how can we test starch, protein in food
Answers
Answer:
Explanation:
Apparatus and materials required:
Test tubes, test-tube stand, test-tube holder, spirit lamp, dropper, filter paper, iodine solution, distilled water, and foodstuff (potato, rice, wheat or maize grains).
Theory:
Starch, a complex carbohydrate, is composed of 15%-20% amylose and 80%-85% amylopectin. It is found in different kinds of cereals such as rice, wheat, maize, etc. After reacting with iodine solution starch forms a dark, blue-black compound. The appearance of blue-black colour is due to the presence of amylase in starch.
Procedure:
1. Take a few small, freshly cut pieces of potato or a few grains of rice or wheat or maize in a clean test tube.
Test for the Presence of Starch in Foodstuff
2. Pour 10 mL distilled water into the test tube.
3. Now, boil the contents of the test tube for about 5 minutes.
4. Allow the test tube to cool.
5. Filter the contents of the test tube through a filter paper.
6. Test the obtained filtrate for the presence of starch by the following method.
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Explanation:
Test for Protein
Take a small quantity of the food items to be tested.
Grind/mash/paste/powder the food item.
Put the food item into a test tube.
Add 10 drops of water and shake the test tube.
Using a dropper add two drops of copper sulphate solution to the test tube.