Separation of xylo-oligosaccharides using ultra- and nanofiltration membranes and investigation of their prebiotic effect

Introduction: Xylo-oligosaccharides (XOS) are potential prebiotics composed of xylose units linked by β-(1-4)-xylosidic bonds. In addition to health benefits, their favourable physicochemical properties and moderate sweetness make them suitable nutritional ingredients for food and feed products. Unlike other prebiotics, XOS can be produced from agricultural and wood residues (corn cobs/stalks, bagasse, rice hulls, birch wood, etc.) by enzymatic hydrolysis of xylan, the main hemicellulosic part of the mentioned sources. This strategy, which includes using renewable plant sources as a source of xylan and enzymes, represents an environmentally friendly process compared to conventional methods and results in a mixture of XOS of various degrees of polymerization (DP), unreacted xylan, and monosaccharide units (xylose). Given that the prebiotic potential of XOS depends on the DP and purity, this research is focused on applying membrane separation techniques to obtain a mixture of higher purity and defined molecular weight with optimal prebiotic activity.