Required practical: Food tests

Question 1

Testing for starch?

Answer 1

Add food solution to a test tube and then add iodine to the test tube
If starch is present, then the iodine will turn from an orange colour to a blue-black colour

Question 2

Testing for sugars?

Answer 2

Add food solution to test tube and then add benedict’s solution
Then place the test tube into a beaker filled with hot water and leave it for 5 minutes
The benedict’s solution will then change from blue to either green, yellow or red depending on the concentration of sugar in the solution

Question 3

Testing for protein?

Answer 3

Add food solution to a test tube and then add biuret solution
If protein is pr3esen the biuret will turn from a blue colour to a purple colour

Question 4

Testing for lipids?

Answer 4

Add food solution to test tube and then add ethanol and gently shake the test tube
If lipids are present the solution will turn a cloudy white colour