How do you test for monosaccharides/disaccharides?

The Benedict's test allows you to test for monosaccharides/disaccharides (also known as reducing/non-reducing sugars).


You take a sample of the test solution and add Benedict's reagent to it, then slowly heat. A reduction reaction occurs that will change the colour of Benedict's reagent, from blue -> green -> yellow -> orange -> brick red, depending upon the amount of reducing sugar you have.


If there is no change, there might still be non-reducing sugars present. Add dilute HCL to break down the disaccharides into monosaccharides, then add NaHCO2 to neutralise the solution. From here you can continue on as we did above.

If there is still no change in colour, there are no sugars present in the test solution.