Expanded Bed Chromatography for Food Separation

—Lysozyme Recovery from Egg White and Crude β-Galactosidase Purification—

Abstract

The mixing (axial dispersion) performance in expanded bed chromatography (EBC) was examined by the pulse response (residence time distribution) curve measurements. The HETP (height equivalent to a theoretical plate or plate height) values were calculated from the peak variance and the peak retention time. The HETP values for EBC did not change appreciably with the expansion degree (1.5-3.5), the column diameter (1.6 and 2.6cm), or the settled bed height (ca. 4-10cm), and ranged between 0.8 and 1.6cm. The breakthrough curves of lysozyme for very small EBC (1.6cm diameter and 3cm settled bed height) are similar to those for fixed bed chromatography (FBC) . This indicates that the adsorption performance of EBC is similar to that of FBC and the scale down of EBC is possible. As a food separation model sysytem lysozyme recovery from egg white by EBC was carried out. The recovery ratio and the purification factor obtained were similar to those with FBC although significant pressure drop increases were observed for FBC. Similarly, crude β-galactosidase was successfully purified by EBC. Several important factors affecting the separation performance of EBC for food separations were discussed.