Abstract: The effects of different saturation degrees and different amounts of fatty acids on the rheological properties and zeta potential of emulsions stabilized by salt-soluble protein extracted from pork Longissimus dorsi were studied. The results showed that the higher the amount of fatty acids was, the stronger the emulsifying activity of the emulsion was. But increased amount of fatty acids could cause more serious stratification of the emulsion. Addition of either oleic acid or linoleic acid could significantly increase the surface active sulphur content. The emulsion particle size distribution curves showed a single peak in a narrower range compared to the blank group. In addition, emulsion viscosity was decreased gradually and finally tended to be stable with the increase of shear rate. For each shear rate, the?shear stress?of the?emulsion increased with higher amount of fatty acids added. The charged particles were unstable as indicated by zeta potential values. In general, higher degree of saturation and higher addition level of C18 fatty acids resulted in better emulsification of C18 fatty acids with salt-soluble pork protein by improving protein membrane formation on the lipid droplet surface.

Key words: salt-soluble protein, oleic acid, emulsifying properties