Ans. It is effortless to test for the starch to identify the presence of carbohydrates in food. For this, we need to take a small number of food items as a sample. Then add a few drops of iodine solution to the food item and observe the change. If the food changes its colour to the shade of combination of blue and black, then we can consider this as the presence of carbohydrates in that food. If the colour is not absorbed, there are no carbohydrates in that food item.