No Taste Without Saliva: Experiment and Explanation

Here's a quick and easy science experiment for you to try today. Can you taste food without saliva?

Materials

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• dry food, such as cookies, crackers or pretzels
• paper towels
• water

Try the Experiment

1. Dry your tongue! Lint-free paper towels are a good choice.
2. Place a sample of dry food on your tongue. You'll get the best results if you have multiple foods available and you close your eyes and have a friend feed you the food. This is because some of what you taste is psychological. It's like when you pick up a can expecting cola and it's tea... the taste is "off" because you already have an expectation. Try to avoid bias in your results by removing visual cues.
3. What did you taste? Did you taste anything? Take a sip of water and try again, letting all that saliva-goodness work its magic.
4. Lather, rinse, repeat with other types of food.

How It Works

Chemoreceptors in the taste buds of your tongue require a liquid medium in order for the flavors to bind into the receptor molecules. If you don't have liquid, you won't see results. Now, technically you can use water for this purpose rather than saliva. However, saliva contains amylase, an enzyme that acts on sugars and other carbohydrates, so without saliva, sweet and starchy foods may taste different from what you expect.

You have separate receptors for different tastes, such as sweet, salty, sour and bitter. The receptors are located all over your tongue, though you may see increased sensitivity to certain tastes in certain areas. The sweet-detecting receptors are grouped near the tip of your tongue, with the salt-detecting taste buds beyond them, the sour-tasting receptors along the sides of your tongue and the bitter buds near the back of the tongue. If you like, experiment with flavors depending on where you place the food on your tongue. Your sense of smell is closely tied to your sense of taste, too. You also need moisture to smell molecules. This is why dry foods were chosen for this experiment. You can smell/taste a strawberry, for example, before it even touches your tongue!