Vitamin C experiment

[Vicki]

I am doing a research project in college looking into vitamin C deterioration in fresh orange juice. I have been diluting the orange juice with distilled water and acetic acid then titrating this dilution with DCPIP. The only thing is I am unsure of why I am using acetic acid. What does this do to the vitamin C? Why is it necessary for this titration? Can anyone help??

[CerebralEcstasy]

Originally Posted by Vicki

I am doing a research project in college looking into vitamin C deterioration in fresh orange juice. I have been diluting the orange juice with distilled water and acetic acid then titrating this dilution with DCPIP. The only thing is I am unsure of why I am using acetic acid. What does this do to the vitamin C? Why is it necessary for this titration? Can anyone help??

Given the following reading:

http://www.jbc.org/cgi/reprint/108/2/563.pdf

It looks as though the acetic acid is used to remove tannins etc. Other sites cite that there are additives (cysteine most notably) to orange juice to stabilize it. So unless you're hand squeezing the orange juice my guess is that is what your acetic acid is doing.

I believe also (you're asking me to remember back 10 years) that the acetic acid is playing a role in minimizing the pH effect.

Hopefully someone with a little more recent experience will answer

[Vicki]

Thank you that does make sense so that helps

[Munin]

care to share your results?