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Analytica Chimica Acta (v.732, #)
Unraveling the evolving nature of gaseous and dissolved carbon dioxide in champagne wines: A state-of-the-art review, from the bottle to the tasting glass by Gérard Liger-Belair; Guillaume Polidori; Virginie Zéninari (pp. 1-15).
Setup used to visualize, through IR video recordings, the volutes of gaseous CO2 desorbing from champagne during the pouring process.Display Omitted► CO2 dissolved in champagne and sparkling wines is responsible for bubble formation. ► Dissolved CO2 content constantly evolves once a bottle is uncorked. ► Gaseous and dissolved CO2 were both carefully monitored, from the bottle to the tasting glass. ► We propose a global overview of phenomena, in tasting conditions.In champagne and sparkling wine tasting, the concentration of dissolved CO2 is indeed an analytical parameter of high importance since it directly impacts the four following sensory properties: (i) the frequency of bubble formation in the glass, (ii) the growth rate of rising bubbles, (iii) the mouth feel, and (iv) the nose of champagne, i.e., its so-called bouquet. In this state-of-the-art review, the evolving nature of the dissolved and gaseous CO2 found in champagne wines is evidenced, from the bottle to the glass, through various analytical techniques. Results obtained concerning various steps where the CO2 molecule plays a role (from its ingestion in the liquid phase during the fermentation process to its progressive release in the headspace above the tasting glass) are gathered and synthesized to propose a self-consistent and global overview of how gaseous and dissolved CO2 impact champagne and sparkling wine science.
Keywords: Champagne; Sparkling wines; CO; 2; Effervescence; Glass shape; Tasting
Rapid monitoring of grapevine reserves using ATR–FT-IR and chemometrics by Leigh M. Schmidtke; Jason P. Smith; Markus C. Müller; Bruno P. Holzapfel (pp. 16-25).
Display Omitted► Vitis vinifera over wintering nitrogen and starch reserves. ► Four vintages, 35 vineyards, 4 grape varieties, 1880 samples. ► Rapid determination using ATR–FT-IR. ► PLS and support vector regression. ► Excellent predictive models with low error.Predictions of grapevine yield and the management of sugar accumulation and secondary metabolite production during berry ripening may be improved by monitoring nitrogen and starch reserves in the perennial parts of the vine. The standard method for determining nitrogen concentration in plant tissue is by combustion analysis, while enzymatic hydrolysis followed by glucose quantification is commonly used for starch. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR–FT-IR) combined with chemometric modelling offers a rapid means for the determination of a range of analytes in powdered or ground samples. ATR–FT-IR offers significant advantages over combustion or enzymatic analysis of samples due to the simplicity of instrument operation, reproducibility and speed of data collection. In the present investigation, 1880 root and wood samples were collected from Shiraz, Semillon and Riesling vineyards in Australia and Germany. Nitrogen and starch concentrations were determined using standard analytical methods, and ATR–FT-IR spectra collected for each sample using a Bruker Alpha instrument. Samples were randomly assigned to either calibration or test data sets representing two thirds and one third of the samples respectively. Signal preprocessing included extended multiplicative scatter correction for water and carbon dioxide vapour, standard normal variate scaling with second derivative and variable selection prior to regression. Excellent predictive models for percent dry weight (DW) of nitrogen (range: 0.10–2.65% DW, median: 0.45% DW) and starch (range: 0.25–42.82% DW, median: 7.77% DW) using partial least squares (PLS) or support vector machine (SVM) analysis for linear and nonlinear regression respectively, were constructed and cross validated with low root mean square errors of prediction (RMSEP). Calibrations employing SVM-regression provided the optimum predictive models for nitrogen ( R2=0.98 and RMSEP=0.07% DW) compared to PLS regression ( R2=0.97 and RMSEP=0.08% DW). The best predictive models for starch was obtained using PLS regression ( R2=0.95 and RSMEP=1.43% DW) compared to SVR ( R2=0.95; RMSEP=1.56% DW). The RMSEP for both nitrogen and starch is below the reported seasonal flux for these analytes in Vitis vinifera. Nitrogen and starch concentrations in grapevine tissues can thus be accurately determined using ATR–FT-IR, providing a rapid method for monitoring vine reserve status under commercial grape production.
Keywords: Fourier transform infrared spectroscopy; Vine reserves; Nitrogen; Starch; Vitis vinifera
Influence of the physiological stage and the content of soluble solids on the anthocyanin extractability of Vitis vinifera L. cv. Tempranillo grapes by José Miguel Hernández-Hierro; Natalia Quijada-Morín; Julián C. Rivas-Gonzalo; M. Teresa Escribano-Bailón (pp. 26-32).
