Designed to enhance the dietary fiber content or reduce the caloric load of foods, an oligosaccharide ingredient can be added to a wide variety of food products to replace conventional carbohydrates. The ingredient is produced using a water-like composition that comprises at least one oligosaccharide and one monosaccharide by saccharification of starch. Membrane-filtering of the composition forms a monosaccharide-rich stream and an oligosaccharide-rich stream.