Separation of lactose from human milk oligosaccharides with simulated moving bed chromatography

The successful separation of the disaccharide lactose from a complex mixture of human milk oligosaccharides (HMOS) with the continuous chromatography of simulated moving bed (SMB) technique is described. Since lactose is the main carbohydrate in human milk with well-known functions for the infant, it is necessary to separate it from the rest of the oligosaccharides to divide them into less complex fractions and analyse their partial unknown functions. For separation of lactose from HMOS two different stationary phases (size-exclusion gel as well as ion-exchange gel) were used. As the main result, it is shown that a size-exclusion gel with the particle size of 50-100 μm and porosity of 50 Å was the preferred stationary phase for our separation process with almost complete lactose separation and stable conditions.