Food Tests

Question 1

Glucose (a reducing sugar)

Answer 1

Add Benedict’s Solution, heat the solution, positive test shows a colour change from blue to orange or brick red

Question 2

Starch

Answer 2

Add drops of iodine solution to the food sample. A positive test will show a colour change from orange-brown to blue-black

Question 3

Protein

Answer 3

Add drops of Biuret Solution to the food sample. A positive test will show a colour change from blue to violet/purple

Question 4

Test for lipids (fats and oils)

Answer 4

Add ethanol and shake. Add an equal amount of cold water. A positive test will show a cloudy (white) emulsion forming