The application relates to a process for drying a composition comprising an alkali metal salt of a compound of general formula (I) R1R2N—CHR3—COOM or formula (II) R1R2N—CHR3CHR3—COOM, in particular N,N-dimethyl glycinate salt, and the use thereof. In the process, the composition, in particular the N,N-di methyl glycinate salt, is dried by feeding the composition into a fluidized bed dryer and subjecting the composition to a heat treatment by contacting the composition in the fluidized bed dryer with a drying gas stream, and during the heat treatment a solution or dispersion of the composition is sprayed onto at least a portion of the composition present in the fluidized bed dryer, or alternatively or in addition the composition, in particular N,N-dimethyl glycinate salt, is fed into a fluidized bed dryer and subjected to heat treatment in the fluidized bed dryer by contacting the composition with a drying gas stream, and the temperature of the composition in the fluidized bed during the heat treatment does not exceed 50° C.