Untersuchungen über Getreideschleimstoffe II. Über die Gelierung wässeriger Lösungen von Weizenmehlpentosanen durch Oxydationsmittel

Aqueous extracts of wheat flour are known to gel readily in the presence of small amounts of oxidizing agents. It is shown by chromatographic fractionation on DEAE‐cellulose that the glycoproteins present in aqueous flour extracts are responsible for the gelation. The UV.‐spectra of the glycoproteins show an absorption maximum at 320 mμ in addition to the protein maximum at 275 mμ. The maximum at 320 mp is enhanced and shifted to longer wave‐lengths by the addition of borate or germanate. This indicates the presence of an o‐dihydroxy or an aliphatic ene‐diol structure in the glycoproteins. Furthermore the maximum at 320 mμ disappears upon oxidation. It is likely that the gelation is caused by an oxidation of the dihydroxy grouping, followed by the formation of cross‐links between the glycoprotein molecules.