Contribution of gas chromatographic and conventional data to the characterisation of majorcan musts and wines by means of pattern recognition techniques

Determination of the composition of three Majorcan red wines and musts (from zona Alta and zona Baja) was performed by gas chromatography. Previous data of the former samples derived from both conventional and capillary gas chromatographic analysis were added to the former physical and chemical data and then treated by two statistical methods of pattern recognition: multiple discriminant analysis (MDA) and hierarchical clustering analysis (CA), in order to re-evaluate a characterisation study on wines and musts. A feature selection of the data by means of the F ratio value was carried out before the statistical techniques were applied. According to MDA, density, alcohol content, colour intensity, nitrogen and cis-3-hexen-1-ol were the major discriminating variables involved in the varietal classification of wines. Baume degree, colour intensity and proline were obtained in the corresponding musts. When distinguishing regions 2-phenylethylacetate and glycerol were selected in wines, and pH and benzyl alcohol in musts. Musts and wines were mainly grouped according to the varietal characteristics of the samples by CA.     

Resveratrol content in wines and musts from the south of Spain

Trans- and cis-resveratrol and their glycosides have been determined in eighty-one samples including musts, substrate wines and commercial wines (red, white and Sherry-type wines) from the south of Spain. Sample analysis was performed using a direct injection technique by HPLC with photodiode array detector. Prior to the injection, the sample was filtered using a filter selected through a complete filtration study. Climatological data can affect total resveratrol levels. Values obtained for total resveratrol content in red wines ranged from 0.038 mg/l in a dry year to 1.164 mg/l for a normal year. The pressure applied to the berries to obtain must, has been object of study in order to ascertain its influence in final resveratrol content. For the same vintage, the total resveratrol content ranged from 0.032 mg/l in a wine, obtained from the lighest pressure musts, to 0.873 mg/l for those obtained from the highest pressure musts. No resveratrol has been found in Sherry wines, being present in the substrate wines in all cases.     

Nutritional composition of commercial pickled garlic

The effect of pulp treatment on the qualitative and quantitative changes to polyphenol compounds, such as anthocyanins and flavanols, in musts and wines from blackcurrant and cherries was investigated. The following variants of pulp treatment were used: hot maceration, hot maceration and pulp pectinolysis with Rohapect MA Plus and Pectopol PM preparations, and also pulp pectinolysis with Rohapect and Pectopol preparations. The method of treatment affected the content of anthocyanins and flavan-3-ols in the musts. Different types of phenolic compounds reacted differently under must-making conditions. Wines made with different treatments presented statistical differences with the control wine and between them for the parameters studied.As a result of the analysis of cherry musts and wines by HPLC, the following flavan-3-ols were identified: catechin, epicatechin, dimer B₂ and trimer C₁. In the cherry wines studied, in the variants subjected to pectinolysis and fermentation in the pulp, epicatechin occurred in a smaller amount than catechin, while in the wines subjected to thermal treatment it was predominant. In the blackcurrant musts and wines the following flavanols were identified: gallocatechin, catechin, epigallocatechin, dimer B₂, epicatechin and trimer C₁. In the cherry musts and wines the following anthocyanin pigments have been identified: cyanidin 3-glucoside, cyanidin 3-rutinoside and cyanidin 3-glucosylrutinoside, the amount of which was the greatest. Anthocyanins identified in the blackcurrant musts and wines were delphinidine and cyanidine glycosides: delphinidin 3-glucoside, delphinidin 3-rutinoside, cyanidin 3-glucoside and cyanidin 3-rutinoside; their aglycones were also found.     

Discrimination of sweet wines partially fermented by two osmo-ethanol-tolerant yeasts by gas chromatographic analysis and electronic nose

Some special sweet wines are obtained by partial fermentation of musts from off-vine dried grapes containing large amounts of sugars. This process is very slow and subject to serious stop problems that can be avoided by using osmo-ethanol-tolerant yeasts. Musts containing 371 g/l of sugars were partially fermented with selected Saccharomyces cerevisiae strains, X4 and X5, to 12% (v/v) and the wines obtained with X5 exhibited a higher volatile acidity but lower concentrations of higher alcohols, carbonyl compounds and polyols than those obtained with X4. A principal component analysis (PCA) of the data provided by an electronic nose (E-nose) afforded discrimination between fermented and unfermented musts, but not between wines obtained with X4 or X5. The PCA applied to the major volatile compounds and polyols shows similar results, but a clear discrimination between wines is obtained by removing the polyols glycerol and 2,3-butanediol from the PCA.     

