Effect of drying temperature on alkylamide and cichoric acid concentrations of Echinacea purpurea.

Root and aerial sections (flower, stem, and leaf) of Echinacea purpurea were dried with hot air at temperatures in the range of 40-70 degrees C, and the concentrations of alkylamides and cichoric acid were determined after drying. Increasing drying temperature decreased from 48 h at 40 degrees C to 9 h at 70 degrees C but resulted in a decreased concentration of cichoric acid in all plant sections with a greater loss from aerial plant parts than from the root. There was, however, no significant difference in the concentration of the alkylamides at any drying temperature. Establishment of operational parameters for the drying of echinacea must therefore be structured around the more labile cichoric acid.