(492d) Oligosaccharide Synthesis in Different Continuous Membrane Reactor Systems

There is a worldwide increasing demand from the consumers for healthier and calorie-controlled foods. Oligosaccharadies (OS), such as fructooligosaccharides (FOS) and galactooligosaccharides (GOS), are considered to be physiologically favourable functional food ingredients which promote the growth of bifidobacteria, and also a wide variety of health benefits has been claimed in connection with this effect. They also help in: (i) reduction of serum cholesterol level; (ii) synthesis of B-complex vitamins; and (iii) enhance absorption of dietary calcium. OS can be thought of as low molecular weight, non-viscous, water-soluble, dietary fibre. OS is a valuable nutritional supplement that is commercially produced by enzymatic synthesis from sucrose that is the substrate for FOS production, or from lactose that is used for GOS synthesis. The enzymatic catalysis is a complex process involving a multitude of sequential reactions leading to the final products. The amount and nature of the OS formed in the enzymatically catalyzed process depends upon several factors including the enzyme source, the concentration and nature of the substrate, the degree of conversion of the substrate, and the reaction conditions. Different membrane supported technologies have been successfully developed and employed for OS synthesis. In this study, the following three continuous membrane reactor systems are presented: (i) single- and multi-stage continuous stirred tank reactor equipped with external membrane module, (ii) chromatography membrane reactor system with immobilized enzymes, and (iii) tubular pipe-in-pipe ceramic membrane reactor system containing two coaxial flow channels. The major challenge in OS production is to achieve a high yield and a high purity of OS. This study provides a comparison of the different membrane reactor systems regarding to their key technical features, operating characteristics, and OS yields.