Electro- and magnetobiology vol:15 issue:3 pages:213-227
Electrical impedance was measured nondestructively in apples (Malus domestica) and tomatoes (Lycopersicon esculentum) over the frequency range 20 Hz-1 MHz. Raw data conform to a single time constant model. Fruit classification and data interpretation are based on the analysis of four derived parameters: low-frequency resistance R(L), high-frequency resistance R(H) constant phase angle (Phi) and characteristic frequency f(0). The most sensitive parameters to ripening and injuries have proven to be low-frequency resistance and constant phase angle.