When it comes to the science behind taste, there's more than meets the eye...well, taste buds. When you lick a sweet and fruity popsicle on a hot, sunny day, how your brain determines the flavor of that ice pop involves more than just the tongue. The mouth, nose and brain all work together to help you arrive at the conclusion that the popsicle is delicious and refreshing. Let's get into the specifics of the science behind taste.The Flavor Sensation Trinity
Flavors are a mix of three sensations: taste, smell and chemosthesis. Let's first discuss taste. Think back to your elementary science class. Remember when you first learned about the taste sensation areas of your tongue? Most likely you remember four areas: salt, sweet, sour and bitter. Scientific studies have determined that there are two additional senses, which are umami (glutamate or neurotransmitter) and calcium. Furthermore, studies have shown that when there is a desire for something salty, for example, that the craving is actually a want for nutrients. In this case, the urge would be for sodium.
The next sensation is smell. If you have had a cold, then you know how it feels to temporarily lose the sense of taste. This is because there are at least 300 receptors in the olfactory organs, or organs that allow you to experience the sense of smell and determine aromas.
The final sensation is chemosthesis, or mouth feel. Let's go back to that popsicle example. We already determined it was sweet and fruity. Chemosthesis determines that the popsicle is cold and causes a slight numbing sensation on the tongue and roof of the mouth requiring you to take intermittent popsicle pauses. You'll also be able to notice that the popsicle is bumpy due to seeds. Now that you know how the sensations of taste, smell and chemosthesis register flavor, let's discuss the science behind your taste buds.
Taste Buds and the Brain
Taste buds are comprised of three types of cells. Type 1 cells make up 50% of the taste bud and are predominately designated for salty taste. Type 2 cells account for 25% and are comprised of receptor cells responsible for sweet, umami, and bitter taste. Type 3 cells account for the remaining percentage of the taste bud and are designated for sour taste. The receptors in the taste bud cells send signals to the brain to determine taste qualities. This process allows us to use to the sense of taste to determine flavor in what we consume.
As earlier discussed, the sense of smell plays a role in taste. This is because the aromatic components inform us about the flavor. Aromas allow us to differentiate between wintergreen versus spearmint or mango versus peach. If we go back to our popsicle example, we noted that it was sweet, cold, fruity, and had seeds. The receptors in the tongue would help differentiate the flavor by comparing the level of acidity versus the level of sweetness. The aroma of the popsicle would send a message to the brain to determine the flavor by associating the smell with a past memory and emotion. Which flavor did your brain, nose, and taste buds decide? Did they arrive at strawberry? Or raspberry?
When it comes to the sense of taste, there is more involved than just the taste buds on the tongue. The cells in the taste buds have receptors that send messages to the brain. The other factor of the experience is the nose and its hundreds of receptors that also send messages to the brain to determine flavor. What do you think about the science behind taste? Did you learn something new?
Source: "Taste, Aroma and the Brain", Perfumer & Flavorist. Volume. 34 April 2009