AJEV
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am. J. Enol. Vitic. 56:2:188-191 (2005)
Copyright © 2005 by the American Society for Enology and Viticulture.
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via ISI Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Genovés, S.
Right arrow Articles by Manzanares, P.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Genovés, S.
Right arrow Articles by Manzanares, P.
Agricola
Right arrow Articles by Genovés, S.
Right arrow Articles by Manzanares, P.

Research Note

Assessment of the Aromatic Potential of Palomino Fino Grape Must Using Glycosidases

Salvador Genovés1, José V. Gil1, Salvador Vallés1, José A. Casas2 and Paloma Manzanares1,*

1 Departamento de Biotecnología de Alimentos, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, P.O. Box 73, 46100 Burjassot, Valencia, Spain; 2 Bodegas González-Byass S.A., Manuel M. González 12, 11403 Jerez de la Frontera, Cadiz, Spain.

* Corresponding author [Email: pmanz{at}iata.csic.es; tel: 34-96-3900022; fax: 34-96-3636301]


   Abstract
Top
 Abstract
Materials and Methods
 Results and Discussion
 Conclusion
 Literature Cited
 
Several purified glycosidases such as {alpha}-L-arabinofuranosidase (ABFB), ß-D-glucosidase (BGLN), and {alpha}-L-rhamnosidase (RHAA) have been used to study the aromatic potential of Palomino fino grape must. The composition of free and bound aromas in Palomino fino must indicated a nonfloral aroma profile, benzyl alcohol being the main compound present in the bound fraction. While the combination BGLN + ABFB + RHAA was able to increase the concentrations of seven terpenyl compounds in wine, the concentrations of the individual compounds remained below their olfactory detection thresholds.

Key words: aroma, Palomino fino, wine, glycosidases

Since the demonstration that the aromatic components of certain grape varieties are present in the grape berry both in free form and bound to sugars in the form of glycosides (Cordonnier and Bayonove 1974, Williams et al. 1982a,b), the usefulness of glycosidases for the release of varietal aromas from precursor compounds during wine-making has been investigated (Günata et al. 1988, 1990). The bound aroma fraction comprises glucosides and disaccharide glycosides such as 6-O-{alpha}-L-arabinofuranosyl-ß-D-glucopyranosides, 6-O-{alpha}-L-rhamnopyranosyl-ß-D-gluco-pyranosides, and 6-O-ß-D-apiofuranosyl-ß-D-glucopyranosides. Compounds such as terpenols, terpene diols, 2-phenylethanol, benzyl alcohol, and C13 norisoprenoids have been shown to be aglycons of such glycosides (Winterhalter and Skouroumounis 1997).

The judicious application of glycosidases to improve wine aroma requires previous knowledge of the aroma potential of relevant grape varieties. In this regard, the free and glycosidically bound aroma fractions of Muscat and Muscat-related grape varieties have been well characterized (Günata et al. 1985). These varieties, rich in free and bound terpenols, produce aromatic wines, whereas nonterpenic varieties rich in bound C13 norisoprenoids, 2-phenylethanol, and benzyl alcohol (López-Tamames et al. 1997) yield more neutral wines. To date, the use of glycosidases to improve wine aroma has mainly focused on Muscat and Muscat-related grape varieties (Günata et al. 1993). Consequently, little is known of the effects of enzymatic treatments on grape must and wines from nonterpenic varieties.

The Palomino fino grape variety cultivated in the Jerez area of Spain is traditionally used for the production of sherry wines. In recent years, the Jerez wineries have also considered the possibility of using this variety for the production of young white wines. Palomino fino grapes are also cultivated in Galicia (northwest Spain), but the resulting table wines are of mediocre quality mainly because of the absence of varietal aromatic compounds (Estévez et al. 2004).

Previous work in our laboratory has reported the technological potential of several transgenic wine yeasts expressing ß-D-glucosidase (BGLN), {alpha}-L-arabinofuranosidase (ABFB), and {alpha}-L-rhamnosidase (RHAA) as tools for increasing the content of volatile compounds in Muscat wines (Sánchez-Torres et al. 1996, 1998, Manzanares et al. 2003). In the present work, we have used glycosidase treatments to investigate the aromatic potential of the Palomino fino grape must. The effect of the addition of pure glycosidases produced from recombinant Saccharomyces cerevisiae wine yeast strains constructed in our laboratory on a must glycoside extract and on the glycoside fraction of a young Palomino fino wine is described.


