Can You Taste With a Plugged Nose? How Smell Affects TasteFeatured science projectScience project video

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Safety concerns:
Take into consideration food allergies and ask your "tasters" about any food allergies they have. Also, be considerate that some people do not like to be blindfolded. If a volunteer does not want to be blind folded, have them close their eyes. Be sure to use a clean spoon for each sample being tasted.

Abstract

Have you ever had a cold and your nose was so stuffy that you food just didn't taste the same? Your sense of smell and your sense of taste are closely related. In this science project, you'll investigate how the two senses work together to help you taste different flavors. Three other volunteer "tasters" will sample various baby foods, fruits, vegetables and meat, while blind folded with their nose plugged. The taster will be asked if they can tell what type of baby food they tasted. They will then see if they can identify the food without their nose plugged, but still blindfolded.

Hypothesis

If someone's nose is plugged and cannot smell, then they cannot detect food flavors as well as when they are only blindfolded.

Objective

In this science project, you will find out how removing the ability to smell (by plugging your nose) limits how well the tongue can determine the taste food. The sense of sight will also not be used so the "tasters" cannot see what they are eating either.

Background

The flavor of food is a sensory experience that is a combination of taste and smell. We use both our sense of taste and our sense of smell when we eat food. Both the tongue and the nose detect the chemicals in food, which then tells our brain the flavor of what we are eating.

There are about 10,000 tiny receptors covering the tongue. These are called taste buds. Taste buds detect five distinct types of tastes each on a different area of the tongue: salty, bitter, sweet, sour and umami (savory).

taste bud receptors

Far back inside nose in what's called the nasal cavity resides a small patch of nerves called the olfactory tract. The chemicals given off by foods are picked up by the nerves in the olfactory tract, which then tell the brain what food is being smelled. These nerves also assist in detecting taste.

olfactory bud and nerve - our sense of smell

The nose and the tongue work best together when it comes to enjoying the flavors of food. When the olfactory tract inside the nose cannot assist in the process of detecting the chemicals in food, the taste buds on the tongue are less able to effectively distinguish tastes. The result is that you cannot completely tell the flavor of a food. With the nose plugged and the eyes closed, one cannot tell the difference between an apple and a pear as both have a very similar texture. One would be more likely to distinguish between a pretzel and an apple though as these foods have different, distinct textures. Comparing foods with similar textures with the eyes closed and nose plugged best demonstrates how smell affects taste.

Scientific Terms

taste buds, salty, sweet, sour, bitter, umami (savory), olfactory tract

Materials

  • a bandana
  • One jar of each type of baby food: peas, carrots, peaches, pears, turkey and gravy (or other meat and gravy)
  • 5+ spoons
  • at least 3 volunteer "tasters"
  • nose plugs (optional)
  • paper and pencil

Procedure

1. Ask your volunteer "taster" if they have any food allergies and if they mind being blindfolded. Modify as necessary.

2. Keep all baby food samples hidden from view of the tasters. Loosen the lids prior to beginning, but do not remove the lids until the volunteer has their nose plugged.

3. Blind fold the volunteer with the bandana (or ask them to keep their eyes shut) and place nose plugs on their nose (or have them plug their nose by pinching it with their fingers). Tell the volunteer they need to remain blind folded with their nose plugged while they taste five (5) different types of baby food.

4. With a clean spoon, give the volunteer (blindfolded and with nose plugged) about a half a spoonful of baby food. Ask them what they think it is. Record the response as a yes or no in the table below on the paper:

peas

carrots

peaches

pears

turkey

Taster #1 blindfolded and nose plugged

Taster #1

only blindfolded

Taster #2

blindfolded and nose plugged

Taster #2

only blindfolded

Taster #3

blindfolded and nose plugged

Taster #3

only blindfolded

5. Repeat with all five (5) types of baby food for all three (3) "tasters" with blindfold and nose plugged. Do not record the responses of anyone who sees or knows what kind of baby food there is. Anyone who knows may be able to determine the flavor because of the texture.

6. Remove the nose plug and repeat step #3-#5 with each baby food type while the taster is still blindfolded.

7. Evaluate which types of baby food was the easiest and which type was the most difficult for the tasters to identify.

Discussion

1. Why is it easier for the tasters to tell what kind of food they were sampling when only blindfolded?

2. Why do you think some foods are harder to tell when blindfolded and with the nose plugged?

Questions & Answers

Can we detect the taste food at all with our nose plugged?

Most people cannot tell what they're eating without their sense of smell when all the foods have similar textures. That is because flavor is a sensory experience of both the nose and the tongue combined. Different people will be able to tell different foods without their sense of smell if they recognize the texture even when pureed as a baby food.

If so, which foods were easiest to tell? Which foods were the hardest to tell?

Answers will vary depending on volunteers' age and ethnicity.

Why should the person conducting the experiment not include their results in the data collected?

The person conducting the experiment knows which types of food there are and can more easily figure out what they are tasting just by the texture of the food.

Make it Your Own

In this experiment, you used baby food with blind folded, nose plugged volunteer tasters. You could also try:

  • jelly beans of various flavors like lemon, strawberry, orange, grape, etc.
  • all citrus fruits cut into small pieces (oranges, lemons, grapefruit, etc.)
  • with a food processor make your own "baby food" that is all similar consistency and chose one food from each of the 5 taste types

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