Enabling egg white protein fractionation processes by pre-treatment with high-pressure homogenization

• HPH (high-pressure homogenization) reduces egg white (EW) viscosity significantly.
• Ovomucin fibrils can be diminished by HPH.
• EW can be filtered after HPH, which is indispensable for chromatographic separation.
• Higher amounts of the target protein lysozyme after HPH.
• Negative effects of common precipitation process can be avoided.

Egg white (EW) includes several proteins with high potential for fractionation processes (lysozyme, ovotransferrin). However, the high viscosity of EW that is caused by the fibrillar protein ovomucin is a limiting factor concerning processability. The common procedure to reduce this viscosity is the precipitation of ovomucin, which, however, results in undesirable dilution effects and loss of proteins. So, the objective of this work was to develop a method to decrease the viscosity of EW without the described disadvantages. Therefore, a high-pressure homogenization process was used. It was demonstrated that it is possible to destroy the EWs’ fibrillar network by homogenization treatment, and thereby, to decrease the viscosity significantly. Additionally, filtration was enabled, which allows the use of EW for e.g. chromatographic fractionation. Simultaneously, it was shown that lysozyme that was entrapped in the fibrillar network was released, and therefore, it is available for fractionation processes in higher amounts.