Rapid interconversion of $\mathrm{\alpha }$-D-glucose and $\mathrm{\beta }$-D-glucose in solution is known as :

The change in the optical rotation due to a change in the equilibrium of two anomers, when the corresponding stereocentres inconvert is known as mutarotation. Rapid interconversion of alpha−D−glucose and/ beta-D - glucose in solution is, therefore known as mutarotation.