Category Archives: Neuroscience

Wine Experts and Foodies: Are They Super Tasters? Or Are They Faking It?

Posted on December 3, 2012 by Becca| 6 Comments

 

I think it’s blatantly obvious that people have different taste preferences:  from food and wine to coffee and cake; if you grab someone off the street and ask them their taste preferences they will say something different than if you grabbed someone else and asked them the same question.

OK, but why is it that we have such variability in our taste preferences?  Is it a result of what our mothers or fathers shoved down our gullets when we were young and developing our tastes (or disdain) for certain things?  Or are we genetically predisposed to enjoying certain things over others?

Turns out, it’s probably a little bit of both, however, recent studies over the past 3 or 4 years have found that genetic variation in oral sensory abilities might very well have the greatest influence on food and beverage preferences.  From a

By William Lawrence (originally posted to Flickr as Geeks Love Wine) [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

marketing standpoint, this finding is very important, as different strategies should be developed for the different genotypes/phenotypes of individuals, since focusing on only one or two strategies may only end up alienating a large subset of the population which would lead to a large underutilized market.

As an aside: Tim Hanni, MW, structured his work around similar concepts, creating the New Wine Fundamentals and Vinotypes, which “allow you to discover your true taste preferences and confidently explore a new world of wines” (quote from myVinotype.com).  I highly recommend you visit his site and explore this fascinating world of discovering your unique wine preferences!

Research on the genetic variation of taste preferences has often focused on how individuals respond to the bitter compound 6-n-propylthiouracil, also known as “PROP”.  This responsiveness places individuals in the different “PROP taster status” categories (a.k.a. phenotypes) of 1) PROP non-tasters; 2) PROP medium-tasters; and 3) PROP super-tasters.  Those in the non-tasters group notice very little to no bitterness; the medium-tasters notice a mild bitterness; and the super-tasters notice an intense bitterness.  Genetic research has found that this variation is due to variations in the TAS2R38 gene, though variations in this gene alone may not explain all variation in taste sensation and preferences.

Those that are PROP super-tasters are often characterized as having greater sensitivity to sour, salt, sweety, and creamy, and also display greater sensitivity to astringency, bitterness, and sourness in alcoholic beverages.  Some say that being a PROP super-taster also predisposes them to being more “acute tasters”, allowing them to pick up more subtle or less obvious tonal nuances in the food or beverage they are tasting.  Depending upon which PROP category / phenotype of which one expresses, the “liking” or preference of particular foods or beverages will change.  Interestingly, PROP categories / phenotypes have been linked in some research studies to diet-related diseases, including obesity and alcoholism.

Though it hasn’t been supported nor disproved in the research literature, it is believed that “foodies” (i.e. those that have “a high liking of food, significant time spent preparing food and choosing ingredients, and a high knowledge of

By Alpha from Melbourne, Australia [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

and interest in new preparation methods, ingredients and flavours” Pickering et al, 2013) are more likely to be PROP super-tasters than “non-foodies”.  The theory is that those that seek out food as a hobby or as a career have more sensitive palates and abilities to distinguish subtle flavors from one another, ultimately resulting in the expression of the PROP super-taster phenotype.  To date, there has been no actual research to confirm this idea, and remains just a theory that is perpetuated throughout the food and beverage industry.

In regards to wine expertise, research has shown that PROP phenotype varies depending upon one’s level of wine expertise, with wine experts experiencing greater PROP sensitivity (i.e. super-tasters) and wine novices experiences less PROP sensitivity (non-tasters or medium-tasters).  In theory, one may expect that foodies and wine experts do not differ in their PROP sensitivity,

One very recent study aimed to address these questions regarding foodies and wine experts and their propensity towards exhibiting a particular PROP phenotype and examined whether or not foodies and wine experts differ from other people in regards to their PROP sensitivity, and whether the PROP sensitivity of the two are similar or unrelated.

Methods

A mail survey/questionnaire was utilized in this study.  5000 surveys were mailed out, 1,011 were returned, and 954 were complete enough for use in statistical analysis (100% complete).  To encourage completion of surveys, cash prizes were awarded (between $20 and $500 USD).

