What are some science experiments on foods?

Answer 1

First, and most dangerously, the electric pickle:

http://www.YouTube.com/watch?v=XqXbhFFzbxw

Simple volcano or explosions out of loosely-capped containers using small quantities of acetic acid (vinegar) and baking soda.

Mentos and Diet Soda.

Using tongs, boil a small amount of water in a soda can over your range. Invert the can over some ice water, it will implode.

Use pH paper to test the pH of different household liquids such as: bleach, water, bottled water, rain water, apple juice, orange juice, vinegar, window cleaner, etc...

Determine the speed of light using a microwave and marshmallows or chocolate:

http://www.physics.umd.edu/icpe/newsletters/n34/marshmal.htm

People should add more, this is never really "answered." If I think of more, I will add them.