| abstract |
Polyphenolic substances such as food dyes, tannins, fruit juices and wine colourings are removed from a solution by adsorption onto a regeneratable adsorbent polyamide of extended surface and controlled porosity. The surface chemistry of the polyamide may be modified by a glutaraldehyde/resorcinol treatment. The polyphenolic substances are recovered by elution with water or other protonic solvent. |