Question

Why sucrose is a non-reducing sugar?

Answer 1

Non – Reducing sugars

• Non-reducing sugars do not have a free ketone or aldehyde group.
• These sugars have acetal in place of hemiacetal.
• An acetal consists of two O-R group, one -R and -H group respectively.
• All these groups are attached to the same carbon.

Sucrose is a non-reducing sugar because

• Sucrose is non-reducing sugar due to the linkage between both the anomeric carbon atoms.
• The two monosaccharide units are held together by a glycosidic linkage between ${\mathrm{C}}_1$ of α-glucose and ${\mathrm{C}}_2$ of β-fructose.
• Since the reducing groups of glucose and fructose are involved in glycosidic bond formation, sucrose is a non-reducing sugar.
• Anomeric carbon of both the monosaccharides are involved in glycoside or acetal formation. So it does not have a free -CHO group