TCA analysis

Chloroanisoles have been shown to be capable of imparting a musty taint to a variety of foods and beverages, including wine. The most potent of the chloroanisoles is 2,4,6-trichloroanisole (TCA). The aroma detection threshold of TCA in wine has been determined as ranging from 1.4 ng/L to 4 ng/L depending on wine type, while 2,3,4,6-tetrachloroanisole (TeCA) has a somewhat higher aroma detection threshold than TCA (reported as 14 ng/L in a Pinot Noir wine). 2,4,6-tribromoanisole (TBA) has been reported in wine with an aroma threshold similar to that of TCA.

The most common causes of musty taint in wine are generally the cork closure or contaminated oak products. In most cases of cork taint investigated, TCA has been shown to be the compound responsible for the musty odour. When contamination in wines has been derived from contaminated oak products (both barrels and chips), both TCA and TeCA, sometimes in combination, have been shown to be responsible for the taint.

The analysis utilises headspace solid phase microextraction (HSP-SPME) with GCMS. All compounds are analysed down to levels at or below their sensory thresholds. Corks are completely submerged for 24 hours in a model wine solution while oak products are soaked in the same model wine solution for 7 days. In both cases, the model wine extract is then analysed as a normal wine. The method provides analysis of the following compounds: 2,6- and 2,4-dichloroanisole, 2,4,6-trichloroanisole, 2,4,6-tribromoanisole, 2,3,4,6-tetrachloroanisole and pentachloroanisole.

How can this analysis assist winemakers?

Where musty taint in wine is encountered, analysis of wines (and corks where relevant) will determine whether chloroanisoles are responsible for the taint. This allows industry to seek appropriate redress, where materials supplied to a winery are responsible for the taint. In addition, screening of oak chips/shavings prior to use will reduce the risk of wines becoming contaminated with chloroanisoles as a result of the use of these products.

How do I submit samples?

Samples should be submitted in glass jars (a 100 mL jam jar is perfect) with double layered aluminium foil between the jar and lid. This is to prevent the absorption of the taint into the plastic insert of the lid.

Prices per analysis
Analysis Cost per analysis (excluding GST) Volume required Target response time
1-7 samples 8+ samples
TCA in wine by Headspace SPME $151 $125 Wine – 100 mL
Cork or oak chips/shavings: 20g
10 working days from receipt of samples
TCA in cork by Headspace SPME $160 $139
TCA in oak chips/shavings by Headspace SPME $164 $142

For more information, please contact AWRI Commercial Services on (08) 8313 6600 or e-mail commercialservices@awri.com.au