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 ¹H and ¹³C Nuclear Magnetic Resonance (NMR) spectroscopy analysis which demonstrated the glycosylation of lactose with α-(1 → 2), α-(1 → 3) and α-(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 α-amylase conditions. The prebiotic effect of lactose derivative hetero-oligosaccharides was tested and no growth in pathogenic strains was observed whereas certain probiotic strains utilised lactose derivative hetero-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.