Question

Homogenization improves:

• A. Shelf life only
• B. Emulsion stability
• C. Protein content
• D. Sugar level

Hint:

Homogenization uses high pressure to break up fat globules.
According to Stokes' Law, smaller particles cream much slower, which physically stabilizes the emulsion.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks about the primary physical property of liquid foods (like milk) that is improved by the process of homogenization.

Step 2: Key Concepts and Approach:
Milk is an oil-in-water emulsion where fat globules are suspended in an aqueous phase.
Because fat is less dense than water, these globules naturally tend to rise to the surface over time, a process known as creaming.

Step 3: Detailed Explanation:

• Stokes' Law of Creaming:
The velocity of creaming ($v$) is governed by Stokes' Law:
\[ v = \frac{2g r^2 (\rho_p - \rho_f)}{9\eta} \]
where $r$ is the radius of the fat globule, $\rho$ represents densities, and $\eta$ is the viscosity.
Reducing the radius ($r$) of the fat globules significantly reduces the rate of creaming.

• Mechanism of Homogenization: Homogenization passes milk under high pressure through a small valve.
This subjects the fat globules to high shear, turbulence, and cavitation, breaking them down from an average size of $3\text{--}4\,\mu\text{m}$ to less than $1\,\mu\text{m}$.

• Resulting Stability: The smaller size of the fat globules increases the surface area and allows them to remain suspended, improving the stability of the emulsion and preventing cream separation.
It does not alter the protein content or sugar level of the food.

Step 4: Final Answer:
Therefore, homogenization improves emulsion stability, corresponding to Option (B).