Physicochemical and functional properties of leftover egg yolk granules after phosvitin extraction

In this study, leftover egg yolk granules, a by-product after phosvitin extraction, were evaluated for the physicochemical and functional properties and the results were compared with those of the egg yolk and whole granule with phosvitin. Leftover granule after phosvitin removal accounted for 12.6% of the dried egg yolk and contained 84.5% protein and 7.98% fat. Scanning electron microscopy (SEM) images of leftover granules indicated the dissociation of aggregates of high density lipoprotein-phosvitin complexes. Protein solubility of leftover granules was markedly influenced by pH and sodium chloride (0.5 and 1 M). The apparent viscosity of leftover granule was higher than egg yolk and whole granule. Compared to whole granule, leftover granule had significantly (P < 0.05) superior foaming and emulsifying properties, but, lower than those of egg yolk. These findings are useful for the food industry for utilization of leftover egg yolk granules for the preparation of various food products.