Capillary electrophoresis analysis of industrial galactooligosaccharides

Galactooligosaccharides are added to infant formula to simulate some of the benefits associated with human milk oligosaccharides, in particular to modulate the gut microbiota. During our study the galactooligosaccharide content of an industrial GOS ingredient was determined by differential enzymatic digestion using amyloglucosidase and beta-galactosidase. The resulting digests were fluorophore labeled and analyzed by capillary gel electrophoresis with laser induced fluorescence detection. Quantification of the results were based on a lactose calibration curve. Utilizing this approach, the galactooligosaccharide concentration of the sample was determined as 37.23 g/100 g, very similar to earlier HPLC results, but requiring only 20 min separation time. The CGE-LIF method in conjunction with the differential enzymatic digestion protocol demonstrated in this paper offers a rapid and easy to use method to measure galactooligosaccharides and should be applicable to the determination of GOS in infant formulas and other products.

Automated summary

In this study, the galactooligosaccharide content of an industrial GOS ingredient was determined using differential enzymatic digestion and capillary gel electrophoresis with laser induced fluorescence detection. The concentration of galactooligosaccharides in the sample was found to be 37.23 g/100 g, similar to previous HPLC results but with a shorter separation time of 20 minutes. The CGE-LIF method combined with the enzymatic digestion protocol provides a rapid and easy way to measure galactooligosaccharides in infant formulas and other products.