Why This Matters:
- Recent infant formula contamination events involving cereulide: Multi-country recalls have underscored the need for robust and reliable cereulide detection methods in powdered infant formula (PIF).
- Matrix complexity is a primary analytical challenge: The lipid- and protein-rich composition of powdered infant formula can significantly limit toxin recovery; in many cases, extraction chemistry—not analytical instrumentation—is the principal bottleneck.
- Limitations of ISO 18465:2017 for cereulide analysis: The current ISO method relies on acetonitrile-only extraction and was validated across diverse food matrices. However, when applied to powdered infant formula contaminated via tainted ingredients, it can underestimate cereulide concentrations by approximately an order of magnitude.
Key Findings: This study conducted by the Nestlé research group proposes and validates a modified extraction protocol specific for testing infant formula and oil for cereulide contamination.1
- Matrix complexity dictates extraction efficiency: The dense, low-moisture, lipid- and protein-rich structure of powdered infant formula sequesters cereulide within the matrix, reducing the efficiency of the acetonitrile-based extraction specified in ISO 18465. Direct extraction from powder yielded recoveries ranging from 4–13% (mean 7%). In contrast, performing the ISO 18465 procedure after an initial water reconstitution step resulted in ~100% recovery (n = 27, CV = 10%).
- Partitioning (“salting-out”) extraction markedly improves recovery: A QuEChERS-based water/acetonitrile partitioning approach significantly enhanced extraction efficiency, achieving high recoveries (~94.9–106.5%) of cereulide from powdered infant formula matrices.
- Improved limits of quantification with the revised protocol:
- 0.1 µg/kg for powdered infant formula and oils
- 0.01 µg/kg for liquid formula
These performance characteristics meet newly established requirements derived from the European Food Safety Authority (EFSA) acute reference dose (ARfD) for cereulide (0.0014 µg/kg body weight/day in infants), corresponding to an action threshold of 0.054 µg/L in reconstituted infant formula.
- Strong analytical robustness: The revised method demonstrated excellent analytical performance, including strong reproducibility, with repeatability and intermediate precision values below 17.7%, supporting suitability for routine analytical application.
Bigger Picture: Detection reliability depends as much on extraction chemistry as on instrument sensitivity. For cereulide surveillance in powdered infant formula, optimized matrix-specific extraction is essential to ensure reliable risk assessment. The work provides compelling evidence that the ISO 18465:2017 method should not be applied to unmodified powdered infant formula and that the enhanced partitioning/salting out approach yields accurate and operationally efficient routine measurement for regulatory and quality assurance programs.
(Image Credit: iStock/Olena Zalevska)
