Separation of alpha-lactalbumin and beta-lactoglobulin using membrane ultrafiltration

• Published in: Biotechnology and bioengineering 2003-07, Vol.83 (2), p.201-209
• Main Authors: Cheang, B, Zydney, A.L
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biotechnology; Cellulose; Electrophoresis, Capillary - methods; Fundamental and applied biological sciences. Psychology; Lactalbumin - isolation & purification; Lactoglobulins - isolation & purification; membrane; Membranes, Artificial; Methods. Procedures. Technologies; Osmolar Concentration; Others; Plastics; Polymers; separation; Sulfones; ultrafiltration; Ultrafiltration - methods; Various methods and equipments; whey; whey protein; α-lactalbumin; β-lactoglobulin
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.10659

There is considerable commercial interest in the preparation of individual whey proteins as high‐value food additives, nutraceuticals, and therapeutics. This study examined the use of membrane filtration for the separation of α‐lactalbumin and β‐lactoglobulin. Stirred cell filtration experiments were performed using both cellulosic and polyethersulfone membranes to determine the optimal pH, ionic strength, and filtration conditions. Selectivities of greater than 55 could be achieved at pH 5.5 and 50 mM ionic strength using a 30‐kD cellulose membrane. A diafiltration process was then designed for the protein separation. A 16‐diavolume filtration yielded β‐lactoglobulin as the retentate product with a purification factor of 100 and recovery of 90%. The α‐lactalbumin was recovered in the filtrate with a purification factor of more than 10 and nearly 99% yield. Model calculations were in good agreement with the experimental data. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 201–209, 2003.