Enzymatic Decoration of Prebiotic Galacto-oligosaccharides (Vivinal GOS) with Sialic Acid Using Trypanosoma cruzi trans-Sialidase and Two Bovine Sialoglycoconjugates as Donor Substrates.

Decoration of prebiotic galacto-oligosaccharides (GOS) with sialic acid yields mixtures of GOS and sialylated GOS (Sia-GOS), novel products that are expected to have both prebiotic and antiadhesive functionalities. The recombinantly produced trans-sialidase enzyme from Trypanosoma cruzi (TcTS), an enzyme with the ability to transfer (α2-3)-linked sialic acid from sialogalactoglycans to asialogalactoglycans, was employed to catalyze this sialylation. As sialic acid acceptor substrates, Vivinal GOS and derived fractions of specific degree of polymerization were taken.

Introducing capillary electrophoresis with laser-induced fluorescence (CE-LIF) as a potential analysis and quantification tool for galactooligosaccharides extracted from complex food matrices.

The analysis and quantification of (galacto)oligosaccharides from food matrices demands both a reproducible extraction method as well as a sensitive and accurate analytical method. Three typical matrices, namely, infant formula, fruit juice, and a maltodextrin-rich preparation, to which a commercial galactooligosaccharide mixture was added in a product concentration range from 1.25 to 30%, served as model substrates.

In-depth characterization of prebiotic galacto-oligosaccharides by a combination of analytical techniques.

A commercial prebiotic galacto-oligosaccharide mixture (Vivinal GOS) was extensively characterized using a combination of analytical techniques. The different techniques were integrated to give complementary information on specific characteristics of the oligosaccharide mixture, ranging from global information on degree of polymerization (DP) to the identity and concentration of individual oligosaccharides. The coupling of high-performance anion-exchange chromatography (HPAEC) to mass spectrometry (MS) was determined to be especially suitable to assign the DP of individual oligosaccharides on the basis of their m/z values as well as their quantification using external standards.