Surveys were mailed to random wine consumers that were on the mailing list of a large wine retailing group in the Northeast of the United States.

The surveys asked participants to rate their “liking” of 64 food items and 14 non-food items.  The food items selected represented a wide range of nutritional groups and values.  Non-food items were randomly placed throughout the food items on the surveys.

Participants were asked to rate their level of wine expertise as novice or beginner, intermediate, high, or expert/very high.  Demographic information was also collected.

PROP phenotypes were determined using filter paper disks that were previously treated with 50mmol/L of PROP.  These disks were included with the surveys that were mailed to participants.  After the surveys were completed, participants were asked to use the PROP disk and rate their experience.

The instructions for using the PROP disks were to “take a sip of water and swish it around your mouth to clean it.  Take the paper disc and place it on the tip of your tongue for 30 seconds or until it is fully wet.  Rate the intensity of the taste of the paper disc by drawing a mark on the scale for your answer”. (Pickering et al, 2013).  Participants were shown a scale with marked degrees of “likeness” and were asked to pick where on the scale their liking of the disk fell.  See Figure 1 for this scale.  Participants were also supplied a picture representation of the instructions for greater ease of use.

Figure 1 from Pickering et al, 2013

Participants were classified as non-tasters if their liking fell in the less than 9mm portion of the scale; medium-tasters if their liking fell between the 9 and 50mm portion of the scale; and super-tasters if their liking fell in the greater than 50mm portion of the scale.  Again, see Figure 1.

Results

  • Gender analysis found that women rated PROP bitterness as more intense than men, indicating women were more likely to be super-tasters than men.
    • Women ranked PROP bitterness 35% higher than men.
  • Age analysis found that there was a small decline in PROP bitterness intensity with age.
    • This may be due to the decline in olfactory function as one ages.
  • In regards to foodies, the authors assumed that foodies would give higher score to food items than non-food items compared to non-foodies; however, results found that there was no such association found between foodies and PROP bitterness intensity.
  • Foodies tended to be older than non-foodies:
    • 51% of foodies were over the age of 61.
    • 29% of non-foodies were over the age of 61.
      • Foodies were also found have more individuals retired, and more with larger incomes, both the researchers attributed to the age factor mentioned just previously.
  • Non-foodies were more likely to be female.
  • In regards to wine expertise, there were many significant findings.
    • Wine experts rated PROP bitterness higher than wine novices.
    • Women ranked PROP bitterness higher than men.
    • PROP bitterness intensity decreased with age.

Conclusions

Several important results can be pulled out of this study. First, it appears as though there is no evidence to support the theory that foodies have increased PROP bitterness intensity or exhibit super-tasting capabilities.  The authors mention several limitations to this study in regards to this result suggest that perhaps the criteria for labeling someone as a foodie in this study was too general, resulting in non-foodies being mistakenly identified as foodies in this analysis.

In the future, the authors suggest further increasing the criteria to be categorized as a foodie to include “time spent preparing food and choosing ingredients; knowledge of food, preparation methods and ingredients; and enjoyment at learning about new foods and food preparation methods.” (Pickering et al 2013).  Also, adding in more “refined” or “complex” foods to the food item list of the survey may help distinguish foodies from non-foodies.

The authors noted that there could have been difficulties distinguishing differences between foodies and non-foodies in regards to the PROP sensitivities, since the sample used to collect data from was bias.  If you recall, the sample was collected from a mailing list at a wine retailer, so customers were already more interested in wine than the average person, which could have biased the entire sample toward having somewhat more intense PROP scores in general than someone who rarely drinks wine.  The people on the wine retailer’s mailing list may have been already more likely to be foodies due to their status as wine lovers than someone else who didn’t voluntarily sign up for the mailing list.  The study should be repeated capturing a greater number and variety of individuals to determine if these results are repeatable, or if they are only applicable to this smaller group of relative bias.

Another result the authors made sure to note was the fact that wine experts tended to be super-tasters compared to less experienced wine drinkers that were either medium-tasters or non-tasters.  They hypothesized that because of this propensity and genetic predisposition to be super-tasters, individuals may be drawn to careers in the wine or food industry.  It would be interesting to see a long-term study where they measured the PROP bitterness intensity scores of

By Agne27 (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons

children as they grew up, and correlate those results with the career path they ended up choosing as adults.  How much do PROP scores change as one grows and develops? Do those children with perpetually high PROP scores end up in fields where they are able to utilize these abilities, such as the wine or food industries?

