Researchers from the Netherlands are part of a team studying pathogens in plant-based products.

Scientists will genetically characterize pathogenic bacteria in plant-based products and map their growth and behavior.

The research aims to assist producers in controlling harmful microorganisms in these products. 

The study, GRASP (Genomic-driven Risk Assessment of Plant-based Foods), focuses on the safety of new products, including dairy alternatives. 

Project partners include the Technical University of Denmark (DTU), Wageningen University and Research, food companies, and product inspection firms.

Understanding the issue
Plant-based raw materials such as oats, peas, and almonds can contain harmful bacteria that produce toxins, such as Bacillus cereus and Clostridium botulinum.

These two types of bacteria are dangerous because they form spores, dormant cells that can withstand extreme conditions like heat and cold. Under favorable conditions, the spores germinate to form living, growing bacteria. This allows them to survive pasteurization and end up in food products.

Not all bacteria behave the same under extreme conditions, with variation within a single bacterial species.

Heidy den Besten, Professor of food microbiology at Wageningen University and Research, said: “Some subgroups are heat-resistant, while others grow well at low temperatures, like in the refrigerator. If we treat all subgroups similarly, their behavior becomes difficult to predict.”

Researchers aim to characterize Bacillus cereus and Clostridium botulinum into subgroups and determine their growth. This will help assess which subgroups are problematic under specific conditions and find ways to control them.

The goal is to develop a tool that allows manufacturers to simulate their production processes to minimize the growth of pathogens and estimate the product’s shelf life.

The work has received €1 million ($1.1 million) in funding through the international platform Plant2Food. This program has €27 million ($29.4 million) available from the Novo Nordisk Foundation, a private funder of scientific research in Denmark for the next three years.

Other ongoing efforts
Wageningen University and Research is also part of another consortium looking at the potential food safety and quality risks of microbial contaminants in plant-based food products, such as dairy alternatives.

This group, coordinated by Nizo Food Research, includes The Coca-Cola Company, Tetra Pak, Bel, Arla Foods, Yili, HP Hood LLC, and FrieslandCampina.

In a study in the International Journal of Food Microbiology, the levels and types of microbial contaminants in 88 different plant-based ingredients were investigated.

Results show the microbial loads of such ingredients vary widely between and within ingredient groups. Spore-forming species that survive heat treatments were detected. Food safety can be at risk if the spore-former can produce toxins. 

“Insight into the occurrence of microbial contaminants in plant-based ingredients, combined with knowledge of their key inactivation and growth characteristics, can be used for the microbial risk assessment and effective design of plant-based food processing conditions and formulations to ensure food safety and prevent spoilage,” said researchers.