Chromatographic fractionation of food-grade oligosaccharides: Recognizing and avoiding sensory-relevant impurities

Flash chromatography utilizing microcrystalline cellulose (MCC) stationary phases and aqueous ethanol mobile phases have shown promise for the production of food-grade oligosaccharides. The current work extends the scope of these systems by demonstrating their use for the production of food-grade maltooligosaccharide preparations enriched in high degree of polymerization (DP) components. Furthermore, it is shown herein that caution must be exercised when using these MCC-based chromatographic systems in order to avoid sensory-relevant contamination of the final oligosaccharide preparations. Such contamination, most notably off-taste, is shown to arise from impurities common to commercially available MCC that manifest under certain chromatographic scenarios. A mitigation strategy based on washing the stationary phase with appropriate aqueous-ethanol solutions (i.e., accounting for the entire mobile phase concentration range) prior to oligosaccharide fractionation is presented as a means by which to avoid contamination.