A Simple Foam-based Strategy for Sequential Isolation of Lysozyme and Ovomucin from Chicken Egg White

Chicken egg white contains valuable functional proteins such as lysozyme and ovomucin, which are widely used in food and medicinal applications. However, efficient and scalable separation remains a challenge. This study devised a simple foam-based approach for the successive isolation of these proteins. Egg white foam was generated and redissolved under optimized conditions using 0.6% sodium dodecyl sulfate at pH 9. Lysozyme was selectively separated by cation-exchange adsorption and eluted with 0.5 M NaCl, while ovomucin was extracted from the supernatant via isoelectric precipitation at pH 4.75. Protein identity and structural integrity were verified by SDS-PAGE, MALDI-TOF mass spectrometry, and FTIR analysis. Lysozyme had significantly higher purity (81.18 ± 10.73%), while ovomucin had higher yield (44.68 ± 2.89%) and weight (0.86 ± 0.06 g) (p < 0.05). Lysozyme produced lower yield (26.38 ± 1.35%) and weight (0.49 ± 0.03 g). These findings suggest a trade-off between purity and yield due to variances in protein characteristics. The proposed process provides a simple, cost-effective, and scalable option for extracting high-value egg white proteins, although more optimization is required to improve ovomucin purity.