Gas Chromatography−Olfactometry and Chemical Quantitative Study of the Aroma of Six Premium Quality Spanish Aged Red Wines

Abstract

The aroma of six premium quality Spanish red wines has been studied by quantitative gas chromatography-olfactometry (GC-O) and techniques of quantitative chemical analysis. The GC-O study revealed the presence of 85 aromatic notes in which 78 odorants were identified, two of which-1-nonen-3-one (temptatively) and 2-acetylpyrazine-are reported in wine for the first time. Forty out of the 82 quantified odorants may be present at concentrations above their odor threshold. The components with the greatest capacity to introduce differences between these wines are ethyl phenols produced by Brettanomyces yeasts (4-ethylphenol, 4-ethyl-2-methoxyphenol, and 4-propyl-2-methoxyphenol), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol), (Z)-3-hexenol, thiols derived from cysteinic precursors (4-methyl-4-mercaptopentan-2-one, 3-mercaptohexyl acetate, and 3-mercaptohexanol), some components yielded by the wood [(E)-isoeugenol, 4-allyl-2-methoxyphenol, vanillin, 2-methoxyphenol (guaiacol), and (Z)-whiskylactone], and compounds related to the metabolism (2-phenylethanol, ethyl esters of isoacids, 3-methylbutyl acetate) or oxidative degradation of amino acids [phenylacetaldehyde and 4,5-dimethyl-3-hydroxy-2(5H)-furanone (sotolon)]. The correlation between the olfactometric intensities and the quantitative data is, in general, satisfactory if olfactometric differences between the samples are high. However, GC-O fails in detecting quantitative differences in those cases in which the olfactive intensity is very high or if odors elute in areas in which the odor chromatogram is too complex.

Volatile composition and sensory characteristics of Carménère wines macerating with Colombian (Quercus humboldtii) oak chips compared to wines macerated with American (Q. alba) and European (Q. petraea) oak chips

“…Q. humboldtii was also the oak with the highest concentration of this compound (Table 2). However, the concentration of this compound was below its perception threshold (40 µg/l, phenolic and smoky notes) (Culleré, Escudero, Cacho, & Ferreira, 2004) in all the wines.Furanic compounds had a similar extraction kinetic in all the wines in contact with oak chips, with the concentration of furfural, 5MF and 5HMF increasing considerably after 7 days' maceration, decreasing gradually during the oak maceration period and the Martínez-Gil, A. M., del Alamo-Sanza, M., Gutiérrez-Gamboa, G., . Volatile composition and sensory characteristics of Carménère wines macerating with Colombian (Quercus humboldtii) oak chips compared to wines macerated with American (Q. alba) and European (Q. petraea) oak chips.…”

“…Probably because this wood, Romanian oak, was that with the highest concentration of this isomer (Table 2). However, in all wines the concentration of this isomer was lower than its perception threshold (790 µg/l) (Culleré et al, 2004), so that differences in the concentration of this isomer found in wines treated with the different oaks are probably not noticeable in their final aroma. Regarding the cis-β-methyl-γ-octalactone, as expected the wines macerated with American oak chips showed the highest concentration, as recorded by several authors (Rodríguez-Bencomo et al, 2008).…”

“…This could be due to the fact that the concentration of these 3 compounds was significantly higher in Q. humboldtii than in the other oak woods (Table 2). In the wine macerated with Colombian chips, the guaiacol concentration exceeded its olfactory threshold (9.5 µg/l, smoke aroma descriptor) (Culleré et al, 2004). Moreover, after 90 days' maceration, the concentration of guaiacol, cis-isoeugenol and syringol in wines macerated with American, French and Romanian oak woods were statistically similar (Table 3).…”

“…The contribution from the American oak wood of this isomer to wine occurred during the entire time studied with the concentration of wine aged with Q. alba being 4 times higher than that found in wines aged with Q. petraea and 15 times higher than Q. humboldtii (Table 3). In this case, the concentration of cis-β-methyl-γ-octalactone was higher than its perception threshold (67 µg/l) (Culleré et al, 2004), especially in wines aged with traditional oak, since in the case of wine aged with Colombian oak it would be at the limit (22 µg/l). Rodriguez Becomo et al, (2009) and Fernandez de Simón et al, (2010), observed that the evolution in wine of these two isomers depend mainly due to the principle of putting oak wood of different origins in contact with wine,., as seen in our results.…”

Solid phase microextraction as a reliable alternative to conventional extraction techniques to evaluate the pattern of hydrolytically released components in Vitis vinifera L. grapes

“…Identification of hydrolyzed components was carried out by: (i) comparing the GC retention times and mass spectra, with those, when available, of the pure standard compounds, (ii) all mass spectra were also compared with the data system library (NIST, 2005 software, Mass Spectral Search Program V.2.0d; NIST 2005, Washington, DC), and (iii) retention index probes (RI) value were determined according to the van den Dool and Kratz [33]. For the RI determination, a C 8 -C 20 n-alkanes series were used, and these values were compared, when available, with values reported in the literature for a BP-20 and similar chromatographic columns [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52].…”