Names | |
---|---|
Preferred IUPAC name
1,3,5-Trichloro-2-methoxybenzene | |
Other names
2,4,6-Trichloroanisole
TCA 2,4,6-Trichloromethoxybenzene | |
Identifiers | |
3D model (
JSmol)
|
|
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.001.585 |
EC Number |
|
KEGG | |
PubChem
CID
|
|
RTECS number |
|
UNII | |
CompTox Dashboard (
EPA)
|
|
| |
| |
Properties | |
C7H5Cl3O | |
Molar mass | 211.47 g·mol−1 |
Melting point | 60 to 62 °C (140 to 144 °F; 333 to 335 K) |
Boiling point | 140 °C (284 °F; 413 K) at 28 Torr |
Hazards | |
GHS labelling: | |
Warning | |
H302, H319, H413 | |
P264, P270, P273, P280, P301+P312, P305+P351+P338, P330, P337+P313, P501 | |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
This article has multiple issues. Please help
improve it or discuss these issues on the
talk page. (
Learn how and when to remove these template messages)
|
2,4,6-Trichloroanisole (TCA) is a chemical compound that represents one of the strongest of off-flavors, substances "generated naturally in foods/beverages [that considerably] deteriorate the quality" of such products. [1] [2] As of 2000, TCA was considered the primary chemical compound responsible for the phenomenon of cork taint in wines, [3] [1] and it has an unpleasant earthy, musty and moldy smell. [2]
Chemically, TCA is a chlorinated derivative of anisole, and it is a formed by the biomethylation of 2,4,6-trichlorophenol. [4] [5] 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. [6] Species implicated include those of the genera Aspergillus, Penicillium, Actinomycetes, Botrytis (e.g. Botrytis cinerea), Rhizobium, or Streptomyces. [7] [8] [6]
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. [9]
TCA has also been suggested as cause of the "Rio defect" in coffees from Brazil and other parts of the world, [10] which refers to a taste described as "medicinal, phenolic, or iodine-like". [5] 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." [1]
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.
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link) An early primary research report on the role of TCA in
cork taint.{{
cite journal}}
: CS1 maint: multiple names: authors list (
link)[
non-primary source needed]
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.
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link) Note, at best, this source states that
2,4,6-trichlorophenol is "the probable precursor of TCA".
Names | |
---|---|
Preferred IUPAC name
1,3,5-Trichloro-2-methoxybenzene | |
Other names
2,4,6-Trichloroanisole
TCA 2,4,6-Trichloromethoxybenzene | |
Identifiers | |
3D model (
JSmol)
|
|
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.001.585 |
EC Number |
|
KEGG | |
PubChem
CID
|
|
RTECS number |
|
UNII | |
CompTox Dashboard (
EPA)
|
|
| |
| |
Properties | |
C7H5Cl3O | |
Molar mass | 211.47 g·mol−1 |
Melting point | 60 to 62 °C (140 to 144 °F; 333 to 335 K) |
Boiling point | 140 °C (284 °F; 413 K) at 28 Torr |
Hazards | |
GHS labelling: | |
Warning | |
H302, H319, H413 | |
P264, P270, P273, P280, P301+P312, P305+P351+P338, P330, P337+P313, P501 | |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
This article has multiple issues. Please help
improve it or discuss these issues on the
talk page. (
Learn how and when to remove these template messages)
|
2,4,6-Trichloroanisole (TCA) is a chemical compound that represents one of the strongest of off-flavors, substances "generated naturally in foods/beverages [that considerably] deteriorate the quality" of such products. [1] [2] As of 2000, TCA was considered the primary chemical compound responsible for the phenomenon of cork taint in wines, [3] [1] and it has an unpleasant earthy, musty and moldy smell. [2]
Chemically, TCA is a chlorinated derivative of anisole, and it is a formed by the biomethylation of 2,4,6-trichlorophenol. [4] [5] 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. [6] Species implicated include those of the genera Aspergillus, Penicillium, Actinomycetes, Botrytis (e.g. Botrytis cinerea), Rhizobium, or Streptomyces. [7] [8] [6]
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. [9]
TCA has also been suggested as cause of the "Rio defect" in coffees from Brazil and other parts of the world, [10] which refers to a taste described as "medicinal, phenolic, or iodine-like". [5] 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." [1]
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.
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link) An early primary research report on the role of TCA in
cork taint.{{
cite journal}}
: CS1 maint: multiple names: authors list (
link)[
non-primary source needed]
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.
{{
cite journal}}
: CS1 maint: multiple names: authors list (
link) Note, at best, this source states that
2,4,6-trichlorophenol is "the probable precursor of TCA".