Vitamin C test

What we did is test oranges for vitamin C (ascorbic acid)
How it works, vitamin C eats starch, and sodium iodide is an indicator for starch.
So we made a solution of starch water and an iodide solution. We put a small amount of starch water in a test tube, and a small amount of iodide. When added the iodide will turn a very dark blue
Then we put some orange juice in the test tube, if the orange has vitamin C in it, the mixture of iodide and starch will go from dark blue to a clear pink.
Apparatus
Solution if sodium iodide.
Solution if potato starch.
Multiple Test tubes.
We tested onions, tomatos, apples, oranges, a random juce, milk, and bread.

The tomato had vitamin C

The apple did not have vitamin C

The orange had vitamin C

The bread did not have any vitamin C

The milk did not have any vitamin C

The onion did have vitamin C

The random juce did not have any vitamin C

There were more that had no vitamin C then did