Method for preparing a purified madder root extract

摘要

The invention pertains to a method for preparing a purified madder root extract comprising the steps of providing a madder root extract comprising one or more contaminants selected from rubiadin and lucidin with a pH of at least 8, contacting the extract with a polystyrene-based resin, and recovering an extract from which contaminants selected from rubiadin and lucidin have been removed at least in part.;It has been found that by the method according to the invention rubiadin and lucidin can be effectively removed from a madder root extract.