Origin and fate of 2,4,6-trichloroanisole in cork bark and wine corks

Abstract

2,4,6-Trichloroanisole (TCA), which is a major cause of cork taint in bottled wine, is already present in the bark of living cork trees to the extent that it can account for the majority of incidences of cork taint in bottled wine. Other post-harvest sources of TCA are known and may add to the forest-derived TCA in cork. Both the origin of TCA in the bark in the forest, and the means by which additional TCA can accumulate in the corks during manufacture, have been examined. TCA can originate from 2,4,6-trichlorophenol (TCP) produced from naturally-occurring phenol and chlorine from sanitisers and cleaning products, and town water. Also, chlorophenol biocides have accumulated in the environment due to the large quantities used in previous times – TCP has been a minor impurity in pentachlorophenol biocides and a major ingredient in other preparations. There is some evidence that chlorophenols were used in pest management in the forest prior to restrictions on the use of these materials. The factors affecting the uptake and loss of TCA by the bark on the tree and by corks during production, and through to their use in the bottling of wine have been considered in this review.