The enzymatic saccharification of starch with Aspergillus niger glucoamylase (GA) and the isomerisation of glucose to fructose with Actinoplanes missouriensis glucose isomerase (GI) were selected as model system to explore the possibilities of using ultrafiltration membrane (UF) devices as enzymatic membrane reactors (EMR). Cassava flour was the substrate for the production of glucose syrups in two different configurations of EMR: a dead-end cell (EMR1) and a continuous stirred tank recycled through a hollow fibre device (HFMR). The optimisation of the process in the latter was also investigated.