Separation and purification of anthocyanins from Roselle by macroporous resins

Anthocyanin is a kind of natural pigment with wide-range industrial application. In the present study, anthocyanins from Roselles were purified through macroporous resins adsorption and desorption process. Roselle anthocyanins were first extracted by water containing 0.2% HCl. Then, the adsorption/desorption performance of six resins was compared. The results showed that the adsorption capacity of DM28 was the largest, while the adsorption rate of DM21 was the fastest among the six resins. The static adsorption isotherm of the resins was simulated by Langmuir and Freundlich models, and the Freundlich model fitted better. The mass transfer zone model was used to analyze the dynamic adsorption of resins on a fixed bed. The mass transfer zone of each resin was calculated and the length of DM21 was the shortest. Anthocyanins in Roselle extract were successfully adsorbed by DM21 fixed bed, and then desorbed by 70% ethanol. After lyophilization, the anthocyanin content in the product was 6-fold increased with value of 214 mg/g. UPLC-QTOF analysis showed that delphinidin-3-O-sambubioside and cyanidin-3-O-sambubioside are the dominant anthocyanins in the product.