Cyclodextrin glycosyltransferase and dextranase catalyze the conversion of starch into mixtures of (cyclo)dextrins and the hydrolysis of dextran into oligodextrans of various molecular weights, respectively. A severe limitation in transgalactosylation reactions is that the targeted products tend to spontaneously undergo undesired consecutive reactions (i.e. hydrolysis reactions to monosaccharides glucose and galactose) 79 . Besides, it has been observed that such monosaccharides formation inhibits the β-galactosidase (i.e. inhibition of transgalactosylation reaction) , which further highlights the need of a product separation in these processes. Finally, selecting producing oligodextran of tailored molecular weight is also a complicated task. Hence, it clearly appears that, in all these biocatalytic reactions, the coupling with membrane technology is of particular interest, since it would afford to enhance the selectivity of the process, and the purity of the targeted product (i.e. desired molecular weight) by operating adequate size-exclusions membrane operations.