Volatile composition of partially fermented wines elaborated from sun dried Pedro Ximénez grapes

In this work, we used a cell immobilisation system consisting of Penicillium chrysogenum fungi (GRAS) bound to the osmotolerant yeast strains Saccharomyces cerevisiae X4 and X5 for the partial fermentation of raisin musts. The resulting wines were compared with others obtained by partial fermentation of musts with free yeasts and with a traditionally produced sweet wine (i.e. without fermentation of the must). The analysis of volatile compounds grouped by aroma series showed the partially fermented musts had a more complex aroma than the traditional wine. Specially prominent among aroma series was that of ripe fruit, followed by the milky and chemical series. The volatiles with the greatest impact on wine aroma as assessed in terms of odour activity were ethyl hexanoate, ethyl octanoate, butyrolactone, isoamyl alcohols, acetaldehyde, ethyl acetate, 2,3-butanediol, acetoin and 2,3-butanedione. A cluster analysis according to the Ward method was performed to assess the similarity between the traditional sweet wine and those obtained by partial fermentation with free and immobilised yeasts revealed small differences between the wines obtained with free and immobilised yeasts, and marked differences between partially fermented and traditionally obtained sweet wine. The wines provided by immobilised yeasts were the most appreciated in the sensory analysis (especially those obtained with X4 yeasts).     

Characteristics of wines fermented with different Saccharomyces cerevisiae strains isolated from the La Mancha region

One hundred and seventy-four strains of Saccharomyces cerevisiae from musts in fermentation were characterized using pulsed-field gel electrophoresis. Of these, 13 strains were selected for their good oenological properties and were used as inocula in laboratory-scale fermentation of an Airén must. Volatile compound and amino acid content of the resulting wines was analysed. Factorial principal component analysis of the data revealed differences between wines according to the strain used in the fermentation. Strains that produce more volatile compound and have an adecuated nitrogen assimilation are recommended to obtain quality wines.     

Monitoring of chemical parameters of oxygen-treated musts during alcoholic fermentation and subsequent bottle storage of the resulting wines

The effect of hyper-oxygenation of Airén white wines on color characteristics, phenolic composition, and volatile profile has been evaluated in different processing steps, not previously reported in conjunction: musts, musts during the alcoholic fermentation, resulting young wines and after 1 year of bottle storage. Hyper-oxygenation treatment achieved a positive effect on color stabilization by means of significantly lower contents of most important phenolic compound families (hydroxycinnamic acid derivatives, benzoic acids, flavonols, and flavan-3-ols) in oxygen-treated musts in fermentation, young wines, and one-year-stored white wines. Therefore, browning was avoided in wines elaborated from hyper-oxygenated musts and their values of a* (green–red component of color) were maintained, in contrast to what occurred in control wines. With regard to volatile profile, the concentration of the majority of individual volatile compounds was significantly higher in wines derived from hyper-oxygenated musts, even after 1 year of bottle storage, especially those derived from alcoholic fermentation (alcohols: 2-methyl-1-butanol and 3-methyl-1-butanol, polar esters: ethyl lactate and ethyl glutarate, C₆ alcohols: 3-methyl-1-pentanol, and acetates: 2-phenylethyl acetate). This study enhances knowledge regarding the effects of hyper-oxygenation process during and after alcoholic fermentation and 1 year of bottle aging, especially as there is scarce literature available on the subject.     

Simultaneous Quantification of Primary, Secondary Amino Acids, and Biogenic Amines in Musts and Wines Using OPA/3-MPA/FMOC-CI Fluorescent Derivatives

ABSTRACT: Free amino acids and biogenic amines occur in musts and wines and affect the course of fermentation in musts and the quality of wines. Each sample was analyzed in 138 min and each analysis involved quantification of 23 amino acids and 10 amines. The detection limit for proline was 27.3 mg/L. The mean detection limit for amino acids was 0.58 mg/L and for amines 0.28 mg/L. Precision was 0.5 to 19.2% for wine samples and accuracy by the standard addition method was 99.8% (recovery value). In all, 33 wines and 39 must samples were analyzed. In wines, ethanolamine, histamine, ethylamine, and putrescine amounted to 93% of the amine content.     

