Mutarotation is the spontaneous change in the specific rotation of an optically active compound when dissolved in water, due to the equilibrium between its $\alpha$ and $\beta$ anomeric forms. It is a characteristic property of reducing sugars. Sucrose is a non-reducing sugar because the glycosidic bond is formed between the anomeric carbon of $\alpha$-D-glucose (C1) and the anomeric carbon of $\beta$-D-fructose (C2). Since it does not have a free anomeric hemiacetal or hemiketal hydroxyl group, it cannot undergo ring opening in solution and thus does not exhibit mutarotation.