Preparation of high-purity lactulose through efficient recycling of catalyst sodium aluminate and nanofiltration: a pilot-scale purification.

Background: Lactulose, a valuable lactose-originated 'bifidus factor' product, is exclusively produced by chemical-based isomerization commercially. A complexing agent of sodium aluminate exhibiting high conversion efficiency and strong recyclable stability is more practical for industrial applications. In this study, efficient purification of high-purity lactulose through recycling of sodium aluminate and further desalination by nanofiltration (NF) was implemented on a pilot scale.