Have you ever seen a chef taste a newly created sauce? First, she might smell it, because a lot of taste is actually smell. Then, she might use a spoon and make sure she tastes the sauce in several spots of in her mouth. Your tongue is covered with about 10,000 taste buds, which detect five different kinds of tastes: salty, bitter, sweet, sour and umami. Umami, discovered by the Japanese, means “savory” and is a characteristic flavor of soy sauce. How do you think these different types of taste receptors are spread around your tongue? Do you like really getting to know your food? Do you have a group of friends who will taste some yummy flavors, and some yucky ones, for the sake of science? If so, we have a fun experiment for you to try.
Problem:Are some parts of the tongue better at detecting certain tastes than others?
- Eight to ten volunteers
- Lemon juice
- Soy sauce
- Strong black coffee
- Five clean cups
- Tape or labels
- Permanent marker
- 2 Spoons
- Cup of water for each volunteer
- Portable garbage container
- First, recruit your volunteers.Make sure they understand what type of experiment you are doing and that they don't have any food allergies.
- Label the cups "Salty," "Sweet," "Sour," "Umami," and "Bitter."
- Next, make a salty solution to test.Measure a ¼ cup of water into a clean cup labeled "Salty"and add two tablespoons of salt.Stir until the salt is dissolved into the water.
- Next, make the sugary solution to test.Measure a ¼ cup of water into a clean cup labeled "Sweet," and add a two tablespoons of sugar to it.Stir until the salt is dissolved into the water.
- Pour 2 tablespoons of lemon juice in the ‘Sour’ cup,2 tablespoons of soy sauce in the ‘Umami’ cup., and2 tablespoons of cold, old coffee in the ‘Bitter’ cup.
- Show a diagram of the taste areas of the tongue to your volunteers.
- Explain that they will toucha cotton swab soaked in the salty solution at each of the four spots on their tongue. For regions B and C, your volunteers need onlytouch on one side or the other. Tell them that they willdetermine where they noticed the salty taste the most.
- Soak a cotton swab for each of your volunteers in the "Salty" solution.
- Hand over the swab, and have the volunteer touch his tonguein the four places. Ask your volunteers to rank where on the tongue the salty taste was most noticeable. Don't let the volunteers hear what the others say during their tests.Why?
- Collect the used cotton swabs before your volunteers set them on the table. Start filling out the following table, using hash marks.
- Have your volunteers take a drink of water and rest for a minute or so.
- Repeat the procedure with each of your other solutions.
The main thing you are likely to notice is how different the results between volunteers will be.Individuals will learn a lot about where they taste the difference substances the most, but what is true for one person is not true for everybody.A few people might not be able to rank the taste strength at all.
Recent studies of the tongue’s taste receptors have shown that receptors for all types of taste are spread throughout the tongue (and cheeks and roof of mouth), so you were unlikely to find that one spot of tongue was much better at detecting one type of taste than another.Sometimes not getting a definitive result teaches us as much asgetting a definite result.