Apple Turns Brown

  ''An apple a day, keep doctor away!"









Have you ever go through this situation?

Your friend calls you up while you just start eating an apple, when you come back to it after awhile, your apple turns into brown all over. Hmmmm…what happened?

Your apple has actually RUSTED!

Why do cut apples turn brown?

The reason is simple! Because apples and others (e.g., pears, bananas, peaches, potatoes) are rich in iron-containing phenols that present in their cells and also contain an enzyme called polyphenol oxidase or tyrosinase. The cells are being damaged once you cut the apple. Then, oxygen from air will reacts with iron and the enzyme in the apple cells, iron oxides form. This oxidation reaction basically forms a sort of rust on the surface of the fruit. If the browned apple is being cut into two again, you’ll notice that the inside is still white. This is because the cells inside were intact, and did not let oxygen to enter inside.

Here, I want to share with you on how to prevent this reaction :)

1.  Cut and keep the apples under water or vacuum packing it. 
   This reduce amount of air from reaching the iron.
2. Rub the cut apples with lemon juice. 
   The acid in the lemon juice can stop the polyphenol oxidase from working.
3. Add some salt to the apples. The salt stops the enzyme. 

P/S: Do not use cutlery that has some corrosion. Because this will increase the rate and amount of the browning by making more iron salts available for the reaction.