Isolation of Milk Oligosaccharides using Solid-Phase Extraction

Abstract

Abstract:A method was developed to isolate mono-and disaccharide-free oligosaccharides from human and bovine milk using a combination of enzymatic digestion of lactose and solid-phase extraction. In the initial trial, 2.5 g of oligosaccharides were isolated from one liter of human milk. In subsequent trials this was increased to over 5 g of oligosaccharides per liter. Compared to filtration-based extraction methods, this procedure allows for further isolation of oligosaccharide fractions via modulation of the column rinsing solvent. Neutral monosaccharide composition of the oligosaccharide polymers was investigated using gas chromatographic analysis of the monosaccharides as alditol acetate derivatives. Results indicate 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 Bifidobacterium longum biovar infantis. Lactose fermentation yielded the greatest production of biomass followed by bovine and human milk oligosaccharides.

Role of IR-improvement in Precision LHC/FCC Physics and in Quantum Gravity

“…In the FCC and other future collider frameworks, the attendant precision physics programs necessitate IR-improved quantum field theory results to exploit properly the respective new physics windows. In quantum gravity, it has been found that resummed IR leads to UV finiteness [10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25]. In what follows, we expand on these developments in IR-improvement of quantum field theory from the standpoint of applications to precision LHC/FCC physics and applications of one of us (BFLW) of quantum gravity.…”

“…One of us (BFLW) has shown [22,23,24,25] that the RQG realization of quantum gravity leads to Weinberg's [91] UV-fixed-point behavior for the dimensionless gravitational and cosmological constants and that the resummed theory is actually UV finite. He has shown further that the RQG theory, taken together with the Planck scale inflationary [92,93] cosmology formulation in Refs.…”

Advances in Fractionation and Analysis of Milk Carbohydrates

“…Intensive biochemical characterization of the carbohydrate molecules and their various bioactivities may facilitate an understanding of their importance in human nutrition and may suggest individual carbohydrate structures to target for industrial production [6]. Recently, many studies reveal the biological significance of some carbohydrates and their potential role as nutraceuticals.…”

An improved method for the purification of milk oligosaccharides by graphitised carbon-solid phase extraction

“…The smallest OS, with a degree of polymerisation of 3, will often behave similarly to lactose when OS are enriched by polarity or size-based methods. Lactose can be hydrolysed enzymatically during sample preparation (Ninonuevo et al, 2007; Ward, 2009). The resulting monosaccharides are smaller and may be separated by size-exclusion approaches; however, it is often preferable to forgo this hydrolysis to avoid OS degradation and improve throughput.…”

“…Although previous publications have characterised the excellent retention characteristics of graphitized carbon in the context of glycan desalting and preconcentration (Packer, Lawson, Jardine, & Redmond, 1998; Redmond & Packer, 1999; Ward, 2009), the efficiency of the technique in separating milk OS and lactose has not been well-characterised, despite its widespread use for this purpose. Past chromatographic and extraction studies have shown that disaccharides, including lactose, can be substantially retained by graphitised carbon (Davies, Smith, Harbin, & Hounsell, 1992; Koizumi, Okada, & Fukuda, 1991; Redmond & Packer, 1999), indicating that extraction conditions would need to be carefully optimised for successful milk OS concentration by porous graphitized carbon (PGC) when lactose is present.…”