   Materials and Methods
Top
 Abstract
 Materials and Methods
Results and Discussion
 Conclusion
 Literature Cited
 
 Extraction of free and bound aroma compounds.   Fractionation of must and wine samples (20 mL), extraction of free and bound aroma compounds, and hydrolysis of must bound fraction aroma compounds by AR2000 (25 g/L; Gist-Brocades, Seclin, France) were performed using methods previously reported (Genovés et al. 2003).

 Extraction of Palomino fino must glycosides.   A batch-wise adsorption and elution procedure using Amberlite XAD-2 resin (Supelco, Bellefonte, PA) was followed for the extraction of glycosides from 2.4 L of Palomino fino must (Genovés et al. 2003). The dry extract was dissolved in 3.0 mL of 50 mM citrate-phosphate buffer pH 5 and defined as must glycoside extract.

 Treatment of must glycosides and wine with glycosidases.   Transformants of the Saccharomyces cerevisiae wine yeast strain T73 (Lallemand Inc., Montreal, Canada) previously generated in our laboratory (Sánchez-Torres et al. 1996, 1998, Manzanares et al. 2003) designated YCB35, YCA1, and YR8 were used for purification of BGLN, ABFB, and RHAA, respectively. Treatments of must glycosides and young Palomino fino wine (pH 3.3, ethanol: 11% [v/ v]) with BGLN (50 mU/mL), BGLN and ABFB (50 and 165 mU/mL, respectively), BGLN and RHAA (50 and 29 mU/ mL, respectively), and BGLN, ABFB, and RHAA (50, 165, and 29 mU/mL, respectively) were carried out. Enzymatic hydrolyses of must glycosides, wine treatments, and the extraction of free aroma compounds were carried out as previously reported (Genovés et al. 2003). All treatments were performed in triplicate.

 GC and GC-MS analysis.   A HP5890 GC equipped with a HP-INNOWax capillary column (60 m x 0.25 mm i.d. x 0.25 µm) (Hewlett-Packard, Waldbronn, Germany) was used for gas chromatography. The operating conditions were as follow: detector (FID) 250°C, injector 220°C, and oven temperature from 50 (10 min) to 180°C at 2.5°C/min, from 180 to 240°C at 5°C/min, and held at 240°C for 20 min. Identification of compounds was determined by comparing retention times with those of standard compounds (Sigma, St. Louis, MO) and the use of an Agilent 5973N MS detector coupled to an Agilent 6890 GC (Agilent Technologies, Waldbronn, Germany) for mass spectrometry.


   Results and Discussion
Top
 Abstract
 Materials and Methods
 Results and Discussion
Conclusion
 Literature Cited
 
 Aroma composition of Palomino fino must.   To assess the aromatic potential of Palomino fino must, the concentration of free and bound aroma compounds was determined (see Table 1Go). Free alcohols isoamyl, 1-hexanol, trans-2-hexenol, 3-methyl-2-butanol, and 2-phenylethanol were present at higher concentrations. Terpenyl compounds were found in low concentrations, with geraniol and 2,6-dimethyl-3,7-octadiene-2,6-diol the highest. This free aroma composition confirms the relatively nonfloral aroma profile of Palomino fino compared to Muscat, Riesling, and Gewurtztraminer varieties (Marais 1983, Günata et al. 1985). Similar results have been described for other nonfloral grape varieties. In some other Galician and Mediterranean grape varieties, geraniol concentrations ranging from 2 to 24 µg/L have been described, whereas 2,6-dimethyl-3,7-octadiene-2,6-diol ranged from 1 to 64 µg/L (López-Tamames et al. 1997). Only traces of geraniol have been detected in juices from the nonfloral Chardonnay variety (Sefton et al. 1993).


View this table:
[in this window]
[in a new window]
  		Table 1 Concentration of free and bound compounds in Palomino fino grape must.
 
