>I'm still trying to find a source that
>gives the pyruvate amounts in foods.

Hi Liz;

This is not a complete answer by any means but after a quick search,
indications are that it appears to be found in relatively low concentrations
in natural foods;

http://www.humankinetics.com/sdsu/content/viewnotes.cfm?sid=33

"Its content in foods, such as citrus fruits and apples, is relatively low."

Marilyn