Cereulide in Food and Baby-Food Products: Regulatory Developments and Analytical Implications

Regulatory Background

On 24 February 2026, the European Commission adopted Implementing Regulation (EU) 2026/459, amending Regulation (EU) 2019/1793. The amendment introduces reinforced official controls and specific measures at EU borders for arachidonic acid (ARA) oil originating in China. Regulation (EU) 2019/1793 provides the legal framework for intensified controls on food and feed of non-animal origin where particular risks have been identified. Amendments are introduced when monitoring data or risk assessments indicate emerging concerns.

In this case, regulatory attention is directed toward cereulide in the context of infant nutrition.

Formation and Occurrence of Cereulide

Cereulide is a cyclic peptide toxin produced by certain emetic strains of Bacillus cereus. Only a subset of B. cereus strains possesses the genetic capacity to synthesise this toxin.

Bacillus cereus is widely distributed in the environment. Its spores are naturally present in soil and dust and may enter cereals, milk-based ingredients or plant-derived raw materials during primary production. The spores are highly resistant and can survive drying, heating and prolonged storage.

Under favourable conditions, spores from emetic strains can germinate and multiply in food. During this growth phase, cereulide may be formed. Situations that allow bacterial proliferation include extended storage at ambient temperature, inadequate cooling or prolonged warm holding.

Once formed, cereulide remains stable. Conventional thermal processing may eliminate viable bacterial cells but does not reliably degrade the toxin. Starch- and protein-rich foods have frequently been associated with cereulide-related incidents, including rice dishes, pasta, potato products, dairy products and ready-to-eat meals. European surveillance data have also linked fruits and vegetables to outbreaks involving Bacillus cereus toxins.

Technological and Hygienic Considerations

From a production perspective, cereulide presents distinct challenges.

Bacillus cereus is capable of forming persistent biofilms on processing surfaces. Such biofilms can act as reservoirs for spores and may contribute to recurring contamination events. Cereulide itself can adhere to stainless steel and glass surfaces and exhibits higher affinity to fatty matrices than to aqueous systems.

In addition to its marked heat stability, cereulide is resistant to a broad pH range and to enzymatic degradation. These characteristics distinguish it from many protein-based microbial toxins.

As a consequence, a product may contain cereulide even in the absence of detectable Bacillus cereus cells.

Relevance for Infant Nutrition and ARA Oil

Infant formula is a particularly sensitive product category due to the vulnerability of the target population.

Arachidonic acid (ARA) oil is commonly added to infant formula to support early development, often in combination with docosahexaenoic acid (DHA). ARA oil is typically produced through controlled microbial fermentation processes. Fermentation requires strict hygiene management, as it involves microbial growth phases under defined conditions.

If emetic Bacillus cereus strains are introduced during production or handling, cereulide formation may occur prior to final heat treatment. Because the toxin is heat-stable, subsequent processing may remove bacterial cells without eliminating the toxin itself.

This mechanism explains why regulatory measures are directed at ingredient-level controls.

Toxicological Assessment

The European Food Safety Authority (EFSA) initially assessed cereulide in 2016 and published an updated rapid risk assessment in early 2026.

In February 2026, EFSA established an Acute Reference Dose (ARfD) of 0.014 µg per kg body weight for infants. The ARfD represents the estimated amount that can be ingested within a short period without appreciable health risk.

Given the low body weight of infants and their relatively high intake per kilogram body weight, the margin between exposure and toxicological threshold may be limited. EFSA indicated that certain concentrations in reconstituted infant formula could result in exceedance of the ARfD.

Analytical Implications

The establishment of a low ARfD fundamentally shifts the analytical perspective.

Where toxicological thresholds are in the low microgram per kilogram range, analytical capability becomes central to exposure assessment. The key question is not solely whether cereulide can be detected, but whether it can be reliably quantified in complex matrices such as infant formula or fatty acid oils.

Testing exclusively for Bacillus cereus does not sufficiently address the hazard. Direct determination of the toxin is required where ingredient-level risk must be evaluated.

Robust analytical assessment therefore requires:

• matrix-specific validation
• suitable limits of quantification
• evaluation of recovery and matrix effects
• documentation aligned with regulatory requirements

In the context of reinforced official controls, analytical data must withstand regulatory evaluation and provide a scientifically defensible basis for compliance decisions.

Analytical Support within the Normec Group

As part of the Normec Group, GALAB provides access to validated cereulide analysis in relevant product and ingredient categories, including infant formula and fatty acid oils.

In the official control context, the examination of Bacillus cereus and cereulide follows a coordinated approach described by the German working group “Arbeitsgruppe Lebensmittel tierischer und sonstiger Herkunft” (ALTS). For the determination of cereulide, ISO 18465:2017 serves as the recognised reference method, based on LC-MS/MS.

Within the framework of the recent EFSA risk assessment, action levels for cereulide in infant formula have been derived. These are based on the newly established Acute Reference Dose (ARfD) of 0.014 µg/kg body weight.

According to the current assessment, concentrations exceeding:

• 0.054 µg/L (infant formula, reconstituted liquid)

• 0.1 µg/L (follow-on formula, reconstituted liquid)

may be considered critical with regard to a potential exceedance of the ARfD.

Against this background, it is essential that the analytical limit of quantification is below these thresholds in order to allow a reliable compliance assessment.

Our currently available limits of quantification for cereulide are sufficiently low to enable a robust evaluation in relation to the derived action levels.Where regulatory scrutiny increases and toxicological margins are narrow, reliable quantification and regulatory clarity are essential components of product safety management.

Conclusion

Cereulide differs from many classical microbiological hazards. Its formation prior to processing, its pronounced stability and its low toxicological threshold require targeted consideration, particularly in sensitive product categories such as infant nutrition.

The recent regulatory developments underscore the importance of ingredient-level risk assessment and robust analytical capability.

Where safety margins are narrow, analytical precision is indispensable.

Sources

Regulatory Framework

• Commission Implementing Regulation (EU) 2026/459 of 24 February 2026 amending Implementing Regulation (EU) 2019/1793EUR-Lex: https://eur-lex.europa.eu/eli/reg_impl/2026/459/oj
• Commission Implementing Regulation (EU) 2019/1793 on the temporary increase of official controls and emergency measuresEUR-Lex: https://eur-lex.europa.eu/eli/reg_impl/2019/1793/oj

Scientific and Toxicological References

• EFSA (2026). Rapid risk assessment on cereulide in infant formula; establishment of an ARfD of 0.014 µg/kg body weight.EFSA Journal. https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2026.9941
• EFSA News (2026). EFSA provides rapid risk assessment on cereulide in infant formula.https://www.efsa.europa.eu/en/news/efsa-provides-rapid-risk-assessment-cereulide-infant-formula
• European Commission Decision on oil rich in arachidonic acid from Mortierella alpina (fermentation-based production).EUR-Lex: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008D0968
• EFSA (2016). Scientific Opinion on risks for human health related to the presence of Bacillus cereus and its toxins in foodstuffs.https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2016.4524
• Granum, P.E., & Lund, T. (1997). Bacillus cereus and its toxins. FEMS Microbiology Letters, 157(2), 223–228.

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