Question

What is the most effective method to reduce the risk of Enterobacteriaceae contamination in milk and dairy products?

• A. Refrigeration
• B. Pasteurization
• C. Filtration
• D. Homogenization

Hint:

Because Enterobacteriaceae are non-spore-forming vegetative bacteria, they are easily destroyed by heat treatment. Therefore, pasteurization is the most reliable method to eliminate them from milk.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Members of the Enterobacteriaceae family are heat-sensitive, Gram-negative, non-spore-forming vegetative bacteria. Eliminating them requires applying a validated thermal process.

Step 2: Detailed Explanation:
- Pasteurization: This standard thermal process (typically \(72^{\circ}\text{C}\) for 15 seconds) is designed to destroy all vegetative pathogens and significant spoilage organisms, including Enterobacteriaceae. This makes it the most effective control method.
- Refrigeration: Slows down the growth of these bacteria but does not destroy them, and some psychrotrophic strains can still multiply slowly.
- Filtration: Removes physical debris but cannot filter out microscopic bacterial cells.
- Homogenization: A mechanical process used to reduce fat globule size and prevent creaming; it does not kill bacteria.

Step 3: Final Answer
The most effective method to eliminate Enterobacteriaceae and reduce contamination risk is pasteurization.