan wine fermentation. Since the liquid was removed, the mash (rice) bed was fluffier than immersed in the saccharified liquid, under ambient condition constantly and it is favorable for starch degradation. This technique made shanlan rice wine tasted sweet and slightly acidic, lower content of alcohol and higher alcohol than in other non-distilled rice wines. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  12. No major role for binding by salivary proteins as a defense against dietary tannins in Mediterranean goats.

    PubMed

    Hanovice-Ziony, Michal; Gollop, Nathan; Landau, Serge Yan; Ungar, Eugene David; Muklada, Hussein; Glasser, Tzach Aharon; Perevolotsky, Avi; Walker, John Withers

    2010-07-01

    We investigated whether Mediterranean goats use salivary tannin-binding proteins to cope with tannin-rich forages by determining the affinity of salivary or parotid gland proteins for tannic acid or quebracho tannin. Mixed saliva, sampled from the oral cavity, or parotid gland contents were compared to the intermediate affinity protein bovine serum albumin with a competitive binding assay. Goats that consume tannin-rich browse (Damascus) and goats that tend to avoid tannins (Mamber) were sequentially fed high (Pistacia lentiscus L.), low (vetch hay), or zero (wheat hay) tannin forages. Affinity of salivary proteins for tannins did not differ between goat breeds and did not respond to presence or absence of tannins in the diet. Proteins in mixed saliva had slightly higher affinity for tannins than those in parotid saliva, but neither source contained proteins with higher affinity for tannins than bovine serum albumin. Similarly, 3 months of browsing in a tannin-rich environment had little effect on the affinity of salivary proteins for tannin in adult goats of either breed. We sampled mixed saliva from young kids before they consumed forage and after 3 months of foraging in a tannin-rich environment. Before foraging, the saliva of Mamber kids had higher affinity for tannic acid (but not quebracho tannin) than the saliva of Damascus kids, but there was no difference after 3 months of exposure to tannin-rich browse, and the affinity of the proteins was always similar to the affinity of bovine serum albumin. Our results suggest there is not a major role for salivary tannin-binding proteins in goats. Different tendencies of goat breeds to consume tannin-rich browse does not appear be related to differences in salivary tannin-binding proteins.

  13. Activities of Tannins--From In Vitro Studies to Clinical Trials.

    PubMed

    Sieniawska, Elwira

    2015-11-01

    Tannins are considered as valuable plant secondary metabolites providing many benefits for human health. In this review information was gathered about bioactivity in vitro and in vivo, as well as about conducted clinical trials. The literature research was based on ScienceDirect, Scopus, and Cochrane databases and presents a wide range of tested activities of tannins. The described clinical trials verify laboratory tests and show the effective health benefits taken from supplementation with tannins.

  14. Relation ofSpodoptera eridania choice to tannins and protein oflotus corniculatus.

    PubMed

    Briggs, M A

    1990-05-01

    Plant secondary compounds such as tannins may influence herbivore choice. To determine if herbivory was influenced by tannin concentration,Spodoptera eridania larvae were given a choice ofLotus corniculatus plants whose chemical profiles were altered by fertilization. Herbivores chose plants that had been grown with symbiotic nitrogen fixation as their only nitrogen source more often than fertilized plants. Choice was related to protein concentration, but not to tannin concentration.

  15. The effect of tannins and pH on the corrosion of metals in wood extracts

    Treesearch

    Samuel Zelinka; D.S. Stone

    2011-01-01

    Tannins and pH are often cited as factors that affect the corrosiveness of wood yet there are few data to confirm these statements. The purpose of this paper is to systematically investigate the effect of tannins and pH on corrosion of metals in wood. Four wood species known to vary in both their pH and extractives were chosen and extracted with water. The pH, tannin...

  16. Tannin diagenesis in mangrove leaves from a tropical estuary: A novel molecular approach

    USGS Publications Warehouse

    Hernes, P.J.; Benner, R.; Cowie, G.L.; Goi, M.A.; Bergamaschi, B.A.; Hedges, J.I.

    2001-01-01

    Molecular-level condensed tannin analyses were conducted on a series of mangrove (Rhizophora mangle) leaves at various stages of decomposition in a tropical estuary. Total molecular tannin yields ranged from 0.5% ash-free dry weight (AFDW) in the most highly degraded black leaves (6-7 weeks in the water) up to >7% AFDW in fresh leaves (80% procyanidin (PC) with the remainder being prodelphinidin (PD). PD tannin, with its higher degree of hydroxylation, proved to be more labile than PC tannin. Average chain length of condensed tannin (degree of polymerization) exhibited an initial increase in response to leaching, but later decreased in the subsequent shift toward abiotic or microbially mediated chemical reactions. Several trends point toward a possible condensation reaction in which tannin plays a role in nitrogen immobilization. These include an apparent inverse correlation between molecular tannin and nitrogen, a positive correlation between molecular tannin and percent basic amino acids, 13C-NMR data indicating transformation of tannin as opposed to remineralization, and 13C-NMR data showing loss of condensed tannin B-ring phenolic carbons coupled with preservation of A-ring phenolic carbon. In addition to condensed tannin, the molecular method used also yielded several triterpenoids. Triterpenoids accounted for up to 3.5% AFDW of the leaf material and exhibited a threefold increase between yellow senescent leaves entering the estuary and black leaves. This trend is likely due to the weakening of protective cuticular membranes during leaf decomposition, which leads to increased yields in the acidic conditions used for tannin analyses. Copyright ?? 2001 Elsevier Science Ltd.

