Science Projects Index

Test for the Presence of Starch

The presence of starch in a food substance can be found out using iodine.

Starch is the main form of carbohydrate in our food.

Buy some iodine solution from a dealer of laboratory chemicals.

Put a few drops into such a thing as rice, bread, potato, tapioca etc.

In the case of fruits, remove their skin and do the test.

The presence of starch is indicated if the solution turns dark blue.

How Is the Starch Digested?

Digestion starts in the mouth itself. The saliva that mixes with the food substances starts the process. Starch molecules in the food are broken into smaller sugar molecules by an enzyme called amylase in the saliva.

Foods that have flavour and taste cause the generation of a large amount of saliva. But foods that don't have flavour don't.

Starch doesn't have flavour.

Put some piece of ordinary bread in your mouth. For some time you get a bland taste, as this starch filled food doesn't have much flavour. But after sometime it will taste better as salivation takes place.