Production of lactose derivative hetero-oligosaccharides from whey by glucansucrase E81 and determination of prebiotic functions

Bioactive oligosaccharides are important compounds for development of functional foods and ingredients. In this study, lactose derivative hetero-oligosaccharides were produced by acceptor reaction of glucansucrase E81 with whey. The synthesis of oligosaccharides was monitored by Thin Layer Chromatography (TLC) analysis followed by (1 ) and C-13 Nuclear Magnetic Resonance (NMR) spectroscopy analysis which demonstrated the glycosylation of lactose with alpha-(1 -> 2), alpha-(1 -> 3) and alpha-(1 -> 4) linkages. Liquid chromatography-mass spectrometry (LC-MS) analysis demonstrated the formation of DP 7 oligosaccharides from whey. The synthesized oligosaccharides were not digested under in vitro human gastric juice and alpha-amylase conditions. The prebiotic effect of lactose derivative hetem-oligosaccharides was tested and no growth in pathogenic strains was observed whereas certain probiotic strains utilised lactose derivative hetem-oligosaccharides as Carbon source and their growth was promoted. These findings can be important to reveal the potential of glucansucrases to produce functional oligosaccharides from different sources including waste materials.