I would also like to see future research investigating the gender result further.  You may recall, this study found that women scored higher PROP intensity scores than men.  What does this mean?  Are women better tasters than men?  There has been some research to suggest this may be the case, but of course, this has been met with some controversy.  They authors didn’t mention much about this in the conclusions, though since it wasn’t their primary focus, I’m not surprised.  I would love to see this result studied further.  In the meantime, please read a guest post by Marlene Rossman on The Academic Wino regarding this very topic:  Women Smell Better!.

Finally, the authors brought up a very fascinating question regarding the use of wine experts’ recommendations to encourage the purchase of particular wines.  It has been shown that people do find expert opinions important when choosing a wine, as it takes some of the “guess work” out of figuring out if the bottle is “good” or not.  The problem with that, the authors raise, is that the differences in PROP bitterness intensity scores of experts versus novices is that experts are inherently going to like and enjoy a certain type of wine, while novices are more likely to enjoy a different type of wine.  This isn’t always going to be the case, but since PROP intensity scores dictate taste preferences, it is fair to assume that the wine the experts deem “quality” and “good tasting” will end up being less enjoyable to the wine novice who prefers a different tasting wine.  This calls into question the usefulness on solely relying on expert opinions to sell wine, and to encourage the use of other marketing strategies to capture those on all ends of the wine preference spectrum.

I’d love to hear what you all think about this topic!  Please feel free to leave your comments and join in the discussion!

Source: Pickering, G.J., Jain, A.K., Bezawada, R. 2013. Super-tasting gastronomes? Taste phenotype characterization of foodies and wine experts. Food Quality and Preference 28: 85-91.

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Women Smell Better!

Posted on November 7, 2012 by Becca| 9 Comments

 

The following is a guest post written by Marlene Rossman.   See her bio at the end of this post.  Alternatively, read her full bio here: Marlene Rossman Bio. (please click “about” to get her bio).  You may also find her on Facebook by clicking here.

My husband often says that I smell great.  Partly joking, he explains that I have a more pleasing aroma than he does AND that I am very sensitive to aromas and odors in wine/food.  Walking into our home one evening after a nice restaurant dinner, I said, “Honey, I smell gas.”  He immediately said,

“It wasn’t me, it must have been the dog.” I explained that I did not mean that kind of gas, but the gas from the stove.  He did not smell anything, but I found that I had left a burner on very, very low!

So why has fine wine traditionally been the preserve of men? And how has the enjoyment of wine became a man thing? There used to be men-only drinking clubs and tasting events where men gathered to share Parker scores and boast about which wines they had the previous night. In 1978, I joined New York’s Les Amis du Vin and was the only women participant for many years. I was also thoroughly ignored by the all- male group, but that’s another story.

Desmond Morris, who gained fame with his 1967 book The Naked Ape,is a British zoologist who focuses on people. Dr. Morris caused quite a controversy in a 1994 TV documentary when he said, “it has been demonstrated scientifically that women have a better sense of smell than men. Men and women

Photo by StateofIsrael: http://farm9.staticflickr.com/8465/8140902367_a8b170c2aa.jpg

evolved with different strengths and weaknesses, and to believe otherwise is to ignore what biology shows to be true… women, for example, will never dominate championship chess because of the nature of their brain functions,” he says. “Men, on the other hand, rightfully should surrender wine-making to women because of the female’s more acute sense of smell.” It has been hypothesized that women’s highly developed sense of smell is a throwback to when women had to identify their offspring by their smell.

Smell is the most important sense with regard to wine because most of what we call wine ‘flavor’ is its aroma. “Women are better at identifying aromas and can detect them at a lower PPM (parts per million) concentration than men,” according to Dr. Ann Noble, a sensory chemist and retired professor from the University of California, Davis, who invented the “Aroma Wheel.” (Dr. Noble’s wheel is credited with enhancing the public understanding of wine tasting and terminology.) That’s not to say that men aren’t terrific wine tasters and appreciators — of course they are (just ask any man!) Anyone can train themselves to be an educated taster, but wine is ultimately about enjoyment.

