Contaminated Chemical in Wine Suppresses Sense of Smell

Oenophiles. You know who you are.


You like to stick your nose into a glass of wine and breathe deeply. But often you get a wet, musty smell.

Scientists have known that the reason for that smell in corked wine is because of a contamination caused by a compound called TCA, or 2.4.6 – trichloroanisole. The chemical forms when the fungi, naturally existing in cork, touch some chlorides found in wine, reports the Daily Mail.

That smell sometimes overwhelms the “nose” of the wine. This can be a problem for wineries because infected corks and TCA can contaminate not just a single batch, but an entire cellar. Ferreting out the tainted corks can be almost impossible. That’s why, since the early 1990s, many wineries have tried to solve the problem by eliminating the use of chlorine-based products.

Now a Japanese scientist has figured out for the first time the molecular mechanism of corked wine and why the TCA masks wine’s pleasant aroma. Dr. Hiroko Takeuchi of Osaka University conducted experiments on insects and humans and found that TCA masks the aroma because it suppresses the sense of smell.

The TCA knocks out the olfactory cells in consumers’ noses. The Daily Mail explains further how the research was conducted:

Dr. Takeuchi and colleagues monitored the activity in the cells of newts exposed to TCA and showed rather than sparking odor perception it suppressed them — even at extremely low concentrations. A series of experiments involving 20 human participants also showed the original odors of wines were reduced when they were contaminated by TCA — causing unpleasant flavors.

“Throughout culinary history, consumers have been disturbed by naturally generated off-flavor substances that can greatly reduce the palatability of foods and beverages,” Takeuchi says. “One of the most potent off-flavor compounds identified to date is TCA – known specifically for inducing a cork taint in wines. Our findings not only reveal a likely mechanism of odor loss but also reveal potential molecular architectures for the development of novel odor-masking agents.”

While unpleasant, the tainted compound is not harmful to humans. Its relative strength in odor also depends on the extent of the contamination as well as the consumer’s sensitivity to it.

Just like wineries have to be concerned about contamination that produces TCA, so do thousands of other manufacturers who have to be careful about their products getting contaminated through mistakes in the manufacturing process or a change in raw material supply. The experts at Polymer Solutions, Inc., specialize in detecting contamination. Their team of scientists can investigate a cause of contamination to help manufacturers control the quality of their products. Like the wineries concerned about their product coming into contact with corks, food packagers need to feel secure that their product won’t contaminate food.

Source: “Musty flavor of corked wine is caused by a chemical the knocks out your sense of smell,” Daily Mail, 9/16/13
Image by J. Nathan Matias.