Alert! Packed Salad is Salmonella Breeding Ground

Precut green leafy vegetables in packes salad may encourage growth of Salmonella, a new study found.

Researchers at the University of Leicester revealed that juices released from precut leaves of lettuce, spinach and other leafy vegetables can encourage the growth of Salmonella pathogen growth by 2,400-fold. It also increased the bacteria's virulence, increasing its ability to cause infection. This happens even when it is kept in the fridge.

"Salad leaves are cut during harvesting and we found that even microlitres of the juices (less than 1/200th of a teaspoon) which leach from the cut ends of the leaves enabled salmonella to grow in water, even when it was refrigerated," Primrose Freestone, microbiologist, and lead author of the study said in a press release.

"These juices also helped the salmonella to attach itself to the salad leaves so strongly that vigorous washing could not remove the bacteria, and even enabled the pathogen to attach to the salad bag container."

According to The Conversation, cases of Salmonella infection caused by green vegetables are getting prominent. The report cited that in February 2016, more than 50 people in Victoria, Australia developed Salmonellosis after eating bagged salad leaves, while in July 2016, 161 people fell ill in the UK after eating mixed salad leaves and two people died.

Although salad is an important component of a healthy diet, they also pose infection risk because they are usually slightly processed after harvesting and consumed raw.

In addition, the study also revealed that once the bagged salad is opened, the bacteria grown much faster. Thus, people are encouraged to consume their bagged salad as soon as possible.

As a result, the researchers recommended that producers must improve food handling and processing for the safety of the consumers, CBS News noted.

The study was published in Applied and Environmental Microbiology.