Backing up Dr. Noble’s research are a number of studies showing women outperform men in tests on odor sensitivity.  Tim Jacobs, Professor of Physiology at Cardiff University (UK), said: “Some studies have shown smells activate a greater region in the brain in women than men. There is a wealth of scientific data showing women’s superiority at identifying and detecting odors at even very small concentrations.” And two other U.S. studies (one in Pennsylvania and one at Yale) showed that women consistently outperformed men in matters of odor identification and smell.

When it comes to wine tasting, the nose will tell you that there have been impartations from oak barrels if you pick up on vanilla, nuts, bread, cereal, or butterscotch smells. Swirl the wine and sniff – if it smells like a wet dog, or a dank basement, chances are the wine has been spoiled by a bad cork (this only happens to about 3% of all wines) A corked wine does not mean that little pieces of cork are floating in the wine.  It means it is spoiled with TCA or trichloroanisole. Try tasting wine when you have a cold, and see what happens. Probably nothing, as the sense of smell is really the sense of taste.

Some research suggests that women’s greater olfactory sensitivity is linked to the hormone estrogen. And a couple of years ago in the United Kingdom, pregnant women were recruited by Tesco (a supermarket) as wine-tasters after bosses found they had better senses of taste and smell. Store chiefs stumbled across the secret when four pregnant women were working in the 40-strong wine department at its HQ. They could all detect subtle differences between wines. Now, bosses are taking on more moms as tasters to choose the best wines to go on sale. Wine-taster Helen McGinn, 31, who was 6 1⁄2 months’ pregnant, said: “Now we will be better equipped than ever to sniff out the best wines for our customers.”

© Marlene Rossman

According to her bio, “Marlene is the wine columnist for Chef magazine and writes on wine for Andy Dias Blue’s Tasting Panel, Sommelier Journal and International Sommelier magazines.  She was the Editor-in-Chief and columnist for Wine Country International magazine, wine columnist/editor for Orange County Home, New York’s Flatiron magazine and wrote for Beverage Media, and Wine Business Monthly. She was the featured commentator with Stephen Spurrier, in a program on “American Wine” produced by Associated Press Television News.  She is a member of the North American Sommelier Association.”  She is a former sommelier and currently the distinguished instructor of wine at UC-Irvine.

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The Nose Knows: Examining the Differences in Olfactory Perception Between Experts and Novices

Posted on September 24, 2012 by Becca| Leave a comment

Olfactory perception is a key mechanism of wine tasting, as smelling the wine tells one a great many characteristics of a given wine which contribute significantly to the overall wine tasting experience.  Do experts possess greater olfactory perception than novices?  Studies have shown that experts possess greater ability to identify, discriminate, and recognize through olfactory mechanisms than novices, though at the same time showing that olfactory sensitivity is the same between the two groups.  In other words, experts and novices are both able to smell the wine at the same threshold level, however experts are better able to tease apart the complex nuances of the wine than novices.

Photo courtesy of Congaman: http://www.flickr.com/photos/congaman/

Many believe that this ability to recognize and identify more odors in wines by experts is due to education and practice, as a result of repetitive exposure to many different styles of wine.  In fact, studies have shown that repetitive exposure to certain odors can increase olfactory sensitivity, so it could be hypothesized that wine experts have a lower olfactory perception threshold than novices.  Studies have also found that each nostril behaves slightly different from one to the other, leading some to believe that perhaps wine experts have a greater ability to utilize this more sensitive nostril than novices.

Mechanistically, there is a significant difference in sensitivity and perception depending upon exactly how one inhales.  When one inhales normally, only 15% of the air coming in passes over the epithelium in the nasal cavity.  Since odor is perceived when gas is exchanged from the air into the epithelial cells, one should aim to maximize the amount of air passing over these cells for greater gas transfer.

How does one do that?

