Physical and Physiological Factors of Ginseng Drying

Effects of drying factors (air temperature, humidity, and root size) on ginseng root drying rate were studied. Dryingrate of fully exposed ginseng roots was estimated with a one-parameter, exponential model over the range of experimentaldesign for temperatures 38.C to 50.C, relative humidity 12% to 24%, and root diameter from 10 to 30 mm. The additive effectof all factors on the drying rate constant k was significant with strong effects of air temperature and root diameter and a weakereffect of relative humidity. For particular drying conditions the drying rate constant can be predicted from linear regressionwith less than 10% error. Physiological effects on ginseng root drying were also significant and the root skin appeared to bea significant limiting factor on drying. The drying rate of intact ginseng roots was as much as 5 to 10 times lower than thatof peeled roots under the same conditions.