Display Omitted► Physiological stage is more important for anthocyanin contents in grapes than °Brix. ► Physiological stage is more important for anthocyanin extractability than °Brix. ► Non-acylated anthocyanins are better extracted from grapes than acylated ones. ► °Brix is related to the relative abundance of acylated anthocyanins.The influence and the extent of the anthocyanin extractability from grape skins at different physiological stages and different soluble solids contents within each stage were investigated. For this purpose three different physiological stages (pre-harvest, harvest and over-ripening) and three soluble solids contents (22, 24 and 26°Brix) within each stage were taken into account using Vitis vinifera L. cv. Tempranillo.This study revealed the influence of physiological stages and soluble solids contents on the amounts of anthocyanins. The most important factor was the physiological stage although the soluble solid contents effect was also relevant, especially for anthocyanins monoglucosides. The highest contents in anthocyanins were found at pre-harvest, following by harvest and finally at over-ripening. Within each physiological stage, the relative abundance of acylated derivatives was influenced by the soluble solids contents. The percentages of acylated anthocyanins tend to decrease as the soluble solids contents.Differences in the anthocyanin extractabilities were highly influenced by the physiological stages and in a lesser extent by the soluble solids contents. The lowest extraction percentages were obtained in pre-harvest samples whatever soluble solids contents. Over-ripening samples present the lowest contents of anthocyanins but these compounds are easily released from tissues to the hydroalcoholic solution providing the highest extraction percentages. Generally, non-acylated anthocyanins were better extracted than the acylated anthocyanins.
Keywords: Anthocyanin extractability; Physiological stages; Soluble solids contents; Colour; Red wine; Tempranillo
Polyphenolic profile as a useful tool to identify the wood used in wine aging by Miriam Sanz; Brígida Fernández de Simón; Estrella Cadahía; Enrique Esteruelas; Ángel Mª Muñoz; Mª Teresa Hernández; Isabel Estrella (pp. 33-45).
Display Omitted► Phenolics in cherry, chestnut, false acacia, European and American ash heartwood were compared. ► The phenolic profile of untoasted and toasted wood is a useful tool to identify the botanical origin. ► Untoasted and toasted woods show different phenolic markers. ► The toasting led to a minor differentiation among species in the polyphenolic profile. ► Our results will allow the recognition of these woods in barrels and alternative to barrel products.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 and ellagic acids and hydrolysable tannins of both the gallotannin and ellagitannin type, can be used as chemical markers.
Keywords: Polyphenols; Wood; Toasting; Aging
Evaluation of bitterness in white wine applying descriptive analysis, time-intensity analysis, and temporal dominance of sensations analysis by Martina Sokolowsky; Ulrich Fischer (pp. 46-52).
Bitterness in wine, especially in white wine, is a complex and sensitive topic as it is a persistent sensation with negative connotation by consumers. However, the molecular base for bitter taste in white wines is still widely unknown yet. At the same time studies dealing with bitterness have to cope with the temporal dynamics of bitter perception. The most common method to describe bitter taste is the static measurement amongst other attributes during a descriptive analysis. A less frequently applied method, the time-intensity analysis, evaluates the temporal gustatory changes focusing on bitterness alone. The most recently developed multidimensional approach of the temporal dominance of sensations method reveals the temporal dominance of bitter taste in relation to other attributes. In order to compare the results comprised with these different sensory methodologies, 13 commercial white wines were evaluated by the same panel. To facilitate a statistical comparison, parameters were extracted from bitterness curves obtained from time-intensity and temporal dominance of sensations analysis and were compared to bitter intensity as well as bitter persistency based on descriptive analysis. Analysis of variance differentiated significantly the wines regarding all measured bitterness parameters obtained from the three sensory techniques. Comparing the information of all sensory parameters by multiple factor analysis and correlation, each technique provided additional valuable information regarding the complex bitter perception in white wine.
Keywords: Bitter; White wine; Time-intensity; Temporal dominance of sensations
Effect of the aging on lees and other alternative techniques on the low molecular weight phenols of Tempranillo red wine aged in oak barrels by Rubén Del Barrio-Galán; Silvia Pérez-Magariño; Miriam Ortega-Heras (pp. 53-63).
Display Omitted► The effect of different alternative techniques to aging on lees was study. ► Molecular weight phenolic compounds of red wines were evaluated in two vintages. ► Hydroxycinnamic acids were the compounds most affected by these treatments. ► In the 2008 vintage the differences between treatments decreased along the aging in barrel. ► A vintage effect was observed due to differences in the initial phenolic composition of wines.The effect of different alternative techniques to the traditional aging on lees on the low molecular weight phenolic compounds of red wines was study as well as their evolution during the aging in oak wood barrels for six months. The study was carried out with Tempranillo red grapes from two consecutive vintages. The techniques assayed were the traditional aging on lees with or without the addition of exogenous β-glucanase enzymes, the use of yeast derivative preparations also with or without the addition of exogenous β-glucanase enzymes, the micro-oxygenation applied together with the aging on lees, and the use of non-toasted oak wood chips.Hydroxycinnamic acids were the compounds most affected by these treatments, mainly in the wines treated with chips and commercial yeast derivative products, which showed higher concentrations of the free acids, compounds that play an important role in wine stabilization color since they can act as anthocyanin copigments.The differences found between the assayed treatments were more important in the 2007 vintage than in the 2008. However, a more significant effect of micro-oxygenation in the 2008 vintage was observed, which could be related to the fact that in this vintage the treatment was longer. In the 2008 vintage, the differences between treatments decreased along the aging in barrel. This vintage effect could be associated to the differences in the phenolic concentration of the initial wines. In this sense more research should be done to corroborate this fact.
