the present invention relates to the transformation of food - grade sugars containing d - fructose , in caramels enriched in oligosaccharides with prebiotic activity by using solid acid catalysts , such as zeolites , clays or ion - exchange resins in its acid form , under heterogeneous conditions , or by using soluble acid polymer catalysts of high molecular weight , under homogeneous conditions , with the possibility of recycling the catalyst , being compatible with discontinuous or continuous production processes . the resulting caramel exhibits prebiotic properties , favoring the development of a beneficial intestinal flora and a repairing effect in the damaged colon .