A numerical model was developed to study the effectiveness of superheated steam, humid air, and dry air as dehydration media for wedge-shaped food products. Superheated steam had slightly higher surface friction loss than humid air and dry air except at lower free-stream temperatures. Superheated steam also exhibited higher heat transfer rates than the other fluids. The combined effect of these two characteristics was the existence of an inversion point in dehydration rate. The inversion point was the temperature at which evaporation rates for the fluids were approximately equal. The inversion points for different wedge angles were observed at approximately 275°C. The evaporation rates were greater for superheated steam than for dry air or humid air when the fluid temperature was above the inversion point. However, the evaporation rates were less for superheated steam than for dry air or humid air when the temperature was below the inversion point.