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Filtration membranes (FMs) are an integral part of electrodialysis with filtration membranes (EDFM), a green and promising technology for bioactive peptide fractionation. Therefore, it is paramount to understand how physicochemical properties of FMs impact global and selective peptide migration to anionic (A−RC) and cationic (C+RC) peptide recovery compartments during their simultaneous separation by EDFM. In this context, six polyether sulfone (PES) membranes with molecular weight cut-offs (MWCO) of 5, 10, 20, 50, 100 and 300 kDa were characterized and used during EDFM to separate peptides from a complex whey protein hydrolysate. Surface charge, roughness, thickness and surface/pores nature of studied PES membranes were similar with small differences in conductivity, porosity and pore size distribution. Interestingly, global peptides migration to both recovery compartments increased linearly as a function of MWCO. However, peptide selectivity changed according to the recovery compartments and/or the peptide’s charge and MW with an increase in MWCO of FMs. Indeed, in A−RC, the relative abundance (RA) of peptides having low negative charge and MW (IDALNENK and VLVLDTDYK) decreased (45% to 19%) with an increase in MWCO, while the opposite for peptides having high negative charge and MW (TPEVDDEALEK, TPEVDDEALEKFDK & VYVEELKPTPEGDLEILLQK) (increased from 16% to 43%). Concurrently, in C+RC, regardless of MWCO used, the highest RA was observed for peptides having low positive charge and MW (IPAVFK & ALPMHIR). It was the first time that the significant impact of charge, MWCO and pore size distribution of PES membranes on a wide range of MWCO was demonstrated on EDFM performances.

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Industrial application of ion‐exchange membranes, the key component of many electro‐membrane processes, is often hindered due to their high cost—result of complex fabrication methods and use of highly engineered precursors. As an alternative to conventional anion‐exchange membrane (AMX), this study focuses on the fabrication of cation‐coated filtration membranes (CCFM‐Type 1 and CCFM‐Type 2) by depositing a thin layer of crosslinked branched polyethyleneimine (PEI)‐based ionomer on top of the porous substrate. The use of commodity precursors (PEI) in combination with energy efficient fabrication processes ensures a low end‐cost for CCFMs. The properties and the performances of these membranes are evaluated and compared with AMX. Though ionic conductance of both CCFMs is found to be lower than AMX, similar electrochemical behavior is observed for all three membranes. In terms of performance, the highest NaCl demineralization rate is given by CCFM‐Type 2, while whey demineralization rate for all three membranes is similar. Energy consumption during both processes is increased for CCFMs probably due to noticeably higher global resistance which the ED system reaches during the process. These promising results suggest the possible application of these cost‐effective CCFMs in electrodialysis demineralization processes as an alternative to commercial AMX at an industrial level.