Fractionation of whey proteins by bipolar membrane electroacidification

Abstract Bipolar membrane electroacidification (BMEA) is a technology offering the coupled effect of demineralization and acidification by using the properties of bipolar membranes to dissociate water molecules at their interfaces and of cation exchange membranes (CEM) to demineralize by migration of low molecular weight ionic species. The aim of the present study was to demonstrate the feasability of BMEA to fractionate whey proteins and to study the effect of protein concentration on its performance in comparison with chemical acidification. These results demonstrated the feasability of BMEA for whey protein separation and the influence of the initial protein concentration on the purity and yield of the separated fraction. At 5% whey protein isolate (WPI) initial concentration, this technology allows the separation of 98% pure β-lactoglobulin (β-lg) fraction with a 44.0% recovery yield. At 10% WPI initial concentration, BMEA allows the production of a β-lg-enriched fraction containing 97.3 of β-lg and 2.7% α-lactalbumin (α-la), for a 98% total protein purity.