Abstract
Mixed matrix membranes (MMMs), which incorporate adsorptive particles during membrane casting, can be prepared simply and have performances that are competitive with other membrane chromatography materials. The application of MMM chromatography for fractionation of β‐Lactoglobulin from bovine whey is described in this article. MMM chromatography was prepared using ethylene vinyl alcohol polymer and lewatit anion exchange resin to form a flat sheet membrane. The membrane was characterized in terms of structure and its static and dynamic binding capacities were measured. The optimum binding for β‐Lactoglobulin was found to be at pH 6.0 using 20 mM sodium phosphate buffer. The MMM had a static binding capacity of 120 mg/g membrane (36 mg/mL membrane) and 90 mg/g membrane (27 mg/mL membrane) for β‐Lactoglobulin and α‐Lactalbumin, respectively. In batch fractionation of whey, the MMM showed selective binding towards β‐Lactoglobulin compared to other proteins. The dynamic binding capacity of β‐Lactoglobulin in whey solution was about 80 mg/g membrane (24 mg β‐Lac/mL of MMM), which is promising for whey fractionation using this technology. This is the first reported application of MMM chromatography to a dairy feed stream. Biotechnol. Bioeng. 2009;103: 138–147. © 2008 Wiley Periodicals, Inc.