Food Test

Question 1

How to test for glucose?

Answer 1

1) Add Benedict’s solution into sample solution in a test tube
2) Heat at 60 – 70 °c in water bath for 5 minutes
3) Take the test tube out and observe
4) If there’s glucose => colour changes from blue to orange or brick red.

Question 2

How to test for starch?

Answer 2

1) Add drops of Iodine solution to the food sample

2) If there are starch => colour changes from orange-brown to blue-black.

Question 3

How to test for protein?

Answer 3

1) Add drops of Biuret solution to the food sample

2) If there’s protein => colour change from blue to violet / purple.

Question 4

How to test for lipids?

Answer 4

1) Mix the food sample with a small amount of ethanol and shake it.
2) Add cold water (have to be the same amount with the ethanol added)
3) If there’s lipid => cloudy emulsion forming.

Question 5

How to test for vitamin C?

Answer 5

• Add 1cm^3 DCIP into a test tube
  (+) It changes to yellow
  (-) It remains the blue colour