Taste Lab
USD Internet Psychology Laboratory


According to Linda Bartoshuk, a noted researcher in the domain of sensory processes, there are large individual differences in the number of taste buds.  Once more, this variation is taste bud density is correlated with self-reported taste magnitudes and food preferences.  For example, SUPERTASTERS (those with the largest number of taste buds), tend to report stronger sensory experiences associated with sweet and bitter foods and tend to avoid spicy dishes and strong alcoholic beverages (see Table 1 for additional details).

 
  SuperTaster Normal Taster  HypoTaster 
Papillae Density1 greater than 1/mm2 0.3-1.0/mm2 less than 0.3/mm2
Sex Distribution 35% women; 15% men    
Bitterness
(Coffee)
Avoids
Adds lots of cream and sugar to coffee
Tolerates
Adds touch of cream and/or sugar to coffee
Indifferent/Likes
Prefers strong, dark coffee and drinks it black
Saltiness Loves Likes Indifferent
Spicy/Hot Avoids Likes Seeks-Out
Acquired Taste for
Alcoholic Spirits
Unlikely
Alcohol "burns" and tastes like gasoline
Somewhat Likely Most Likely
Alcohol tastes somewhat sweet
Openness to
Culinary Experiences
Not Very
"Picky" eater
Moderate Very
Seeks-out bold/intense flavors

Table 1.
Characteristics of Supertasters versus non-Supertasters

 

 

Although it is difficult to count the exact number of taste buds on a person's tongue, we can obtain a "proxy" measure which is highly correlated with taste bud count.  That is: the taste buds themselves are imbedded in the walls of relatively large structures known as fungiform papillae.  These structures are large enough to be counted under low magnification.  Thus, the number of fungiform papillae counted in an area of the tongue can serve as a means for documenting individual differences in taste buds density.

In this lab, the TA will assist you by (1) Applying food coloring to the front of your tongue, and (2) Capturing a magnified photograph of the "stained" region of your tongue.  The TA will provide you with a digital copy of this picture of your tongue.  You will be required to carefully count the number of fungiform papillae in the 40 mm2 area of your tongue that was sampled by the photograph.  The blue "stain" helps to make the large diameter fungiform papillae more discriminable from the smaller, and more numerous, filiform papillae which surround them (See page 534 of your textbook for a schematic representation of the anatomy of the human tongue).

 

 

 

Figure 1.
Fungiform Papillae Revealed via Blue Food Coloring "Stain" of the Tongue

 

Taste Bud Photographic Survey - 100 mm2 (Subject 209) Papillae Count (N=42; Density=0.42/mm2; Normal Taster)

Figure 2.
Fungiform Papillae Count under Low Magnification

 

Finally, whether or not one is a supertaster/normal taster/hypotaster appears to be under the genetic control of a "dominant" allele that follows Mendelian rules of inheritance. Inherit the dominant allele from BOTH parents and you become a supertaster (roughly 25% of population).  Inherit the recessive allele from BOTH parents and you become a hypotaster (25% of population).  Inherit the dominant allele from only one parent and you become a normal taster (50% of population).  In an interesting twist, possessing a copy of this same dominant allele determines whether or not you can taste a special class of chemicals (e.g., phenylthiocarbamide or PTC).  If one places a small paper strip laced with PTC in one's mouth, the supertaster will experience an intense, utterly vile bitter taste sensation while the hypotaster (who received no copies of the dominant allele) will exhibit complete taste "blindness" for PTC.  Those with a single copy of the dominant allele (normal tasters) will experience a taste sensation somewhere in the middle of these two extremes.  Your TA will provide you with a PTC taste strip so you can perform this assessment yourself.

Step-by-Step Procedure
Taste Bud Density and Taste Sensitivity Lab

Step 1.  Rate the magnitude of your experience for several categories of taste stimuli.
(Cups containing various taste stimuli will be provided by the TA for today's lab)

A.  Grapefruit Juice (Bitterness)
     Rate this taste from 0 (not bitter at all) to 10 (among most bitter tastes I have experienced)
        0 --- 1 --- 2 --- 3 --- 4 --- 5 --- 6 --- 7 --- 8 --- 9 --- 10

B.  Lemon Juice (Sour)
     Rate this taste from 0 (not sour at all) to 10 (among most sour tastes I have experienced)
        0 --- 1 --- 2 --- 3 --- 4 --- 5 --- 6 --- 7 --- 8 --- 9 --- 10

C.  Apple Juice (Sweetness)
     Rate this taste from 0 (not sweet at all) to 10 (among sweetest tastes I have experienced)
        0 --- 1 --- 2 --- 3 --- 4 --- 5 --- 6 --- 7 --- 8 --- 9 --- 10

D.  Soy Sauce (Saltiness)
     Rate this taste from 0 (not salty at all) to 10 (among most salty tastes I have experienced)
        0 --- 1 --- 2 --- 3 --- 4 --- 5 --- 6 --- 7 --- 8 --- 9 --- 10

E.  Life Saver Mint (General Flavor Intensity Measure)
     Rate this taste from 0 (not strong at all) to 10 (among strongest tastes I have experienced)
         0 --- 1 --- 2 --- 3 --- 4 --- 5 --- 6 --- 7 --- 8 --- 9 --- 10

We won't be tasting any stimuli from the UMAMI category today, but think about the last time that you really enjoyed a juicy steak, a greasy pizza or a grilled cheese sandwich.  These uniquely savory/satisfying taste experiences represent UMAMI (Just think high calorie, fatty junk food).

Step 2.  Taste the PTC taste strip.
Rate your experience (Circle one):    Bland Taste(0)       Somewhat Bitter(1)       Very Bitter (2)

Step 3.  Count the number of taste buds within the square on the magnified picture of your tongue
Number of fungiform papillae ___________
Fungiform papillae density ______________ (per mm2) (i.e., raw count divided by 40)

Step 4.  Report your data from Steps 1-3 above to your TA.
     Your TA will compile all the results from the class and see how the subjective taste data correlates with taste bud density and PTC taste status.

 

 

Lab Report

1.  Based on the information in Table 1, what kind of a taster are you (Super Taster, Normal Taster or HypoTaster)? Explain your decision.

 

 

 

 

2.  Is your computed papillae density consistent with the type of taster you think you are?

 

 

 

3.  Using the data collected from the entire class, find and report the correlation between fungiform papillae density and the detection of PTC.  Describe how these two variables are related. Explain why?

 

 

 

 

 

4.  Using the class data, find the correlation between the type of taster and the papillae count.  Do these findings match your expectations?  Why or why not?

 

 

 

 

5.  What is the relationship between the magnitude estimation data for Bitter/Salty/Sweet/Salty/Minty and the papillae count?  Interpret these findings.
 


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