They are white waxy substances, which become brownish when exposed to air and light, owing to autooxidation. This is due to the presence of unsaturated fatty acid in the molecule. They are soluble in alcohol and other fat solvents. They are hygroscopic and mix well with water to form cloudy, colloidal, and slimy solution. They don’t have definite melting point. Pure lecithin is a mild emulsifying agent, but when combined with carbohydrates and proteins, they are more effective. They lower the surface tension of aqueous solution.