Isolation of Milk Oligosaccharides using Solid-Phase Extraction

摘要

A method was developed to isolate mono- and disaccharide-free oligosaccharides from human and bovine milkusing a combination of enzymatic digestion of lactose and solid-phase extraction. In the initial trial, 2.5 g of oligosaccharideswere isolated from one liter of human milk. In subsequent trials this was increased to over 5 g of oligosaccharidesper liter. Compared to filtration-based extraction methods, this procedure allows for further isolation of oligosaccharidefractions via modulation of the column rinsing solvent. Neutral monosaccharide composition of the oligosaccharide polymerswas investigated using gas chromatographic analysis of the monosaccharides as alditol acetate derivatives. Resultsindicate oligosaccharides are approximately made up of 24% fucose, 41% galactose, 22% glucose and 13% glucosamine.Isolated bovine and human milk oligosaccharides were compared to lactose as fermentation substrates for Bifidobacteriumlongum biovar infantis. Lactose fermentation yielded the greatest production of biomass followed by bovine and humanmilk oligosaccharides.