Question

how can you identify the action of saliva on starch ​

Answer 1

The starch present in the flour traps the iodine inside its structure and hence blue colour is observed. Saliva has amylase enzyme in it which dissolves starch to simpler sugars and hence the solution with saliva in it could not show blue colour due to lack of starch

Answer 2

Explanation:

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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 colour in presence of iodine solution.

hope this helps ❤️❤️