By sniffing instead of simply inhaling normally, one is significantly increasing the amount of air entering the nasal cavity, thereby significantly increasing the amount of gas exchanged at the air/epithelial boundary.  This ultimately increases the olfactory systems’ ability to detect volatiles and other odors.  Interestingly, the mechanisms of sniffing and normal smelling are activated by different parts of the brain, therefore it can be argued that experts are better able to activate the portion of the brain than novices, which may or may not be a factor of experience.

Exercise: 

Try smelling your wine by simply breathing in normally.  Then, after a brief break, try smelling the wine again by sniffing rapidly for the same length of time as prior.  Do you notice a difference?

The goal of the study presented today aimed to examine the differences in olfactory perception between wine experts and novices, and to determine if there is a difference in perception based on nostril location (left or right) and if there is a difference in this nasal lateralization between experts and novices.

Methods

40 participants were split up into two groups and age-matched: wine experts and wine novices.  Each group had an equal number of males and females, to look for possible gender differences.  Experts were recruited from the French County Institute of Wine and Taste.  The average age of the expert group was 50 years and 3 months (standard deviation of 12 years), and the average age of the novice group was 51 years and 6 months (standard deviation of 11 years).  All participants claimed normal smell sensitivity and no history of chemical exposure that would potentially damage olfactory perception ability.

Wines used in the study were Savagnin 2005 (12.8% alcohol; Benoit: Pupillin, France), Morgon 2007 (12.5% alcohol; Gauthier: Villié-Morgon, France), and Riesling 2007 (12.5%; Lorentz; Bergheim, France).  A dilution series was prepared for each wine using deionized water.  The full series included 20 steps, with step 1 being the most dilute wine (i.e. mostly water with a little wine) and step 20 being the most concentration (i.e. mostly wine with a little water).  50mL of each dilution was placed into black wine glasses (to eliminate the variable of color/vision).  A 50mL glass of deionized water was used as the negative control.

The experiment was divided into three different sessions over the course of three weeks.

  • Session 1: Right nostril testing using Riesling and left nostril testing using Morgon.
  • Session 2: Right nostril testing using Savagnin and left nostril testing using Riesling.
  • Session 3: Right nostril testing using Morgon and left nostril testing using Savagnin.  The third session also included a butanol control sensitivity test.

Each session lasted 1.5 hours with a 15 minute break in between right and left testing.

After each session, participants were asked to score irritant properties and overall enjoyment of the wine on a 0-10 scale.  For irritant properties, 0 was not irritant and 10 was strongly irritant.  For overall enjoyment, 0 was very unpleasant and 10 was very pleasant.

During each session, whichever nostril was not being tested was plugged.  The sessions consisted of force-choice trials: each trial consisted of 2 glasses; one being the negative control (water) and the other being one of the wine dilutions.  Participants were asked to identify by smell which glass contained the wine.  Testing of each wine began at the most dilute concentration, so as to avoid olfactory receptor adaptation.  Each wine concentration was tested 3 times.  Threshold was determined when a participant correctly identified the glass containing wine three times at two consecutive concentration levels.  According to the authors, the probability of guessing correctly was 1 out of 64.

Results

Butanol/Alcohol Detection

  • Butanol detection tests showed there was no significant effect of expertise, gender, or nostril location.

Wine Detection

  • Novices had lower wine detection thresholds than experts.
    • In other words, novices were more sensitive to detecting if a glass contained wine or water than experts.
    • There was no significant effect of gender or nostril location for any of the wines.
    • Novices had a lower detection threshold in the left nostril than experts.
      • There were no significant differences between experts and novices in regards to the detection threshold of the right nostril.
      • The detection threshold for the Savagnin wine was lower than the other two wines for both groups and either nostril.

Irritant Status

  • Novices scored wines as more irritating than did the experts.
  • There was no significant gender or nostril effect, nor was there any significant interaction between group and nostril.

Overall “Acceptability”

  • Novices scored wines as less pleasant than did the experts.
  • There was no significant gender or nostril effect.
  • Experts rated wines as more pleasant than did the novices using the right nostril.
    • There were no significant differences with the left nostril.

What do these results mean?

The results of this study found that novices appear to have greater sensitivity to wine than experts when using the right nostril, though there were no differences between the groups using the left nostril.  In regards to irritation, novices found the wine to be more irritating to the nose than did the experts.  In regards to overall pleasantries, novices found the wine to be less pleasant overall than did the experts, and experts also found the wine even more pleasant using their right nostril.

