Science Buddies: "Ask an Expert"

Hello,

I recently conducted an experiment where I use different concentrations of salt in 100ml of water, in attempt to recover already discolored cylindric apple cores (2cm long). The higher the salt concentration, the whiter the apple is.

I understand why the apple turns brown at the beginning, however what I don't understand is how and why salt can recover (whiten) a browned apple.

Thank you!
SM

Dear sm2468,

Apples turn brown because of oxidation. Salt can recover a browned apple because it interferes with the apple's oxidation. According to howstuffworks, "salt around the outside of the food draws water molecules out and replaces them with salt molecules until the amount of salt is equal inside and out". This shows that salt can pull water away from an apple, meaning that it is harder for oxygen to reach its surface.

I hope this helps you understand why salt can recover a browned apple.

RicaC

Dear RicaC, thanks for your answer!

Dear sm2468,

No problem. I am glad I was able to help!

RicaC