Keywords: Aging on lees; Yeast derivative; Oak chips; Glucanase enzymes; Red wine; Phenolic compounds
Contribution of non-volatile and aroma fractions to in-mouth sensory properties of red wines: Wine reconstitution strategies and sensory sorting task by María-Pilar Sáenz-Navajas; Eva Campo; José Miguel Avizcuri; Dominique Valentin; Purificación Fernández-Zurbano; Vicente Ferreira (pp. 64-72).
The clustering of 12 red wines according to the non-volatile chemical composition (left plot) and to a sorting task performed by a group of 35 trained panelists asked to group wines according to in-mouth similarities (right plot) are equivalent. The chemical parameters protein precipitable proanthocyanidins (PAs) and total phenolic content, linked to astringency, are the main drivers of global in-mouth perception in red wines.Display Omitted► Aroma perception is not a major driver of the in-mouth sensory perception of red wine. ► The chemical compounds causing astringency (mainly precipitable PAs) drive in-mouth perception. ► The role of aroma is more important whenever astringency, total phenols and PAs levels are smaller. ► When a red-black fruit odor nuance is clearly perceived, a strong reduction in astringency occurs. ► Aroma release patterns depend on the interaction between aroma compounds and the non-volatile matrix.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.
Keywords: Key words; Wine; Aroma; Orthonasal; Retronasal; Perceptual interactions; Astringency; Bitterness; Fruitiness; Proanthocyanidins
Influence of climatic conditions on the phenolic composition of Vitis vinifera L. cv. Graciano by Raúl Ferrer-Gallego; José Miguel Hernández-Hierro; Julián C. Rivas-Gonzalo; M. Teresa Escribano-Bailón (pp. 73-77).
Display Omitted► Differences between phenolic maturity pattern of grape skins and seeds. ► Evaluation of skins and seeds in a separate way to decide the harvest time. ► The effects of vintage and vineyard on the phenolic composition were observed. ► Relationship between oenological parameters, climatic data and phenolic compounds.The influence of different climatic conditions on the phenolic composition of grape skins and seeds of Vitis vinifera L. cv. Graciano – an autochthonous cultivar from Rioja and Navarra regions (Spain) – was evaluated during ripening in a separate way. Graciano grapes from two different vineyards with different climatic conditions and from two different vintages (2008 and 2009) were analysed. Clear differences between phenolic maturity pattern of grape skins and seeds were observed. In this context, it may be important to evaluate the phenolic maturity of seeds and skins in a separate way in order to decide the optimal harvest time. It was also noticeable that the effect of vintage (mainly due to changes in climatic conditions) may affect the changes in the phenolic composition of both grape skins and seeds. Although in a lesser extent, the effect of the vineyard was also observable, and it was especially relevant in vintages with irregular climatic conditions such as 2008 vintage.In a second strand, results obtained from the phenolic composition of grape seeds and skins at harvest, oenological parameters at harvest and climate conditions during vegetative stage were evaluated and relationships among the aforementioned variables were revealed.
Keywords: Climatic conditions; Grapes; Graciano; Maturity; Phenolic compounds
Preliminary study to determine the phenolic maturity stage of grape seeds by computer vision by Francisco J. Rodríguez-Pulido; Raúl Ferrer-Gallego; M. Lourdes González-Miret; Julián Carlos Rivas-Gonzalo; María Teresa Escribano-Bailón; Francisco J. Heredia (pp. 78-82).
Display Omitted► Polyphenols content and colorimetric parameters change in grape seeds along maturation. ► Linear relationships between chemical data and image analysis data have been found. ► The maturity stage of grape seeds can be assessed by image analysis.The applications of computer vision technology for acquiring and analysing images have been extended to the quality evaluation in food industry. This technique involves great advantages for the objective, rapid, non-contact and automated quality inspection and control. The aim of this work was to evaluate the potential of the computer vision to determine the phenolic maturity stage of grape seeds. Up to 21 phenolic compounds were determined by HPLC–DAD-MS in order to obtain reference values to develop the model. The CIELAB parameters, area, aspect, roundness, length, width and heterogeneity of seeds were analysed using a DigiEye® system. The technique reported in this work can be a good and rapid tool for taking decisions at harvest time. Notwithstanding, a comprehensive study should be made in order to develop more robust models.
Keywords: Image analysis; Colour; Vitis vinifera; Grape seeds; Phenolics
Polyphenols in red wine aged in acacia ( Robinia pseudoacacia) and oak ( Quercus petraea) wood barrels by Miriam Sanz; Brígida Fernández de Simón; Enrique Esteruelas; Ángel Mª Muñoz; Estrella Cadahía; Mª Teresa Hernández; Isabel Estrella; Juana Martinez (pp. 83-90).
Display Omitted► Polyphenolic composition of two 100% Syrah wines aged in acacia and oak barrels was studied. ► The nonanthocyanic phenolic profile was a useful tool to identify wines aged in acacia barrels. ► Dihydrorobinetin, robinetin, 2,4-dihydroxybenzoic aldehyde and acid, fustin, butin were exclusive of acacia wines. ► The identification of these wines will be easy also after short aging times, as two months.Polyphenolic composition of two Syrah wines aged during 6 or 12 months in medium toasting acacia and oak 225L barrels was studied by LC–DAD-ESI/MS. A total of 43 nonanthocyanic phenolic compounds were found in all wines, and other 15 compounds only in the wines from acacia barrels. Thus, the nonanthocyanic phenolic profile could be a useful tool to identify the wines aged in acacia barrels. Among all of them the dihydrorobinetin highlights because of its high levels, but also robinetin, 2,4-dihydroxybenzaldehyde, a tetrahydroxydihydroflavonol, fustin, butin, a trihydroxymethoxydihydroflavonol and 2,4-dihydroxybenzoic acid were detected at appreciable levels in wines during aging in acacia barrels, and could be used as phenolic markers for authenticity purposes. Although longer contact time with acacia wood mean higher concentrations of phenolic markers found in wines, the identification of these wines will also be easy after short aging times due the high levels reached by these compounds, even after only 2 months of aging.