According to the authors of this study, these results indicate that there is a more important lateralization aspect to wine tasting for novices than there is for experts.  In other words, one side of the nose is more sensitive to novice tasters than experts, who have the ability to sense wine equally in both nostrils.  This result actually turned out to oppose the original hypothesis of this study, which stated that experts would have greater olfactory sensitivity to wine than novices.  The authors suggest that this result may be due to the fact that experts are trained to use both nostrils evenly, whereas novices will detect the wine better on whichever nostril is more sensitive to odor cues.

Other studies have found that olfactory sensitivity may not be a requirement for wine characteristics identification, but that the development of cognitive strategies and attention to detail is what sets the two groups apart.  The current study did not examine this hypothesis, though it could potentially explain the results found therein.

I have no formal training in this area of neuroscience (other than what I’ve read in papers) so I could be light years out of the ballpark, but one idea that I was thinking was that perhaps these results could be explained by experience and time.  Specifically, perhaps the odor of wine is so novel for beginners that they can tell pretty quickly if there is something slightly “off” about the glass that they smell.  Of course, when I say “off”, I don’t mean to say that the wine was bad, but that it is different than the water or other beverages they are used to smelling.

Perhaps with wine experts, the novelty of the general wine odor has since worn and they have been relatively desensitized in that regard.  I would like to see a study that followed an individual from “wine novicehood” to “wine expert”, all the while measuring olfactory sensitivity and odor perception/identification throughout the entire course of development.  This would obviously be a long-term study, but I would think there could be a fair amount of interest to participate in this type of study.

I would also like to see the study repeated with a larger sample size, as at the current size of 20 participants per group, the results may not be generalizable to the greater population as a whole.

What about you all?  How would you interpret the results of this study?  There’s a lot more work to be done, so there could be many different interpretations worthy of further research.  Please tell us what you think by commenting!

Source:  Brand, G., and Brisson, R. 2012. Lateralisation in wine olfactory threshold detection: Comparison between experts and novices. Laterality 17(5): 583-596.

DOI: 10.1080/1357650X.2011.595955

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Determining Wine Preferences by Olfactory Cues and Aromatic Attributes

Posted on September 4, 2012 by Becca| 2 Comments


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Studies on olfactory influences on physiological and neurological responses are not new to science.  It has been found that 80% of flavor sensations during eating in humans are attributed to the olfactory system (i.e. smelling).  It is also well known that in humans, and many other living things with functioning olfactory systems, the sense of smell also acts as a sort of defense mechanism against possible threats. 

http://www.earthlife.net/birds/images/procellariiformes/fulmar.jpg

For example, something very foul smelling may trigger a defensive response, as the smell may indicate danger or poison if ingested.  Evolution has taken advantage of these responses over time, which can be seen in the example of the Fulmar bird.  The Fulmar, which is closely related to the Albatross, is an extremely foul-smelling bird, with even smellier eggs.  This provides the bird with protection against most predators, as the stench will nearly always trigger a danger response in the predator thus leaving the bird and/or eggs unscathed.

I realize I’m getting away from wine quite a bit, however, it is important to note that responses to olfactory cues (i.e. the aroma of that wine you have in your glass) have an underlying evolutionary and physiological origin that is common across many different living systems.  Also, I’m kind of a geek and love sharing my random knowledge of science.

Anyway, I digress….

It is known that olfactory cues from food can alter one’s impression of the food.  Does it smell good to you?  This may trigger a positive response in your brain.  Does it smell like rotten eggs?  This may trigger a warning signal in your brain to not eat it due to possible danger.  Olfactory triggers in the brain are distributed via two major pathways: through the limbic system and the frontal cortex.  The first pathway, through the limbic system, influences the signals made by the hypothalamus and pituitary gland in the brain, and by which olfactory responses can alter mood and behavior without the individual being consciously aware of the change.  The second pathway, through the frontal cortex, is where the conscious decisions occur and are processed with past memories and experiences to help make a determination of the identification of the odor.

http://cheriwalters.com/wp-content/
uploads/2010/03/smelling-wine-300×199.jpg

 

When it comes to wine, the aroma is often assessed to determine wine quality as well as one’s likeability of the wine.   Studies have shown even the hunger level experienced by the person smelling the wine can change how one feels about the aroma and therefore the quality/likeability of the beverage.

