Which of the following correctly pairs the preservation method with its mechanism of action?

• A. Salting: decreases the amount of oxygen.
• B. Pasteurization: adds bacteria to increase acidity.
• C. Refrigerating: lowers the temperature to slow bacterial growth.
• D. Canning: decreases the available moisture, which helps bacterial growth.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the preservation methods mentioned: salting, pasteurization, refrigerating, and canning. Each method works by targeting specific factors that affect microbial growth or food spoilage.
2. Step 2: Analyze salting: Salting preserves food primarily by decreasing the available moisture through osmosis, which inhibits bacterial growth. It does not decrease oxygen levels.
3. Step 3: Analyze pasteurization: Pasteurization involves heating food to a specific temperature to kill or reduce harmful bacteria, not by adding bacteria or increasing acidity.
4. Step 4: Analyze refrigerating: Refrigeration lowers the temperature of food, which slows down the metabolic and reproductive rates of bacteria, effectively slowing bacterial growth.
5. Step 5: Analyze canning: Canning preserves food by sealing it in airtight containers and often involves heat treatment to kill bacteria. It decreases oxygen availability and moisture is usually retained, which inhibits bacterial growth rather than helping it.