A major question rested heavily on the minds of certain people in the scientific community: can you taste carbonation?
One way to answer that question would be to consume a carbonated beverage in an environment which prevents the bubbles from bursting.
Ryba added that the taste of carbonation is quite deceptive. “When people drink soft drinks, they think that they are detecting the bubbles bursting on their tongue,” he said. “But if you drink a carbonated drink in a pressure chamber, which prevents the bubbles from bursting, it turns out the sensation is actually the same. What people taste when they detect the fizz and tingle on their tongue is a combination of the activation of the taste receptor and the somatosensory cells. That’s what gives carbonation its characteristic sensation.”
Perhaps some of you are interested in a little bit of history. What on Earth prompted people to indulge in fizzy beverages? Hint: it predates Coca-Cola.
In 1767, chemist Joseph Priestley stood in his laboratory one day with an idea to help English mariners stay healthy on long ocean voyages. He infused water with carbon dioxide to create an effervescent liquid that mimicked the finest mineral waters consumed at European health spas. Priestley’s man-made tonic, which he urged his benefactors to test aboard His Majesty’s ships, never prevented a scurvy outbreak. But, as the decades passed, his carbonated water became popular in cities and towns for its enjoyable taste and later as the main ingredient of sodas, sparkling wines, and all variety of carbonated drinks.
Other research has been conducted on our sense of taste for sweet, sour, salty, bitter and savory. Jayaram Chandrashekar, Ph.D., David Yarmolinsky Ph.D. and Lars von Buchholtz, Ph.D. teamed up to find the source responsible for detecting the taste of carbonation.
Here is the science of what they found:
Carbonic anhydrase 4, or CA-IV, is one of a family of enzymes that catalyzes the conversion carbon dioxide to carbonic acid, which rapidly ionizes to release a proton (acid ion) and a bicarbonate ion (weak base). By so doing, carbonic anhydrases help to provide cells and tissues with a buffer that helps prevent excessive changes in pH, a measure of acidity.
The scientists found that if they eliminated CA-IV from the sour-sensing cells or inhibited the enzyme’s activity, they severely reduced a mouse’s sense of taste for carbon dioxide. Thus CA-IV activity provides the primary signal detected by the taste system. As CA-IV is expressed on the surface of sour cells, Chandrashekar and co-workers concluded that the enzyme is ideally poised to generate an acid stimulus for detection by these cells when presented with carbon dioxide.
They worked with mice, which have a sense of taste similar to human. The question remains, why do mammals taste carbonation at all?
The scientists are still not sure if carbon dioxide detection itself serves an important role or is just a consequence of the presence of CA-IV on the surface of the sour cells, where it may be located to help maintain the pH balance in taste buds. As Ryba says, “That question remains very much open and is a good one to pursue in the future.”
Thanks to their hard work you can rest assured it is not merely your imagination.