Sweetener Chromatographic separation

Chromatography is a technology of choice for large scale and continuous purification nutrition processes, allowing the separation of several components by using different principle operating on Strong Acid Cation (SAC) resins:

Ion exclusion on SAC, K⁺ form: molasse de-sugarisation
Size exclusion on a SAC Na⁺ or K⁺ form: glucose enrichment
Ligand exchange on a SAC Ca²⁺ form: glucose-fructose, mannitol-sorbitol, glucose-galactose separation

The main resin specification are the bead size (from 220 µm to 350 µm), the uniformity coefficient (UC less 1,1), and the % DVB-crosslinking (from 5 to 8%), and depending the process different forms available (Ca²⁺ , Na⁺, K⁺)

These specifications of the resin will affect the separation (product purity) and the process conditions:

Small particle size decreases the theoretical plate height and therefore improves the separation, but increases the pressure drop of the resin bed so limiting the flow rate.
Narrow size distribution will allow better separation
Low DVB content improves the separation but reduce the chemical resistance (possible oxidation of the resin) and increase also the pressure drop.

The limiting factors are the pressure drop, and the oxidation of the resin.

Several chromatographic systems are existing, but the most common ones are the simulated moving bed (SMB) for the separation of two components, and the sequential SMB for more than two components.