title: Fractionation of a galacto-oligosaccharides solution at low and high temperature using nanofiltration.
abstract: Like in many applications, solutions of high sugar content can cause serious problems due to microorganism contaminations. Hence, the main aim of this work was to study a nanofiltration process for GOS purification at 5 °C and 60 °C that may circumvent or reduce potential microbial growth. Process performances and rejection behaviors of monosaccharide as well as individual GOS components were compared. Operating at 5 °C is more advantageous especially with respect to the oligosaccharide (OS) recovery yield. Using a NF membrane (NP030) at 45 bar, a product purity of 85% (based on monosaccharide content) and an OS recovery yield of 82% could be achieved. However, a low average permeate flux of 3 L/m2h had to be accepted. A diafiltration step improved product purity to 90% with 30% losses of OS. A qualitative theoretical discussion shows that a possible change of the pore radius distribution depending on temperature could play a role in solute rejection as well as selectivity.
authors.affiliation: Department of Biotechnology, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom 73000, Thailand.
authors.forename: Suwattana
authors.initials: S
authors.lastname: Pruksasri
authors.affiliation: Institute of Food Technology, BOKU University of Natural Resources and Life Sciences, Vienna, Austria.
authors.forename: Thu-Ha
authors.initials: TH
authors.lastname: Nguyen
authors.affiliation: Institute of Food Technology, BOKU University of Natural Resources and Life Sciences, Vienna, Austria.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Haltrich
authors.affiliation: Institute of Food Technology, BOKU University of Natural Resources and Life Sciences, Vienna, Austria.
authors.forename: Senad
authors.initials: S
authors.lastname: Novalin
keywords: Galacto-oligosaccharides (GOS); Nanofiltration; Pore radius distribution; Rejection; Selectivity