Were You Born a Picky Eater? You & Your Papillae !

Does broccoli taste bitter? Is eating hot peppers intensely painful? Is icing on a cake too sweet? Scientific evidence suggests a strong genetic basis for food preferences; it's not just something that you learned at home...... and it's all on the tip of the tongue.

Watch:

*Take the Tour of the Tongue - watch the Taste Primer and The Five Tastes.

Humans are born with a genetically determined number of taste buds. The mushroom-shaped structures on the tip of your tongue are called fungiform papillae. Recent studies have found an average of 1-3 taste buds per papilla ( However, there was considerable variation in the occurrence of taste buds; the number of taste buds in a single papilla varied from 0 to 27. No dependence upon sex or age could be demonstrated for this variation (( The number of fungiform papillae ranged from 171 to 253 (mean 195) in one study and 22-74 papillae/cm2 in another ( These were located predominantly at the tip.

Linda Bartoshuk, professor of surgery and taste researcher at Yale University School of Medicine, divides people into three groups: supertasters (25% of the population), medium tasters (50%) and nontasters (25%). According to her research, supertasters have many more taste buds per square centimeter, which enables them to experience the taste, temperature and texture of foods more intensely than nontasters.

Are eating behaviors learned? Watch - Obesity Begins at Home

Pre-lab Questions: (use the following site to supplement your answers as needed:

1. What is the relationship between papillae, taste buds, taste cells, microvilli, receptors?

2. What is the evolutionary significance of being able to detect each of the 5 different tastes?

sweet -

sour -

bitter -

umami -

salty -

3. Use the following terms to describe how you actually taste sweet/bitter/umami and sour/salty: receptor, channel, signal transduction

ACTIVITY: WHAT KIND OF TASTER ARE YOU?

Taste each of the food items listed below and rate them with a number from 1-100 according to the accompanying chart. (rate qualitatively with the descriptive term first by marking somewhere along the line, and then select the number)

Food / Rating (1-100)
whole milk (fatty)
sour candy / lemon juice (sour)
icing (sweet)
black coffee or grapefruit juice (bitter)
soy sauce (salty)
mint Lifesaver (general taste intensity)

Next try a simplified adaptation of Bartoshuk's taster test using blue food coloring and a reinforcement ring for a three-hole binder. While we can't count the number of taste buds on your tongue, we can approximate their density by counting the number of fungiform papillae located on your tongue.

1. Measure the diameter of the inner portion of the reinforcement.

diameter = ______mmarea = (diameter/2)2 X 3.14 = ______mm2

2. Use a cotton swab to wipe some blue food coloring on the tip of your tongue. Place the reinforcement somewhere on the front 2 cm of your tongue. We will be using it to "calibrate" the measurements. Use a camera to take a picture of your tongue OR use a hand lens to count all of the larger fungiform papillae (not the smaller filliform papillae) in the reinforcement.

How many papillae did you have inside of the reinforcement? ______

Repeat for 2 other areas in the front 2 cm of your tongue.

Area / #papillae / #papillae/mm2
1
2
3
AVG
Range

Calculate the number of papillae per mm2 (#papillae/area of inside of reinforcement) and put the result in the data table above.

3. Collect class data in the table below. Calculate the average, range and standard deviation for each type of taste.

4. Make scatter plot graphs of average # of papillae/mm2 vs. each taste rating (# papillae vs. milk; # papillae vs. sour, etc.)

5. Is there a relationship between # of papillae and how intensely you perceive tastes - are you a "supertaster"? Make a linear regression line for each scatter plot and look for the correlation value. Perfect correlations are +1 and -1. Correlations values below -.5 and above .5 are usually significant. Use the information at: to help you with your answer/graph caption.

Class Data:

Person # / avg # papillae / mm2 / score on fatty test / score on sour test / score on sweet test / score on bitter test / score on salty test / score on general taste
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
AVG
RANGE
STD DEV

Need help with statistics?

QUESTIONS:

First, watch the Nova ScienceNow episode on Picky Eaters at:

Also watch – Blocking Bitter Taste:

1. Based on the data that you collected, how would you classify yourself as a taster? Where did you typically fall in the range of class data for each taste? Does the table at accurately describe you?

2. What might be some evolutionary advantages or disadvantages to being a particular type of taster?

3. What other factors might explain a person's food preferences?

4. How could scientists and the food industry use this information to help improve human nutrition and healthier eating?

5. Read the 2 brief articles below. Also read the article or listen to the podcast at:

How is that different people can smell, taste and see the world differently? Think genes, mutations/variations, protein structure!

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