Germany highlights risks from packaged sprouts and salads

The Federal Institute for Risk Assessment (BfR) also said that contamination during the growth and harvesting of the products, as well as the fact that some bacteria are carried by animals and occur naturally in the environment also contribute.

But the agency said incidents of foodborne illnesses from the vegetables were relatively low compared to that from pork and poultry.

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Potential hazard​

Studies by the group found that while both products are stored under refrigerated conditions they still carry a risk of contamination with bacteria such as Listeria monocytogenes, Salmonella and E.coli, as well as viruses such as Norovirus and hepatitis A. Soy bean sprouts or alfalfa as well as ready-to-eat mixtures of leaf lettuce and uncooked vegetables such as white or red cabbage and carrots can therefore become a health hazard for humans, added the body.

The federal agency said a study of 59 samples of fresh packaged sprouts and shoots found the numbers of bacteria in sprouts “increase considerably within a few days” and​ have an above average microbial load when they reach the best before date”. A study of 133 bagged salads in 2008 found five per cent contained Listeria – particularly mixed salads consisting of white cabbage.

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Causes ​

The BfR lists a range of potential causes for bacterial contamination along the entire supply chain. Irrigation with contaminated water or use of manure during growing can trigger bacterial growth. The cultivation of sprouts in special containers promotes the growth of bacteria and regular intermediate cleaning should be carried out.

A lack of hygiene during processing such as the use of contaminated washing water or a lack of refrigeration can further promote this. Whole lettuce and white cabbage can provide natural protection against bacteria but this is broken once the vegetables are cut, with the release of cell sap providing a medium for the bacteria to multiply, said the body.

Bacteria can also adhere to the surface of plants – especially white cabbage. While the extent to which they do this has not been quantified exactly, it is “certain bacteria multiply much slower in plant cells than in animal cells​”, said the BfR.

Washing ​

The body concludes the risk from sprouts and ready-to-eat salads is lower that that from pork and poultry and it recommends thorough washing before consumption to reduce the bacterial load.