Scientists artificially applied infectious COVID-19 virus to the surfaces of the foods and packaging, and measured how the amount of virus present on those surfaces changed over time.

The researchers found that virus survival varied between grocery items, but for most of the foods tested they noticed a “significant drop” in levels of contamination after the first 24 hours.

On raspberries, the virus survived for variable lengths of time depending on conditions, but the report’s authors noted that the fruit’s pitted surfaces “may protect the virus from desiccation.” Apples, however, could have antiviral properties because of chemicals in their skin, the researchers noted, citing previous studies.

Meanwhile, the FSA’s scientists said deli items that were high in protein and saturated fats with a high water content supported longer virus survival—noting that past research had found COVID-19 could survive on processed meets for 21 days in a refrigerator.

“The long survival time of SARS-CoV-2 on sliced ham and cheddar cheese, with their high protein, saturated fat, and water content, highlight the importance of proper food handling to prevent any contamination by virus prior to consumption,” the study’s authors said.

While the CDC also says the virus can be spread via contaminated surfaces in some cases, the organization says there is currently no evidence that handling or consuming food can spread COVID-19.

While the FSA’s researchers acknowledged that several studies had found the risk of infection via contaminated groceries was “extremely low,” their findings had shown that some foods and food packaging material “can sustain infectious virus for a significant length of time.”