BIOT 254 |
| In this project we developed a production process of galacto-oligosaccharides (GOS) and posterior chromatographic separation for separating and purifying GOS. GOS, also known as Bifidus growth factor, are produced from whey permeate or lactose. GOS and other non-digestible oligosaccharides are known to have many beneficial health effects, and are expected to have wide applications as prebiotic food ingredients and dietary supplements. The process for GOS production from whey lactose involves two sequential immobilized enzyme reactors and a chromatographic separation process for purification of GOS. Lactases, β-glycosidase enzymes, from Aspergillus oryzae (fungi) and Bacillus circulans (bacterium) were used to convert lactose to GOS by a transgalactosylation reaction. Products containing 28% of GOS (at 50% conversion) and 40% of GOS (at 60% lactose conversion) were obtained using lactase from A. oryzae and B. circulans, respectively. Two sequential plug-flow reactors with the immobilized β-galactosidases were used to convert lactose (400g/L) to GOS with a high productivity of 2000 g/L/h, which is about 100-fold higher than most other processes. To further increase the GOS content in the final product, a simulated moving bed (SMB) chromatographic technique was studied to separate GOS from lactose and monosaccharides. SMB offers a high efficiency due to the continuous operation and efficient use of the mobile and stationary phases, allowing high sample loading with improved productivity and saving 90% in solvent consumption as compared with conventional liquid chromatography methods. |
|
Poster Session
5:30 PM-7:30 PM, Wednesday, August 22, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Biochemical Technology |