In a two-stage high-pressure milk homogenizer, which of the following operational functions are performed by the respective stages?
Options:
(A) First stage operates at high pressure ($15-20\text{ MPa}$ / $150-200\text{ bar}$) to shatter fat globules into sub-micron sizes via intense shear, cavitation, and turbulence
(B) Second stage operates at lower pressure ($3-5\text{ MPa}$ / $30-50\text{ bar}$) to break up fat globule clusters and clumps, ensuring uniform dispersion
(C) Homogenization increases milk viscosity and creates a richer, whiter appearance due to increased light scattering from smaller fat globules
(D) Homogenization completely eliminates the need for pasteurization
Answer Key:
A, B, C
Step-by-Step Solution & Explanation
1. First stage shatters globules down from $4\;\mu\text{m}$ to lt; 1\;\mu\text{m}$ (A is true).
2. Second stage de-clusters aggregated globules (B is true).
3. Greater number of micro-droplets scatters light efficiently, whitening the milk and increasing body (C is true).
4. Homogenization is purely mechanical; milk must still be pasteurized to destroy pathogens and inactivate native lipases (D is false).