Most compounds found in the free aroma fraction were also present in the bound fraction. 2-Pentanol, trans-3-hexenol, and 1-octen-3-ol were the only alcohols not detected in a bound form. In contrast, 3-ethyl-4-methyl-pentanol was detected only in the bound fraction. The total bound alcohol fraction was more than 3-fold greater than that of the free fraction, 1-butanol and benzyl alcohol being the main constituents of the bound fraction. These results also indicate that Palomino fino is a neutral cultivar (Voirin et al. 1992). With respect to terpenyl compounds, all those detected in the free fraction were also present in the bound fraction, whereas cis-isoeugenol, 3,7-dimethyl-1,7-octanediol and the two isomers of 2,6-dim-ethyl-2,7-octadiene-1,6-diol were found only in the bound fraction. (Z)-2,6-Dimethyl-2,7-octadiene-1,6-diol and geraniol were the principal terpenes present in the bound fraction. Similar findings have been described for the Albariño variety (López-Tamames et al. 1997). Linalool, trans-furanic linalool oxide, and nerol concentrations in the bound fraction were 9-, 7- and 4-fold greater, respectively, than those found in the free fraction.

 Effect of enzymatic treatment on must glycoside extract and wine.   3-Methyl-3-butenol, 1-hexanol, cis-3-hexenol, trans-2-hexenol, 1-heptanol, 3-ethyl-4-methyl-pentanol, 1-octanol, benzyl alcohol, cis-furanic linalool oxide, linalool, nerol, and cis-isoeugenol were hydrolyzed by the enzymatic activities from the must glycoside extract (results not shown). All eight alcohol glycosides were hydrolyzed by the combinations BGLN + ABFB and BGLN + ABFB + RHAA. For terpenyl compounds, only the triple combination of enzymes was able to release all of them. Linalool was quantitatively the main terpene liberated by enzymatic action on Palomino fino must, whereas geraniol and the two isomers of 2,6-dimethyl-2,7-octadiene-1,6-diol, the main terpenyl compounds in the bound fraction (Table 1Go), were not released by any of the enzymatic treatments. The best enzymatic combination for linalool release was BGLN + ABFB + RHAA.

3-Pentanol, 3-methyl-3-butenol, cis-3-hexenol, trans-2-hexenol, 1-heptanol, benzyl alcohol, trans- and cis-furanic linalool oxide, linalool, {alpha}-terpineol, nerol, (Z)-2,6-dimethyl-2,7-octadiene-1,6-diol, and geranic acid were released in enzymatically treated wines (results not shown). Only in wines treated with BGLN + ABFB + RHAA were there statistically significant increases in all alcohols. (Z)-2,6-Di-methyl-2,7-octadiene-1,6-diol showed the greatest increase in concentration compared to the other terpenes in all gly-cosidase-treated wines. The combination BGLN + ABFB + RHAA is the best enzymatic treatment, being able to release all of the terpenyl compounds.

While the ability of enzymatic treatments to release aroma compounds from a Palomino fino must glycoside extract and wine has been demonstrated, it seems unlikely that these treatments would have a direct impact on wine aroma since terpene concentrations are below their olfactory detection threshold (Marais 1983). Similar results have been described for glycosidase-treated wines from the Emir grape, a white variety from Turkey characterized by low levels of monoterpenes both in free and bound forms. Nevertheless, glycosidase-treated Emir wines were found by sensory analysis to be more intense in honey, lime, and smokey attributes compared to control wines (Cabaroglu et al. 2003).


   Conclusion
Top
 Abstract
 Materials and Methods
 Results and Discussion
 Conclusion
Literature Cited
 
The current study contributes to the characterization of different grape varieties and to the assessment of the use of glycosidases in winemaking for the enhancement of wine aroma. Recent analysis of Palomino wines produced by different S. cerevisiae yeast strains has highlighted variations in volatile compound composition and sensorial characteristics, suggesting yeast selection as another approach to increase the aroma of young wines from the Palomino fino grape variety.


   Footnotes
 
Acknowledgments: This work was supported by project VIN01-018-C2 from the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria of the Spanish Government.The authors thank A.P. MacCabe for critical reading of the manuscript.

Manuscript submitted July 2004; revised October 2004


   Literature Cited
Top
 Abstract
 Materials and Methods
 Results and Discussion
 Conclusion
 Literature Cited
 
Cabaroglu, T., S. Selli, A. Canbas, J.P. Lepoutre, and Z. Günata. 2003. Wine flavor enhancement through the use of exogenous fungal glycosidases. Enzyme Microb. Technol. 33:581–587.

Cordonnier, R.E., and C.L. Bayonove. 1974. Mise en évidence dans la baie de raisin var. Muscat d’Alexandrie de monoterpènes liés revelables par une ou plusieurs enzymes du fruit. C.R. Acad. Sci. Paris 278:3387–3390.

