Volatile compounds in wine

Ferreira, V., Escudero, A., Fernandez, P. E., and Cacho, J. (1997). Changes in the profile of volatile compounds in wines stored under oxygen and their relationship with the browning process. Z. Lebensm. Unters. Forsch 205, 392-396. 

Pozo-Bayon, M. A., Pueyo, E., Martfn-Alvarez, P. J., and Polo, M. C. (2001). Polydimethylsi-loxane solid-phase microextraction-gas chromatography method for the analysis of volatile compounds in wines Its application to the characterization of varietal wines.. Chromatogr. A 922,267-275. 

Torrija, M.J., Beltran, G., Novo, M.T., Poblet, M., Guillamon, J.M., Mas, A., Rozes, N. (2003) Effect of fermentation temperature and Saccharomyces species on the cell fatty acid composition and presence of volatile compounds in wine. Int. J. Food Microbiol., 85, 127-136. 

Nevertheless, the most studied ethanol effect is related to its capacity to modify solution polarity, thus altering the gas-liquid partition coefficient. An increase in ethanol content has been shown to decrease the activity coefficients of many volatile compounds in wine because of an increase in solubility (Voilley et al. 1991). Hartmann et al. (2002) showed a decrease in the recovery of 3-alkyl-methoxy-pyrazynes extracted with a divinylbenzene/carboxen SPME fibre from wine model systems when the ethanol content increased from 0% to 20%. Similarly, Whiton and Zoecklein (2000) reported that a small increase in ethanol content (from 11 % to 14%), in general, reduced the recovery of typical wine volatile compounds. Both of these studies suggest that increasing the alcohol content will reduce the release of volatile compounds from wines. 

Lopez, R., Aznar, M., Cacho, J., Ferreira, V. (2002). Determination of minor and trace volatile compounds in wine by solid-phase extraction and gas chromatography with mass spectrometric detection. J. Chromatogr. A, 966, 167-177. 

Esters, not fusel alcohols, actually comprise the most abundant group of volatile compounds in wines Rapp (26) has listed over 300 esters and lactones found in grapes, musts and wines. The esters are largely responsible for the fmity aromas associated with wine (52), especially young wine (27). Of the esters, ethyl acetate predominates by some two orders of magnitude (see 40) however, the low aroma thresholds of a number of the fatty acid ethyl esters makes them of sensory import nonetheless (27). 

Table 5.6 Sensory thresholds and levels of common fermentative sulphur volatile compounds in wines from Trentino (Northern Italy) in the international grape varieties Chardonnay and Merlot and the red berries native grape varieties Marzemino and Teroldego. Samples were from the five vintages 1998 and 2001-2004 (Fedrizzi et al., 2007a).

Cabredo-Pinillos, S., Cedron-Fernandez, T. and Saenz-Barrio, C. (2004) Comparison of different extraction methods applied to volatile compounds in wine samples previous to the determination by gas chromatography, Anal. Lett., 37(14), 3063-3084. 

Analysis of volatile compounds in wine is usually performed by gas chromatography (GC) coupled with flame ionization (FID) or GC/... 

Sample preparation for GC/MS analysis of volatile compounds in wines and extracts was usually performed by liquid-liquid extraction with dichloromethane (Cutzach et al., 1997 Perez-Coello et al., 1999 Cadahia et al., 2003). Direct extraction of volatiles from the wood by headspace (HS) solid-phase microextraction (SPME) using a polydimethylsiloxane (PDMS) fiber allowed to analyze compounds,... 

TABLE 7.4. The HS-SPME and GC/MS Conditions Used for Analysis of Wood Volatile Compounds in Wine and Wood Extracts2... 

Wine aromas are made up of several hundreds of volatile compounds, at concentrations ranging from several mg/1 to a few ng/1, or even less. The olfactory perception thresholds of these compounds also vary quite considerably. Consequently, the olfactory impact of the volatile compounds in wine depends both on concentration and type. Certain compounds, present in trace amounts, on the order of ng/1, may play a major role in aroma, whereas other, much more plentiful, compounds may make only a slight contribution. Furthermore, the impact of each component on the... 

Castro, R. Natera, R. Duran, E. Garcia-Barroso, C. (2008). Application of solid phase extraction techniques to analyse volatile compounds in wines and other enological products. European Food Research and Technology 228,1-18... 

High-performance liquid chromatography (HPLC) may be used for the simultaneous separation of ethanol and other wine constituents such as carbohydrates, glucose, fructose, and saccharose, coupled with either refractive index or Fourier transform infrared (Fl lR) detection. Ethanol may also be codetermined with other volatile compounds in wine by gas chromatography with flame ionization detection. It is important to note that chromatographic methods for the analysis of ethanol are not suitable where accurate determinations are required. 

Characterization of Volatile Compounds in Wine-Stopper Cork... 

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