1 Mark each
1. A small quantity of the food item to be tested is taken. If the food is solid, it should be either made into a paste or powdered.
2. Some of the food material is taken in a clean test tube and 10 drops of water are added to it. These are then mixed properly by shaking the test tube.
3. Using a dropper, two drops of copper sulphate solution is added to the test tube followed by ten drops of caustic soda solution.
4. The contents are mixed well and the test tube is allowed to stand for a few minutes.
5. If the solution turns violet,  it indicates the presence of protein in the food item.