Bacteria

Many people believe in the "5- second rule," which says food is safe to eat if picked up quickly. Is this true, and does the type of surface (wood, carpet, or concrete) change how much bacteria transfers to food?

1. We washed our hands and put on gloves

2. We cut apples into equal-sized pieces

3. We labeled three Petri dishes: Wood\, Carpet\, and Concrete.

4. We dropped one apple piece onto the wood floor for 5 seconds.

5. After 5 seconds\, we picked it up and used a clean cotton swab to swab the apple

6. We rubbed the swab onto the agar in the Petri dish labeled “Wood.”

7. We repeated the same steps for the carpet and concrete using new apple pieces and clean swabs each time.

8. We closed the Petri dishes and left them in a warm place 2-3 days.

9. After 2-3\, we counted the number of bacteria colonies that grew on each plate.

10. We recorded our results in a table.

Many people believe in the 5-second rule, which says food is safe to eat if you pick it up quickly. However, scientists have found that bacteria can transfer to food almost instantly.

In 2003, Jillian Clarke tested the 5-second rule and found that bacteria can stick to food in less than 5 seconds. Later, researchers at Rutgers University discovered that bacteria can transform in less than one second and that surface type makes a difference.

This research shows that food can pick up germs quickly, even if it is only on the floor for a short time.

We counted the number of bacteria colonies on apples dropped in wood, carpets, and concrete for 5 seconds. Each surface was tested three times, and the average was calculated.

Surface type. Trial 1. Trial 2. Trial 3 Wood. 12. 15. 14 Carpet. 25. 28. 27 Concrete. 18. 20. 19

In this experiment, we tested whether the 5-second rule is true by dropping apples on wood, carpets, and concrete for 5 seconds and measuring bacteria growth. Our results showed that the carpet has the most bacteria colonies, while the other surfaces had fewer. This means that surface type does affect how much bacteria transfers to food. Our hypothesis was correct because we predicted that carpet would have the most bacteria. The results showed that carpet can hold a lot of dirt and germs in its fibres, which can transfer to food. This experiment shows that food can pick up bacteria even after only 5 seconds on the floor. Therefore, the 5-second rule may not always be safe.

Clarke, Jillian. “The 5-Second Rule.” 2003 experiment on bacteria transfer.

Rutgers University. (2016). Study on the 5-second rule and bacterial transfer.

“Researchers debunk ‘five-second rule’: Eating food off the floor isn’t safe.” ScienceDaily, Sept. 9, 2016. https:// www.sciencedaily.com/releases/ 2016/09/160909112406.htm

“Still Good? 5-Second Rule a Myth, Study Finds.” Livescience.com, 2016 https:// www.livescience.com/56158-5-second-rule-myth.html

We would like to thank the teacher Ms James, for helping me plan and understand what we are supposed to do. We would also like to thank our parents for buying us these materials and using their time to help us.