Electroporation theory predicts higher damage for tissue with larger cells, however, direct correlation between PEF damage efficiency and cells size was rarely observed. Many other factors like tissue structure, the shape of the cells, their orientation in external field and their electro-physical properties may affect efficiency of PEF induced damage. The objective of this study was correlation of PEF-induced damages with energy consumption, cell size and conductivity contrasts through the investigation of the effects of PEF in different fruit and vegetable tissues. Efficiency of permeabilisation of selected fruit and vegetable tissues (apple, potato, carrot, courgette, orange and banana) at 293 K by pulsed electric field with electric field strength (E) of 400 V.cm~(-1) and 1000 V.cm~(-1) and pulse duration (t_p) 1000 μs was studied experimentally. The mean cell radius (< r >) was within 30 - 60 μm and the ratio of electrical conductivities of the intact and damaged tissues (σ_i /σ_d) was within 0.07 - 0.79 for the studied tissues. The characteristic damage time τ was defined and the theoretical Monte Carlo model was developed and checked for typical characteristics of potato tissue. The theoretical Monte Carlo model was able to explain differences in behavior of characteristic damage time (τ) and specific power consumption (W) in potato and orange accounting for the σ_i/ σ_d ratio. It was predicted that the optimal electric field strength E_(opt) (at minimum power consumption) was dependent on the conductivity ratio σ_i / σ_d. The value of E_(opt) was an increasing function of σ_i / σ_d , and for a plant tissue with large σ_i / σ_d ratio ( σ_i / σ_d ≈1) it was desirable to apply PEF treatment at high E values. However, the PEF treatment at small fields allowed regulation of damage selectivity, i.e. possibility of preferential damage of large cells.
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