Ultrafiltration Fractionation of Bovine Hemoglobin Hydrolysates: Prediction of Separation Performances for Optimal Enrichment in Antimicrobial Peptide

Hydrolysis of bovine hemoglobin (bHb), the main constituent of bovine cruor by-product, releases a natural antimicrobial peptide (NKT) which could present a major interest for food safety. To enrich this, tangential ultrafiltration can be implemented, but ultrafiltration conditions are mainly empirically established. In this context, the application of a simulation method for predicting the NKT yield and enrichment was investigated. Ultrafiltration performances were studied for decolored bHb hydrolysates at different degrees of hydrolysis (DH; 3%, 5%, 10% and 18%) and colored hydrolysates (3% and 5% DH) with 1 and 3 kg center dot mol(-1) regenerated cellulose membranes. The simulation method helped to identify the most promising hydrolysate (in terms of NKT enrichment, yield and productivity) as the 3% DH colored hydrolysate, and UF conditions (volumetric reduction factor of 5 and 3 with 1 and 3 kg center dot mol(-1) membrane, respectively) for higher antimicrobial recovery. A maximal enrichment factor of about 29 and NKT purity of 70% in permeate were observed. The results showed that the antimicrobial activity was in relation with the process selectivity and NKT purity. Finally, this reliable method, applied for predicting the ultrafiltration performances to enrich peptides of interest, is part of a global approach to rationally valorize protein resources from various by-products.

Automated summary

This study investigated the use of a simulation method to predict the yield and enrichment of NKT during ultrafiltration of bovine hemoglobin hydrolysates. The results showed that the 3% DH colored hydrolysate was the most promising in terms of NKT enrichment, with a maximal enrichment factor of about 29 and NKT purity of 70% in the permeate. This reliable method for predicting ultrafiltration performances to enrich peptides of interest is part of a global approach to valorize protein resources from various by-products.