Chromatographic Separation of Isomaltooligosaccharides on Ion-Exchange Resins: Effect of the Cationic Form

Abstract

Prebiotic isomaltooligosaccharides (IMOs) are composed of α-Dglucose units linked by glucosidic α (1∅6) bonds and they remain intact until reaching the large bowels, where they are metabolized by bifidobacteria and lactobacillus. These saccharides can also be synthesized enzymatically, wherein the reaction media is composed of monosaccharides (glucose and fructose), disaccharides (sucrose and maltose), IMOs (the product of interest) and dextrans. Dextrans are readily separated by solvent precipitation; however, continuous chromatographic separation (simulated moving bed or SMB) should be an interesting option for the enrichment and purification of IMOs from monoand disaccharides. The objective of the present work was to measure fundamental adsorption data of IMOs, mono-and disaccharides in preparative columns packed with ion-exchange resin of different cationic forms (K + , Ca + , H + and Na + ), so as to verify the influence of the cation on the selectivity and capacity. Ion exchange in H + form showed the best performance in terms of selectivity between maltose and maltotriose, but the resin in the K + form had superior adsorption capacities. Additionally, on the basis of equilibrium theory, optimal SMB operating conditions for resin H + will yield the highest productivity as compared with the other cationic forms.

Gluco‐oligosaccharides as potential prebiotics: Synthesis, purification, structural characterization, and evaluation of prebiotic effect

“…The strength of the formed cation–sugar complexes determines the degree of sugar adsorption, which is dependent on the number and orientation of the OH groups, and also the hydration and ionic radius of the counterion (Havlicek & Samuelson, 1975; Jones et al., 1960). It was reported that the strongly acidic cation‐exchange resins in different cationic forms (H + , Na + , K + , and Ca 2+ ) all preferentially adsorb monosaccharides (e.g., glucose and fructose) over disaccharides (e.g., sucrose and maltose) and IMOs with higher DP (Rabelo et al., 2012), which is mainly attributed to the size exclusion effect. A similar adsorption study was conducted on GOS (Wisniewski et al., 2014).…”

“…A similar adsorption study was conducted on GOS (Wisniewski et al., 2014). Both studies found that sulfonated PS‐DVB in the H + form showed the highest productivity and selectivity for oligosaccharides separation (Rabelo et al., 2012; Vente et al., 2005). The strongly basic anion exchange resins functionalized with quaternary ammonium groups have also been used for the separation of anionic and neutral oligosaccharides (Lee, 1996).…”