Testing For Protein - The Biuret Test

Aim: To test if a sample of food contains protein

Method:
1. Place about 2mL of the sample into a test tube and add 5 drops of sodium hydroxide
2. Add 5 drops of copper sulfate
3. Shake the test tube gently from side to side

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

Conclusion: 

Testing for Complex Sugars - The Iodine Test

Testing for Complex Sugars - the Iodine Test 

Aim - To test if a sample of food contains complex sugars

Method - 

1. Place about 2mL of the sample in a test tube.

2.  Add 3-5 drops of iodine and mix. 

  

Testing for Simple Sugars - The Benedict's Test

Testing for Simple Sugars - The Benedict's Test

Aim - To test a sample of food to determine whether it contains simple sugars 

Method -
1. Place about 2mL of the sample into a test tube and then add 5 drops of Benedict's Solution
2. Heat with a Bunsen Burner until it changes colour. Do not boil