Purification and fractionation of bioactive peptides through membrane filtration: A critical and application review

The health-promoting properties of bioactive peptides are well-known, however, the lack of scalable processes for purifying the bioactive peptides limits their commercial production viability. Recently, membrane filtration has been of great interest to scientists and industries to recover bioactive peptides. The effect of various factors including feed pH and concentration, membrane surface and pore size, and the operational parameters such as the transmembrane pressure and flow rate on the performance and selectivity of membranes for peptide fractionation are discussed in detail. Furthermore, the advantages and challenges of each membrane system are presented. Ultrafiltration (UF) and Nanofiltration (NF) have been found to be one of the best methods for the purification of peptides on the basis of their molecular weight. Studies show yield, purification, and product quality of UF and NF separation is comparable with chromatography processes but with higher productivity and at a lower cost. Research continues to improve the productivity of the UF process. The development of enzymatic membrane reactors (EMRs) is recognized as an effective technology for online enzyme recycling and peptide purification. On the other hand, electrodialysis with UF membrane (EDUF) seems to be an ultra-selective process for the separation of peptides. This process benefits from the size-based exclusion abilities of UF and the charge selectivity of electrodialysis (ED). However, despite its high selectivity, the peptide migration rate and recovery yield of EDUF is still low compared to the UF separation process.