Testing the protein - the biuret test

Aim: To test if a sample of food contains protein

Equipment: Test Tube, sodium hydroxide (NaOH), copper sulfate (CuSO), food sample.

Method:

Results: If the solution remains blue, then no protein is present. If the solution changes to a purple colour then protein is present in the sample.

Conclusion:  The food sample was: Egg, and after adding the sodium hydroxide and copper sulfate it turned purple

For the second sample food, we used milk. and after adding the sodium hydroxide and copper sulfate it turned purple. After a couple of drops of sodium hydroxide