How Miracle Berries Alter Your Taste Buds (feat. Physics Girl, Eons, Two Cents, Space Time and more)

These lemons, they’re completely normal, but
we did alter the taste buds of these PBS hosts- Lemon.
-just a little bit. All right. I love lemons, so let’s see how this goes. Today on Reactions, we’re investigating the
sweet and sour secrets of the miracle berry. Well, if I knew it was going to taste sweet. Whoa. Whoa. Oh, my God. It tastes like it is covered in sugar. It’s coated in sugar. It tastes like lemonade. Like straight up lemonade. That’s so intensely sweet. Tastes like a super sweet kumquat. You’ve probably seen videos like this-
Today I’m going to be eating this miracle berry and then eating this extremely, extremely
spicy noodle. -in which people eat increasingly ridiculous
things to see if miracle berries change their flavor, and that got us wondering, do miracle
berries have limits? As it turns out, the answer is yes. Yes, they do. That tastes pretty normal. And we think we might know why. I am going to eat this whole Oreo, though. First things first. This is your tongue. This is a taste bud. These are gustatory cells. Gustatory cells, also known as a taste receptor
cells. Every taste bud contains taste receptor cells
for all the basic tastes; sweet, sour, bitter, salty and umami. So that tongue map that you learned about
in middle school, in which every taste is limited to a specific region of your tongue,
that’s wrong. Each of these gustatory cells has proteins
that detect its specific taste. This is the protein that lets you taste sweet. When sugar or other sweet things bind to the
outside part, the protein changes shape. Yes, on the inside of the cell too, and that
starts a signal cascade, which ends by telling your brain, “Dude, sweet.” Miracle berries hijack this process. Scientists think it works like this. First you have to eat a miracle berry or miracle
berry pill, both of which contain a protein called miraculin. We gave your favorite PBS hosts miracle berry
pills. Can I go for it? Go for it. Okay. As you let the pill dissolve in your mouth,
miraculin binds to the sweet taste receptor and then nothing happens because miraculin
by itself doesn’t change the shape of the receptor protein, so you taste basically nothing. But when you eat something sour like this
lemon- A lemon!
-the acid in the lemon interacts with the sweet receptor protein and the miraculin,
causing the protein to change shape, just like when sugar binds, so you taste sweet. It’s like a lemon gumdrop, very sugary. Humans have known that miracle berries plus
sour things equal sweet for hundreds of years, but in 1969 a few scientists tried to get
a more specific handle on exactly which sour things tasted sweetest after eating miracle
berries, so they had people taste a bunch of different acids; lactic, which is in sour
milk, oxalic, which is in rhubarb, acetic, which is what makes vinegar sour, but also
formic acid, which is in bee and ant venom, and hydrochloric acid, which is the same acid
that’s in your stomach. Just a little safety note from us here at
ACS, please do not put hydrochloric acid in your mouth. 1969 was a different time, I guess. Anyway, they discovered that hydrochloric
acid, the strongest acid they tested, didn’t taste nearly as sweet as acetic acid. Weak acids like the citric acid found in lemons
tend to work better than strong acids like hydrochloric, which is good for the health
of your mouth. More recent research has revealed that miraculin
somewhat blocks sugars from binding to the sweet receptor, which means that sweet things
that have no acid in them taste kind of flat. It’s like less-sweet Oreo. It’s like the cream just disappeared and all
you have is cookie. As far as we know, miraculin only binds to
the sweet receptor, and because you have taste receptor proteins for a wide variety of tastes,
most other flavors remain the same. The food might just taste a little sweeter. It still tastes like mustard but it’s sweeter. It’s like a honey mustard. The spiciness of capsaicin is still there,
for example- So, definitely still tastes spicy. You still get the heat. It’s still kind of hot. It’s like a sweet chili sauce. Mmmm.
-and the tomatoiness of a tomato. Whoa. They taste like they’re candied. Gross. Oh, my God, I can’t believe I’m doing this. So unless you actually like the taste of the
food to begin with, don’t expect an actual miracle. Ugh. Still tomato. Still gross. Sorry. If you want to learn exactly why 15 packets
of red hot spiciness is so spicy, we’ve got you covered. Happy eating, and we’ll see you next week.