The Auswine Forum

About 35 years ago when I briefly taught high-school science/maths subjects there was a particular chemical used to illustrate genetic-related differences in taste. Some people could taste the chemical, others could not. My memory of those days is dimmed (or probably repressed)...

Does anyone know what this particular chemical and test is?

Found it! Isn't Google wonderful?

It's phenylthiourea (I kept getting confused with phenylketonuria)!!

"Phenylthiourea papers, for example, taste bitter to seven out of ten people, and sodium benzoate papers taste sweet, salty, bitter, or tasteless to different people."

teacher, is that becos the different people place the papers on different parts of their respective tongues? i remember being taught (by way of the visual aid showing multi coloured portions of a tongue) that different parts of the tongue is sensitive to different tastes...

Another food related example is coriander.

A significant minority of people find it tastes like soap.

meshach wrote:teacher, is that becos the different people place the papers on different parts of their respective tongues? i remember being taught (by way of the visual aid showing multi coloured portions of a tongue) that different parts of the tongue is sensitive to different tastes...

Not this one, doesn't matter which part of the tongue you place the phenylthiourea, it's a specific genetic trait, you either taste it or don't. You are correct though, different parts of the tongue are sensitive to the different types of taste and the number/density of actual taste buds varies a lot across the population.

Anonymous wrote:Another food related example is coriander.

A significant minority of people find it tastes like soap.

I'm very, very glad I'm in the majority on this one!

There are several chemicals with these properties. Check out the Taste Laboratory of Linda Bartoshuk, PhD., Yale University School of Medicine for more on the subject. The relevant page is here. There is also a piece with her and Jacques Pépin, celebrity chef and cookbook author, talking about taste where she gives Pépin the PROP (propylthiouracil) test. Oddly enough Bartoshuk cannot taste PROP.

Bartoshuk has also published on the myth of the tongue taste map, unfortunately that part of her site is not up yet - the site has been under constructions for months. The basis of her argument is as follows

The study of patients with taste disorders (i.e. 'experiments of nature') suggests that the old tongue maps (e.g. sweet on the tip, bitter on the back) that often appear in textbooks are wrong. If they were correct, severing the taste nerves that innervate the front of the tongue would result in a loss of the ability to taste sweet, etc. This does not occur. Severing these nerves has little effect on everyday taste experience because taste nerves inhibit one another. Damaging one nerve abolishes its ability to inhibit others and the release-of-inhibition compensates for the damage. Bartoshuk LM. Ciba Found Symp. 1993;179:251-62.

Mike

KMP wrote:Oddly enough Bartoshuk cannot taste PROP.

Interesting article Mike, but I suspect supertasters are in the minority, therefore it's not odd that she isn't one, even if it's more likely to occur in females.

I know I'm not one, but look at all that chilli, wonderful super-spicy foods and all those big reds that I wouldn't be able to cope with if I was.

It would be interesting to have this test available easily and cheaply to wine-drinkers (Glen Green, how about it?) I suspect it would turn out to be more common amongst pinot lovers and Mt Mary fanatics.

Can you just imagine it, rocking up to a wine- tasting where 10% of the tasters are wearing little badges ordered after passing Glen's test-kit, "I'm a SuperTaster!" and prattling on ad-infinitum about the esoteric herbs, spices, minerals etc thay can see in the wine?

It happens now without the badges, but they would be easier to avoid if they wore one.

Red Bigot wrote:Can you just imagine it, rocking up to a wine- tasting where 10% of the tasters are wearing little badges ordered after passing Glen's test-kit, "I'm a SuperTaster!" and prattling on ad-infinitum about the esoteric herbs, spices, minerals etc thay can see in the wine?

It happens now without the badges, but they would be easier to avoid if they wore one.

I think it happens a lot in tasting notes! Might just be the diversity in sensory abilities but whenever I go to a tasting of wines that have received high scores from certain individuals a lot of the folks present have a hard time picking out the flavors described in the tasting notes provided. But they sure are mouth watering tasting notes! Hmmmm love that creosote!

