Selective Separation of the Major Whey Proteins Using Ion Exchange Membranes

Binding capacity (mg/cm²) of β-lactoglobulin, α-lactalbumin, and BSA on the strong and weak anion exchange membranes (MA15). Error bars represent the range of binding capacities from duplicate trials.

a) Permeate protein concentration (C) expressed as a proportion of the feed concentration (C₀) after passing 350mL of a 1mg of protein/mL of binary protein solution through a strong anion exchange membrane (MA75). Error bars represent the range of results from duplicate trials. b) Permeate protein concentration (C) expressed as a proportion of the feed concentration (C₀) after passing 300mL of a 1mg of protein/mL of binary protein solution through a weak anion exchange membrane (MA75). Error bars represent the range of results from duplicate trials.

a) Individual protein concentrations in the permeate (C) as a proportion of the feed concentration (C₀) after loading 300mL of a 1mg of protein/mL of whey solution through a strong anion exchange membrane (MA75). Error bars represent the range of results from duplicate trials. b) Individual protein concentrations in the permeate (C) as a proportion of the feed concentration (C₀) after loading 300mL of a 1mg of protein/mL of whey solution through a weak anion exchange membrane (MA75). Error bars represent the range of results from duplicate trials.

Protein compositions (%) of the elution fractions recovered after loading 50, 100, and 300mL of a diluted whey (1mg of protein/mL) onto a strong anion exchanger (Q75) and a weak anion exchanger (D75) compared with the protein composition of the whey feed. Error bars represent the range of protein composition (%) from duplicate trials.

Binding capacity (mg/cm²) and total protein (β-lactoglobulin, BSA, and α-lactalbumin) recovered in permeate wash and eluate after loading varying amounts of a diluted whey solution (1mg of protein/mL) onto both the strong (Q) and weak (D) anion exchange membranes (MA75). Error bars represent the range of binding capacities and protein recovery from duplicate trials.

Total protein (β-lactoglobulin, BSA and α-lactalbumin) eluted (mg) and total protein recovered in the elution fraction of the mass bound (%) after loading varying amounts of a diluted whey solution (1mg of protein/mL) onto both the strong (Q) and weak (D) anion exchange membrane (MA75). Error bars represent the range of eluted protein from duplicate trials.

Comparison of binding capacity (mg) for standard BSA and β-lactoglobulin solutions in phosphate buffer and milk permeate when passed through the strong (Q) and weak (D) anion exchange membranes (MA15). Error bars represent the range of binding capacities from duplicate trials.