A new study that replicated commercial pasteurization in a government facility provides reassurance that heat treatment kills the avian flu virus in cow’s milk, US officials said on Friday.
When the avian flu known as H5N1 was first found in dairy cows in the United States earlier this year, no experiments were conducted to determine whether heat treatment eliminated the virus in cow milk. However, officials were reassured by research demonstrating that pasteurization of eggs, which involves heating at a lower temperature for a shorter period of time, was effective, according to Food and Drug Administration’s Donald Prater.
A research conducted in April discovered no evidence of infectious, live virus in store-bought samples of pasteurized milk, however they did contain dead remains of it.
Some subsequent modest trials attempting to imitate pasteurization yielded inconsistent outcomes.
The new study was conducted at a federal research laboratory in Athens, Georgia, using bespoke equipment designed to more closely replicate commercial pasteurization.
It also allowed for sampling at various stages along the process. The milk passes through multiple heating processes before being flash-heated, and the study discovered that the virus was inactivated even before it reached the 161-degree, 15-or-more-seconds “flash pasteurization” stage, which is considered the most important step in making milk safe.
“This information really fills an important gap in our understanding of how commercial pasteurization inactivates the virus,” says Prater.
The study has not yet appeared in a peer-reviewed journal.
