A process for isolating the metalloprotein lactoferrin and the enzyme lactoperoxidase from milk and milk products on an industrial scale is disclosed. The process includes the steps of adsorbing these proteins to a cation exchanger by passing milk or the milk derivatives over the cation exchanger at a high superficial velocity (more than 500 cm per hour) and at a high liquid load (100-600 bed volumes per hour); eluting these proteins, separately or simultaneously, by elution with one or more salt solutions, so as to form one or more eluates; and optionally followed by drying of the eluates.