By Blake Jackson
After bird flu was found in Texas dairy cows in March 2024, Cornell University researchers acted fast to study its survival in milk. Professor Diego Diel and food safety expert Nicole Martin worked together to answer dairy industry concerns.
Their research, published in Nature Communications, revealed that the H5N1 avian flu virus can stay alive in raw milk for up to eight weeks when kept in the fridge.
To test milk safety, the team pasteurized the milk using standard methods: 63°C for 30 minutes and 72°C for 15 seconds. Both methods destroyed the virus completely.
“That means if you drink pasteurized milk, even if it accidentally comes from a contaminated farm, you are safe,” said first author Mohammed Nooruzzaman, assistant research professor of population medicine and diagnostic sciences (CVM). “Pasteurization completely negated the virus.”
They also tested lower heat levels. Heating milk to 60°C for just five seconds or 54°C for ten minutes also killed the virus. This process, called thermization, gives an extra layer of protection for raw milk users.
In another related study, researchers found that bird flu virus can survive in certain raw milk cheeses for up to 60 days. This shows that aging does not guarantee safety. However, applying mild heat before cheese-making can make the milk safer.
These findings are helpful not only for consumers but also for cheese makers and milk processors who want to prevent the virus from spreading. The FDA and New York Agriculture Department supported the study.
The Cornell team continues to help the industry through regular online food safety sessions. “That the industry knows they can come to us for that guidance is really important,” said Martin. “And it is really about guidance – this is not industry-ending. They want to know the best practices, and our studies take those first couple of steps in the right direction.”
Photo Credit: cornell-university
Categories: New York, Education, Livestock, Dairy Cattle, Poultry