• Optical Properties and Whiteness of Bovine Milk:
• Light Scattering (Tyndall Effect):
• The characteristic opaque white appearance of milk is caused by the light-scattering properties of colloidal particles:

• Colloidal calcium caseinate micelles (diameters $50 - 300\text{ nm}$).
• Emulsified milk fat globules (diameters $1 - 10\ \mu\text{m}$).
  • Even after complete mechanical removal of fat (skim milk), milk retains an opaque, bluish-white appearance due to Rayleigh scattering by suspended calcium caseinate-phosphate micelles.

• Conclusion: Colloidal calcium caseinate (Option 3).

• Determination of Solids-Not-Fat (SNF) via Lactometer Reading:
• Analytical Role:
• Corrected Lactometer Reading (CLR) measures specific gravity. Combined with Gerber fat percentage, it calculates % SNF (Solids-Not-Fat) using Richmond's equation:

• Vital rapid platform test for detecting illegal watering down or skimming of market milk supplies.
• Conclusion: SNF % in milk (Option 2).

Correct option: (2) SNF % in milk

Evaluating the Assertion and Reason concerning Design for pressure and temperature:

The correct answer is Option 1: Both A and R are correct and R is the correct explanation of A.

• Physical Principles of Food Freezing Engineering:
• Latent Heat Removal: Freezing requires removing the latent heat of crystallization ($333.5\text{ kJ/kg}$) to transform liquid water into ice.
• Osmotic Shifts: Extracellular ice growth concentrates extracellular solutes, drawing intracellular water outward by osmosis.
• Supercooling: Rapid nucleation under high supercooling generates small, uniform intracellular ice crystals, protecting food cellular architecture.
• Freezing Curves: Freezing curve profile depends on soluble solids, cryoscopic depression, and moisture content.
• Conclusion: A, B, C, D (Option 2).

Correct option: (2) AB,C,D