Bovine Hemoglobin Enzymatic Hydrolysis by a New Ecoefficient Process—Part I: Feasibility of Electrodialysis with Bipolar Membrane and Production of Neokyotorphin (α137-141)

Abstract

Neokyotorphin (α137-141) is recognized as an antimicrobial peptide and a natural meat preservative. It is produced by conventional enzymatic hydrolysis of bovine hemoglobin, a major component of cruor, a by-product of slaughterhouses. However, during conventional hydrolysis, chemical agents are necessary to adjust and regulate the pH of the protein solution and the mineral salt content of the final hydrolysate is consequently high. To produce this peptide of interest without chemical agents and with a low salt concentration, electrodialysis with bipolar membrane (EDBM), an electromembrane process recognized as a green process, with two different membrane configurations (cationic (MCP) and anionic (AEM) membranes) was investigated. Hydrolysis in EDBM showed the same enzymatic mechanism, “Zipper”, and allowed the generation of α137-141 in the same concentration as observed in conventional hydrolysis (control). EDBM-MCP allowed the production of hydrolysates containing a low concentration of mineral salts but with fouling formation on MCP, while EDBM-AEM allowed the production of hydrolysates without fouling but with a similar salt concentration than the control. To the best of our knowledge, this was the first time that EDBM was demonstrated as a feasible and innovative technology to produce peptide hydrolysates from enzymatic hydrolysis.

Special Issue “Membrane Technologies for Sustainable Biofood Production Lines”

“…However, the hurdles are still high when dealing with scale-ups and real-life conditions. In their papers, Abou Diab et al [ 5 , 8 ] developed and proposed a new green application of EDBM to the production of bioactive peptides from a by-product of slaughterhouses, which fits perfectly with the concept of a circular economy. Indeed, hemoglobin from blood, once hydrolyzed, allows the bioproduction of active peptides that can then be reused on meat or meat products to increase their preservation and inocuity.…”

“…In their papers, Perreault et al [ 1 ], Ge et al [ 3 ], Wang et al [ 4 ], and Abou Diab et al [ 5 ], reported the fouling of membranes by respectively polyphenols and anthocyanins (UF membrane), charged organic anions (anion exchange membranes), and divalent ions (cation exchange membrane), amino acids, and peptide or hem-peptide (cation-exchange membrane). Concerning the mechanisms, the results of the study by Ge et al [ 3 ] indicated that the membrane fouling is caused by two different mechanisms: electrostatic interactions of charged organic anions with the anion exchange membranes and precipitation of Ca 2+ and Mg 2+ on the cation exchange membrane, by reaction with OH − ions generated by water dissociation.…”

“…The chemical cleaning with alkaline and acid was proposed to mitigate these fouling and scaling [ 3 ]. In their work, on the production of hydrolysate from bovine hemoglobin by electrodialysis with bipolar membrane (EDBM), Abou Diab et al [ 5 ] explained the fouling of perm-selective cation exchange by the fact that, according to the pH of the solution and the release of hem alone or protein fragments containing hem and peptides during hydrolysis, peptides may have first interacted electrostatically (positive residues) into the scattered cavities of the thin charged layer (forming the perm-selective layer). Indeed, into these scattered cavities, the negatively fixed groups of the cationic matrix were reachable and, afterwards, hem or the protein fragments containing hem interacted with these already adsorbed peptides via hydrophobic interactions.…”

“…These results confirmed the hypothesis developed by Persico and Bazinet [ 6 ] for a perm-selective cationic membrane and a whey protein hydrolysate. Additionally, Abou Diab et al [ 5 ] proposed to minimize the fouling by applying pulsed electric field or an overlimiting current regime, by changing the configuration or by modification of ion-exchange membranes. The main avenues to minimize foulings and scalings by different species present in water or food fluids and the mechanims and ways to mitigate them are presented in detail in the paper of Bazinet and Geoffroy [ 7 ].…”

“…The optimal ED desalination conditions were at a current density of 5 mA/cm 2 and pH of 5, with a 64% desalination rate, a 29.8% amino acid loss rate, and that without compromising the original flavor. With the goal of producing a bioactive hydrolysate, from bovine cruor, a slaughterhouse waste, Abou Diab et al [ 5 , 8 ], developed a new membrane-based hydrolysis process. In these studies, EDBM was demonstrated for the first time as an ecoefficient and innovative technology to produce peptide hydrolysates from enzymatic hydrolysis of bovine hemoglobin with low mineral salt concentration.…”