Student Submitted - Fruit browning

Today's post was submitted by Aleeyah B, one of my AP chemistry students. As a sub assignment after the AP chemistry exam, I had students submit two posts for this blog. I'll be posting them over the next few weeks.

You know when you cut a piece of fruit and it turns brown after a while, or a banana peel? This article explains how to stop this from happening. This is actually because of a chemical reaction called oxidation. Fruits contain an enzyme called polyphenol oxidase, also called PPO. When the fruit is completely intact, everything stays inside the peel. However, if the fruit is bruised or cut, oxygen in the air goes into the fruit. The enzyme I mentioned before, PPO, reacts with oxygen and turns into something called melanins. This causes the browning we see. This process is called enzymatic oxidation. So the article just explains ways to slow this oxidation reaction.

I found it interesting that fruits turning brown does not necessarily mean that it is going bad. I always viewed brown fruits as spoiled, but now I might view that differently.

Learn more about fruit browning at this link.