IN Brief:
- The TERA project has received DKK6.3 million to examine pathogen persistence in plant-based foods.
- Researchers will combine microbiology, data science, DNA sequencing, and high-resolution microscopy to study complete microbial communities.
- The work aims to identify microbial fingerprints that could complement established food-safety risk assessment methods.
University of Copenhagen Department of Food Science researchers are examining how complete microbial communities influence pathogenic bacteria in plant-based foods, seeking to add an ecological layer to microbiological risk assessment rather than considering individual organisms largely in isolation.
The TERA project — Ecological Risk Assessment of Pathogen Persistence in Plant-Based Foods — has received DKK6,335,419 through Independent Research Fund Denmark’s Sapere Aude programme. Led by Associate Professor Henriette Lyng Røder, the research will combine microbiology, food science, data science, DNA sequencing, and high-resolution microscopy.
Plant-derived raw materials can carry complex communities of microorganisms, with different species competing, interacting, and responding to their surrounding environment. The Copenhagen team wants to establish whether the structure of those communities affects the ability of disease-causing bacteria to survive or adapt inside food.
Conventional food-safety assessment already uses variables including temperature, pH, product composition, processing conditions, and the presence or concentration of particular microorganisms. Those controls remain fundamental, but they do not describe every interaction occurring between the numerous organisms that can be present in a raw material or finished product.
Associate Professor Henriette Lyng Røder of the University of Copenhagen Department of Food Science said: “If we want to understand why harmful bacteria behave differently in otherwise similar foods, we need to consider the entire microbial community.”
TERA will investigate whether particular microbial patterns occur alongside increased pathogen persistence. The researchers describe these patterns as microbial fingerprints, with the longer-term objective of determining whether they can provide useful additional information when microbiological risks are assessed.
DNA sequencing will be used to characterise the organisms present within food environments rather than concentrating solely on an individual target pathogen. High-resolution microscopy will provide information on how microorganisms are physically organised, while data analysis will be used to search for repeatable relationships within the resulting datasets.
The combination is necessary because two products with similar headline characteristics can contain very different microbial communities. Differences in raw-material origin, handling, processing, formulation, and storage can alter which organisms are present and the conditions under which they compete or coexist.
Existing HACCP systems, microbiological criteria, challenge testing, and process controls are not being replaced by the research. The stated objective is to provide a foundation for future assessment methods that could integrate microbial ecology alongside established food-safety approaches.
That distinction is important because the work remains at the research stage. Detecting a microbial pattern in an experimental dataset is different from showing that the same pattern can reliably predict pathogen behaviour across commercial products, processing environments, and variable raw materials.
The challenge becomes particularly relevant as product developers work with a wider range of plant-derived ingredients and processing routes. Thermal treatment, fermentation, chilled manufacture, minimally processed products, and extended shelf-life systems create different microbial conditions even when products sit within the same broad food category.
Reformulation can alter those conditions again. Changes in moisture, acidity, nutrient availability, ingredient source, or processing intensity can affect the surrounding microbial population, meaning safety performance cannot automatically be transferred from one formulation to another without supporting evidence.
The Copenhagen work is intended to explore whether microbial-community information can help explain some of those differences. A reliable ecological indicator could eventually support the design of challenge studies or help researchers identify conditions that deserve closer investigation, although TERA has not yet established such a tool.
Its methods also reflect the increasing volume of biological data available to food scientists. Sequencing can identify organisms that conventional culture methods may not fully describe, but the resulting datasets are considerably more complex and require analytical methods capable of distinguishing meaningful relationships from coincidental variation.
Turning that complexity into something useful to food safety will be the difficult part. An assessment method used in production or regulatory work has to deliver repeatable information, function within practical sampling constraints, and provide an interpretation that can support a decision rather than simply describing a microbial ecosystem in greater detail.
The TERA programme therefore begins with a more fundamental question: whether the behaviour of a pathogen can be linked consistently to the wider community around it. If the project identifies repeatable microbial fingerprints, subsequent work will still be needed to establish how those findings can be validated and incorporated into practical risk assessment.
The research adds a new layer to the study of plant-based food safety without changing the immediate control obligations on food businesses. Its eventual value will depend on whether the ecological relationships found through sequencing, microscopy, and data analysis can be reproduced well enough to improve predictions of when pathogens are most likely to persist.
