Direct lysozyme separation from egg white by dye membrane affinity chromatography

An affinity membrane from hydrophylised polyethylene hollow fibre as the support matrix was prepared. Red HE-3B was immobilised on the membrane and the adsorption behaviour of pure lysozyme solutions and homogenised egg white was investigated. Dye density (1.7 micromole ml-1) and maximum binding capacity (26 mg lysozyme ml-1) are comparable to those of commercial gel matrices. Dynamic binding capacity did not change when residence time was reduced from 3 to 1 min. A method for direct lysozyme separation from egg white was developed, with a productivity of 12 kg lysozyme m-3 h-1. The purity of the eluted lysozyme, as determined by HPLC, was 88%, with a recovery of 92%. Dynamic capacity was kept constant at 70% of the maximum binding capacity for at least 10 cycles through membrane regeneration with 0.1 M NaOH and 1 M NaCl. Functional properties of egg white, as judged by viscosity and foaming capacity measurements, did not change after the chromatographic lysozyme depletion.