Broadband dielectric spectroscopy was employed to investigate the kinetics of the mutarotation of D-fructose. In this article, D-fructose tautomerization behavior in pure melt is revealed. By monitoring structural relaxation time shift, we were able to determine speed in temperature range 303-333 K and the activation energy for this phenomenon. It is equal to 107 kJ/mol, which is very high in comparison to the solvated system. We have also shown the influence of this process to the gamma-relaxation (secondary relaxation process). Dielectric spectroscopy derived complex information about mutarotational dynamics.