Why Did We Evolve to Taste Sour Flavors?

Why Did We Evolve to Taste Sour Flavors?

December 15, 2019 100 By William Morgan


When you eat something sour, your tongue is
actually tasting protons! YES I’m positive! Hang with me though, cuz, it gets weirder. First, to understand all this sour-y strangeness,
we have to understand how the tongue tastes things to begin with, and just saying ‘taste
buds’ ain’t gonna cut it. Those little bumps on your tongue are called
papillae, and located in the crevices of each papilla are your taste buds. Each of those taste buds contains clusters
of sensory cells, and when a compound from your food comes in contact with them, it causes
a chain reaction in nearby nerve cells, bringing the message all the way back to the brain. There, the message combines with the messages
from your nose to create what we experience as taste. But with sour tastes, things happen a little
differently. Foods that are “sour” are registered that
way because they’re acidic. Citrus fruit has citric acid, vinegar has
acetic acid, and most sour candies contain citric or malic acid. When you eat these foods, the acids dissolve
in your saliva and their hydrogen ions split off– these ions then make their way down
to your little sensory cells! But instead of just activating a receptor
at the edge of the cell, like what happens with sweet and savory flavors, the hydrogen
ions actually enter the cell via specialized ion channels. Upon entry they set off that chain reaction
that tells your brain it’s time to pucker up. And TBH, this might be the coolest thing we
taste. We’re tasting IONS. Them’s Protons! I mean, our sweet receptors evolved to recognize
simple carbohydrates like boring old glucose, and savory (or umami) receptors and bitter
receptors both recognize different groups of proteins. Which is kind of cool, i guess. But tasting protons? That’s awesome. But, as far we know, tasting electrons just didn’t serve any evolutionary purpose. The thing is, sour doesn’t really have an
evolutionary purpose anyway. Or rather, we haven’t figured out what singe purpose it would be yet. The other tastes make sense– things that
taste sweet give us energy, salty things give us sodium to maintain a whole host of body
function, umami things are rich in protein, and bitter tastes warn us of potential toxicity.But
sour?? It’s kind of a mixed bag. Some sour things- like Vitamin C- are necessary
for survival. But others — like spoiled food, could make
us sick. In the end, not only are sour candies the
best but now you can pucker up and then tell all your friends about how awesome these sour
proton kids taste. Then they can shush you at the movies. Shush! Movies! Don’t forget to subscribe to Seeker for
more videos! And if you’ve got a sweet spot for food
science – I just did a deep dive over on Seeker Plus into the science of meat, watch it here. Fun fact: I eat sour candy at every movie. Every time. I love sour stuff I can’t get enough of it. Thanks for watching.