If you drop food on the ground and pick it up immediately, can you still eat it? Finally there is an answer

Legend has it that

If food falls on the ground, just pick it up quickly.

Bacteria don't have time to touch the food

Still safe to eat

This saying is widely circulated among the people.

So!

Is this really the case?

Can you pick up and eat food that has fallen on the ground?

Just pick it up in a few seconds and it's fine?

How was the time limit of a few seconds arrived at?

In fact, as early as the beginning of 2006, Professor P. Dawson, who is engaged in food science research at Clemson University, conducted a series of experiments on the "5-second rule" and published the experimental results in the academic journal The Journal of Applied Microbiology.

Dawson and his colleagues first evenly covered the ceramic tile with a culture solution containing salmonella and cultured it at room temperature to observe the changes in the number of bacteria over time. The experimental results showed that the bacteria were very tenacious. In a dry environment, the number of bacteria per square centimeter of ceramic tile could reach thousands after 24 hours. After 672 hours, or 28 days, there were still dozens to hundreds of bacteria per square centimeter of ceramic tile, and this number of bacteria was enough to transfer from the ceramic tile surface to food.

Next, they used sausage slices to contact wood, tiles and carpets on which Salmonella had been cultured for 5 seconds, 30 seconds or 60 seconds, and repeated the same experiment using bread slices and tiles cultured with Salmonella to observe how different food types, different floor types, different bacterial incubation times and different contact times affected the amount of bacterial transfer.

Image source: Pixabay

The experimental results show that when food comes into contact with wood or tiles that have just been contaminated by bacteria, the bacterial transfer rate (i.e. the ratio of the number of bacteria on the food to the total number of bacteria on the food and the floor) can reach 50%-70%. As the growth time of bacteria on the floor increases to 24 hours, the transfer rate will slowly drop to 10%-30%, but even so, the number of bacteria transferred to the food is still hundreds to thousands per square centimeter. There is no obvious difference in the amount of bacteria transferred between sausages and bread. It is worth noting that compared with wood and tiles, the bacterial transfer rate from carpet to food is much lower, only less than 1%. However, don't mistakenly think that carpets are safer and more hygienic and are good partners for the "5-second rule". In fact, because the environment of carpets is more suitable for bacterial growth, even if the bacterial transfer rate is so low, the absolute number transferred is still almost the same as that of wood and tiles, and carpets have a long-lasting ability to maintain bacterial activity. Under the same culture conditions, the amount of bacteria on carpets after 24 hours can reach 10-100 times that of wood and tiles. The experiment also showed that the number of transferred bacteria has nothing to do with the contact time between the food and the floor. Five seconds of contact brings almost the same amount of bacteria as 10 seconds or 60 seconds. The transfer of bacteria occurs immediately.

After this series of experiments, Dawson and his colleagues concluded that in the process of bacteria transferring from the floor to the food, the growth time of the bacteria on the floor plays an important role in the number and amount of bacteria transferred, while the type of food and the contact time between the food and the floor have little effect. It seems that whether it is 3 seconds, 5 seconds or 10 seconds, we are not faster than bacteria.

If food falls on the floor, the safest thing to do is: Don't eat it

Many people may object:

I've eaten food that fell on the floor before, and I didn't get sick.

Of course, whether you will get sick after eating it depends on whether the bacteria on the food are pathogenic, the number of bacteria, and your own resistance.

The reason you don’t get sick may be that you haven’t encountered pathogenic bacteria, or it may be thanks to your immune system.

In other words, you are gambling with your life and health.

Bacteria are invisible to the naked eye, and even a clean floor may still contain pathogens. "Pick it up quickly" cannot prevent food from being contaminated by bacteria.

You should know that some "vicious" E. coli can cause food poisoning with just a small amount, and for people with weakened immunity, it can even lead to death in severe cases.

Therefore, to be on the safe side, it is better not to eat food that has fallen on the ground. Especially for the elderly and children with weak immunity, they should not take risks.

In fact, the bacterial contamination process has already begun when food touches the ground, and we cannot see bacteria with our naked eyes. Therefore, if the food that falls on the ground does not have a complete shell, the safest way is not to eat it.

Source: Chongqing Tianji Network Co., Ltd.

This article is a comprehensive compilation of the official WeChat account of Self-Is the Great Doctor, Dingxiang Doctor, and 39 Health Network

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