Effects of applied current modes on the migration selectivity of peptides from a porcine cruor hydrolysate during electrodialysis with ultrafiltration membrane

Abstract

Pepsic hydrolysis of porcine hemoglobin produces various antimicrobial peptides, however, within such complex hydrolysates, certain peptide bioactivities remain unexpressed. Electrodialysis with ultrafiltration membrane (EDUF) addresses this by separating peptides from hydrolysates based on peptide charge and molecular mass, resulting in fractions with increased bioactivity. This study aims to assess the impacts of different current modes (continuous current (CC), pulsed electric field (PEF) and polarity reversal (PR)) on peptide migration selectivity, which has never been reported. Different combinations of pulse and pause or reversed pulse were tested: 1 s/1 s and 10 s/1 s. This investigation focused on the 31 most migrating peptides and their 6 main physicochemical characteristics. Three groups of current conditions with similar performances were observed: (1) CC, PEF 10 s/1 s and PR 10 s/1 s (Averaged final migration rate of 5.0 g/m2h and energy consumption of 48.7 Wh/g of peptide); (2) PEF 1 s/1 s (9.0 g/m2h and 61.0 Wh/g of peptide), and (3) PR 1 s/1 s (3.3 g/m2h and 95.6 Wh/g of peptide). CC, PEF, and PR 10 s/1 s facilitated the migration of mainly cationic peptides with low molecular masses and were the most selective conditions. PR 1 s/1 s allowed the migration of some anionic peptides with lower molecular masses, due to the short polarity reversal. This study demonstrated for the first time the effects of the electrical current mode and condition associated on migration selectivity of peptides during EDUF and their performances. Modifying the electrical current mode offers a new way to optimize separation selectivity and generate specific peptide populations in the recovery compartment with potentially different bioactivities.