Process for demineralising a milk protein composition, milk protein composition obtainable by said process, and facility for implementing said process

A process for manufacturing a demineralised milk protein composition (MPC2), wherein it comprises the following steps:

• (i)—providing a milk protein composition (MPC) comprising anions, monovalent cations and divalent cations;
• (ii)—electrodialysis of the milk protein composition (MPC) on a first electrodialyser, said first electrodialyser comprising unit cells, each unit cell comprises three compartments:
• a first compartment supplied with at least acid salt, a second compartment delimited between two cationic membranes and receiving said milk protein composition (MPC), and a third compartment, wherein each unit cell is configured to substitute at least a part of the monovalent cations and divalent cations of the milk protein composition (MPC) by hydrogen ions H+ coming from the first compartment in the milk protein composition (MPC) to obtain an at least partially demineralised and acidified milk protein composition (MPC1) having a pH less than or equal to 4, wherein step (ii) is a step of substitution exclusively of cations;
• (iii)—electrodialysis of the milk protein composition (MPC1) obtained in step (ii) on a second electrodialyser, said electrodialysis step (iii) comprises the extraction of both anions and cations;
• wherein said process comprises the addition of at least one basic solution to the milk protein composition during at least one of the following:
• during step (iii);
• during step (iii) and after step (iii);
• after step (iii), to raise the pH of the milk protein composition (MPC1);
• (iv)—recovering the demineralised milk protein composition (MPC2).