## 4 Discussion
under 20 mS/m conductivity increased from 17.21% to 83.29%. Therefore, the degree of cell membrane damage increases with the increase in electric field strength, and electric field strength is an important factor that significantly affects the rate of microbial cell membrane damage. In addition, the processing time also affects the _R. solani_ cell membrane damage rate. From the experimental results, the \(p\) value of the cell membrane damage rate was 0.0068 (_p_ < 0.01), and the effect was extremely significant. Our results are consistent with the findings of [PERSON] [23], who found that in the samples receiving 1, 5, and 25 pulses, 5 and 25 pulses were more effective, which demonstrated that the more the number of pulses are applied to the sample, the greater the damage to the cell. That is, increasing the processing time can affect the damage degree of the sample cells (Processing time = Pulse number x Pulse duration; processing time is linear with the number of pulses), which is consistent with our experimental results. Furthermore, the effect of pulse duration on microbes is relatively complicated. The \(p\) value of the cell membrane damage rate in this experimental pulse duration model is 0.0996 (_p_ > 0.05). Thus, the effect of pulse duration on the cell membrane damage rate of _R. solani_ is not significant, which was consistent [PERSON]'s findings. However, some studies have shown an inverse relationship. [PERSON] [24] studied the electric field strength E between 100 and 400 V/cm, the pulse duration (i, was 10, 100, and 1000 \(\upmu\)s, and the inter pulse duration (\(\Delta\)t) was 100 \(\upmu\)s. The samples with the same PEF processing time showed significantly higher damage efficiency at larger pulse durations, and the pulse duration had a notable effect on the microorganisms. We speculate that the reason for the influence of pulse duration might be because the pulse duration has a specific threshold; when the pulse duration increases to a certain extent (that is, exceeds the threshold value), the effect of the experiment is significant, while the increase in the pulse duration of this experiment is small, so the impact is not significant. In the present study, on applying a PEF, the substances in the cells (especially the electrolytes) were expelled, and the conductivity of the mycelium suspension changed accordingly. The degree of damage of the plasma membrane was reflected by the changes in conductivity. In addition, the absorbance value of mycelium suspension at 510 nm was determined by measuring the amount of extracellular alkaline phosphatase eluted under different treatment conditions, so as to determine the degree of cell wall damage. The results showed that the absorbance of the _R. solani_ suspension was mainly related to the change in electric field strength (voltage amplitude) (_p_ < 0.01), while the pulse duration and processing time had little effect on the absorbance (_p_ > 0.05). The increase in the absorbance indicates that the PEF treatment causes 'cell damage effects' on the cell membrane of _R. solani_, which in turn causes cell death. It is well known that the electric field strength and total processing time are the main factors determining microbial inactivation following PEF treatment [25]. In the present study, the conductivity method detected the effect of the electric field strength and PEF processing time on _R. solani_ cell damage. However, only the effects of electric field strength were detected by the absorbance method, which influenced the _R. solani_ cell damage. The conductivity method more accurately revealed the cell damaging effects of the PEF process parameters on the mycelium suspension. As the absorbance method is used to determine the initial concentration of the mycelium suspension, when the absorbance cannot exceed a certain threshold, the measured data have a good linear relationship, and the absorbance value accurately reflects cell loss, while there is no such restriction for determining cell damage by detecting conductivity values.