Fractionation of Glycomacropeptide from Whey Using Positively Charged Ultrafiltration Membranes

Area of Science:

• Biotechnology
• Materials Science
• Food Science

Background:

• Cheese whey is a rich source of valuable proteins, including bovine glycomacropeptide (GMP).
• Traditional methods for protein fractionation, such as chromatography, can be expensive and complex.
• Ultrafiltration (UF) offers a potential alternative for dairy protein separation.

Purpose of the Study:

• To investigate the use of surface-modified ultrafiltration membranes for the selective fractionation of bovine glycomacropeptide (GMP) from cheese whey.
• To enhance the selectivity and purity of GMP separation using charged membranes.
• To evaluate the salt tolerance and efficiency of the charged UF system.

Main Methods:

• Surface modification of 1000 kDa ultrafiltration membranes with positively charged polyhexamethylene biguanide polymer brushes.
• Fractionation of cheese whey at a pH near the isoelectric point of GMP.
• Utilizing salt-tolerant charged membranes for direct whey processing without dilution.

Main Results:

• A 14-fold increase in selectivity for GMP was achieved using charged membranes compared to unmodified ones.
• A single-stage membrane system yielded 90% pure GMP, while a three-stage system achieved 97% purity.
• The charged membranes demonstrated salt tolerance up to 40 mS cm⁻¹, enabling direct fractionation from undiluted cheese whey.

Conclusions:

• Salt-tolerant charged ultrafiltration membranes provide a highly selective and efficient method for fractionating bovine glycomacropeptide from cheese whey.
• This approach offers a promising, cost-effective alternative to chromatography for producing high-purity protein fractions from dairy streams.
• The developed UF system avoids water dilution, simplifying the process and preserving the whey's original composition.