Phosvitin extraction and phosphopeptides characterization from chicken egg yolk

Abstract: Phosphopeptides derived from egg yolk phosvitin have been reported to exhibit various physiological functions. However, commercial use of phosvitin phosphopeptides (PPPs) has been hampered due to the lack of a simple and economic method to prepare PPPs. The purposes of this study were to develop a protocol to extract phosvitin from egg yolk, and to prepare and characterize phosphopeptides derived from enzymatic hydrolysis of phosvitin. The phosvitin prepared in this study had comparable or higher purity and recovery than previous methods. The atomic ratio of nitrogen to phosphorus (N/P) describes the density of phosphorus in peptide sequences. A lower value relates to higher density of phosphorus and high phosphorus content is preferred for bioactivities. The phosvitin hydrolysate showed comparable or lower N/P ratio than purified casein phosphopeptides. Novel phosphopeptides with high phosphorylation degree were identified. The protocols developed in this study could be used for laboratory uses and industrial scale-up. The phosphopeptides identified in this study are expected to exert multi-physiological functions and to be developed as functional food ingredients.