Forced-Air Drying of Ginseng Root: Pilot-Scale Control System for Three-Stage Process

Pilot-scale experiments were conducted to evaluate a three-stage temperature control system (38-50-38C) for ginseng root drying. Feedback for determining temperature change points was provided by measuring root shrinkage in digital images of the root bed. Shrinkage kinetics observed during the first stage were used to predict the drying rate for the third stage and an exponential model was used to predict the time required for the roots to reach an average moisture content of 0.11g/g (db). Based on experimental tests, the root mean square error for the final moisture was 0.025g/g (db).