EXPERIMENT

to test (a)the presence of starch in the given food sample (b) the presence of the adulterant metanil yellow in dal.

plzz explain what are the materials required and what would happen ?

To test the presence of starch in a food item, 

• Take a paste of food sample. 
• Pour iodine solution on it. 
• To prepare iodine solution, take tincture iodine and mix it with a test tube half filled with water.
• If a blue-black colour appears, it indicates the presence of starch

Metanil Yellow is an adulterant which when mix with dals which can cause paralysis in humans.

• To test it, take approximately 5g of dal in a test tube and add 5 ml of water into it
• Shake the test tube well, add 2-3 drops of conc. HCl to the test tube.
• The appearance of pink colour in the solution confirms the presence of metanil yellow in dal.