Emulsion: These are liquid-liquid colloidal systems, i.e., the dispersion of finely divided droplets in another liquid. If a mixture of two immiscible or partially miscible liquids is shaken, a coarse dispersion of one liquid in the other is obtained which is called emulsion. Generally, one of the two liquids is water. There are two types of emulsions. (i) Oil dispersed in water (O/W type) and (ii) Water dispersed in oil (W/O type).

In the first system, water acts as dispersion medium. Examples of this type of emulsion are milk and vanishing cream. In milk, liquid fat is dispersed in water. In the second system, oil acts as dispersion medium. Common examples of this type are butter and cream.

Emulsions of oil in water are unstable and sometimes they separate into two layers on standing. For stabilisation of an emulsion, a third component called emulsifying agent is usually added. The emulsifying agent forms an interfacial film between suspended particles and the medium. The principal emulsifying agents for O/W emulsions are proteins, gums, natural and synthetic soaps, etc., and for W/O, heavy metal salts of fatty acids, long chain alcohols, lampblack, etc.

Which of the following statement about emulsions is true?

Digestion does not involve the process of emulsification

The correct answer is option 2. Digestion does not involve the process of emulsification.

Emulsification is an essential process in the digestion of fats in the human body.

When we consume food containing fats, such as oils or fatty acids, they are initially in the form of large globules that are not easily absorbed by the body. To facilitate their digestion and absorption, these large fat globules need to be broken down into smaller droplets. This is where emulsification comes into play.

During digestion, bile salts produced by the liver and stored in the gallbladder are released into the small intestine. Bile salts are amphiphilic molecules, meaning they have both hydrophilic (water-attracting) and hydrophobic (water-repelling) regions. When bile salts come into contact with fat globules in the small intestine, they surround the fat globules, with their hydrophobic regions interacting with the fat molecules while their hydrophilic regions face outward towards the watery environment of the intestine.

This action of bile salts effectively breaks down the large fat globules into smaller droplets, a process known as emulsification. These smaller fat droplets have a much larger surface area compared to the larger globules, which makes them more accessible to digestive enzymes called lipases.

Lipases are enzymes responsible for breaking down fats into smaller molecules that can be absorbed by the intestinal lining. The increased surface area provided by emulsification allows lipases to efficiently catalyze the hydrolysis of fats into fatty acids and glycerol, which can then be absorbed by the body for energy or storage.

In summary, emulsification is a crucial step in fat digestion that helps to break down large fat globules into smaller droplets, facilitating their digestion and absorption in the small intestine.