Book 1, Question 128 · Video
Why Do Apples Turn Brown? A Chemical Suntan!
Cut an apple and it starts to brown. The cut lets oxygen in, and an enzyme in the apple cells meets natural compounds and browns them. Acids in lemon juice slow the enzyme and help
Read the full answer →What Crafty Clover says in this video
Intro
Hi! I'm Crafty Clover! Let's discover something amazing. Why do apples turn brown?
The Big Idea
When you cut an apple, you start a tiny chemistry experiment! Three things meet: oxygen from the air, a helper called an enzyme, and natural compounds inside the apple. Together, they make brown.
Oxygen In
Step one: a cut lets oxygen in. Apple skin works like a raincoat, keeping air out. But when you cut or bite an apple, you break open lots of tiny cells, and oxygen from the air slips right in.
Enzyme Browns
Step two: an enzyme browns the apple compounds. Inside the cells, an enzyme meets natural compounds called polyphenols. Normally they're kept apart, but cutting mixes them up. The enzyme helps oxygen join the compounds, turning them brown.
Lemon Juice
Step three: lemon juice slows the change. Acids in lemon juice slow the enzyme down, and its vitamin C grabs the oxygen first. So the apple stays pale and fresh-looking for longer.
A Closer Look
Let's take a closer look at a cut apple! Cutting breaks open the apple's cells. Inside, the enzyme meets the apple compounds. Oxygen joins in, and brown color forms. That brown is a pigment called melanin, the same kind that gives skin a suntan!
Quick Facts
Quick facts! Browning is like a chemical suntan, not rot! A brown apple is still safe to eat. It's just not as pretty. Bananas, pears, and potatoes turn brown for the same reason. Keeping cut apples cold, or dipped in water, also slows browning.
Think Like a Scientist
Now, think like a scientist! With a grown-up's help, cut two apple slices. Leave one slice plain. Brush lemon juice on the other. Wait fifteen minutes, then check. Which one is browner? Try other ideas too, like plain water or salty water!
Outro
So apples turn brown when oxygen, an enzyme, and apple compounds team up, and a squeeze of lemon slows them down! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!