Impact of conductivity on the performances of electro-acidification and enzymatic hydrolysis phases of bovine hemoglobin by electrodialysis with bipolar membranes for the production of bioactive peptides

• Published in: Separation and purification technology 2021-08, Vol.269, p.118650, Article 118650
• Main Authors: Abou-Diab, Mira, Thibodeau, Jacinthe, Fliss, Ismail, Dhulster, Pascal, Nedjar, Naima, Bazinet, Laurent
• Format: Article
• Language: English
• Subjects: Bioactive peptides; Bovine hemoglobin; Conductivity level; Electrodialysis with bipolar membrane; Enzymatic hydrolysis; Hydrolysis degree; Life Sciences; Membrane fouling
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2021.118650

•Conductivity affected the acidification duration and the global resistance.•MCP membranes in EDBM-0.9 mS/cm were the only ones fouled by peptides.•Higher salt content decreased membrane fouling via electrostatic interactions.•Higher salt content destabilized the activity of pepsin.•The one-by-one mechanism appeared at pH 3.5. Production of bioactive peptides from slaughterhouse wastes with a final low salt content by electrodialysis with bipolar membranes (EDBM) has recently been demonstrated as an innovative and efficient technology. However, a limitation in the electro-acidification process was noticed due to membrane fouling. In this context, the aim of the present work was to identify process conditions that could reduce peptide fouling in EDBM. Hence, two different conductivity levels (0.9 mS/cm and 4.5 mS/cm) were investigated in bipolar/monopolar (anionic and cationic) configuration and compared to conventional hydrolysis in the same conductivity conditions as well as a conventional hydrolysis using a buffer solution. The impact of such conductivity levels was studied during EDBM especially on membrane fouling and hydrolysis parameters: 1) kinetics of the enzymatic mechanism, 2) degree of hydrolysis and 3) peptide population. The results showed the same enzymatic mechanism “one-by-one” for all the conditions but a slower enzymatic kinetics for EDBM-0.9 mS/cm. EDBM-0.9 mS/cm allowed the production of bioactive peptides but with fouling formation on MCP while EDBM-4.5 mS/cm allowed the production of bioactive peptides without any fouling. Finally, optimizing certain conditions for further studies would lead to a promising green process to substitute synthetic additives used to protect food by antimicrobial peptides from blood slaughterhouses.