jf0c04603_si_001.pdf (253.49 kB)
Molecularization of Foam-Active Saponins from Sugar Beet Side Streams (Beta vulgaris ssp. vulgaris var. altissima)
journal contribution
posted on 2020-09-11, 16:05 authored by Matthias Edelmann, Corinna Dawid, Katharina Hochreiter, Theo Ralla, Timo D. Stark, Hanna Salminen, Jochen Weiss, Thomas HofmannThis work focuses
on the isolation and characterization of saponins with a very low
bitter intensity originating from sustainable plant materials, in
particular the sugar beet pulp by-product stream. Via a concise foam
activity screening of saponin-containing materials, which gives indications
for their emulsifying ability, sugar beet root extract was selected
and examined for low bitter saponins by means of activity guided fractionation.
Individual saponins were isolated from sugar beet pulp, which was
identified as the most convenient sugar beet saponin source. Liquid
chromatography–tandem mass spectrometry (LC–MS/MS) analysis
and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic
resonance (NMR) spectroscopy led to the unequivocal identification
of the major, slightly bitter tasting compounds as a series of eight
saponins. The complete assignment of 1H and 13C NMR signals for several saponins was carried out for the first
time. A small-scale foam activity assay was established and applied
to a broad spectrum of the isolated and commercially available saponins.
Additionally, orosensory recognition thresholds were determined. Not
only high recognition thresholds were determined (thresholds >1000
μmol/L) but also fundamental information about the foaming behavior
of mono- and bidesmosidic saponins was collected. The obtained results
are relevant to the utilization of saponins from other plant materials
or by-product streams and for the use of sugar beet saponins as food
additives.