Biological Molecules Food Tests

Question 1

Test for Glucose/Reducing Sugars

Answer 1

Benedict Solution + heat (solution must be liquid)

From blue to orange if Positive

Question 2

Test for Starch

Answer 2

Drops of Iodine Solution

The color change form violet to blue/black means it’s positive

Question 3

Test for Proteins

Answer 3

Biuret Solution

Color change to purple indicates positive result

Question 4

Test for Lipids

Answer 4

Ethanol Emulsion

The food sample is mixed with ethanol and added to an equal volume of cold water.

The test is positive if an emulsion is formed

Emulsion* = substance that does not dissolve in water