Question

What is an emulsifying agent? Give one example?

Answer 1

Hint: We have studied that emulsifiers or emulsifying agents are compounds that stabilize the emulsions. An emulsifier keeps immiscible compounds separating by increasing the stability of the substance. These substances form a film around the dispersed globules or lower interfacial tension in an emulsion. Emulsion contains tiny particles of one liquid which suspends in another liquid.

Step-By-Step answer:
Emulsions are stabilized by addition of an emulsifier or emulsifying agent. The chemical structure of the emulsifier contains both lipophilic and hydrophobic parts. In addition to this protective barriers emulsifiers stabilize the emulsion by reducing the tension of the system. Some substances enhance stability by imparting a charge on the droplet surface thus it reduces the contact between droplets and decreasing the potential for coalescence.

Example of emulsifying agent- We know that ice cream is an emulsion which contains ice crystals and unfrozen aqueous phase whose freezing point is depressed due to presence of salt, sugar and polysaccharide stabilizers. Monostearate and monolaurate are effective emulsifying agents of ice cream. Emulsifying agents coat the fat of the milk and enhances the ability of protein film to surround air cells in the ice cream. Thus it results in an improved whippabililty, smoother texture and body, slower melting rate and drier appearance.

Note : We know that emulsion is a mixture of two immiscible liquids. So it is a colloid where both phases are liquids. Many food products are examples of emulsion. Food emulsifying agents are widely used nowadays. Emulsifiers are integrated with stabilizers in proprietary blends sometimes but their function and actions are very different from stabilizers.