Question

we cannot test the presence of proteins all food items?​

Answer 1

Answer:

Following steps are used to test if a food item contains protein. 

1) Take a small quantity of the food items to be tested.

2) Grind/mash the food item.

3) Put the food item into a test tube.

4) Add 10 drops of water and shake the test tube.

5) Add two drops of copper sulphate solution to the test tube, using a dropper. 

6) Add 10 drops of caustic soda solution using a dropper and shake the test tube.

7) Let the test tube rest in a test tube stand for a few minutes.

8) Observe the colour of the mixture.

9) Violet colour indicates the presence of proteins in the tested food item.