Biology - Food Tests

Question 1

What is the test for Glucose?

Answer 1

• Add Benedict’s solution in a test tube
• Heat for 5 minutes over bunsen burner
• Positive test shows blue to brick red colour change

Question 2

What is the test for starch?

Answer 2

• Add a few drops of iodine to the food sample
• Positive test shows orange-brown to blue-black

Question 3

What is the test for protein?

Answer 3

• Add Biuret solution to the sample
• Positive test shows blue to violet/purple

Question 4

What is the test for lipids?

Answer 4

• Mix food sample with 4cm3 of ethanol and shake
• Allow time for sample to dissolve in ethanol
• Strain ethanol solution into another test tube
• Add the solution to 4cm3 of cold water
• Positive test shows cloudy emulsion forming