Significance
Although both glucose and fructose are reducing sugars, sucrose is not because it does not contain anomeric hydroxyl groups, and does not reduce the chemicals present in its structure through oxidation.
Identification
It is possible to test a substance such as sucrose for the qualities that make it a reducing sugar using Fehling's solution, a mixture of copper sulfate, distilled water, Rochelle salt and sodium hydroxide. In the presence of reducing sugars, the copper sulfate in the solution will oxidize and turn red.