Certified Cheese Professional Practice Exam

What is the effect of pasteurization on Listeria Monocytogenes?

1. It enhances their growth

2. It neutralizes them

3. It has no effect

4. It completely eliminates them at certain temperatures

The correct answer is: It completely eliminates them at certain temperatures

Pasteurization is a heat treatment process that is primarily used to eliminate pathogenic microorganisms in food and beverages. Specifically for Listeria monocytogenes, which is a significant foodborne pathogen, pasteurization has a pivotal role in ensuring food safety. When pasteurization is applied, particularly at the correct temperatures and durations, it effectively reduces and can completely eliminate Listeria monocytogenes from food products. The effectiveness of this process relies on maintaining specific temperature conditions that are known to be lethal to the bacteria. For instance, heating at temperatures around 161°F (72°C) for a minimum of 15 seconds will typically result in the destruction of Listeria monocytogenes. This ability of pasteurization to reduce or entirely remove pathogens is critical in dairy processing, ensuring that products such as milk and cheese are safe for consumption. Understanding the specific temperatures and times that are effective against Listeria monocytogenes is essential for any cheese professional, as it helps in implementing proper safety measures in food handling and processing.