| abstract |
Polyphenol substances, such as food colors, tannins, fruit juices and wine colors, are extracted from a solution by adsorption on an adsorbent polyamide which can be regenerated and has a large surface area and controlled porosity. The surface chemistry of the polyamide can be modified by treatment with glutaraldehyde-resorcinol. The polyphenol substances are recovered by elution with water or with another proton solvent. |