Impact of Pressing Conditions on the Phenolic Composition,Radical Scavenging Activity and Glutathione Content of Brazilian <Emphasis Type="Italic">Vitis vinifera</Emphasis> White Wines and Evolution During Bottle Ageing

The pre-fermentation techniques applied during the production of white wine, such as skin maceration or grape pressing, can directly affect the quality of the final product. There is a constant search for methods that can enhance the sensorial characteristics, such as varietal aromas, and phenolic composition of white wines. The aim of this study was to investigate the effect of different pressing conditions on the phenolic composition, antioxidant activity and glutathione content of white musts and wines produced in southern Brazil and to evaluate these characteristics during bottle ageing. By applying different pressures, three fractions of musts were obtained: free-run must, light pressed must and heavy pressed must. The musts and their corresponding wines were analysed by spectrophotometric and chromatographic assays. Pressing positively affected the chemical composition of the musts and wines, and the wines produced with pressed fractions of the musts presented higher polyphenol content and radical scavenging power. The main phenolic compounds affected by the pressing conditions were caftaric acid, catechin and epicatechin. During bottle ageing, an increase in certain individual phenolic compounds could be observed by liquid chromatography. Samples produced with heavy pressed musts presented a higher browning index. Furthermore, the application of pressure to the grape musts during winemaking increased the contents of total glutathione by factors of up to 22 and 15 for light pressed and heavy pressed musts, respectively. After 8 months of bottle ageing, the glutathione content decreased in all samples.     

Changes to polyphenols in the process of production of must and wines from blackcurrants and cherries. Part I. Total polyphenols and phenolic acids

The effect of pulp treatment on the qualitative and quantitative changes to polyphenol compounds exhibiting antioxidant properties, in musts and wines from blackcurrants and cherries was investigated. The following variants of pulp treatment were used: hot maceration, hot maceration and pulp pectinolysis with Rohapect MA Plus and Pektopol PM preparations, and also pulp pectinolysis with Rohapect and Pektopol preparations. Blackcurrant musts contained from 4800 to 6600 mg l^-1 of total polyphenols and cherry musts from 3060 to 3920 mg l^-1. The fermentation process caused a decrease in polyphenols content of approximately 25%. In production of fruit wines, the pulp treatment method had a considerable effect on the total content of polyphenols. In blackcurrant wines the highest extraction of polyphenols was obtained after pectinolysis with a Rohapect preparation. In the case of cherry wines the highest content of these compounds was extracted during pectinolysis with a Pektopol preparation. In musts and wines the presence of the following compounds, derivatives of hydroxycinnamic acid, was determined: neochlorogenic, chlorogenic, caffeic, p-coumaric and ferulic acids. The content of neochlorogenic acid was the highest both in musts and wines from blackcurrants and cherries and amounted to 41.7-126.3 mg l^-1, and 24.7-35.3 mg l^-1 respectively for blackcurrants and 74.3-87.7 mg l^-1and 44.5-71.4 mg l^-1 respectively for cherries. The enzymatic preparation Pektopol PM contained an enzyme acting as depsidase. It broke down chlorogenic acid and other compounds to simple phenolic acids (caffeic acid, p-coumaric acid).     

Effect of activated carbon on ochratoxin A reduction in “Pedro Ximenez” sweet wine made from off-vine dried grapes

The application effect of an activated carbon on Ochratoxin A (OTA) contents was studied in small-scale winemaking trials in musts from sun-dried grapes Pedro Ximenez variety. For this experiment a 2 × 3 × 4 factorial arrangement was used in the same batch, the factors being adsorbent (control and activated carbon), time (1, 2, and 3 h), and adsorbent dose (control, 0.12, 0.24, and 0.36 g/L). Immunoaffinity columns to sample clean-up and enzyme-linked immunosorbent technique were utilized for OTA determination. The two-parameter Freundlich equation was used to evaluate the adsorption data and the K _F values obtained ranging from 0.11 to 2.68. Activated carbon at 0.24 g/L dose was the most effective treatment to reduce OTA, up 70% in sweet wines. The mean percentages reduction of color parameters (intensity and tone) and total polyphenol index of the wines were 9.8, 3.5, and 4%, respectively. The study demonstrates that this treatment can be successfully applied as a suitable technique to reduce OTA contents of the musts and sweet wines during the early winemaking processes.     

