apple browning

[Freedom]

Hi guys!

you know how when you cut open an apple it goes brown...what is the brown stuff?

Ta!

[baikuza]

I think the brown colour is caused by the oxydation. something in apple oxydate with the air and become brown

[victor]

To prevent it, just use citric acid that you can get it fron citrus..this can prevent from air oxydation.
Regards
Victor

[chemistry_freako]

Yes, it's due to oxidation. One example would be the ascorbic acid (Vitamin C) contained in the apple.

U might find this useful:
http://www.geocities.com/perfectapple/brown.html

[Freedom]

Cool.

So, say i wanted to do an investigation into apple browning, can anyone give me an idea of what i should test for?

Ta!

[biostudent84]

There are certain enzymes in apples (can't remember their names this early in the morning) that cause the oxidation. They are also in potatoes as well. Uncooked potatoes brown like that when cut, but not if they have been cooked. The heat from cooking them denatures the enzymes, and no oxidation takes place.

[CynMari]

Since the reaction involves a change of color, you could measure color intensity (with a spectrophotometer) to indicate the rate of browning.

[mith]

Try freezing the apple and see if browning occurs.

[mothorc]

Hi
The brown color that you saw is cause by the oxidation of phenolic substances. The phenolic substances appear at the wound of plant tissue
and it react with oxygen in the air.
Good luck

[ankitshah64]

Apple contains iron and when the cut apple expose to air, the enzyme called "tyrosinase" helps to oxidize and turn apple in brown (brown colour is response to reaction occured). However, the apple dipped with lemon juice or sulphur dioxide prevents this reaction since they are anti-oxidants.

[hurly]

When the apple gets oxidized, does it loose it's antioxidants and all the other nutritions that a normal apple has?

It's not like it's dangerous to eat an oxidized aka brown apple, is it...?

[Winter]

no, i dont think it is dangerous...
if you don't put lemon juice in a fruit salad with apples in it, the apples will turn brown. It's still edible even if its not pretty...

Also, soaking potatoes in water until you cook them will prevent them from becoming brown.