Bipolar Membrane Electroacidification of Demineralized Skim Milk

Abstract

The aim of this study was to evaluate the effect of decreasing the mineral content of skim milk by electrodialysis (ED) prior to electroacidification with bipolar membrane (BMEA) on the performance of the process, the chemical composition, and the physicochemical and functional properties of the isolates produced. ED used to demineralize the skim milk solution was very efficient. However, the electroacidification parameters were influenced by the demineralization level of the skim milk solution: the energy efficiency was decreased with an increase in demineralization, but it was still possible to perform BMEA at a very low conductivity level. Moreover, the isolates produced by BMEA after electrodialysis demineralization at different rates showed similar chemical composition, except on potassium and lactose contents for 75% demineralized isolate. These isolates, except on protein load for 75% demineralization rate, showed similar physicochemical and functional properties, whatever the demineralization rate. Keywords: Electrochemical acidification; electrodialysis demineralization; precipitation kinetic; functional properties; casein isolate