Qualitative Tests for Carbohydrate Detection

Qualitative tests for the determination of carbohydrates in the given sample are a crucial part of before getting into major analytical procedures. Every mono-, oligo-, and poly-saccharide vary depending upon the number of carbohydrate molecule present in it as well as changes in the side chains. Thus, every carbohydrate molecule has distinct functions and properties. Depending upon these physio-chemical properties of the carbohydrates, they respond to certain specific chemical reactions under certain conditions. Only mono- and dis-saccharides respond to the solubility test as they are soluble in water at room temperature. The Molisch test is only for the determination of the presence of carbohydrate, not depending on the types of it. The iodine test gives a result for polysaccharides. Whereas Fehling, Benedict and Osazone tests distinguish between reducing and non-reducing sugars. The Bradford test differentiates between mono- and di-saccharide-reducing sugars. Seliwanoff test is only for sucrose which is a non-reducing sugar. Bial’s test is to determine the presence of pentose sugars.

Keywords: Bradford test, Bial’s test, Benedict test, Carbohydrate, Fehling test, Iodine test, Monosaccharide, Molisch test, Oligosaccharide, Osazone test, Polysaccharide, Qualitative, Solubility, Seliwanoff test.