Compositions comprising ergothioneine and a trimethylamine absorber are provided. Also provided are methods for preventing, reducing or minimizing the fishy, amine odor, due to trimethylamine, that is associated with the processing and/or storage of a preparation containing ergothioneine, by combining with the ergothioneine, during processing or prior to storage, a trimethylamine absorber in an amount sufficient to prevent the detection of any trimethylamine odor by the human nose. A method is further provided for ameliorating the methylamine odor associated with an aqueous ergothioneine-containing preparation after it has developed a fishy trimethylamine odor.