Mike

Linda spoke at last years AWITC, very interesting talk, actually it was good to see some more molecular/genetic research especially in sensorily related fields. Interestingly, a comparison to chilli or hot/spicy foods was formed, ie. those who have high thresholds for such foods were generally not supertasters.

I think you will find that the bulk of people are tasters, however sensory attributes are easily learnt, therefore can then be readily detected. Accordongly, someones tasting notes in essence can not be wrong, there were a few around a few years back (industry, not this forum) who would often reject the ideas that others had about wines. This is, in my opinion inappropriate, olfactory observations about wine is individual specific, consequently there is no right or wrong as to what you taste.

Cheers
Colin.

vinum wrote:Linda spoke at last years AWITC, very interesting talk, actually it was good to see some more molecular/genetic research especially in sensorily related fields. Interestingly, a comparison to chilli or hot/spicy foods was formed, ie. those who have high thresholds for such foods were generally not supertasters.

I think you will find that the bulk of people are tasters, however sensory attributes are easily learnt, therefore can then be readily detected. Accordongly, someones tasting notes in essence can not be wrong, there were a few around a few years back (industry, not this forum) who would often reject the ideas that others had about wines. This is, in my opinion inappropriate, olfactory observations about wine is individual specific, consequently there is no right or wrong as to what you taste.

Cheers
Colin.

It's strange, but I really started to pick up more individual characters in wines after I started getting into eating more spicy food! (Mexican & Thai)

My friends would always say that I must be burning out my taste buds with the chilli, and yet it seemed to have the opposite effect; I had the theory that by adjusting for the heat your senses are more intensely tuned in.

Then again, it just could have been because I was drinking more wine instead!

Cheers
Ian

Red Bigot wrote:

Anonymous wrote:Another food related example is coriander.

A significant minority of people find it tastes like soap.

I'm very, very glad I'm in the majority on this one!

Talk to me about it. I spent ten years working in Thailand. Pity one of the people I worked with (a Thai) had it so bad she couldn't have it in her kitchen lest it contaminate other foods.

David

vinum wrote:Linda spoke at last years AWITC, very interesting talk, actually it was good to see some more molecular/genetic research especially in sensorily related fields. Interestingly, a comparison to chilli or hot/spicy foods was formed, ie. those who have high thresholds for such foods were generally not supertasters.

I think you will find that the bulk of people are tasters, however sensory attributes are easily learnt, therefore can then be readily detected. Accordongly, someones tasting notes in essence can not be wrong, there were a few around a few years back (industry, not this forum) who would often reject the ideas that others had about wines. This is, in my opinion inappropriate, olfactory observations about wine is individual specific, consequently there is no right or wrong as to what you taste.

Cheers
Colin.

I donÂ’t have a problem with people offering their opinion on what flavors they believe they can detect in a wine. But the variety of flavor descriptors offered for any individual wine by a group of tasters suggests confusion exists in correctly identifying an aroma and there may be numerous explanations for this inability.

There is some data out there that our abilities to accurately detect flavors in mixtures can be quite limited and may not improve with training. One study examined whether a previously established limited capacity to discriminate and identify the components of olfactory mixtures resulted from the participants' lack of familiarity with the task, training designed to optimize cognitive and perceptual performance, or professional experience in odor discrimination. The participants were a trained panel of 10 women (23-43 years old), and an expert panel of 8 male professional perfumers and flavorists (25-55 years old). The individual chemical stimuli were 7 common dissimilar odorants of equal moderate intensity. An air dilution olfactometer delivered a single odorant or a mixture containing up to 5 odorants. The results indicated that for both panels only 3 or 4 components of a complex mixture could be discriminated and identified and that this capacity could not be increased by training. Therefore, the limit may be imposed physiologically or by processing constraints. Livermore A, Laing DG. J Exp Psychol Hum Percept Perform. 1996. 22:267-77.

What is interesting about this study is that the data show that a single odor can be identified about 97% of the time irrespective of the individual but five odors in a mixture were identified correctly 3% of the time. One conclusion reached was that “identification of more than three to four odors in a complex mixture was extremely difficult”.

The upshot of this, for me, is that when I see the confident description of half a dozen aromas for a single wine in a tasting note IÂ’m more than just a little suspicious. The individual either has extraordinary powers or its another case of BS.

