Question

conduct experiment to test starch please follow me​

Answer 1

Answer:

Starch testing

1) heat a plant leaf in boiling water for 30 seconds (this stops its chemical reactions)

2) heat it in boiling ethanol for a few minutes (this removes most of its colour)

3) wash with water and spread onto a white tile.

4) add iodine solution from a dropping pipette.

I hope it will be helpful to you friend

Answer 2

Objective:

To test the presence of starch in the given food sample.

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:

• Take a few small, freshly cut pieces of potato or a few grains of rice or wheat or maize in a clean test tube.
• Pour 10 mL distilled water into the test tube.
• Now, boil the contents of the test tube for about 5 minutes.
• Allow the test tube to cool.
• Filter the contents of the test tube through a filter paper.
• Test the obtained filtrate for the presence of starch by the following method.

Precautions:

• Use test-tube holder for holding the test tubes and keep the mouth of the test tube away from yourself while heating.
• Use clean test tubes.
• Do not use too much of iodine solution.