Define observation or inference for barfoed test?
1. Reddish brown precipitate is seen on the sides and bottom of the tube. The precipitate of the sides and bottom indicates the presence of monosaccharides.
2. Disaccharides are weak reducing agents and therefore do not reduce cupric ions in an acidic medium. Hence Barfoed's test is used to differentiate between disaccharides and monosaccharides. .
3. Monosaccharides being strong reducing agents can reduce cupric ions in acidic medium without enediols. This is a specific test for monosaccharides so polysaccharides do not respond to the test.