Recovery of milk whey proteins by foam separation

Abstract

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, Xs, were determined from a proposed estimating method using data obtained in batch mode. At pH 7, K and Xs were determined using the data obtained in continuous mode. K and Xs 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. Xs 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.