Quantification of major milk oligosaccharides in a range of formulated milk powder products using high performance liquid chromatography-multi reaction monitoring-mass spectrometry

In formulated milks for infants and children, oligosaccharides such as galacto-oligosaccharides and/or fructo-oligosaccharides are commonly added. This paper, however, discusses the determination of the concentration in infant and follow-on formulations of the major acidic oligosaccharides: 3′-sialylactose (3′SL), 6′-sialylactose (6′SL), 6′-sialyllactosamine (6′SLN) and disialyllactose (DSL) that are endogenous to bovine milk. These oligosaccharides were measured in infant, follow-on and growing up formulas purchased in the Chinese and Malaysian markets. Of these oligosaccharides, 3′SL was the most abundant, followed by 6′SL and 6′SLN, but DSL was not quantifiable due to its concentration being lower than the limit of quantitation in most samples. We observed little or no differences in the levels of 3′SL or 6′SL in Malaysian and Chinese formulas, but the levels of 6′SLN in all Malaysian samples were found to be higher than those in the samples from China.