Enzymatic Synthesis of Prebiotic Carbohydrates from Lactose: Integration of Osmotic Membrane Distillation with Batch Reactor System

Abstract

This study aimed to enhance galactooligosaccharide (GOS) yield by maintaining high lactose concentration levels using osmotic membrane distillation (OMD) throughout the synthesis. The main problem influencing GOS yield during transgalactosylation is the decrease of lactose concentration over extended reaction periods. By integrating OMD with a continuous stirred batch reactor, water was progressively removed from the reaction medium. Compared to a standard batch reactor, the OMD-integrated system not only increased GOS yield by a maximum of 20.1% but also reduced the time needed for equivalent lactose conversion about 15–90 min. This integration particularly boosted the formation of longer-chain GOS. A consistent GOS yield of 67% was achieved, with up to 28% lactose conversion, surpassing the non-integrated reactor’s performance. The proposed reactor design shows promise for enhancing GOS production efficiency while concurrently concentrating the reaction medium in a single step.