  17. Hydrolyzable tannins as "quantitative defenses": limited impact against Lymantria dispar caterpillars on hybrid poplar.

    PubMed

    Barbehenn, Raymond V; Jaros, Adam; Lee, Grace; Mozola, Cara; Weir, Quentin; Salminen, Juha-Pekka

    2009-04-01

    The high levels of tannins in many tree leaves are believed to cause decreased insect performance, but few controlled studies have been done. This study tested the hypothesis that higher foliar tannin levels produce higher concentrations of semiquinone radicals (from tannin oxidation) in caterpillar midguts, and that elevated levels of radicals are associated with increased oxidative stress in midgut tissues and decreased larval performance. The tannin-free leaves of hybrid poplar (Populus tremulaxP. alba) were treated with hydrolyzable tannins, producing concentrations of 0%, 7.5% or 15% dry weight, and fed to Lymantria dispar caterpillars. As expected, larvae that ingested control leaves contained no measurable semiquinone radicals in the midgut, those that ingested 7.5% hydrolyzable tannin contained low levels of semiquinone radicals, and those that ingested 15% tannin contained greatly increased levels of semiquinone radicals. Ingested hydrolyzable tannins were also partially hydrolyzed in the midgut. However, increased levels of semiquinone radicals in the midgut were not associated with oxidative stress in midgut tissues. Instead, it appears that tannin consumption was associated with increased metabolic costs, as measured by the decreased efficiency of conversion of digested matter to body mass (ECD). Decreased ECD, in turn, decreased the overall efficiency of conversion of ingested matter to body mass (ECI). Contrary to our hypothesis, L. dispar larvae were able to maintain similar growth rates across all tannin treatment levels, in part, because of compensatory feeding. We conclude that hydrolyzable tannins act as "quantitative defenses" in the sense that high levels appear to be necessary to increase levels of semiquinone radicals in the midguts of caterpillars. However, these putative resistance factors are not sufficient to decrease the performance of tannin-tolerant caterpillars such as L. dispar.

  18. Wine Flavonoids in Health and Disease Prevention.

    PubMed

    Fernandes, Iva; Pérez-Gregorio, Rosa; Soares, Susana; Mateus, Nuno; de Freitas, Victor

    2017-02-14

    Wine, and particularly red wine, is a beverage with a great chemical complexity that is in continuous evolution. Chemically, wine is a hydroalcoholic solution (~78% water) that comprises a wide variety of chemical components, including aldehydes, esters, ketones, lipids, minerals, organic acids, phenolics, soluble proteins, sugars and vitamins. Flavonoids constitute a major group of polyphenolic compounds which are directly associated with the organoleptic and health-promoting properties of red wine. However, due to the insufficient epidemiological and in vivo evidences on this subject, the presence of a high number of variables such as human age, metabolism, the presence of alcohol, the complex wine chemistry, and the wide array of in vivo biological effects of these compounds suggest that only cautious conclusions may be drawn from studies focusing on the direct effect of wine and any specific health issue. Nevertheless, there are several reports on the health protective properties of wine phenolics for several diseases such as cardiovascular diseases, some cancers, obesity, neurodegenerative diseases, diabetes, allergies and osteoporosis. The different interactions that wine flavonoids may have with key biological targets are crucial for some of these health-promoting effects. The interaction between some wine flavonoids and some specific enzymes are one example. The way wine flavonoids may be absorbed and metabolized could interfere with their bioavailability and therefore in their health-promoting effect. Hence, some reports have focused on flavonoids absorption, metabolism, microbiota effect and overall on flavonoids bioavailability. This review summarizes some of these major issues which are directly related to the potential health-promoting effects of wine flavonoids. Reports related to flavonoids and health highlight some relevant scientific information. However, there is still a gap between the knowledge of wine flavonoids bioavailability and their health

  19. Uric Acid and Antioxidant Effects of Wine

    PubMed Central

    Boban, Mladen; Modun, Darko

    2010-01-01

    The aim of this article is to review the role of uric acid in the context of antioxidant effects of wine and its potential implication to human health. We described and discussed the mechanisms of increase in plasma antioxidant capacity after consumption of moderate amounts of wine. Because this effect is largely contributed by acute elevation in plasma uric acid, we paid special attention to wine constituents and metabolic processes that are likely to be involved in uric acid elevation. PMID:20162741

  20. Oenology: red wine procyanidins and vascular health.

    PubMed

    Corder, R; Mullen, W; Khan, N Q; Marks, S C; Wood, E G; Carrier, M J; Crozier, A

    2006-11-30

    Regular, moderate consumption of red wine is linked to a reduced risk of coronary heart disease and to lower overall mortality, but the relative contribution of wine's alcohol and polyphenol components to these effects is unclear. Here we identify procyanidins as the principal vasoactive polyphenols in red wine and show that they are present at higher concentrations in wines from areas of southwestern France and Sardinia, where traditional production methods ensure that these compounds are efficiently extracted during vinification. These regions also happen to be associated with increased longevity in the population.