With the arrival of spring warmth, more greenery, which everyone was already so bored with, began to appear on sale. Very soon the time for summer vegetable salads will come, but at the same time the risk of intestinal infections will increase. Moreover, greens are often associated with outbreaks of E. coli and other pathogens. Moreover, scientists have noticed that most often diseases occur when consuming certain types of it, such as spinach, romaine lettuce and green leaf lettuce. Therefore, a team of researchers from the United States decided to find out what determines the likelihood of infection when eating greens, why it differs among different herbs, and how to avoid infection.
Scientists warn that greens, especially leafy greens, should be stored in the refrigerator
From which greens are at risk of contracting intestinal infections
As scientists explain, they regularly see outbreaks of intestinal infections due to lettuce, but at the same time, people rarely become infected after eating cabbage and other cabbage vegetables. This motivated the team to conduct an unusual study – they infected the leaves of five vegetables with E. coli O157:H7, and observed what happened to the bacteria after storing the leaves at different temperatures: 4°C, 20°C and 37°C.
As a result, the authors of the work found that the survival of bacteria depended on two factors – the ambient temperature and the properties of the leaf surface, such as roughness and the presence of a natural waxy coating, which is known to be present on cabbage (because of it, water does not linger on the leaf surface , but collects into droplets and rolls off).
E. coli multiplies more slowly on cabbage than on lettuce
Salad must be stored in refrigerator
As researchers report in Food Microbiology, at room temperature and above, E. coli multiplies rapidly. Accordingly, there is a high risk of contracting an intestinal infection. But if you put the salad in the refrigerator, then at a temperature of 4 degrees there is a sharp decrease in the bacterial population. Thus, if the salad is kept in the refrigerator, the risk of infection is reduced.
But, what’s most interesting is that with cabbage the situation is the opposite. At high temperatures, E. coli on its surface develops much more slowly than on lettuce. But if the cabbage is put in the refrigerator, the bacteria can survive longer, of course, if they were present initially.
However, in general, the risk of contracting an intestinal infection when eating raw cabbage is much less compared to lettuce. In addition, cabbage, unlike lettuce, is most often subjected to heat treatment. As a result, the risk of infection is reduced even further.
Cabbage juice has antibacterial properties
The researchers also infected a section of leaves with E. coli O157:H7 to compare how the bacteria multiplied in undamaged and damaged areas. When a leaf is damaged, it secretes a sap that contains nutrients that stimulate bacterial growth. However, research has shown that spinach and kale have antimicrobial properties that kill E. coli. Moreover, scientists have discovered that cabbage juice can be used as a natural antimicrobial agent. For example, they applied it to a lettuce leaf, and this led to its disinfection.
How to avoid getting an intestinal infection
Scientists do not discourage eating raw vegetables and fruits, as they are very healthy. For example, greens are rich in vitamins and minerals. As we previously told you, raw greens are especially recommended to eat in the summer heat. However, it is necessary to follow certain rules that are known to everyone, but not everyone carefully follows them.
Greens must be washed thoroughly before eating
First of all, greens must be washed thoroughly. A study found that rinsing lettuce helps reduce bacteria. However, it is impossible to completely get rid of them, since they are tightly attached to the leaf. In addition, as mentioned above, greens must be stored in the refrigerator. This will not only prevent the proliferation of pathogens, but also avoid a new infection by insects.
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And most importantly, do not forget to wash your hands before eating. Most often, intestinal infections occur not because of products, but because they are poorly washed. By the way, even disinfectants cannot replace proper hand washing. You can read more about this at the link.