Structural and dynamical impact of water dilution on egg yolk properties

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