Question

to test presence of starch and fat in given food samples

Answer 1

rice, potato, and by use of iodine because it is use to test the fat and starch in the food. If fat and starch is present in the food so the color will be change in blue or black in color.

Answer 2

The iodine test is used to test for the presence of starch. Starch turns an intense "blue-black" colour upon addition of aqueous solutions of the triiodide anion, due to the formation of an intermolecular charge-transfer complex. In the absence of starch, the brown colour of the aqueous solution remains.