This is a classic GCSE Science experiment. If the food sample turns blue/black when iodine solution is added, it indicates that starch is present. If there is no starch in the sample, the iodine solution will remain orange/brown. We carry out the experiment with 7 different samples:
- Soluble Starch
Soluble starch was used to demonstrate the positive result and confirm the liquid was indeed iodine solution.
Starch was identified in the potato, pasta and bread. There was no appreciable amount of starch in any of the other samples.