Question

Test for starch-iodine test

Answer 1

Aim: To test the presense of starch in any food.
Materials required: Food item, iodine solution,test tube.
Procedure: Put the food item in the test tube, then apply some iodine solution in it...
Observation:The food item turns blue-black in colour.
Conclusion:The food item contains starch.
(OR)
Observation:Any change doesn't happen.
Conclusion:The food item doesn't contain starch.

Answer 2

Iodine test is used to check the presence of starch in the food or any other biological compound. Bench iodine solution is used for this test which is 0.1M solution of potassium triiodide. Any sample to be tested is taken in test tube (10cm3) and 5-10 drops of bench iodine solution are added to it. If the color of the solution does not change i.e. it remains brown, it means that starch was not present in the sample. If the color of the solution turns bluish black, it indicates the presence of starch in the sample.