• Source: 2,4,6-Trichloroanisole

2,4,6-Trichloroanisole (TCA) is an organic compound with the formula CH3OC6H2Cl3. It is the symmetric isomer of trichloroanisole. It is a colorless solid.




Occurrence


2,4,6-Trichloroanisole represents one of the strongest of off-flavors, substances "generated naturally in foods/beverages [that considerably] deteriorate the quality" of such products. It is also a component of some drinking waters. It has also been detected in blood samples.




= Wine

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As of 2000, TCA was considered the primary chemical compound responsible for the phenomenon of cork taint in wines, and it has an unpleasant earthy, musty and moldy smell.




= Coffee

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TCA has also been suggested as cause of the "Rio defect" in coffees from Brazil and other parts of the world, which refers to a taste described as "medicinal, phenolic, or iodine-like". In investigation of the mechanism of its role in producing off-flavor effects, it was found to "attenuate olfactory transduction by suppressing cyclic nucleotide-gated channels, without evoking odorant responses."




Formation


TCA is formed by the methylation of 2,4,6-trichlorophenol. More generally, it may be produced when naturally occurring airborne fungi and bacteria are presented with chlorinated phenolic compounds, which they then convert into chlorinated anisole derivatives. Species implicated include those of the genera Aspergillus, Penicillium, Actinomycetes, Botrytis (e.g. Botrytis cinerea), Rhizobium, or Streptomyces.
The chlorophenol precursor, 2,4,6-trichlorophenol, is used as a fungicide; more generally, related compounds can originate as contaminants found in some pesticides and wood preservatives, or as by-products of the chlorine bleaching process used to sterilize or bleach wood, paper, and other materials.




Further reading


Marsili, R. (2000). "Solid-Phase Microextraction: Food Technology Applications". In Wilson, Ian D. (ed.). Encyclopedia of Separation Science. New Yor, NY: Academic Press. pp. 4178–4190. doi:10.1016/B0-12-226770-2/06791-0. ISBN 9780122267703. Over the last two decades, the incidence of mouldy and musty off-flavours in cork-sealed wines has increased significantly. 2,4,6-Trichloroanisole (TCA) has been identified as the primary chemical responsible for cork taint. The human olfactometry threshold for TCA is 4–10 ng L−1 in white wine and 50 ng L−1 in red wine. In the case of wine, a worldwide loss of roughly US$1 billion per year is attributed to cork taint.
Science Direct Staff (June 2023). "2-4-6-Trichloroanisole" (Science Direct citation sample/listing). Retrieved June 26, 2023.
Buser, H.R.; Zanier, C. & Tanner, H. (1982). "Identification of 2,4,6-Trichloroanisole as a Potent Compound Causing Cork Taint in Wine". Journal of Agricultural and Food Chemistry. 30 (2): 359–362. doi:10.1021/jf00110a037.{{cite journal}}: CS1 maint: multiple names: authors list (link) An early primary research report on the role of TCA in cork taint.




See also


2,4,6-Tribromoanisole




References

Kata Kunci Pencarian:

• Senyawa berbau
• 2,4,6-Trichloroanisole
• Cork taint
• Electrophysiology
• Aroma compound
• TCA
• 2,4,6-Tribromoanisole
• Wine fault
• Chateau Montelena
• FLSmidth
• Nomacorc