Working to ensure safe peanuts and berries, now and in the future

Between November 2024 and February 2025, dozens of people in the Netherlands were infected with hepatitis A. Eight people were even hospitalised. After a survey, RIVM and the Municipal Health Service concluded that frozen blueberries might have been the source of the infections. The Dutch Food and Consumer Product Safety Authority (NVWA) swiftly took a sample of the fruit to Wageningen, where a team of researchers was ready to spring into action. After examining the sample, they found that the berries were indeed infected with the hepatitis A virus. These results were immediately shared with the NVWA. The supermarket that had sold the product launched a major recall.

Wageningen Food Safety Research (WFSR) knows the importance of safe food. With more than 400 employees, WFSR mainly performs Statutory Research Tasks (WOT tasks) to ensure food safety in the Netherlands. Every day, researchers check food products for compliance with national and European regulations. For example, they look for pathogens like salmonella and check food for chemical and pharmaceutical residues, including pesticides and antibiotics. The results of their research are sent directly to the NVWA, the government agency that monitors food safety. 

But there are more actors in the food chain, all of whom play a role in food safety. How do they ensure that consumers can eat a bag of peanuts without worrying, for example? “It starts with the producer,” says Jeroen Rijk, subprogramme leader Contaminants at WFSR. “The food producers themselves are responsible for the safety of the products they supply. That means that a peanut produced in the United States may already have been checked by the grower or importer wanting to ship the goods to Europe.”

An American peanut takes several weeks to reach Europe by container ship. During this journey, moist conditions can cause all kinds of fungi to grow. Once the batch arrives in the port of Rotterdam, the NVWA may come and take a sample. “For food entering the EU, the European Commission determines how many samples the competent authorities must take,” says Rijk. “For peanuts from the US, samples are taken from 20% of all batches entering Europe.” 

So for every five batches of peanuts arriving in the port of Rotterdam, one is checked on average. That batch, usually consisting of hundreds of large bags, is set aside in a warehouse. “The NVWA inspector then takes as many as 100 samples from different bags, totalling 20 kilos of peanuts. These are then transported to Wageningen,” says Rijk.  
Which is where WFSR comes in. The Natural Toxins team investigates whether peanuts contain mycotoxins. These are toxins produced by fungi. Rijk: “From the peanuts received, we make a representative laboratory sample. The researchers grind the peanuts and add water to them to create a slurry, a kind of peanut butter. A portion of that mixed slurry will be examined. They have to extract this part, adding a liquid that extracts the fungal toxins.” 

The final step involves using an analytical technique that measures fungal toxins. This analyses several fungal toxins simultaneously. “If any are found, you see a spike,” Rijk continues. “We can then calculate a content. An analysis report is drawn up which we send to the NVWA.”

Meanwhile, the rest of the batch of peanuts is still in the warehouse in Rotterdam, waiting to be released. That means time pressure behind WFSR's analyses. “For mycotoxins in peanuts, we have three to five days,” says Rijk. “But for perishable goods like fruit and vegetables, which we check for pesticides, it obviously needs to be done much faster. Our job then has to be done within 24 hours.” If the peanuts are deemed safe by the NVWA, they will be allowed to enter Europe. If not, the NVWA will decide what to do with them. 

WFSR measures hundreds of samples of peanuts and other foods every day. But its work goes a lot further than that. If necessary, WFSR can operate as a crisis organisation to carry out analyses within hours - as in the case of the contaminated blueberries. At the NATO summit held in The Hague in 2025, Wageningen researchers were also on standby to respond immediately to any food safety incidents.

However, part of WFSR's food safety research does not focus on controls and incidents, but rather on the risks that may arise in the long term. This is what Bjorn Berendsen and Arjen Gerssen do. Berendsen is programme leader WOT Food Safety Policy at WFSR, Gerssen leads the WOT Food Safety Enforcement.

“In recent years, you regularly hear reports of eggs and fish containing excessive concentrations of PFAS, for example,” adds Gerssen. “We started researching PFAS some 15 years ago, when scientists warned that it could become a problem. We responded to this by developing measurement methods and generating and sharing knowledge with government agencies so that they can plan a relevant policy.” 

Changes in the food system can be very gradual, or very acute. In their work, Berendsen and Gerssen see the impact of climate change, the sustainability transition and geopolitical shifts in particular. 

“Climate change has a huge impact on our food system,” says Berendsen. Some effects are very direct: surface water warming, for example, leads to an increase in algae. These produce toxins that can be dangerous if they enter the food system. 

The changing climate is also shifting trade flows, Berendsen continues. “If it becomes too hot or too dry to grow a product in country X, production moves to country Y.” There they produce in a different way, a country outside the EU might use different plant protection products. You then run the risk of products containing substances you don't want.” In preparation for this, WFSR developed a measurement strategy that also allows them to investigate crop protection products used outside Europe.

Livestock health is also under increasing pressure. As our climate gets warmer and more humid, the risk of infections increases. Berendsen: “What can be done to keep animals resilient? Treating animals preventively, giving supplements, mixing herbs into the feed? It is important to start thinking now about whether these adjustments could lead to new risks, and how to deal with them. This year, for example, we collaborated on an NVWA study on the potential effects of climate change on food safety.”  

In such surveys, WFSR benefits from the large amount of data at the organisation's disposal, says Gerssen: “Data science has received a huge boost in recent years. We now employ 20 people studying new ways of collecting and processing data.” 

As climate change takes hold, it is increasingly important to design the food system more sustainably. Cultured meat, insects as fodder, reuse of waste streams, reduced pesticide and antibiotic use: Berendsen and Gerssen see all kinds of sustainable and circular developments coming along. These in turn may also have implications for food safety, says Berendsen: “If farmers are limited in their use of plant protection products, they need to choose alternatives. What are the risks involved? Or take the protein transition: it would be good if we eat more plant-based food, and less meat. But which plants? And are there any new risks associated with that?'

Finally, WFSR constantly faces geopolitical changes. Berendsen and Gerssen noticed this in 2022, after the Russian attack on Ukraine. Gerssen: “This led to a huge shortage of Ukrainian sunflower oil, which suddenly had to be imported from other countries. We then check whether the oil contains plant protection products, for example, or whether traders have added a different oil to take advantage of the high prices.” 

US tariff policy could have a major impact on commodity flows in the near future. Such geopolitical shifts are often difficult to predict, unlike gradual processes such as climate change. It makes WFSR's work more complicated, but also more important. “Consumers should not have to worry about food safety, that’s our job,” concludes Berendsen.