Trichloroanisole in Wine

Evans, T.J., C.E. Butzke, and S.E. Ebeler. 1999. Analysis of 2,4,6-trichloroanisole in wines using solid-phase microextraction coupled to gas chromatography mass spectrometry. J. Chromatogr. A 786 293-298. 

Riu, M., Mestres, M., Busto, O. and J. and Guasch, J. (2002) Determination of 2,4,6-trichloroanisole in wine by headspace solid-phase microextraction and gas chromatography-electron-capture detection,/. Chromatogr. A, 977(1), 1-8. 

Fontana, R, Patd, S., Banerjee, K., Altamirano, J. (2010). Ultrasound-Assisted Emulsification Microextraction for Determination of 2,4,6-Trichloroanisole in Wine Samples by Gas Chromatography Tandem Mass Spectrometry. /. Agric. Food Chem., Vol.58, N°8, pp. 4576-4578, ISSN 15205118. 

Haas, D., GalUer, H., Habib, J., Melkes, A., Schlacher, R., Buzina, W., et al. (2010). Concentrations of viable airborne fungal spores and trichloroanisole in wine ceUars. International Journal of Food Microbiology, 144, 126-132. 

Alzaga, R., Ortiz, L., Sanchez-Baeza, E, Pilar, M., Bayona, XM. (2003) Accurate determination of 2,4,6-trichloroanisole in wines at low parts per trUhon by solid-phase microextraction followed by GC-FCD. Journal of Agricultural and Food Chemistry, 51,35Q9- 551A. 

Snow, M.S. The determination of 2,4,6-trichloroanisole in wine using headspace trap with GC/MS. http //las.perkinelmer.com/content/Application Notes/246trichloroanisoleinwi-... 

Cork flavor, or the olfactory defect caused by moulds, is the commonest of the undesirable flavors found in wine. In most cases, the cork is responsible for tainting wine with 2,4,6-trichloroanisol (TCA) (Tanner et al. 1981). However, barrelled wine may also be contaminated with 2,3,4,6-tetrachloroanisol (TeCA) that can be present in the damp atmosphere of wine cellars in the presence of woods treated by polychlorophenols. TCA has a slightly different aroma than TeCA but the two contaminants are often confused. Another possibility is that the cork itself may be contaminated by other corks (TCA) or by TeCA. 

Cork taint is a musty/moldy off-odor in wine. It is related to the cork stopper, a wine botde closure made from the bark of the cork oak (Quercus suher). In a correlation between sensory evaluation and chemical analysis, 2,4,6-trichloroanisole (TCA) has b n identified as a major impact component. In sensitivity tests of a group of trained wine judges, a geometric mean of the minimum detectable concentrations of TCA has been determined at 4.6 ng/L. 

The various contaminations in foods are due to the presence of compounds dangerous for consumer health or that affect organoleptic characteristics of the product. Ochratoxin A (OTA) and biogenic amines are dangerous for human health, and their legal limits are fixed in grape and wine. Due to their negative sensory properties and very low sensory thresholds, 2,4,6-trichloroanisole and ethylphenols have to be practically absent in wine, or present at as low a level as is possible. 

Figure 8.6. Origin of 2,4,6-trichloroanisole in cork used for making stoppers for bottled wines.

Buser, H.-R., C. Zanier, and H. Tanner. 1982. Identification of 2,4,6-trichloroanisole as a potent compound causing cork taint in wine. J. Agric. Food Chem. 30 359-362. 

Jonsson, S. Hagberg, J. van Bavel, B. (2008). Determination of 2,4,6-Trichloroanisole and 2,4,6-Tribromoanisole in Wine Using Microextraction in Packed Syringe and Gas Chromatography-Mass Spectrometry. Journal of Agricultural and Food Chemistry 56, 4962-4967... 

Analysis of Off-Flavor Compounds in Food 2,4,6-Trichloroanisole (TCA) in Wine Analysis of flavor compounds in food comprises different approaches (1) target compound analysis focused on the detection and quantification of known compounds responsible for specific flavor features, (2) profiling volatile compounds done either to get a knowledge of food flavor/volatile compounds composition or, aided with multivariate analysis (MVA), for the identification of the origin of specific foods or their adulteration, and (3) sensory-oriented identification and quantification of key odorants (also off-odorants) of particular foods. 

One of the major problems associated with the disinfection of water supplies by chlorination is that the chlorinated water may produce the so-called chlorophenolic taste produced by a reaction between the added chlorine and phenol and some of its homologs that are present in trace amounts. The chlorination of phenol proceeds by the stepwise substitution of the 2-, 4-and 6-positions of the aromatic ring. Initially, phenol is chlorinated to form either 2- or 4-chlorophenol. Then 2-chlorophenol is chlorinated to form either 2,4- or 2,6-dichlorophenol, while 4-chlorophenol forms 2,4-dichlorophenol. Both 2,4- and 2,6-dichlorophenol are chlorinated to form 2,4,6-trichlorophenol, which reacts with aqueous chlorine to form a mixture of non-phenoHc oxidation products. 2,4,6-Trichloroanisole was the first compound identified as the source of taints in wines, perceived as... 

Secondary metabolites produced by infections of fungi or bacteria can damage the quality of cork. The worst one is trichloroanisole (2,4,6-TCA) that is primarily responsible for the typical cork taint and causes drastic losses in the wine industry. Good wine specialists can recognize a TCA content in wine of about 2 ng/1, while usual consumers notice concentrations between 5 ng/1 and 10 ng/1. The cork industry made a lot of efforts to solve this problem because it became very serious during the recent years. A number of processes were developed mainly using overheated steam to reduce the TCA concentration in the cork. But even with the best of such plants, a TCA reduction of only 70% can be reached. 

Solid-phase microextraction has been investigated for the analysis of 2,4,6-trichloroanisole, a cork taint compound, in wine samples [16]. This solvent-free procedure was coupled to GC-MS under selective ion monitoring (SIM) conditions using a fully deuterated internal standard ([ H5]trichloroanisole) for quantitative purposes. The SPME-GC-MS method was demonstrated to be selective, precise, and sensitive with a 5 ng limit of quantification. 

However, is not the analysis of minor wine volatiles that still presents difficulties. With the level of sensitivity and automation of the analytical techniques, the determination of many odorants at /rg/L level is a simple analysis. The difficulties come when the analytes of interest cannot be easily determined using a single non-selective-preconcentration step. This will happen when the analytes are difficult to extract because they are very polar and/or not very volatile or when they are present at very low levels. The concentration level at which the analysis of an aroma compound becomes difficult is related to its polarity and to the quality of its mass spectrum. Eor instance, the analysis of 2,4,6-trichloroanisol (TCA) at, let s say, 20 ng/L is not a very difficult analysis, because this molecule is quite nonpolar (easily extractable, relative volatile) and has a mass spectrum with abundant high mass ions.In contrast, the analysis of methional or of sotolon at 1 /rg/L is quite difficult because these compounds are very polar (difficult to extract, not very volatile) and their mass spectra lack powerful ions. For these difficult analytes, some of which are very important wine impact aromas, specific strategies must be developed ... 

Although over 100 volatiles from finished corks have been reported (2-3), the one component that has been identified 4) as the major cause for cork taint is 2,4,6-trichloroanisole (TCA). In a recent study of Australian wines (5), 100% of the tainted wines, assessed by wine industry personnel, had TCA at or above the sensory threshold. The European QUERCUS study found TCA to be responsible for a musty/moldy taint in at least 80% of cases when it was detected in bottled wines. This makes TCA the most significant impact compound in regard to cork taint, and consequently made it the focus of our analytical developments. 

Mass spectrometry is also applied in the control of pesticides and other contaminants (e.g., 2,4,6-trichloroanisole), detection of compounds formed by yeast and bacteria, determination of illegal additions to the wine. Liquid chromatography/mass spectroscopy (LC/MS) methods for determination of toxins in the wine (e.g., ochratoxin A) have been proposed (Zollner et al., 2000 Flamini and Panighel, 2006 Flamini et al., 2007). 

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