Estévez, P., M.L. Gil, and E. Falqué. 2004. Effects of seven yeast strains on the volatile composition of Palomino wines. Int. J. Food Sci. Technol. 39:61–69.

Genovés, S., J.V. Gil, P. Manzanares, J.L. Aleixandre, and S. Vallés. 2003. Candida molischiana ß-glucosidase production by Saccharomyces cerevisiae and its application in winemaking. J. Food Sci. 68:2096–2100.

Günata, Y.Z., C.L. Bayonove, R.E. Baumes, and R.E. Cordonnier. 1985. The aroma of grapes. I. Extraction and determination of free and glycosidically bound fractions of some grape aroma components. J. Chromatogr. 331:83–90.

Günata, Y.Z., C.L. Bayonove, C. Tapiero, and R.E. Cordonnier. 1990. Hydrolysis of grape monoterpenyl ß-D-glucosides by various ß-glucosidases. J. Agric. Food Chem. 38:1232–1236.

Günata, Y.Z., S. Bitteur, J.M. Brillouet, C. Bayonove, and R.E. Cordonnier. 1988. Sequential enzymic hydrolysis of potentially aromatic glycosides from grape. Carbohydr. Res. 184:139–149.

Günata, Z., I. Dugelay, J.C. Sapis, R.L. Baumes, and C.L. Bayonove. 1993. Role of enzyme in the use of the flavor potential from grape glycosides in winemaking. In Progress in Flavor Precursor Studies. P. Schreier and P. Winterhalter (Eds.), pp. 219–234. Allured Publishing, Carol Stream, IL.

López-Tamames, E., N. Carro-Mariño, Y.Z. Günata, C. Sapis, R. Baumes, and C. Bayonove. 1997. Potential aroma in several varieties of Spanish grapes. J. Agric. Food Chem. 45:1729–1735.

Manzanares, P., M. Orejas, J.V. Gil, L.H. de Graaff, J. Visser, and D. Ramón. 2003. Construction of a genetically modified wine yeast strain expressing the Aspergillus aculeatus rhaA gene encoding an {alpha}-L-rhamnosidase of enological interest. Appl. Environ. Microbiol. 69:7558–7562.[Abstract/Free Full Text]

Marais, J. 1983. Terpenes in the aroma of grapes and wines: A review. S. Afr. J. Enol. Vitic. 42:49–60.

Sánchez-Torres, P., L. González-Candelas, and D. Ramón. 1996. Expression in a wine yeast strain of the Aspergillus niger abfB gene. FEMS Microbiol. Lett. 145:189–194.[ISI][Medline]

Sánchez-Torres, P., L. González-Candelas, and D. Ramón. 1998. Heterologous expression of a Candida molischiana anthocyanin- ß-glucosidase in a wine yeast strain. J. Agric. Food Chem. 46:354–360.[ISI][Medline]

Sefton, M.A., I.L. Francis, and P.J. Williams. 1993. The volatile composition of Chardonnay juices: A study by flavor precursor analysis. Am. J. Enol. Vitic. 44:359–370.[Abstract/Free Full Text]

Voirin, S.G., R.L. Baumes, J.C. Sapis, and C. Bayonove. 1992. Analytical methods for monoterpene glycosides in grape and wine. II. Qualitative and quantitative determination of monoterpene glycosides in grape. J. Chromatogr. 595:269–281.[ISI][Medline]

Williams, P.J., C.R. Strauss, and B. Wilson. 1982a. Use of C18 reversed-phase liquid chromatography for the isolation of mono-terpene glycosides and nor-isoprenoid precursors from grape juice and wines. J. Chromatogr. 235:471–480.

Williams, P.J., C.R. Strauss, B. Wilson, and R.A. Massy-Westropp. 1982b. Novel monoterpene disaccharide glycosides of Vitis vin-ifera grapes and wines. Phytochemistry 21:2013–2020.

Winterhalter, P., and G.K. Skouroumounis. 1997. Glycoconjugated aroma compounds: Occurrence, role and biotechnological transformation. In Biotechnology of Aroma Compounds. R.G. Berger (Ed.), pp. 73–105. Springer-Verlag, Berlin.





This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via ISI Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Genovés, S.
Right arrow Articles by Manzanares, P.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Genovés, S.
Right arrow Articles by Manzanares, P.
Agricola
Right arrow Articles by Genovés, S.
Right arrow Articles by Manzanares, P.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS