Many people have rules about dropping food on the ground including the ever-famous “5-second rule.” Drop food on the ground as long as you pick it up in 5 seconds, then it is still “good” to eat.
A new study was recently published in Applied and Environmental Microbiology and states that “the food is already contaminated with bacteria“!
“The 5-second rule is a significant oversimplification of what actually happens when bacteria transfer from a surface to food,” said study lead researcher Donald Schaffner, a professor and extension specialist in food science.
“Bacteria can contaminate instantaneously,” he said in a Rutgers news release.
The deciding factor in bacteria contamination is Moisture. Bacteria uses moisture to move. So the more water associated with the food, the faster the contamination.
“Transfer of bacteria from surfaces to food appears to be affected most by moisture,” said Schaffner.
Which foods fared the best and the worst in the study?
Not surprisingly, watermelon has the most bacteria. Last on the list was gummy candy.
Another factor for bacteria? The floor.
Food dropped on the carpet had fewer bacteria than tile or stainless steel. Interestingly, wood floors varied with contamination.
So, you might want to think twice about eating that slice of watermelon after accidentally dropping it on the floor.