Should you wash bagged salad? Here’s what to look out for

There are not many studies that have compared fresh-cut and pre-packaged produce in terms of food safety. According to the findings of a study conducted by the Istituto Zooprofilattico Sperimentale delle Venezie in 2015, the level of contamination by pathogenic bacteria in pre-washed salads is lower than in fresh, untreated vegetables. At an industrial level, treatment with peracids makes it possible to remove all chemical residues without altering the product’s organoleptic properties – and therefore without compromising its colour, flavour or aroma.

From a nutritional point of view, industrial washing and cutting may result in the loss of certain micronutrients. In particular, some studies report a reduction in vitamin C and polyphenols (antioxidant molecules). However, the available evidence does not show any significant nutritional differences.

The mineral and fibre content is comparable to that of the unpackaged product. This means you still have the advantage of being able to easily incorporate healthy portions of vegetables into your daily diet.

According to the research cited, the most effective method of cleaning at home involves the use of chlorine-based disinfectants. To find the right commercial product, simply check the label for the presence of chlorine or food-grade sodium hypochlorite. You then simply need to follow the instructions to dilute the product in drinking water and proceed with rinsing.

Raw fruit and vegetables may harbour bacteria, viruses and other microorganisms originating from the soil or irrigation water. Adherence to hygiene standards and thorough washing greatly reduce the risk, but do not eliminate it entirely. It is, however, important to be aware of and prevent foodborne illnesses. The main pathogens that may be associated with fruit and vegetables are Salmonella, Listeria, Escherichia coli, Norovirus and Yersinia. Other risks stem from the hepatitis A virus.

In such cases, according to some research, washing pre-packaged salads as well is an extra precaution against, for example, toxoplasmosis. This infection, caused by a parasite, is dangerous for pregnant women. During pregnancy, it is advisable to rinse the salad under running water and dry it thoroughly; disinfectants and bicarbonate of soda do not appear to offer any significant protection against toxoplasma eggs and spores.

The likelihood of traces of Toxoplasma being present in fresh-cut produce is low but not zero. This was confirmed by a study across ten European countries, coordinated by the Italian National Institute of Health, which examined over three thousand samples of washed, ready-to-eat salads. Of all the countries, the Italian figures are the most reassuring.

However, consumers must also do their bit to prevent products from going off.

Fresh-cut produce, which can be found in the chilled section of the supermarket, must also only be consumed if the cold chain remains unbroken. Once at home, they should be stored in the fridge (at a temperature between 0°C and +4°C) and consumed by the use-by date. In any case, they must look undamaged and the packet must not have excessive condensation.

We have already discussed how to assess the freshness of food in the factsheet “Can I rely on my sense of smell to tell if food has gone off?” .

Finally, take a look at the label. It is advisable to choose reputable brands and to check that the packaging shows not only the use-by date but also the dates of harvesting and packaging. Generally, these products have a shelf life of around 7 days in winter and 5 days in summer, but it is advisable not to consume them more than 4 days after packaging.

Read the full article on the dottoremaeveroche website, run by Fnomceo