Selection of Volatile Aroma Compounds by Statistical and Enological Criteria for Analytical Differentiation of Musts and Wines of Two Grape Varieties

ABSTRACT: Aroma compounds in Airen and Macabeo musts and wines were submitted to multivariate analysis of variance and only those significantly depending (p < 0.05) on grape variety, prefermentative treatment, and exhibiting no significant interaction were selected for discriminant analysis. Benzyl alcohol, Z‐3‐hexen‐1‐ol, hexanoic acid, benzaldehyde, β‐ionone, and E‐nerolidol contents in musts were used to calculate 2 discriminating functions, which allow classifying 100% of all must by variety and treatment. Discriminant analysis carried out with 1‐propanol, isoamyl alcohol, 2‐phenylethanol, ethyl acetate, ethyl propanoate, ethyl lactate, isobutyl acetate, and 7‐butyrolactone contents in wines, allows to establish 2 other functions, which led to accurate classification of 100% of the wine samples.     

Influence of several enzymatic treatments on aromatic composition of white wines

Albariño wines were treated enzymatically at industrial scale, and the effect of both aromatic extracting and clarifying enzymes on the aroma were evaluated and compared. A commercial enzyme (Endozym cultivar) was added during maceration to two musts; clarification enzyme (Depectil clarification) was added to other two wines after fermentation (control wines), and in other four wines were applied the both commercial enzymatic treatments (Endozym cultivar and Depectil clarification, or Rapidase Xpress and Depectil clarification). Volatile compounds were analysed by gas-chromatography (FID and mass spectrometric detection) and by sensory analysis. All the wines, independently of the type of enzyme, presented different aromatic characteristics in comparison to the control wines, above all the wines obtained from the enzyme applied during maceration which showed the highest contents in varietal compounds and in other desirable compounds, such as benzene derivatives, ethyl esters or phenylethyl acetate. The employ of maceration and clarification enzymes as a whole seemed not be suitable because this combination could be cancel the released aromas by the glycosidase enzyme during the pellicular contact. Principal component analysis of chemical data corroborated these effects, because a very clear and good differentiation was achieved between the wines treated only with the maceration enzymes (glycosidase activity) opposite to the wines subjected to the other enzymatic treatments. These results are also closely related to the sensory analysis, which indicated that the glycosidase enzymatic treatment seemed to be effective for the improvement of the aroma of Albariño wines.     

Relationship between nitrogen content in grapes and volatiles,namely heavy sulphur compounds,in wines

Ammonium salts were added to white grape musts, before alcoholic fermentation, in order to evaluate their influence on the heavy sulphur compound and aliphatic higher alcohol composition of resulting wines. Six grape musts were used (Trajadura, Pedernã, Loureiro, Azal Branco, Avesso and Alvarinho). Ammonium supplementation of Trajadura and Pedernã grape musts, with the highest nitrogen level, did not influence the content of heavy sulphur compounds and aliphatic higher alcohols in wines; however, the addition of ammonium salts to grape musts with low initial nitrogen content, such as Loureiro, Azal Branco and Avesso, led to a higher production of 1-propanol and a lower production of isoamyl alcohols and sulphur compounds, e.g. S-methyl thioacetate, 2-mercaptoethanol, acetic acid-3-(methylthio)propyl ester, 3-mercapto-1-propanol, 4-(methylthio)-1-butanol, 3-(ethylthio)-1-propanol, 3-methylthiopropionic acid and N-3-(methylthiopropyl)acetamide. For Alvarinho grape must, a decrease in sulphur compound concentrations in wines was only observed for 3-methylthiopropionic acid, acetic acid-3-(methylthio)propyl ester and 2-mercaptoethanol.     

