Identification and purification of pigments in red speckled kidney bean(Phaseolus vulgaris L.) by macroporous resin

In order to determine the optimum macroporous resin and condition for purifying pigments extracted from red speckled kidney bean(Phaseolus vulgaris L.), the adsorption and desorption properties of five different resins were studied. Also, paper chromatography and ultraviolet-visible spectrum methods were applied to identify the pigments purified by macroporous resins. Results show that macroporous resin HPD400 is favorable in purification of the kidney bean pigments: adsorption rate of pigments(solvent pH 1) to HPD400 resin is 88.38%. 75% ethanol(pH 2) is suitable for elution. And, there are two main components of the purified pigments, which are primarily identified as pelargonidin -3-glucoside and peonidin-3-glucoside.