Separation of di- and trisaccharide mixtures by comprehensive two-dimensional liquid chromatography. Application to prebiotic oligosaccharides.

Carbohydrates are one of the most important ingredients in foods. They are normally present as complex mixtures with different glycosidic linkages, monomeric units and degrees of polymerization. This structural heterogeneity impairs their comprehensive characterization and requires the use of analytical techniques with high resolving power and sensitivity.

Changes in Caprine Milk Oligosaccharides at Different Lactation Stages Analyzed by High Performance Liquid Chromatography Coupled to Mass Spectrometry.

Changes of the abundance of caprine milk oligosaccharides (CMO) at different lactation stages have been evaluated by hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-Q MS) and nanoflow liquid chromatography-quadrupole-time-of-flight mass spectrometry (nano-LC-Chip-QTOF MS). Eight major oligosaccharides (OS) were quantified at different lactation stages by HILIC-Q MS, while the use of nano-LC-Chip-QToF MS allowed expanding the study to forty-nine different OS by monitoring neutral non- and fucosylated species, as well as acidic species containing not only N-acetyl-neuraminic acid or N-glycolyl-neuraminic acid residues but also the combination of both sialic acids. Overall, the most abundant OS decreased with lactation time, whereas different trends were observed for minor OS.