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Egg and milk proteins are widely used in food products for several reasons, including their nutritive value and their emulsifying and heat-gelling properties. Few studies have used systematic experimental design to examine the ingredient interactions in food protein mixtures. A new study of milk, egg yolk and albumen blends uses Scheffe simplex-centroid design to investigate ingredient interactions and their effect on functional properties. Foaming properties reveal antagonistic effects, while heat gelling and emulsifying properties reveal synergistic effects.

The effect of mineral cations on the microstructure of egg yolk granules was examined. Sodium chloride destabilized the granular structure while sodium from the salt replaced the calcium bound to the proteins. However, iron binding was not affected by sodium. Granule dialysis partially releases calcium and destabilized the granular structure. EDTA bound all cations and also destabilized the granular structure and the phospholcalcic bridges. The presence of bivalent or trivalent cations at low concentrations stabilized the structure and protected the granules from degradation caused by changes in pH or ionic strength.