Keywords: Robinia pseudoacacia; Barrels; Polyphenols; Toasting; Wine
Sensory representation of typicality of Cabernet franc wines related to phenolic composition: Impact of ripening stage and maceration time by Yves Cadot; Soline Caillé; Alain Samson; Gérard Barbeau; Véronique Cheynier (pp. 91-99).
Display Omitted► Style of wine was predicted by multiparametric models involving phenolics compounds. ► Wines, grapes and juice at devatting and grapes at harvest were analysed. ► Sensory representation was related first to harvest date, then to maceration time. ► Importance of anthocyanins and proanthocyanidins. ► Thiolysis yield significant, but requires elucidation.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 results suggest that the wine sensory quality established by the expert panel, is linked as expected to grape quality at harvest, reflected by sugar and anthocyanin contents, but also by thiolysis yield, which requires elucidation.
Keywords: Phenolics; Sensory analysis; Flavonoids; Typicality; Cabernet franc
Ultrasound assisted extraction of phenolic compounds from grapes by Ceferino Carrera; Ana Ruiz-Rodríguez; Miguel Palma; Carmelo G. Barroso (pp. 100-104).
Display Omitted► UAE allows for the extraction of phenolic compounds from grapes in 6min. ► UAE showed high reproducibility: RSD<5%. ► UAE was a suitable method for its application in grapes through the ripening period.A new ultrasound-assisted extraction method was developed for the determination of phenolic compounds present in grapes. Several extraction variables including extraction temperature (0–75°C), output amplitude (20, 50 and 100%), duty cycle (0.2s, 0.6s and 1s), the quantity of sample (0.5–2g), and the total extraction time (3–15min) were evaluated. One of the most widely used extraction methods of polyphenol extraction has been used as reference method. Three parameters were compared: total amount of phenolic compounds, total amount of anthocyanins and total amount of tannic components. The resulting method produced similar or higher recoveries for these three parameters; however a much shorter extraction time was needed: 6min (ultrasound assisted extraction method) instead of 60min (reference method).Analytical properties for the new method were established, including limit of detection, limit of quantification, repeatability and reproducibility.The developed method was applied to two different types of grapes in different ripening degree.
Keywords: Ultrasound-assisted extraction; Grapes; Anthocyanins; Phenolic compounds; Tannins
CIEL* a* b* parameters of white dehydrated grapes as quality markers according to chemical composition, volatile profile and mechanical properties by Luca Rolle; Manuela Giordano; Simone Giacosa; Simone Vincenzi; Susana Río Segade; Fabrizio Torchio; Benedetta Perrone; Vincenzo Gerbi (pp. 105-113).
Display Omitted► CIEL* a* b* parameters are chemical–physical markers of dehydrated grape. ► Blue color of berry skin is a marker of the noble rot infection. ► Blue grapes are characterized by a high content of gluconic acid and δ-lactones. ► Green and gold grapes are characterized by high values of skin hardness.In the oenological sector, the withering process is of particular importance in the production of dry and sweet dessert wines due to the total or partial use of overripe and/or dehydrated grapes.This complex process leads to several changes in the chemical–physical characteristics of white grape berries affecting the wine quality and, at the end of the dehydration period, different visual attributes are usually present in the berry skins.The aim of this work, therefore, was to study the properties of Erbaluce dried grapes of varying external colors, classified into three groups based on reflectance colorimetry (green, gold and blue).The chemical composition, volatile profile and mechanical attributes were investigated, focusing on establishing relationships between CIEL* a* b* parameters of dehydrated grapes and their chemical–physical characteristics.The higher values of the glucose–fructose ratio, together with the higher content of sugars, gluconic acid and glycerol, but lower titratable acidity, suggests the presence of Botrytis cinerea Pers. infection in blue withered berries, which has been microbiologically confirmed.Regarding the instrumental mechanical properties, blue dehydrated grapes were characterized by a lower skin hardness and higher skin thickness in agreement with the higher weight loss experienced. Finally, the determination of free and bound volatile compounds showed that some of them were only found in blue withered berries, δ-lactones being considered the main chemical markers of the noble rot infection that are important for the odor character. C-10 alkyl massoia lactone was the most abundant volatile compound in blue botrytized grapes.
Keywords: Dehydrated grapes; Grape color; Volatile compounds; δ-Lactones; Instrumental mechanical properties; Berry skin hardness
Validation of a method for the analysis of biogenic amines: Histamine instability during wine sample storage by Benoit Bach; Stephanie Le Quere; Patrick Vuchot; Magali Grinbaum; Laurent Barnavon (pp. 114-119).
