How will you prove that the food stored in leaves os starch

To prove the food stored in leaves is starch "we will use a iodine indicator, if the leaf turn blue-black then it is confirmed that the leaf has starch. "

Explanation:

To prove the stored food in leaves is starch, first we will take a leaf, then we will treat the leaf in hot water followed by alcohol. The leaf will die when comes in contact with hot water and the alcohol will help us in the break down of the chlorophyll. Which will fade the green color. Now, we will put iodine, which we use as an indicator in the leaf, when it turn blue-black, it is confirmed that starch is present in the leaf. Sometimes the leaf will turn reddish brown, which depicts the absence of starch.