Sunday, March 20, 2016

IN FAVOR of ODOR SENSITIVITY TRAINING

Friend of Pairteas and tea connoisseur Marzi Pecen has recently been looking into the issue of olfactory training, and we have been having discussions concerning its purpose and value. Her goal is to create an experiential training that enables people to appreciate the full panoply of flavors in teas. While the training would be fun for amateurs, professionals in the tea world would benefit, just as have the wine experts in the study presented today.*

As you may have seen in the post of March 9th—on odor mixtures and how we experience them—training can have an effect on the experience of odors for people who can already detect the odors. What about training for people for whom the odor threshold is very high, in other words who have difficulty smelling the compound even at very high concentrations? Can training lower thresholds?

As it turns out there are two odorants in wine that are important for wine flavor, namely linalool and diacetyl, for which people’s thresholds vary. Linalool has a cool, floral/citrus odor, while  diacetyl has a buttery odor. Both of these compounds are present in tea.

Tempere and colleagues decided to try to help wine experts with a high threshold develop the ability to smell these compounds. They divided their experts into two groups, one which would be trained on linalool and the other on diacetyl. The participants were given a bottle of the training solution, and “were instructed to sniff the sample bottle everyday for 1 month and note their training times in a logbook. The following instructions were communicated: ‘To benefit from this training, choose a quiet moment and sniff repeatedly two or three times for approximately one minute.’ “

After the month of training, the participants were brought into the lab and their thresholds for the two compounds measured. As you can see from the graph below, participants’ thresholds to the training odor improved significantly, but there was no improvement in the untrained odor. 



Of course, not everyone improved to the same degree. The following graph shows the change for each participant. As you can see, participants varied somewhat in their starting threshold dilution, the group trained on diacetyl more so than the group trained on linalool, which may account for the differences in improvement seen for the two groups.



Another interesting effect: the improvement with training on either compound was greatest for wine growers, merchants, and brokers, and least for oenologists/wine makers. Apparently the initial thresholds for the two groups of wine experts was not different, so a reason for the differential training effect is not clear. Previous taste training, as manifested by some form of degree, showed no effect.

Of course we do not know where, in the path from nose to brain and back, training has an effect. And as I noted in my post of March 9th, odors may be perceived quite differently in the presence of other odors. So how we might scale this type of training up for the large number of odorants in wine or tea is a big question.

Nevertheless, this work suggests to me that all of us could potentially profit from more focussed sensory training.


* S. Tempere, E. Cuzange, J. C. Bougeant, G. de Revel, G. Sicard. Explicit Sensory Training Improves the Olfactory Sensitivity of Wine Experts. Chemosensory Perception. June 2012, Volume 5, Issue 2, pp 205-213. DOI: 10.1007/s12078-012-9120-1

1 comment:

  1. Thank you for the mention, Virginia! I am looking forward to sharing the class prototype with you soon. I can see that this will be a great tool for tea aficionados & culinary professionals alike.

    Of course anyone interested in being notified can pop out to Pecen.net and sign up for my mailing list.

    Marzi

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