2,4,6-Trichloroanisole

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.{{Cite journal| doi = 10.1073/pnas.1300764110| issn = 1091-6490| author = Takeuchi, Hiroko; Kato, Hiroyuki & Kurahashi, Takashi | title = 2,4,6-Trichloroanisole is a Potent Suppressor of Olfactory Signal Transduction| journal = Proceedings of the National Academy of Sciences| date = 2013-09-16| volume=110| issue = 40| pages = 16235–16240| pmid=24043819| pmc=3791788| bibcode = 2013PNAS..11016235T| doi-access = free}}{{primary source inline|date = June 2023}}{{Cite book |last=Jackson |first=Ron S. |title=Wine tasting: a professional handbook |date=2009 |publisher=Academic Press |isbn=978-0-12-374181-3 |edition=2nd |series=Food science and technology international series |language=En |chapter=Chapter 3: Olfactory Sensations}} It is also a component of some drinking waters.{{cite journal|doi= 10.1016/0043-1354(95)00173-5|title= Taste and odour threshold concentrations of potential potable water contaminants|date= 1996|last1= Young|first1= W.F.|last2= Horth|first2= H.|last3= Crane|first3= R.|last4= Ogden|first4= T.|last5= Arnott|first5= M.|journal= Water Research|volume= 30|issue= 2|pages= 331–340|bibcode= 1996WatRe..30..331Y}} It has also been detected in blood samples.{{cite journal |doi=10.1007/s002440010298 |title=Identification of Hydroxylated PCB Metabolites and Other Phenolic Halogenated Pollutants in Human Blood Plasma |date=2002 |last1=Hovander, t. Malmberg, m. Athanasia |first1=L. |last2=Malmberg |first2=T. |last3=Athanasiadou |first3=M. |last4=Athanassiadis |first4=I. |last5=Rahm |first5=S. |last6=Bergman |first6=A. |last7=Wehler |first7=E. K. |journal=Archives of Environmental Contamination and Toxicology |volume=42 |issue=1 |pages=105–117 |pmid=11706375 |bibcode=2002ArECT..42..105H }}

As of 2000, TCA was considered the primary chemical compound responsible for the phenomenon of cork taint in wines,{{cite book | author = Marsili, R. | date = 2000 | chapter = Solid-Phase Microextraction: Food Technology Applications | title = Encyclopedia of Separation Science | editor = Wilson, Ian D. | location = New York, NY | publisher = Academic Press | chapter-url = https://www.sciencedirect.com/science/article/abs/pii/B0122267702067910 | doi = 10.1016/B0-12-226770-2/06791-0 | pages = 4178–4190 | isbn = 9780122267703 | quote = 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.}} and it has an unpleasant earthy, musty and moldy smell.

TCA has also been suggested as cause of the "Rio defect" in coffees from Brazil and other parts of the world,These include Central and South America.{{fact|date = June 2023}} 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."

TCA is formed by the methylation of 2,4,6-trichlorophenol.{{Citation |last=Pereira |first=Helena |title=Chapter 14 - Wine and cork |date=2007-01-01 |url=https://www.sciencedirect.com/science/article/pii/B9780444529671500169 |work=Cork |pages=305–327 |editor-last=Pereira |editor-first=Helena |access-date=2024-01-14 |place=Amsterdam |publisher=Elsevier Science B.V. |isbn=978-0-444-52967-1}}{{Cite journal | author = Spadone, Jean Claude; Takeoka, Gary & Liardon, Remy| title = Analytical Investigation of Rio Off-Flavor in Green Coffee| journal = Journal of Agricultural and Food Chemistry| doi = 10.1021/jf00091a050 | year = 1990| volume = 38| pages = 226–233}} Note, at best, this source states that 2,4,6-trichlorophenol is "the probable precursor of TCA". 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.{{Cite journal |last=Cravero |first=Maria Carla |last2=Bonello |first2=Federica |last3=Pazo Alvarez |first3=Maria del Carmen |last4=Tsolakis |first4=Christos |last5=Borsa |first5=Daniela |date=24 June 2015 |title=The sensory evaluation of 2,4,6-trichloroanisole in wines: The sensory evaluation of 2,4,6-trichloroanisole in wines |url=https://onlinelibrary.wiley.com/doi/10.1002/jib.230 |journal=Journal of the Institute of Brewing |language=en |volume=121 |issue=3 |pages=411–417 |doi=10.1002/jib.230}} Species implicated include those of the genera Aspergillus, Penicillium, Actinomycetes, Botrytis (e.g. Botrytis cinerea), Rhizobium, or Streptomyces.{{Cite web |last=Crane |first=Louise |title=Trichloroanisole: Cork taint |url=https://www.chemistryworld.com/podcasts/trichloroanisole-cork-taint/3010280.article |access-date=2024-01-14 |website=Chemistry World |language=en |publication-date=22 March 2019}}With regard to circumstantial evidence, Spodone, et al., op. cit., note that Rio off-flavor is associated with "beans heavily infested with various fungi (Aspergilli, Fusaria, Penicillia, Rhizopus, etc.) and bacteria (Lactobacilli, Streptrococci)".

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.NTP (National Toxicology Program). 2021. "2,4,6-Trichlorophenol", Report on Carcinogens, Fifteenth Edition. Research Triangle Park, NC: U.S. Department of Health and Human Services, Public Health Service. https://ntp.niehs.nih.gov/go/roc15

DOI: https://doi.org/10.22427/NTP-OTHER-1003

• {{cite book | author = Marsili, R. | date = 2000 | chapter = Solid-Phase Microextraction: Food Technology Applications | title = Encyclopedia of Separation Science | editor = Wilson, Ian D. | location = New Yor, NY | publisher = Academic Press | chapter-url = https://www.sciencedirect.com/science/article/abs/pii/B0122267702067910 | doi = 10.1016/B0-12-226770-2/06791-0 | pages = 4178–4190 | isbn = 9780122267703 | quote = 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 web | author = Science Direct Staff | date = June 2023 | title = 2-4-6-Trichloroanisole | format = Science Direct citation sample/listing | url = https://www.sciencedirect.com/topics/chemistry/2-4-6-trichloroanisole | access-date = June 26, 2023}}
• {{cite journal | author = Buser, H.R.; Zanier, C. & Tanner, H.| title = Identification of 2,4,6-Trichloroanisole as a Potent Compound Causing Cork Taint in Wine. | journal = Journal of Agricultural and Food Chemistry| doi = 10.1021/jf00110a037| year = 1982 | volume = 30 | issue = 2 | pages = 359–362}} An early primary research report on the role of TCA in cork taint.

• 2,4,6-Tribromoanisole

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Category:Chlorobenzene derivatives

Category:Phenol ethers