Display Omitted► This paper reports on the validation of an optimized method for the biogenic amines analysis. ► During validation, instability of histamine over time was observed. ► As an application, the biogenic amines content in Rhône valley wines was studied. ► This method was proposed to the OIV to become a reference method.This paper reports on the development of an optimized method for the simultaneous analysis of eight biogenic amines (histamine, methylamine, ethylamine, tyramine, putrescine, cadaverine, phenethylamine, and isoamylamine). The analytical method thus proposed has the following advantages: the easy derivatization of wine, the quantification of biogenic amines and a complete degradation of excess derivatization reagent during sample preparation in order to preserve the column. It consists in reversed phase separation by HPLC and UV–vis detection of the aminoenones formed by the reaction of amino compounds with the derivatization reagent diethyl ethoxymethylenemalonate (DEEMM). The usefulness of this technique was confirmed by an alternative oenological analytical method for the validation, quality control and uncertainty assessment (OIV Oeno 10/2005). The method was validated and proposed as a reference method to the International Organization of Vine and Wine (OIV). As a specific application of the proposed method, the biogenic amine content of Rhône valley wines was investigated.
Keywords: Biogenic amines; Wine; Derivatization; High-performance liquid chromatography
Study of anthocyanic profiles of twenty-one hybrid grape varieties by liquid chromatography and precursor-ion mass spectrometry by M. De Rosso; L. Tonidandel; R. Larcher; G. Nicolini; V. Ruggeri; A. Dalla Vedova; F. De Marchi; M. Gardiman; R. Flamini (pp. 120-129).
Display Omitted► Anthocyanins of 21 hybrid red varieties were studied. ► Profiles determined by LC/DAD, compounds identified by precursor-ion LC/MS. ► 25 different compounds were identified. ► The method is very selective for analysis of diglucoside anthocyanins in grape. ► 3 varieties are particularly interesting for the natural colorants industry.The anthocyanins of 21 hybrid red varieties produced by crossing V. vinifera, V. riparia, V. labrusca, V. lincecumii and V. rupestris species, the profiles for which have not yet been reported, were studied. Profiles were determined by LC/DAD, and identification of single anthocyanins was confirmed by LC/MS precursor-ion analysis. Anthocyanidin precursors (pelargonidin at m/ z 271, dephinidin at m/ z 303, cyanidin at m/ z 287, petunidin at m/ z 317, peonidin at m/ z 301, and malvidin at m/ z 331) and precursors of monoglucoside compounds allowed 24 different compounds to be identified. Analysis of precursor ions of monoglucoside anthocyanins at low capillary voltage revealed the signals of diglucosides only, providing a very selective method for analysis of diglucoside anthocyanins in grape. According to anthocyanin profile, the samples were subdivided into two groups: one characterized by the substantial presence of diglucoside compounds (particularly Seyve Villard 23-399 and Seyve Villard 23-369) and one by the scarce presence or practical absence of diglucosides (Seibel 10878, Burdin 4077, and Galibert 238-35). Particularly interesting for producing anthocyanin for the natural colorant industry were the varieties Siebel 8357, Bacò 30-12 and Terzi 100-31.
Keywords: Anthocyanic profile; Hybrid grape; Liquid chromatography; Precursor-ion mass spectrometry
Proteins and enzymatic activities in Erbaluce grape berries with different response to the withering process by Simone Vincenzi; Serena Tolin; Luca Cocolin; Kalliopi Rantsiou; Andrea Curioni; Luca Rolle (pp. 130-136).
Display Omitted► In Erbaluce grapes, the berries with noble rot can be separated on the basis of color. ► Noble rot development decrease considerably chitinase and esterase activity. ► The main protein in infected berries is an induced beta-glucanase.During the off-vine natural withering process of Erbaluce (white) grapes to obtain “Erbaluce Caluso” Passito wine, some berries change in color from green-yellow to blue. This phenomenon appears at different extents in different years and might be related to several parameters, such as temperature and humidity during withering, grape composition and Botrytis cinerea loading. To better understand the mechanism involved in color variation, the metabolic changes corresponding to this event were studied.At the end of the withering process berries with different colors were separated using a reflectance spectrophotometer, obtaining three color classes identified as “green” ( L*=40.3, a*=−0.56, b*=15.20), “gold” ( L*=37.7, a*=5.01, b*=14.12) and “blue” ( L*=28.6, a*=0.89, b*=−0.67).The three groups of berries had different water contents, the blue berries containing about 30% less water than the green ones. Samples were crushed and the juices were analyzed. The juice yield for blue berries was less than 50% of that of the other two classes, confirming their higher dehydration level.Protein extraction from de-seeded berries was carried out using two different protocols, the first involving a treatment with phenol (to remove polyphenolic substances) and the second based on an extraction with a mild detergent (to recover the proteins to be used for enzymatic analyses).No trace of laccase activity was found in any of the samples, although DNA analysis, by quantitative PCR, suggested the presence of B. cinerea infection in the blue grapes. Chitinase activity of the blue berries was only 30% of that of the other two samples, as confirmed also by zymographic analysis on electrophoretic gels. The same was found also for esterase activity, which was lower (of about 85%) in the blue berries, which, in contrast, showed the highest beta-glucosidase activity.The electrophoretic analysis of the protein extracts revealed strong differences among the samples. Compared to the green and gold ones, the blue berries showed a complete absence of bands corresponding to chitinases and the appearance of unusual protein bands. Mass spectrometry analysis showed that these latter proteins were of grape origin, the main of them corresponding to β-1,3-glucanase, although no significant increase in glucanase activity was measured in the corresponding protein extract.
