1. Sucrose is a disaccharide that composed of α – D glucose and β – D fructose. In sucrose Cl of α – D glucose is joined to C2 of D – fructose. The glycosidic bond thus formed is called α – 1, 2- glycosidic bond. Since both the carbonyl carbons (reducing carbons) are involved in the glycosidic bonding, sucrose is a non-reducing sugar.
2. But maltose contains two molecules of x – D glucose units that are linked by an α – 1, 4 – glycosidic bond. Anomeric carbon of one unit and C – 4 of other unit are connected together. Smce one of the glucose bas the carbonyl group intact it acts as reducing sugar.
