The adequate functionalization of magnetic/organic nanocomposites with beta-galactosidase provides adequate nanoenvironment for reaction media and improved production of galacto-oligosaccharide from lactose with additional advantage related with magnetic removal of enzyme derivative and reuse (our results indicated retention level of 76% after 10 cycles of application). In this work, we have explored different combination of parameters for enzyme action in order to improve the action of magnetic nanopar titles/polypyrrole/enzyme in the galacto-oligosaccharide production. (C) 2016 Elsevier B.V. All rights reserved.