Keywords: Dehydrated grapes; Grape color; Grape proteins; Botrytis; Enzymatic activities
Direct determination of organic acids in wine and wine-derived products by Fourier transform infrared (FT-IR) spectroscopy and chemometric techniques by U. Regmi; M. Palma; C.G. Barroso (pp. 137-144).
Display Omitted► A calibration model was developed for organic acids in wines and related products. ► Excellent results were found for most organic acids in high level ranges. ► FT-IR calibration is highly dependent upon the reference method reliability.FT-IR with partial least squares (PLS) was used to establish a full calibration model for tartaric acid, malic acid, lactic acid, succinic acid, citric acid and acetic acid in wines, vinegars and spirits. Sample pre-treatment was not required except for filtering.The PLS method was employed and FT-IR spectra were correlated with the results from a reference HPLC method. In the validation with an independent set of samples, a strong correlation with the reference values was demonstrated for the highest concentration range (>0.6gL−1) in all acids but the correlation was much weaker in the lower range (<0.6gL−1).In the case of acetic acid, however, good results were obtained in the low concentration range for both red and white wine and for spirit drinks. This finding explains the fact that calibration and validation of the FT-IR spectroscopy method depends very strongly on the composition of the sample set and on the quality of the reference analysis.It was not possible to obtain a single calibration for all of the analysed samples and in some cases individual calibrations for specific samples were required. This situation was due to the different matrixes in the studied samples: 12–15% ethanol (wines), 30–40% ethanol (spirits) and 6–10% acetic acid (vinegars). As a result, a calibration model was developed for each acid in red and white wine, tartaric acid, acetic acid and total acidity in vinegar, and acetic acid in spirit drinks.
Keywords: FT-IR spectroscopy; Organic acids; Red and white wine; Spirits; Vinegar; Partial least squares regression
Anthocyanin identification and composition of wild Vitis spp. accessions by using LC–MS and LC–NMR by Alexander Acevedo De la Cruz; Ghislaine Hilbert; Céline Rivière; Virginie Mengin; Nathalie Ollat; Louis Bordenave; Stéphane Decroocq; Jean-Claude Delaunay; Serge Delrot; Jean-Michel Mérillon; Jean-Pierre Monti; Eric Gomès; Tristan Richard (pp. 145-152).
The skin berry composition and concentration of anthocyanins in 4 different species were analyzed: V. vinifera, V. amurensis, V. cinerea and V. X champinii. LC–MS and LC–NMR were used to separate and identify the structure of anthocyanins present in these species. In particular, newly reported cis isomers of p-coumaric-derivatives were identified.Display Omitted► We analyzed the composition and concentration of anthocyanins of 4 Vitis species. ► We used LC–MS and LC–NMR to separate and identify the structure of anthocyanins. ► We identified 33 different anthocyanins. ► We identified newly reported cis isomers of p-coumaric-derivatives.The composition and concentration of anthocyanins of grape berry skins were analyzed in order to assess phenotypic variation between four grape wine varieties belonging to 4 different species: Vitis vinifera, Vitis amurensis, Vitis cinerea and Vitis X champinii. High-performance liquid chromatography coupled to mass spectrometry (LC–MS) and NMR spectroscopy (LC–NMR) were used to separate and identify the structure of anthocyanins present in these species. Combination of LC–MS and LC–NMR data resulted in the identification of 33 anthocyanins. In particular, newly reported cis isomers of p-coumaric-derivatives were identified (petunidin-, peonidin- and malvidin-3-(6- p-coumaroyl)-5-diglucoside). In V. cinerea and V. vinifera, anthocyanins were monoglucoside derivatives whereas in V. amurensis and V. X champinii, both mono- and diglucoside derivatives were identified. Malvidin-, delphinidin- and petunidin-derivatives were, respectively, the most abundant components in V. cinerea and V. vinifera, V. amurensis and V. X champinii.
Keywords: Anthocyanin; Vitis; spp.; Grapevine; LC–MS; LC–NMR
Colorimetric characteristics of the phenolic fractions obtained from Tempranillo and Graciano wines through the use of different instrumental techniques by Matilde García-Marino; M. Luisa Escudero-Gilete; M. Teresa Escribano-Bailón; M. Lourdes González-Miret; Julián C. Rivas-Gonzalo; Francisco J. Heredia (pp. 153-161).
The aim of the present work was to determine whether there is any relationship between measurement by transmission and reflection (in the latter case, with and without contact with the sample). We also evaluated which methodology used would offer a better interpretation of the results in visual terms. For this purpose, different colorimetric techniques such as transmission spectrophotometry, diffuse reflectance spectrophotometry and spectroradiometry were applied. The samples consisted of increasing dilutions (0, 20, 40, 60, 80 and 100%) of the phenolic fractions obtained from 4 wines: Tempranillo (T) and Graciano (G) monovarietal wines, and two 80:20 mixtures: M (wine elaborated by blending grapes) and W (a blend of the T and G wines) (9 fractions per wine). Fractionation was performed using gel permeation chromatography with a Toyopearl HW-40S column, and the dilutions of the fractions were performed with synthetic wine (pH=3.6). The spectroradiometric measurements permitted the differences due to the dilution effect on the fractions to be established more clearly than with the results obtained using diffuse reflectance and spectrophotometry. Thus, this technology is very suitable for use in comparative interpretations by the human eye. In turn, we assessed the changes in colour due to the effect of dilution on the fractions, observing that the effect of dilution led to an increase in the values of lightness (L*), while the chroma values (C*ab) followed the opposite trend, in agreement with its role as a variable related to chromatic intensity or vividness of the sample. In contrast, hue (hab) did not seem to be affected by dilution of the fractions, in consonance with the qualitative nature of this parameter.
