Introducing Capillary Electrophoresis with Laser-Induced Fluorescence Detection (CE-LIF) for the Characterization of Konjac Glucomannan Oligosaccharides and Their in Vitro Fermentation Behavior

Abstract

The application of capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) as a tool for the characterization of complex carbohydrate structures was investigated for konjac glucomannan (KGM) oligosaccharide mixtures and the monitoring of their structural changes during 72 h of in vitro fermentation with human gut flora. Different types of KGM oligosaccharide mixtures were produced from a KGM polysaccharide using endo-beta-(1,4)-mannanase and endo-beta-(1,4)-glucanase. Distinction of structures emerging from different enzymatic KGM digests and detection of acetylated oligosaccharides were possible by both CE-LIF and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Using CE-LIF it could be shown that the endo-beta-(1,4)-glucanase digest exhibited a large degradability of the DP2, DP3, DP5, and DP6 components during in vitro fermentation, whereas the endo-beta-(1,4)-mannanase digest was digested only slightly, thereby highlighting the influence of structural characteristics on the fermentability by human gut flora.

Effect of galactooligosaccharides andBifidobacterium animalisBb-12 on growth ofLactobacillus amylovorusDSM 16698, microbial community structure, and metabolite production in anin vitrocolonic model set up with human or pig microbiota

“…To evaluate the use of GOS by the microbiota, the extent of oligosaccharide degradation was determined in samples collected from TIM-2 (conditions ii and iii) by High performance anion exchange chromatography (HPAEC) on a Dionex ISC 3000 system (Dionex, Sunnyvale, CA), equipped with a Dionex CarboPac PA-1 column (2 9 250 mm) in combination with a CarboPac PA-1 guard column (2 9 50 mm) (Albrecht et al, 2009). Briefly, samples were adjusted to a final theoretical concentration of 0.05 mg mL À1 GOS (assuming no degradation), heated at 100°C for 10 min for inactivation of digestive enzymes, and 20 lL was injected through a Dionex ISC3000 autosampler.…”

CE‐LIF‐MSn profiling of oligosaccharides in human milk and feces of breast‐fed babies

“…For CE analysis, SPE-extracted carbohydrates present were derivatized with the fluorescent APTS overnight at room temperature as reported elsewhere [26]. Briefly, 1 nmol xylose was added to each sample volume (100-200 mL) as internal standard and mobility marker.…”

Capillary electrophoresis for monitoring bioprocesses

“…Glucose, galactose, and xylose were also analyzed in kefiran and in milk fermentation using kefir grains . CE‐LIF was used to monitor changes in konjac glucomannan oligosaccharide mixtures through in vitro fermentation with human gut flora . CE with UV detection was applied for monitoring microbial liquid fermentation production of xylitol from xylose within 6 min .…”