Explain The proteins stabilize emulsions

The proteins stabilize emulsions and contribute  physical  and rheological properties,  like thickness,  viscosity, elasticity   and  rigidity that  determine resistance to droplet coalescence. Ionization of amino acid side chains may also take place depending on the pH and this provides electrostatic repulsive force that favors emulsion stability. This functional property is important in the formation of many common food products, such as salad dressings and sausages.  

Proteins are generally poor  stabilizers of water/oil  (w/o) emulsion. You will be reading about emulsions in details in unit 7 of this course.  This  may  be  attributable  to   the    predominantly hydrophobic  nature  of  most proteins, causing the  bulk  of  an adsorbed  protein   molecule  to  reside  on  the  water  side  of interface.