Keywords: Wine colour; Anthocyanins; Tempranillo; Graciano; Colorimetric techniques; CIELAB
Application of LC–MS and tristimulus colorimetry to assess the ageing aptitude of Syrah wine in the Condado de Huelva D.O. (Spain), a typical warm climate region by B. Gordillo; F.J. Rodríguez-Pulido; N. Mateus; M.L. Escudero-Gilete; M.L. González-Miret; F.J. Heredia; V. de Freitas (pp. 162-171).
The study of the evolutions of different wine pigment families, copigmentation/polymerisation processes and colour characteristics during the first year of ageing in oak barrel has allowed the assessment of the ageing aptitude of Syrah wines from “Condado de Huelva D.O.”, a warm climate region. A total of 32 anthocyanic pigments were identified, including 14 major compounds from grape and 18 minor derivatives formed during the vinification. The anthocyanin profile changed towards more chemical complexity, being vitisin-like pyranoanthocyanins the predominant minor pigments during the first month of ageing. As wine became older, a progressive increase on the content of 4-vinylcatechin, 4-vinylphenol and 4-vinylcatechol compounds took place. Results showed that copigmentation occurred during the whole process of ageing inducing visual perceptible colour effects. Simultaneously to the copigmentation decrease, the degree of polymerisation increased during ageing, being maximum at 9 months old wines (77%). The colour of wines evolved progressively in a positive way from 3 to 9 months of ageing, becoming darker and with more vivid colour. However, from 9 to 12 months of ageing, the chemical structure of wines was negatively affected resulting in lighter, with more red-orange hues and less vivid colours. The inclusion of the chemical and colorimetric information on the PCA model allows us to reach very good discriminations among the Syrah wines with different wood contact period.
Keywords: Ageing process; Copigmentation; Detailed pigment composition; Quality colour; Oak wood
Determination of total polyphenol index in wines employing a voltammetric electronic tongue by Xavier Cetó; Juan Manuel Gutiérrez; Manuel Gutiérrez; Francisco Céspedes; Josefina Capdevila; Santiago Mínguez; Cecilia Jiménez-Jorquera; Manel del Valle (pp. 172-179).
Display Omitted► Array of voltammetric sensors modified with nanoparticles or conducting polymers. ► It has been applied in wine analysis to predict polyphenol content index. ► Uses data processing tools such as discrete wavelet transform and artificial neural network. ► Identification of phenolics like gallic acid, catechin, caffeic acid, catechol. ► Predicted polyphenol index agreees with Folin–Ciocalteau method and I280 index.This work reports the application of a voltammetric electronic tongue system (ET) made from an array of modified graphite-epoxy composites plus a gold microelectrode in the qualitative and quantitative analysis of polyphenols found in wine. Wine samples were analyzed using cyclic voltammetry without any sample pretreatment. The obtained responses were preprocessed employing discrete wavelet transform (DWT) in order to compress and extract significant features from the voltammetric signals, and the obtained approximation coefficients fed a multivariate calibration method (artificial neural network-ANN-or partial least squares-PLS-) which accomplished the quantification of total polyphenol content. External test subset samples results were compared with the ones obtained with the Folin–Ciocalteu (FC) method and UV absorbance polyphenol index ( I280) as reference values, with highly significant correlation coefficients of 0.979 and 0.963 in the range from 50 to 2400mgL−1 gallic acid equivalents, respectively. In a separate experiment, qualitative discrimination of different polyphenols found in wine was also assessed by principal component analysis (PCA).
Keywords: Voltammetric sensors; Electronic tongue; Artificial neural network; Wine analysis; Folin–Ciocalteu; Polyphenol
Mesoporous silica SBA-15, a new adsorbent for bioactive polyphenols from red wine by V.V. Cotea; C.E. Luchian; N. Bilba; M. Niculaua (pp. 180-185).