Now this, of course, is not the last word on this complex subject. Mixtures of some compounds can increase their perception while mixtures of others can decrease perception. It would be interesting to see if studies have been done to determine if the relative volatility of compounds in wine contribute to changes in wine aroma (IMHO this may play a significant role in the so called breathing effect attributed to decanting).

Mike

While I definately see your point Mike, I am inclined to disagree - well in part at least. Often during blending trials, notes for the wine we are putting together would more often than not see more than 6 aromatic discriptors. Both myself and my partner see this as important in differentiation of wines for classificaiton, yes there are occasions where wines appear fairly dumb, however generally we are looking for similar complexing characteristics amongst vintages. Moreover, although I did not take the prop test, I would be fairly confident that I was a taster (curse this love for chilli).

On a completely different level, another interesting feature found from Lindas research was the fact that women were generally better tasters than guys. Any thoughts?

Cheers
Colin.

vinum wrote:While I definately see your point Mike, I am inclined to disagree - well in part at least. Often during blending trials, notes for the wine we are putting together would more often than not see more than 6 aromatic discriptors. Both myself and my partner see this as important in differentiation of wines for classificaiton, yes there are occasions where wines appear fairly dumb, however generally we are looking for similar complexing characteristics amongst vintages. Moreover, although I did not take the prop test, I would be fairly confident that I was a taster (curse this love for chilli).

On a completely different level, another interesting feature found from Lindas research was the fact that women were generally better tasters than guys. Any thoughts?

Cheers
Colin.

Hi Colin

Without meaning to cast doubt on the ability of either you or your partner I think the question is whether the 6 or more descriptors that you note are accurate recordings of the aromas. That was the point of the study by Livermore and Laing. The groups they studied did provide false or incorrect answers, although oddly enough this did not increase in number as the mixtures became more complex.

I think many of us can rattle off 3 or 4 descriptors pretty quickly and by spending time over a wine add a few more. If there are a bunch of folks discussing the wine then there is sure to be some agreement (or not!) on additional aromas; I'm never really sure how much of a role suggestion plays in this last one and so if I record the descriptors of others in my own TNs I note that it was from someone else and not me. I had an interesting experience with this recently at a tasting of Bordeaux wines. One wine (from memory the oldest wine in the group - 1995 Chateau Troplong-Mondot, St Emilion) had a very unusual aroma. I was very confused by it and the folks at my table all offered their suggestions and with each suggestion I pretty much could smell what they were saying. It was one of those occasions where you sit back and say "OK, my nose and brain are no longer talking the same language".

As regards women being better tasters. One study did find that women of reproductive age can improve their ability to smell certain compounds. They concluded This increased sensitivity (averaging five orders of magnitude) was observed only among females of reproductive age. These observations provide convincing evidence that female olfactory acuity to a variety of odorants can vastly improve with repeated test exposures. They also suggest a sensory basis for the anecdotal observation of greater olfactory sensitivities among females and raise the possibility that the olfactory-induction process may be associated with female reproductive behaviors such as pair bonding and kin recognition. Gender-specific induction of enhanced sensitivity to odors. Dalton P, Doolittle N, Breslin PA. Nat. Neurosci. 2002 5:199-200.

Mike

Red Bigot wrote:

Anonymous wrote:Another food related example is coriander.

A significant minority of people find it tastes like soap.

I'm very, very glad I'm in the majority on this one!

Soap would be preferable for me it is like biting on metal or fingernails down a blackboard.

Some years ago Margaret Throsby interviewed Ian Hemphill (Hemphill spices in Sydney) he said it was one in 10 who are intolerant. Certainly in my case and I understand in general it only is a problem with the leaves, seeds or roots no problem. Fortunately my tolerance is improving but can't eat Vietnamese as a result.

DJ

Hi Mike,

I will try and dig out the paper that Linda presented at the AWITC, if you want it I can forward it on to you.

Cheers
Colin.

vinum wrote:Hi Mike,

I will try and dig out the paper that Linda presented at the AWITC, if you want it I can forward it on to you.

Cheers
Colin.

Absolutely, I'd like to see it. Thanks.