Question

Boojho took some grains of boiled rice in a test tube ‘A’ and Paheli took boiled and chewed rice in a test tube ‘B’. Both of them poured 3-4 drops of iodine solution into the test tube and observed the colour change. Explain why test tube ‘B’ did not give a blue-black colour on the addition of iodine?

Answer 1

Since test tube B has boiled rice which were chewed for 3-5 minutes, the saliva present in mouth has acted upon starch to break down into sugars. So it does not show any color in presence of iodine solution.