When COVID-19 first emerged and caused a historic global pandemic, questions naturally arose about how the virus was spread.
One possibility is that people picked it up from contaminated surfaces, a scenario that leads to a wave of deep cleansing, panic buying hand sanitizer and questions about whether it is safe to open mail or Unpack groceries without wiping them down first.
The current, new research from the UK’s Food Standards Agency (FSA) which looked at whether the virus can survive on grocery items shows that being careful with some food items may not be It’s a completely odd idea.
The foods tested “are often sold loosely on supermarket shelves or uncovered at snack bars or market stalls, they can be difficult to wash, and they’re often consumed,” the team said. without further processing, such as cooking.”
They also tested food packaging materials that are very common or used on products where food consumption may involve direct contact between the mouth and the packaging.
Scientists artificially applied the infectious COVID-19 virus to the surfaces of food and packaging, and measured how the amount of virus present on those surfaces changed over time. The surfaces have been tested in a range of temperatures and humidity levels over time periods that reflect their typical storage conditions.
Viral concentrations applied to items represent respiratory droplets that land on them, such as if an infected person coughs or sneezes nearby.
The researchers found that virus survivability varied between grocery items, but for most of the foods tested, they found that contamination levels were “significantly reduced” after 24 first hour.
Some goods, including bell peppers, bread, ham and cheese, were found to have infectious viruses on them days after they were contaminated. On some surfaces, such as croissants, the virus persists and can be transmitted for hours.
The study’s authors broke down their findings by foods.
Fruits and vegetables
Scientists at the FSA say previous research has shown COVID-19 is expected to survive better at cold temperatures than at ambient food storage temperatures.
“But for the fresh vegetables presented in this report, the difference between survival in cold and ambient conditions is not so clear,” they said in the published report. in this week.
They said the virus lasted the longest—up to 5 days—on broccoli when it was stored at 23 degrees Celsius (73 degrees Fahrenheit) with 31% humidity. Meanwhile, COVID lives on bell peppers for up to 7 days when the peppers are chilled at 6 degrees Celsius.
On raspberries, the virus persists for varying lengths of time depending on conditions, but the report’s authors note that the pitted surface of the fruit “may protect the virus from drying out.” However, the researchers note, citing previous studies, apples may have antiviral properties thanks to chemicals in their skins.
Cakes and cakes
According to research results, COVID-19 lasts longer on white bread crust than on brown bread crust. They speculate that this may be due to the higher fiber content in brown bread.
The tested pastries, including croissants and chocolate, quickly inactivated the virus, the researchers said. They theorize that this may be because baked goods are coated with a liquid egg wash that may have an inhibitory effect on COVID-19.
“Eggs have the highest content of arachidonic acid in the human diet,” the study’s authors said. “It has been suggested that arachidonic acid, and other unsaturated fatty acids, which are high in eggs, could act as antiviral compounds.”
Research shows that the virus has a very low survival rate on olives—even just one minute after being contaminated.
The team notes that, like apples, it’s possible that chemicals in the olive skins inactivated the virus.
Meanwhile, FSA scientists say deli foods high in protein and saturated fat with high water content support longer viability of the virus — noting that previous research has found that COVID-19 can survive on prepared foods for 21 days in the refrigerator.
The long survival of SARS-CoV-2 on sliced ham and cheddar cheese, with its high protein, saturated fat and water content, highlights the importance of the study’s authors, said the study’s authors. of proper food handling to prevent any transmission of the virus prior to consumption”. speak.
Researchers found that COVID can survive for up to a week on plastic surfaces and several days on cartons. They say the virus can survive on aluminum cans for hours, not days.
They did note, however, that the foods in the study were artificially contaminated and therefore do not reflect the levels of contamination that can be found in grocery stores. They added that food with lower levels of contamination would take less time for the virus to drop to undetectable levels.
Experts at the Centers for Disease Control and Prevention (CDC) say COVID is mainly spread when an infected person exhales droplets containing the virus, which are then inhaled or found by others. to another person’s eyes, nose, or mouth.
While the CDC also says the virus can be spread through contaminated surfaces in some cases, the organization says there is currently no evidence that handling or consuming food can spread COVID-19.
“Follow food safety guidelines when handling and cleaning fresh produce,” the organization advice. “Do not wash the product with soap, bleach, disinfectants, alcohol, disinfectants or any other chemicals.”
While the FSA researchers admit that learn many times found the risk of infection through contaminated groceries to be “extremely low,” their findings indicating that certain foods and food packaging materials “can sustain infectious viruses.” for a substantial period of time”.
“There is a possibility of transmission through contaminated food if the food comes into direct contact with the mouth and mucous membranes,” they say, but they note that the significance of their findings is unclear because inhalation Respiratory droplets are considered the primary cause. route of COVID infection.