Application of Electrical Impedance Analysis to Assessment of Freezing Injury in Chicory Roots

Chicory (Cichorium intybus L var foliosum cv.) root was used to investigate the change in electrical impedance and potassium ion leakage during cold storage, and some quantitative relations between the electrical impedance and cell membrane permeability. It is showed that the cell membrane permeability, and the rate of potassium ion leakage increase, while the electrical impedance decreases with the development of freezing injury in chicory root. The change in electrical impedance in chicory roots stored at 0℃, -1℃, -3℃ was remarkable negatively correlated with the potassium ion leakage rate. At low frequency there was relatively little change and the highest value in impedance (20～100 Hz). Therefore, it is feasible that the electrical impedance analysis can be used to estimate the freezing injury of plant.