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Recent reports that H5N1 avian influenza virus was detected in milk raised a question On whether the U.S. milk supply is safe to drink. According to the Federal Food and Drug Administration, the answer is yes. As long as the milk is pasteurized.
Nevertheless, Sales of raw (unpasteurized) milk increaseDespite warnings from health experts that raw milk can contain ingredients such as: high level virusalong with many other pathogens.
as extended food scientist In status Areas where selling raw milk is legalI provide technical support to processors to help them produce high-quality, safe dairy products, and I also love helping people understand the confusing world of pasteurization methods on milk labels and why experts strongly discourage the consumption of raw milk or products made from raw milk.
Map: The Conversation, CC BY-NDSource: real facts about raw milkget dataDownload image was created with data wrapper
What makes milk unsafe?
Like many foods, dairy products have inherent risks that can cause various illnesses and even death. Our milk comes from animals that graze outdoors and live in barns. Milk is picked up from farms by tanker trucks and delivered to processing plants. These environments have many opportunities to become contaminated with disease-causing pathogens and food-spoilage microorganisms.
for example, listeria monocytogenes It can be acquired from environmental sources such as soil and water. Mild infections with listeriosis cause flu-like symptoms. Unfortunately, more serious cases are all too common and can cause miscarriage in pregnant women and women with listeriosis. In extreme cases it can lead to death.
Other pathogens commonly associated with dairy products and raw milk Contains E. coliIt can cause severe gastrointestinal infections and can cause kidney damage. campylobacter, the most common cause of diarrheal disease in the United States.and SalmonellaIt causes symptoms such as abdominal pain and diarrhea.
Keep your drinks safe with heat
In the 1860s, French microbiologist Louis Pasteur He discovered that heating wine and beer killed the microorganisms that caused spoilage, which was a serious problem in France at the time.
This heating process, which came to be known as pasteurization, was adopted in the United States before World War II, when cow’s milk served as cow’s milk. 25% of all foodborne illness outbreaks in the United States. In 1973, the federal government mandated that all milk sold across state lines in the United States be pasteurized, and in 1987, Ban on interstate sales of raw milk.
Pasteurization involves continuously heating all particles of food to a specific temperature in order to kill the most heat-resistant pathogens associated with that product. Different organisms respond differently to heat, so controlled scientific studies are needed to determine how much time at a particular temperature kills a particular organism.
Since 1924, pasteurization in the United States has been guided by: Grade “A” Pasteurized Milk Ordinancewhich is updated every two years to reflect current science and has been adopted as a federal guidance document. all 50 states. Pasteurization equipment in the United States must meet stringent requirements, including sanitary design, safety controls, and material standards.
Sterilization method
Dairy processors can choose from several different types of pasteurization. When executed properly, these methods yield the same result: pathogen-free milk. Processors may process milk beyond minimum times or temperatures to extend the shelf life of the product by providing an additional safety margin or reducing bacteria that cause milk spoilage. .
Bat sterilizerAlso known as batch pasteurizers, they are often used by small-scale processors processing limited quantities. The milk is pumped into a temperature-controlled tank with an agitator and heated to a minimum of 145 degrees Fahrenheit (63 degrees Celsius), where it is held continuously for 30 minutes. It is then cooled and pumped out of the vat.
The most common method used for commercial milk is High temperature short time sterilization, can process large amounts of milk. Milk is pumped at high speed through a series of thin plates until it reaches a minimum temperature of 161 F (71 C). He then passes through the holding tube for 15 seconds and the temperature is automatically checked and cooled down for safety.
The most complex and expensive systems are: Ultra-low temperature sterilizer and ultra-high temperature sterilizer, pasteurizes milk in just seconds at temperatures over 285 F (140 C). This approach destroys many spoilage microorganisms and gives milk a significantly longer shelf life than other methods. However, products made this way may have a more “cooked” flavor.
Ultra-high temperature products are processed in a sterile environment and packaged in sterile packaging such as lined cartons or pouches. Store unopened for up to 1 year. Super high temperature packaging makes it safe for children to take milk to school for lunch every day.
avian influenza in milk
detection of Fragments of avian influenza virus in milk This is a new challenge for the dairy industry. Scientists don’t know the full extent of the risks to humans, but they’re learning.
Previous studies have shown that virus particles remain in the milk of infected cows; Pasteurization inactivates the virus. However, the FDA advises consumers not to drink raw milk due to limited information about it. Whether it is possible to transmit avian influenza.
The agency is also calling on producers not to produce or sell raw dairy products, including raw milk and cheese, made from cows showing symptoms of the disease.
It’s never a good time to get food poisoning. This is the beginning of food poisoning. ice cream season. With new strains of avian influenza emerging and scientists still learning how avian influenza is transmitted, I agree with the FDA that raw milk poses risks that are not worth taking.
Kelly Elizabeth Karejian is funded by the USDA.