Earlier this year, a team of Japanese researchers set out to study the decision-making process for selecting one’s favorite wine by using olfactory cues as well as physiological and neurological markers.  To tell you the truth, I had a hard time with this paper, which I think can be partially blamed on the poor translation.  Several times, what I was reading was not coherent sentences, which forced me to interpret what they were trying to say.  Though the paper in and of itself was not the most properly edited, the topic is one I don’t see come up as often as others and so I wanted to share it with you all today.

Experiment I: Mental Impressions of Wine

For the first part of their experiment, the researchers had subjects smell wines to determine certain characteristics without tasting them.  They recruited 24 students with no wine knowledge, and divided them up into a wine lovers group, and a non-wine lovers group.  Subjects were asked to smell the wines, then answer a questionnaire in which they had to give the wines one of five criteria: “refreshing”, “amiable”, “favorite”, “delicious”, and “poised”.

The research team used analytical hierarchical process (AHP) to analyze the qualitative and quantitative aspects of a decision made on the wines, which according to the authors, has not yet been used in this type of experiment with wine.  AHP is a mathematical technique that is used for multi-criteria decision-making processes.  The decision problem is presented as a structure hierarchy, with the overall goal/decision positioned at the top.  The next level of the hierarchy consists of criteria relevant to this overall goal/decision, while the bottom level are the alternatives being evaluated (the different wines in this example).  This method of analysis, coupled with Principle Components Analysis (PCA) allowed the researchers to determine the subjects’ preferences for each wine.

Experiment II: Neuro-physiological responses to wine aromas

For this experiment, 16 subjects (8 wine lovers and 8 non-wine lovers) were seated in an environmentally-controlled room with the edge of a wine glass placed on a stand 10 centimeters under the nostril for the subjects to sniff.  Subjects were presented with a non-odor solution, an alcoholic solution, and seven different wines.  Solutions and wines were presented to subjects for three minutes at one minute intervals in a random order.  Each subject underwent this experiment twice.  Blood-oxygen levels were also measured, which were done so by using NIRS and EEG measuring caps.

Figure 2 from Koike et al, 2012.

As an aside, I wanted to point out an example of the awful translation/editing done on this paper. Figure 2 shows an image of the experimental set up for Experiment II.  Notice anything odd in this picture?  Wine by the Grass?  Really?  I swear, I did not alter this photograph in any way shape or form.  Here is the icing on the cake:  to describe the image in detail, the text read something like this: “…the edge of a blade of grass kept on a stand was placed under 10 centimeters from the nostril for the subject to sniff the wine aroma”.  I’m sorry, but was there not a single person that could speak any English editing this translation?  You can’t make this stuff up.

Again, I digress….

So what did this study find?

  • This study found that for wine lovers, the criteria of “Favorite” was rated of highest importance in both empty and moderately empty stomach conditions, while the criteria “Poised” was rated lowest. 
  • Not surprising, “Amiable” and “Delicious” were rated higher in empty stomach conditions than in moderately empty stomach conditions.
  • For wine lovers and non-wine lovers, the highest ranked wine was Wine #3 and Wine #5 for both stomach conditions.
  • For wine lovers with the moderately empty stomach condition, Wines #3 and #5 at first significantly increased blood-oxygen levels compared to the non-odor solution in the left and right sides of the subjects’ foreheads, respectively.

o   Wine #3 significantly changes blood-oxygen levels at 2 and 3 minutes compared to the non-odor solution.

o   For non-wine lovers, blood-oxygen levels remained unchanged.

  • For wine lovers with the empty stomach condition, blood-oxygen levels increased in the third minute when Wine #3 was given.

o   For non-wine lovers, blood-oxygen levels remained unchanged.

So, what does this all mean?

