If you're tempted to pick up food you've dropped on the floor, think again! A new study has debunked the "5-second rule" that state food (or even cutlery) dropped on the floor will not be much contaminated with bacteria provided it is picked up within five seconds of being dropped.

Apparently, bacteria from a surface transfers to food in split of a second; in fact, in some cases, the transmission happens in less than a second, the study divulged.

According to study co-author Donald Schaffner, the 5-second rule is an underestimation of what happens when bacteria actually transfers from the floor to food. Rubbishing the 5-second rule, Schaffner, a microbiologist and professor at Rutgers University in New Jersey said in a statement that bacteria can contaminate immediately.

In the study, the researchers contaminated four separate surfaces - carpet, wood, ceramic tile and stainless steel - with bacteria. Then they dropped food on each surface allowing it to sit for a specific time i.e. less than 5 seconds, 5 seconds, 30 seconds and 5 minutes. The researchers analyzed four food types including watermelon, bread and butter, bread and gummy candy.

The results were quite surprising. It was found that the longer the food was allowed to sit on the floor, the more bacteria were transferred on to the food. Meanwhile, some bacterial contamination took place in less than a second.

Among the tested food types, watermelon picked up the most bacteria. Gummy candies, on the other hand, picked up the least. The researchers expected the high rate of contamination for watermelon citing the food's moisture level. Schaffner explained this by pointing out that bacteria do not have legs and they move with the moisture. In order words, the wetter the food, the higher the chances of transfer.

As far as the surface is concerned, carpet had a low rate of bacteria transfer to the food as opposed to the other surface types.

Aside from the amount of time the food is left on a surface, it was found that several other factors influence how much bacteria accumulates, the researchers noted. The said factors include the type of surface food falls on, and the also the type of food.

The 5-second rule was also analyzed a couple of years ago as well, and it was found that the amount of time food sits on the floor significantly influences the amount of bacteria that are transferred to the food, according to reports on Live Science.

The Aston University (UK) researchers led study, reached a totally different conclusion. Their finding reportedly provided a scientific basis for the 5-second rule as food that's picked up from the floor within a few seconds of it falling is less likely to be contaminated as compared to food that is allowed to sit on the surface for a longer amount of time.

The research was not published in a peer-reviewed journal.