Structural and dynamical impacts of water dilution on egg yolk properties

Since antiquity, artists have been using egg yolk as an additive in the preparation of tempera paints. Mixture of egg yolk and water acts as the dispersing medium for pigments to start with, but once applied on canvas, it acts as a binder and plasticiser, imparting adhesive properties to the applied paint. A series of water/egg yolk mixtures are investigated here using a combination of rheology, Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) spectroscopy and relaxometry and small angle X-ray scattering (SAXS). The effects of water dilution on the organisation of the main egg yolk components, plasma and granules are explored. The results show that added water affects the tertiary/quaternary protein structure leading to a destabilization of the lipoprotein dispersion.