Benedicts test for non-reducing sugars

What is a reducing sugar?

All monosaccharides and some disaccharides are reducing sugars (can donate electrons or reduce another molecule)

What chemical is used?

Benedict’s reagant

What is the 1st step of the test?

Place the sample to be tested in a boiling tube, if not liquid grind it up

What is the 2nd step of the test?

Add an equal volume of Benedict’s

What is the 3rd step of the test?

Heat the mixture gently in a boiling water bath for 5 minutes

What reaction will occur?

Reducing sugars react with copper ions in benedict’s, addition of electrons to blue Cu2+ ions reducing them to brick red

What is a positive result?

A brick red precipitate forming

What does green colour indicate?

Low conc of reducing sugar

What does yellow/orange colour indicate?

Medium conc of reducing sugar

What does red colour indicate?

High conc of reducing sugar

What kind of test is it?

Qualitative