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High multiplication of germs in packed salads - unforeseen health risk


Plant juice from broken leaves increases the risk of salmonella
Many people like to eat fresh salad. But what do you do when fresh salad is not available? Then we often grab pre-packed salad bags. Researchers have now found that broken leaves in such salad bags extremely increase the risk of food poisoning. Appropriate lettuce can even increase the growth of salmonella by 2,400 times.

The University of Leicester scientists found in an investigation that packaged lettuce has an increased risk of multiplying Salmonella. The doctors published the results of their study in the journal "Applied and Environmental Microbiology".

Washing the salad does not improve
Many packaged salads are sold in bags in the supermarket. Such salads often contain broken leaves. These broken leaves increase the risk of developing Salmonella pathogens. Even if we wash our salad, it makes no difference, the experts warn. The salmonellae adhere so well to the lettuce leaves that even washing them heavily cannot remove them, the British newspaper “The Telegraph” quotes the experts.

Packaged salads should be avoided if possible
Bags of packaged lettuce are a real breeding ground for deadly salmonella. The broken leaves in such lettuce can increase the likelihood of food poisoning by 2,400 times, the authors explain. Liquid can then leak from these broken leaves in the sealed bags, which causes the growth of Salmonella pathogens. For this reason, private households should avoid such salads as much as possible, the scientists add.

Plant juices massively increase the growth of Salmonella
The results show the need to ensure that farmers who grow lettuce must comply with high food safety standards. Even small traces of the released plant juices can cause the salmonella to multiply, the doctors explain.

Effects of a Salmonella disease:
A salmonella infection can cause high fever, vomiting and diarrhea. Such an illness is very uncomfortable for most people. Experts warn that it can even be fatal for older people and very young children with a compromised immune system.

Study examines danger of broken leaves in salad bags
The current study examined for the first time the exposure to Salmonella in packaged salad bags. The researchers did not examine the levels of salmonella in purchased salad bags. They examined the bacteria on the damaged leaves and on the surface of the plastic bags, reports the "Telegraph".

Salmonella sticks to the surface of plastic bags
According to the researchers, the leaking plant sap made the Salmonella virulent. This increased the potential threat to consumers. The plastic bags were cut into 2 cm sections. Then the scientists tested how strongly the salmonella adhered to the surface in so-called biofilms.

Storage in the refrigerator has no advantages against the proliferation of Salmonella
The salmonella levels reached were virulent enough to infect humans when the salad was no longer packaged. The bacteria also multiplied on the lettuce leaves when kept cool in the refrigerator. It is worrying that salmonella exposure in the study also increases in the cold environment of a refrigerator, the researchers explain. The temperature of refrigerators is typically around 4 degrees Celsius. Even the plant juice of two hundredths of a teaspoon is enough to increase the risk of infection of the salad.

Wash the lettuce every time before eating
If you are not using a fresh salad, you should definitely buy pre-packed lettuce uncut. The salad always has to be washed before consumption, even if it has already been washed, explains Dr. Kimon Karatzas from the University of Reading opposite the “Telegraph”. It is also very important that such foods are stored in the refrigerator. However, neither really helps against the salmonella that occurs.

Outbreaks of food poisoning have increased in recent years
In recent years there have been an increased number of food poisoning outbreaks associated with fresh salad products, the scientists warn. In these cases, the salads were mostly contaminated with Salmonella and E. coli. (as)

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