Relationship between feed concentration and bioactive cationic peptide recovery: Impact on ecoefficiency of EDUF at semi-industrial scale

Abstract

Electrodialysis with ultrafiltration membrane (EDUF) is currently investigated at semi-industrial scale (560 cm2 of effective electrode surface) for the separation of bioactive cationic peptides. In this study, the focus was put on the impact of the initial whey protein hydrolysate (WPH) concentration, and the effect of current intensity have been tested. Experiments at 2%, 4% and 8% (w/v) WPH showed that a proportional relationship exists between the initial WPH concentration, and the quantity of peptides recovered. The cationic recovery fractions contained 16 peptides in similar amount as the previous work although including newly identified sequences. Thus, selectivity of the cationic recovery fraction was even improved. The working parameters used allowed obtaining a final 4.7% peptide yield after 6-h runs at 8% WPH. Aiming at nutraceutical applications built on the important ACE-inhibitory and DPP-IV inhibitory activities observed (6 times and 4 times higher than those of the initial WPH, respectively), two types of eco-efficiency scores were established based on those bioactivity values. Considering these scores, using the cationic recovery fractions as an antidiabetic product seems to be the most promising avenue. Preliminary results yielded by an experiment at higher current intensity are also very encouraging due to a barely increased environmental impact cost conjugated to a significantly higher peptide yield and preserved bioactivities. With all these new results, EDUF can be viewed as a promising industrial technology for the recovery of bioactive peptides in the perspective of ecoefficient strategies.