Which of the following will not show mutarotation?

Mutarotation is the change in optical rotation observed when a sugar is dissolved in water due to the equilibrium between its alpha and beta anomers. This occurs only if the anomeric carbon is free and not involved in a glycosidic bond.

Let's examine each option:

Option A: Maltose
Maltose is a disaccharide formed from two glucose units linked by an α-1,4-glycosidic bond. The anomeric carbon of the first glucose is bonded, but the second glucose has a free anomeric carbon. Therefore, maltose can undergo mutarotation.

Option B: Lactose
Lactose is a disaccharide of galactose and glucose linked by a β-1,4-glycosidic bond. The anomeric carbon of galactose is bonded, but the glucose unit has a free anomeric carbon. Hence, lactose shows mutarotation.

Option C: Glucose
Glucose is a monosaccharide with a free anomeric carbon in its cyclic form. When dissolved, it equilibrates between α-D-glucose and β-D-glucose, showing mutarotation.

Option D: Sucrose
Sucrose is a disaccharide of glucose and fructose linked by an α-1,β-2-glycosidic bond. Here, both anomeric carbons (C1 of glucose and C2 of fructose) are involved in the glycosidic bond. Neither anomeric carbon is free to open and form the open-chain aldehyde or ketone required for mutarotation. Therefore, sucrose does not show mutarotation.

Hence, the correct answer is Option D.