A first systematic study on the impact of pulsed electric field parameters on peptide migration during separation of a whey protein hydrolysate by electrodialysis with ultrafiltration membrane

Improving the separation efficiency of peptide-rich streams remains a key challenge in the valorization of dairy protein hydrolysates. Recent findings suggest that applying pulsed electric field (PEF) during electrodialysis with ultrafiltration membrane (EDUF) can influence peptide migration and reduce energy consumption. In this first systematic study, six PEF conditions, defined by different pulse/pause durations (1 s/1 s, 5 s/1 s, 5 s/5 s, 10s/1 s, 10s/5 s, 10s/10s) were applied to separate a whey protein hydrolysate (WPH). The impact on peptide migration, system resistance, specific energy consumption, and membrane conductivity was assessed. The duty cycle (pulse duration divided by total cycle time), was introduced for the first time in EDUF and emerged as the most influential parameter, showing a strong correlation with process performance. Low duty cycle conditions enhanced migration and minimized energy consumption. These improvements were attributed to concentration polarization (CP) relaxation during the pause duration and favorable electroconvective vortices (ECVs) activity occurring at the beginning of each pulse, as a higher number of pulses increases the frequency of ECV appearance and their positive effect on peptide migration. The membranes preserved their conductivity and separation performance throughout the experiments, suggesting stable operating conditions and no detectable performance loss. This study provides new insights into how mechanisms known in conventional electrodialysis such as CP and ECVs formation may also occur in EDUF, opening new ways to improve process separation by varying pulse and pause durations.