Determination of flavan-3-ols and trans-resveratrol in grapes and wine using HPLC with fluorescence detection

Concentrations of trans-resveratrol, catechin and epicatechin were analyzed in musts and wines produced from seven red and four white grape cultivars from various wine growing regions of Turkey. Phenolics were quantified using an HPLC method optimized for the separation of wine phenolics. Wine samples contained higher phenolics levels than the corresponding musts. With the exception of Semillion, white wines and musts contained lower concentrations of phenolics than red wines and musts. However, the white cultivar Semillion had the highest concentrations of catechin and epicatechin among all wine and must samples. Semillion wine catechin and epicatechin were 13.7 and 11.8 mg/L, respectively. The highest level of trans-resveratrol among the white cultivars was found in Narince wine (1.93 mg/L). Within the red wine and must cultivars, Bo?azkere, Öküzgozü, and Cabernet contained the highest concentrations of flavan-3-ols and trans-resveratrol. Catechin was the major phenolic in all wines and most musts. Epicatechin was the major phenolic in 6 of the 11 must samples, but none of the wine samples. trans-Resveratrol was generally found in lowest concentrations in both wines and musts.     

Indigenous Saccharomyces cerevisiae strains and their influence on the quality of Cataratto, Inzolia and Grillo white wines

The present paper deals with three new strains of Saccharomyces cerevisiae, isolated in old wineries of Sicily, which were microbiologically and molecularly characterized and tested for their ability to produce white wines. Examined in terms of their growth pattern, fermentation vigour, sulphite tolerance, fermentative power, spore formation, and production of acetic acid, hydrogen sulphide and phenolic off-flavours, the strains were utilized as starters in experimental fermentations of musts obtained from the cultivars Inzolia, Grillo and Catarratto. Further, the three musts were also fermented using two commercial S. cerevisiae strains. The quality of the wines produced was confirmed by their principal oenochemical parameters, by sensory analysis and qualitative and quantitative determination of the volatile aroma constituents. All the data were statistically elaborated. Interestingly, the new selected yeasts were able to increase the pear notes (Z)-ethyl-4-decenoate, (E)-ethyl-3-decenoate, and (Z)-ethyl-3-decenoate which are fundamental for the aroma of these Sicilian wines. From our results, the new yeast strains were found to produce white wines of a quality which was not inferior to those obtainable with the best commercial strains selected in other geographical areas, but also with a distinctive aromatic profile.     

Comparative study of the volatile composition in wines obtained from traditional vinification and from the Ganimede method

BACKGROUND: This study compares the volatile composition between wines obtained from vinification carried out by the traditional method or using a new method of vinification (so‐called Ganimede). For this, Shiraz, Merlot and Cabernet Sauvignon musts were fermented by both vinification methods. RESULTS: The volatile compounds that were above their threshold of perception in the wines were practically the same, irrespective of the vinification method used. Most of the compounds studied did not present significant differences in their concentrations between the wines obtained from the traditional and the new vinification methods. When there were significant differences, the concentration of alcohols and acids was higher in the wines vinificated by the traditional method rather than in the wines vinificated by the Ganimede method, whereas for esters, the concentration in the wines depended on the grape variety. CONCLUSION: The Ganimede method favoured polyphenol extraction without greatly affecting the studied volatile composition of the wines. Copyright © 2008 Society of Chemical Industry     

Phenolic Content and Antioxidant Activity of Primitivo Wine: Comparison among Winemaking Technologies

ABSTRACT: 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, β‐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 β‐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 β‐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 cardiovascular diseases. The mechanisms involved in this protective effect are not completely understood although they appear related to the presence of phenolic compounds. To increase the intake of these compounds without increase of the wine consumption, it is necessary to improve their extraction during maceration. This study could represent a helpful tool for wineries aimed to know the way to increase the antioxidant content of their wines, thus changing them in functional beverages and prolonging their shelf life.     

Antioxidant activity in relation to the phenolic profile during the winemaking of sweet wines Vitis vinifera cv. Cabernet Sauvignon

The phenolic profile during the winemaking of Cabernet Sauvignon sweet wines has been studied, including the stages of controlled grape drying and the posterior maceration of the fortified musts with their skins. Each phenolic family has been correlated individually with the antioxidant activity measured by the 2,2,‐diphenylpicrylhydrazyl assay. Linear regressions with a confidence level superior to 99% have been found with hydroxybenzoic acids, esters of hydroxycinnamic acids, flavan‐3‐ol derivatives, tannins, anthocyanin adducts, polymers and polymeric pigments. With a multiple correlation, the antioxidant properties of musts and sweet wines were explained jointly by the families of polymeric pigments and flavan‐3‐ol derivatives. The musts during the drying process and the wines during the maceration presented a different phenolic composition and were distinguished using a cluster analysis and a principal component analysis.