Availability of membrane technology for purifying and concentrating oligosaccharides

The effectiveness of combined membrane processing with ultrafiltration (UF) and nanofiltration (NF) for purifying and concentrating oligosaccharides from chicory rootstock was examined. Commercially available powdered chicory rootstock was adopted as the model material for the process. First, a crude extract solution was prepared by dissolving and stewing the powder in hot water, the solution was prefiltered using soy cloth and then the solution was clarified by UF and purified and concentrated by NF. The resulting NF retentate, in which mono- and disaccharide content was reduced from 9.0% of the initial solution to 2.6%, was obtained as a 20-fold concentrated product. High-performance liquid chromatography analysis showed that the NF membrane had specificity of rejection for saccharides of particular degrees of polymerization and rejection performance remained constant throughout the processing. On the whole, the results indicate that the combined membrane-processing system is quite promising for value-added products using purified and concentrated oligosaccharides.