Simultaneous determination of mono-, di-, oligo- and polysaccharides via planar chromatography in 4 different prebiotic foods and 60 naturally degraded inulin samples

Oligo- and polysaccharides, especially fructooligosaccharides and inulin, are increasingly used as food ingredients. They are reported to stimulate the growth of bifidobacteria and are therefore used as prebiotics. As mono-, di-, oligo- and polysaccharides can together be present in food, an HPTLC method was developed for analyzing all in a single development. This method was used for both, effective food screening and quantification on the same plate. After a minimal sample preparation (aqueous extraction, dilution and filtration) and application, the samples were separated on an HPTLC plate silica gel 60 with acetonitrile - water 4:1 (V/V), containing 3.6 mM natural product reagent A. For a good reproducibility of the separation, the control of the layer activity was recommended. For up to 20 samples in parallel, the HPTLC analysis took 45 min (2.3 min/sample) with running costs of ca. 7 Euro (0.35 Euro/sample). Determination coefficients of the calibration curves were obtained between 0.9980 and 0.9998. The high degree of automation proved the method to be robust and suited for routine analysis, especially in food control. The newly developed method was successfully tested with 4 different prebiotic food and 60 naturally degraded inulin samples. A minimal sample preparation along with the determination of the intact inulin and FOS allowed the evaluation of the natural inulin degradation profile, as shown for naturally degraded inulin samples. This fast analysis might also be of interest in other fields that study, for example, plant breeding, edible insects, functional feed and metabolic processes.