Application of Ion Exchange and Adsorption Techniques for Separation of Whey Proteins from Bovine Milk

Abstract

Background: The world’s production of whey is estimated to be more than 200 milliontons per year. Although whey is an important source of proteins with high nutritional value andbiotechnological importance, it is still considered as a by-product of the dairy industry with loweconomic value due to low industrial exploitation. There are several challenges in the separation ofwhey proteins: low concentration, the complexity of the material and similar properties (pI, molecularmass) of some proteins.Methods: A narrative review of all the relevant papers on the present methodologies based on ionexchange and adsorption principles for isolation of whey proteins, known to the authors, was conductedResults: Traditional ion exchange techniques are widely used for the separation and purification ofthe bovine whey proteins. These methodologies, based on the anion or cation chromatographicprocedures, as well as the combination of aforementioned techniques are still preferential methodsfor the isolation of the whey proteins on the laboratory scale. However, more recent research on ionexchange membranes for this purpose has been introduced, with promising potential to be appliedon the pilot industrial scale. Newly developed methodologies based either on the ion exchangeseparation (for example: simulated moving bed chromatography, expanded bed adsorption, magneticion exchangers, etc.) or adsorption (for example: adsorption on hydroxyapatite or activatedcarbon, or molecular imprinting) are promising approaches for scaling up of the whey proteins’purification processes.Conclusion: Many procedures based on ion exchange are successfully implemented for the separationand purification of whey proteins, providing protein preparations of moderate-to-high yieldand satisfactory purity. However, the authors anticipate further development of adsorption-basedmethodologies for the separation of whey proteins by targeting the differences in proteins’ structuresrather than targeting the differences in molecular masses and pI. The complex composite multilayeredmatrices, including also inorganic components, are promising materials for simultaneousexploiting of the differences in the masses, pI and structures of whey proteins for the separation.