The primary result of this study was that both wine lovers and non-wine lovers identified Wine #3 as their “favorite” wine, followed by Wine #5.  The study also found that blood-oxygen levels significantly increased for wine lovers in the third minute of exposure to the wine aroma for Wine #3 compared to non-odor and alcoholic solutions.  However, for the non-wine lovers, this increase in blood-oxygen level was not found, and instead no significant changes were noted.  According to the authors of this study, these results indicate that there is a discrepancy between the psychological expression and the physiological response when smelling wine.

Some studies have found that there is a differing cortical response to the expectation of eating food when the subject was hungry versus full.  This study found that blood-oxygen levels decreased from seconds in empty stomachs to minutes in moderately empty stomachs, possibly indicating that the reward response to the wine aroma was decreased and satisfied.  In other words, smelling the wine on an empty stomach more quickly satiated the subject than smelling the wine on a fuller stomach, since a fuller stomach is already more satisfied.

It is important to note that this blood-oxygen response was only found with wine lovers.  With non-wine lovers, there was no significant change in blood-oxygen levels when presented with wine aromas.  According to the authors, this may indicate that non-wine lovers are satisfied by wine aroma.  In other words, they may not feel any sort of pleasurable emotion when smelling wine.

“The Big Reveal”

Which wines were Wine #3 and Wine #5, the “favorites” identified by the subjects in this study.  Wine #3 turned out to be wine made from Niagara grapes, and Wine #5 was made from Campbell Early grapes; both grapes belonging to Vitis labrusca and having sweet aromas and sweet tastes.  The other wines not ranked as highly by the study subjects were Vitis vinifera and dry.  The authors suggest that the sweet aroma of the two “favorite” wines for subjects in this study could be leaving a psychological positive impression on them. 

What do I think?

Perhaps is preference again due to the evolutionary development of a scent-based defense mechanism.  Maybe a sweet smell triggers a positive response that there is something good to eat present, while an astringent or bitter smell (as one may find in some dry wines) may trigger a more negative response indicating to the individual that poison or danger may be afoot.

http://wine-zag.com/wp-content/
uploads/2011/01/what-wine-do-I-like.jpg

This preference could also be attributed to the study subject population.  The study subjects were students (i.e. young and inexperienced) with no prior wine knowledge other than knowing whether or not they liked wine at all.  Since they have not yet had many wine experiences, these results could be related to the fact that inexperienced wine drinkers tend to gravitate toward sweeter wines than drier wines.

Overall, while the results may be interested from a purely scientific standpoint, they can in no way be extrapolated to any other population.  The study subjects were (assumingly) all Japanese students, the age of which I am assuming is relatively young.  The study subjects are all very inexperienced in wine.  Also, the sample size was extremely small, with only 16 subjects participating in Experiment II.  The results of this study can only therefore be interpreted for this tiny subset of a population and cannot be assumed to be the reality for other populations.  Would the results of this study be the same as if it were repeated on French wine experts?  I highly doubt it (though I could be wrong…).

I am also very disappointed with the quality of editing and the translation of this paper.  Some of the mistakes are cringe-worthy (see Figure 2 above) and should absolutely have not passed through the editors without so much as a “hey, that doesn’t make that much sense…”.  I’d also like to see the study repeated using a larger and more diverse population (including not only wine novices but also wine experts and general wine enthusiasts).  Finally, what about taste?  Though olfactory cues are a huge player in determining preferences, one cannot forget about taste.  Do decisions made solely by olfactory cues change when taste is introduced?  

I’m certain there are many other things that could be improved in this study, but I’ll leave that up to you all to suggest in your comments below.  What do you think about this topic and this research?  Please feel free to leave your comments below!

References:

Koike, T., Kamimura, H., Shimada, K., Yamada, H., and Kaneki, N. 2012. Determination of Favorite Wine from Comparison of Wine Aroma Attributes. Kansei Engineering International Journal 11(1): 41-50.

http://www.fivesenses.com/Documents/Library/5%20%20Future%20Olfactory%20Research.pdf Accessed 09/03/2012

http://listverse.com/2010/12/23/10-birds-with-truly-odd-defenses/  Accessed 09/03/2012
I am not a health professional, nor do I pretend to be. Please consult your doctor before altering your alcohol consumption habits. Do not consume alcohol if you are under the age of 21. Do not drink and drive. Enjoy responsibly!

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