One-Step Purification of Lactoferrin from Crude Sweet Whey Using Cation-Exchange Expanded Bed Adsorption

In order to purify lactoferrin from crude sweet whey in one step, an expanded bed adsorption process was proposed with cation-exchanger Fastline SP. A series of experiments were carried out to assess the possibility of this process and optimize the operating conditions. First the adsorption equilibrium and kinetics of lactoferrin with Fastline SP were measured. The results indicated that Fastline SP had a fast adsorption of lactoferrin and was suitable for high-velocity operation. Then the expansion properties, liquid mixing, and breakthrough behaviors in the expanded bed were investigated, and the expansion factor was set at 2.0. In addition, the elution condition was optimized as 0.5 M NaCl in the phosphate buffer (pH 7.0). Finally, lactoferrin was successfully recovered with a high purity of 88.5% and a reasonable recovery of 77.1% in a single step. The purification factor reached 553.