Recovery of milk whey proteins by foam separation

Milk whey proteins recovery was conducted with foam separation. Experiments were conducted by batch mode in pH 4–8. The separation rate was evaluated by the rate constant of the first-order kinetic equation . Both recovery efficiency and separation rate were highest at pH 7. Overall equilibrium adsorption constant , K , and saturated adsorption density, X s , were determined from a proposed estimating method using data obtained in batch mode. At pH 7, K and X s were determined using the data obtained in continuous mode. K and X s determined by both operation modes were agreed well. Adsorption parameters of the major proteins in milk whey (bovine serum albumin (BSA), α-lactalbumin (LA), and β-lactoglobulin (LG)) were estimated by the proposed estimating method in pH 4–7. X s is largest at pH 5 and the K of LG over pH 5 was larger, which suggested that LG was the most hydrophobic species among them. • Conducting recovery of proteins from milk whey solution by foam separation. • Langmuir’s adsorption parameters can be determined by the proposed estimating method. • Estimated adsorption parameters verified with continuous mode operation. • Saturated adsorption density was largest at pH 5 in the range of pH 4–7. • β-lactoglobulin was considered most hydrophobic in the range pH 5–7.