## 3 Results
### Effect of Different Pulse Voltages on Electrical Conductivity  
The pulse voltage significantly influenced the measured conductivity values towards higher pulse voltages (Figure 3a-d). For 8 out of 10 investigated pulse voltages, the highest  
Figure 2: Electrical conductivity analysis to test heterogeneity within and between distinct potato tissue regions (medulla, perimedulla, cortex, and cortical medulla). (**a,b**) Conductivity between 1 Hz and 5 MHz, averaged over N = 6 potato samples. The shaded area in (**a**) indicates the standard deviation. (**c,d**) Relative conductivity as compared to the perimedulla 1 region. Again, data points were averaged between samples and shaded areas indicate the standard deviation. (**e**) ANOVA results comparing mean conductivity at 1000 Hz. ANOVA results for other frequencies are stated in Supplementary Tables S1 and S2. relative conductivity change was observed near 1000 Hz; the remaining two showed peaks near 10 Hz and 100,000 Hz (Table 2). At 1000 Hz, the relative conductivity increased from 230 \(\pm\) 85% to 1644 \(\pm\) 233% as the applied voltage was raised from 200 V to 1000 V. \begin{table}
\begin{tabular}{l l l l l l l l l l l} \hline  & & & & \multicolumn{4}{c}{**Pulse Voltage**} & \\  & **100 V** & **200 V** & **300 V** & **400 V** & **500 V** & **600 V** & **700 V** & **800 V** & **900 V** & **1000 V** \\ \hline \(\Delta\sigma_{rel\_max}\) (\%) & 14 & 232 & 671 & 825 & 905 & 1131 & 1294 & 1354 & 1357 & 1671 \\ \(f_{\Delta\sigma_{rel\_max}}\) (Hz) & 185,717 & 1483 & 1818 & 7 & 1483 & 1552 & 1483 & 1439 & 1660 & 1660 \\ \(f_{opt10}\) (Hz) & 100,000 & 1000 & 1000 & 10 & 1000 & 1000 & 1000 & 1000 & 1000 \\ \hline  & & & & \multicolumn{4}{c}{**Number of Pulses**} & & & & \\  & **5** & **10** & **15** & **20** & **30** & **40** & **50** & **60** & **70** & \\ \hline \(\Delta\sigma_{rel\_max}\) (\%) & 149 & 476 & 771 & 1049 & 964 & 1309 & 1523 & 1652 & 1565 & 1565 & \\ \(f_{\Delta\sigma_{rel\_max}}\) (Hz) & 3372 & 1660 & 1575 & 1575 & 1575 & 1724 & 1859 & 1859 & 1859 & 1859 & \\ \(f_{opt10}\) (Hz) & 10,000 & 1000 & 1000 & 1000 & 1000 & 1000 & 1000 & 1000 & 1000 & 1000 \\ \hline \end{tabular}
\end{table} 
Table 2: Frequencies with highest relative conductivity changes. Per set of experiments and parameter investigated, the highest relative conductivity change observed (\(\Delta\sigma_{rel\_max}\)), the corresponding frequency at which \(\Delta\sigma_{rel\_max}\) was measured (\(f_{\Delta\sigma_{rel\_max}}\)), as well as the optimum decade for detecting PEF-induced conductivity changes (\(f_{opt10}\)) are listed. Figure 3: The analysis of electrical conductivity of potato tissue at various pulse voltages (between 100 V and 1000 V across a frequency range of 1 Hz to 5 MHz (N = 6). (**a**) Three-dimensional conductivity map with standard deviation for different pulse voltages (N = 6). (**b**) Mean conductivity plots for different pulse voltages. (**c**) Three-dimensional plots of relative conductivity for different pulse voltages compared to a control group (”Ctrl”) with standard deviation. (**d**) Mean relative conductivity values. At 1 kHz, the mean conductivity increased significantly from the control value of 0.025 \(\pm\) 0.004 S/m to 0.08 \(\pm\) 0.019 S/m for 200 V (\(p\) = 0.0099). At 400 V and above, very significant and extremely significant conductivity changes (\(p\) < 0.01) were observed (Figure 4a). The smallest \(p\)-value was observed at 700 V, with mean conductivity increasing from the control to 0.337 \(\pm\) 0.060 S/m (\(p\) = 0.0007). The highest mean conductivity was measured at 1000 V, 0.428 \(\pm\) 0.082 S/m (\(p\) = 0.0009). Table 3 summarizes conductivity at 1 kHz; extended results (mean conductivity values and ANOVA results at other frequencies) are provided in Supplementary Tables S5 and S6.