Recent media reports have focused on the potential dangers associated with human consumption of raw – or unpasteurized – milk and eggs, connecting them as possible transmitters of avian influenza, a virus spreading among cattle and poultry in the United States.
Keith Schneider, a professor of food safety at the University of Florida Institute of Food and Agricultural Sciences, describes the process of pasteurization and emphasizes its importance to consumers.
Q: What is pasteurization?
A: Typically, pasteurization is the application of heat over a given time. All steps are a combination of both. So, you can increase temperature and process for shorter times or use lower temperatures and longer processing times. These values are calculated on the temperature required to kill a specific pathogenic microorganism. Different microorganisms require different heating regimes. For most commercial processes, the most conservative time and temperature are used to ensure the inactivation of all the most probable pathogenic microbes.
Q: What food and drink items are most commonly pasteurized in the United States?
A: Any bottled, boxed or canned liquid is typically pasteurized. But I would imagine milk and juice are No. 1 and No. 2.
Q: Is there any risk associated with the human consumption of unpasteurized food and drinks? If so, what are they?
A: Yes. Without pasteurization, certain products can contain harmful microorganisms that can result in illness and even death.
Q: What are the benefits of pasteurization?
A: The benefits of pasteurization are simple. In addition to reducing or eliminating harmful microorganisms, it reduces spoilage and increases shelf life.
Q: How are eggs pasteurized?
A: Pasteurized eggs are heated in warm water baths, using a controlled time and temperature to inactivate bacteria that might be present. This uses the “low and slow approach,” so the temperature isn’t high enough to cook the eggs, but it will inactivate pathogenic microbes.
Q: Is there any nutrition loss when food and drinks are pasteurized?
A: Yes and no. Advocates of raw milk consumption claim it can help treat allergies and that pasteurization removes beneficial vitamins. With the exception of decreasing riboflavin (vitamin B2), pasteurization does not significantly decrease the nutritional value of milk. However, even when pasteurized, milk still remains an excellent source of riboflavin. Pasteurized milk is perfectly fine and does not have a significant impact on health compared to the potential risks raw milk carries. The one thing that’s being looked at with more scrutiny is raw milk and protection against milk allergies. The evidence is not conclusive at this point.
Q: Is there anything else related to pasteurization you would like to add?
A: What most people forget is that these heat treatment processes were designed to prevent human casualties and to extend the shelf life of food. Most people don’t remember or know of the historical outbreaks. Unfortunately, when conducting research, people will search the internet and focus on those sites that reinforce the answers they’re looking for.
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