Display Omitted► The SBA-15 was hydrothermally synthesized and characterized by SAXRD, BET and SEM. ► The data showed that SBA-15 is capable to concentrate quercetin from wine. ► SBA-15 is an alternative material for extracting valuable compounds from wines.The aim of this paper is to evaluate the ability of the mesoporous silica SBA-15 to adsorb polyphenols from red wine. The mesoporous molecular sieve silica SBA-15 was hydrothermally synthesized in acidic media and characterized by SAXRD, BET, EDX and SEM. The adsorption behavior of mesoporous silica SBA-15 was investigated at 5°C for 24h using an adsorbent dose of 8gSBA-15L−1 red wine. The total polyphenols content expressed as mg of gallic acid equivalents (GAEL−1) was estimated from the standard curve of gallic acid (absorbance at 280nm). HPLC chromatograms of methanolic extract from mesoporous SBA-15 at 256, 280, 324, and 365nm exhibits the strong retention of quercetin and cis-resveratrol and a reasonable retention of trans-resveratrol, catechin, epicatechin, rutin, and phenolic acids ( meta- and para-hydroxybenzoic, vanillic, caffeic, syringic, salicylic and para-coumaric acids).The obtained data showed that mesoporous silica SBA-15 was capable approximately to concentrate quercetin 4900 times and cis-resveratrol 1400 times.The verifiable diminution of polyphenolic compounds content in red and white wines avoid the oxidative browning process without modification of wine color. Due to their beneficial to human health thanks to antioxidative, antiinflamatory, antiviral, antihypersensitive, cardioprotective, anticarcinogenic and antimutagenic properties the polyphenolic extract might prove interesting as pharmaconutrients or as dietary sources.
Keywords: Phenolic compounds; Mesoporous silica SBA-15; Adsorption; Red wine; HPLC-DAD
Chemistry of ascorbic acid and sulfur dioxide as an antioxidant system relevant to white wine by Célia Barril; Andrew C. Clark; Geoffrey R. Scollary (pp. 186-193).
Display Omitted► Use of flow injection analysis and liquid chromatography for the monitoring of oxidative processes relevant to white wine. ► A range of sulfur dioxide to ascorbic acid initial mole ratios was used to evaluate the combined effects of the antioxidant system. ► The ascorbic acid degradation products were found to be weak binders of sulfur dioxide under wine conditions.The impact of the combined ascorbic acid and sulfur dioxide antioxidants on white wine oxidation processes was investigated using a range of analytical techniques, including flow injection analysis for free and total sulfur dioxide and two chromatographic methods for ascorbic acid, its oxidative degradation products and phenolic compounds. The combination of different analytical techniques provided a fast and simultaneous means for the monitoring of oxidation processes in a model wine system. In addition, the initial mole ratio of sulfur dioxide to ascorbic acid was varied and the model wine complexity was increased by the inclusion of metal ions (copper(II) and iron(II)). Sulfur dioxide was found not to be a significant binder of ascorbic acid oxidative degradation products and could not prevent the formation of certain phenolic pigment precursors. The results provide a detailed insight into the ascorbic acid/sulfur dioxide antioxidant system in wine conditions.
Keywords: Ascorbic acid; Sulfur dioxide; Xanthylium cations; Xylosone; 3-Hydroxy-2-pyrone; 2-Furoic acid; White wine oxidation
Development of reliable analytical tools for evaluating the influence of reductive winemaking on the quality of Lugana wines by Fulvio Mattivi; Bruno Fedrizzi; Alberto Zenato; Paolo Tiefenthaler; Silvano Tempesta; Daniele Perenzoni; Paolo Cantarella; Federico Simeoni; Urska Vrhovsek (pp. 194-202).
Display Omitted► New LC–MS method for the analysis of reduced and oxidised glutathione and methionine. ► Improved quantification of free varietal thiols by means of GC–MS/MS. ► Improved quantification of bound varietal thiols by means of UPLC–MS/MS. ► Free and bound varietal thiols identified for the first time in Lugana wines. ► Developed methods effective in evaluating the process of winemaking of Lugana wine.This paper presents methods for the definition of important analytical tools, such as the development of sensitive and rapid methods for analysing reduced and oxidised glutathione (GSH and GSSG), hydroxycinnamic acids (HCA), bound thiols (GSH-3MH and Cys-3MH) and free thiols (3MH and 3MHA), and their first application to evaluate the effect of reductive winemaking on the composition of Lugana juices and wines.Lugana is a traditional white wine from the Lake Garda region (Italy), produced using a local grape variety, Trebbiano di Lugana. An innovative winemaking procedure based on preliminary cooling of grape berries followed by crushing in an inert environment was implemented and explored on a winery scale.The effects of these procedures on hydroxycinnamic acids, GSH, GSSG, free and bound thiols and flavanols content were investigated. The juices and wines produced using different protocols were examined. Moreover, wines aged in tanks for 1, 2 and 3 months were analysed.The high level of GSH found in Lugana grapes, which can act as a natural antioxidant and be preserved in must and young wines, thus reducing the need of exogenous antioxidants, was particularly interesting. Moreover, it was clear that polyphenol concentrations (hydroxycinnamic acids and catechins) were strongly influenced by winemaking and pressing conditions, which required fine tuning of pressing.Above-threshold levels of 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA) were found in the wines and changed according to the winemaking procedure applied. Interestingly, the evolution during the first three months also varied depending on the procedure adopted. Organic synthesis of cysteine and glutathione conjugates was carried out and juices and wines were subjected to LC–MS/MS analysis. These two molecules appeared to be strongly affected by the winemaking procedure, but did not show any significant change during the first 3 months of post-bottling ageing. This supports the theory, already proposed in the literature, that there are other synthetic pathways for free thiol formation.
Keywords: Glutathione; Varietal thiols; Hydroxycinnamic acids; High performance liquid chromatography–mass spectrometry (HPLC–MS); Ultra Performance Liquid Chromatography – tandem mass spectrometry (UPLC-MS/MS); Gas chromatography – tandem mass spectrometry (GC–MS/MS)