• Objective of Blanching Vegetables Prior to Freezing:
• Enzymatic Degradation: Raw vegetable tissues contain endogenous oxidative enzymes, predominantly polyphenol oxidase, peroxidase, catalase, and lipoxygenase.
• Mechanism: Freezing merely retards enzymatic reaction rates but does not stop them; during extended frozen storage, unblanched vegetables develop off-odors, rancidity, tough textures, and browning.
• Blanching: Brief exposure to boiling water ($95 - 100^\circ\text{C}$) or steam for 1–5 minutes inactivates these spoilage enzymes, preserves natural pigments (chlorophyll), and expels intercellular respiratory gases.
• Conclusion: inactivate the enzymes (Option 1).

Correct option: (1) inactivate the enzymes

• Etiology of Salmonellosis Food Infection:
• Clinical Manifestations: Acute onset of watery diarrhea, severe abdominal cramps, nausea, and high fever starting 12 to 72 hours following ingestion.
• Food Infection vs Intoxication:
• Salmonella enterica causes a true food infection, invading the epithelial lining of the small intestine and colon and causing inflammatory enteritis.
• In contrast, Staphylococcus aureus, Clostridium botulinum, and Bacillus cereus primarily cause food intoxications mediated by preformed exotoxins (enterotoxin, neurotoxin), which typically produce rapid vomiting within 1–6 hours without sustained high fever.
• Conclusion: Salmonella (Option 4).

Correct option: (4) Salmonella

• Dietary Lipid Requirement for Fat-Soluble Vitamin Absorption:
• Fat-Soluble Vitamins (A, D, E, K):
• Non-polar, lipophilic micronutrients that cannot dissolve directly in aqueous gastrointestinal fluids.
• Absorption Physiology:
• Dietary fats (triglycerides) stimulate gallbladder contraction, releasing bile salts into the duodenum.
• Bile salts, monoglycerides, and fatty acids spontaneously aggregate into mixed micelles, encapsulating vitamins A, D, E, and K to transport them across the intestinal unstirred water layer into enterocytes for packaging into chylomicrons.
• Conclusion: Fats (Option 3).

Correct option: (3) Fats