Identification of Anthocyanins Isolated from Black Bean Canning Wastewater by Macroporous Resin Using Optimized Conditions

Anthocyanins from black bean canning wastewater were isolated and purified on a laboratory scale by column chromatography, and then identified by high performance liquid chromatography electrospray tandem mass spectrometry. Dynamic adsorption and desorption were performed in glass columns packed with Sepabead Sp700 to optimize the purification process. Different temperatures during adsorption and desorption (25 ̊C and 35 ̊C) did not significantly affect the adsorption and desorption ratio. The adsorption ratio was significantly reduced when the flow rate increased from 1.5 mL/min to 2.5 mL/min. However, desorption ratio was not affected by flow rate (from 1.5 mL/min to 0.3 mL/min). Ethanol concentration (from 30% to 60%) was not a significant factor for desorption ratio. Four kinds of anthocyanins were identified in black bean canning wastewater. The major anthocyanins were delphinidin 3-glucoside, petunidin 3glucoside and maldvidin 3-glucoside, with a small amount of petunidin 3, 5-diglucoside also present.