Microplastics in Food and Baby Food: The Accredited μFTIR Analysis Method

Microplastics in food represent one of the most complex and debated analytical and environmental challenges of recent years. Generally defined as plastic particles smaller than 5 millimeters, their ubiquity in ecosystems has progressively drawn the attention of the scientific community and regulatory authorities toward assessing the potential transfer of these emerging contaminants along the agrifood supply chain.

As concerns over food contaminant testing continue to grow, reliable microplastics analysis has become essential for ensuring food safety and consumer confidence. Within this scenario, the infant and toddler food sector (baby food) demands the highest level of monitoring and scientific rigor. Consumers in this age group constitute a biologically vulnerable population; consequently, food quality control and the analytical characterization of food matrices dedicated to them require certified, cutting-edge methodologies capable of combining sensitivity, selectivity, and accuracy.

Microplastics Detection and Determination: Matrix Complexity and Standardization

Microplastics testing and microplastics determination in food products is historically challenging due to the heterogeneity of food matrices, including the presence of proteins, lipids, and carbohydrates that can interfere with the analysis, as well as the wide variety of existing plastic polymers.

To meet the market demand for precise, reliable contaminant analysis, the food testing laboratory network of Mérieux NutriSciences have developed, validated, and accredited a dedicated methodology specifically designed for microplastics analysis in food products.

The primary objective of this accredited method is to evaluate the presence or absence of microparticles, while simultaneously offering a detailed polymer characterization, including:

• Polymer chemical composition
• Number of particles identified in the sample
• Their size range

The Principle of Analysis: μFTIR / FTIR Microscopy (Fourier-transform Infrared microscopy)

The technique of choice used by our food testing laboratory to ensure data selectivity and confirmation of chemical composition is Fourier-transform infrared microscopy (μFTIR / FTIR microscopy), based on FTIR spectroscopy.

FTIR spectroscopy generates a genuine “fingerprint” of the material, making it a powerful technique for polymer identification in microplastics analysis. When coupled with microscopy, it enables individual microparticles to be visually isolated and analyzed, providing highly reliable polymer identification across a broad range of plastic materials commonly encountered in industrial and environmental contexts, such as:

• Nylon and Polyurethane (PU)
• Polyethylene (PE)
• Polypropylene (PP) and Polystyrene (PS)
• Polyethylene Terephthalate (PET) and Polyvinyl Chloride (PVC)
• Polytetrafluoroethylene (PTFE), Polyoxymethylene (POM), and Polyvinyl
• Alcohol (PVA)

Sensitivity and Metrological Performance of the Test Method

In terms of analytical sensitivity, the method features an extremely low Limit of Quantification (LOQ), ranging between 1 and 10 particles. This sensitivity varies depending on the portion of the sample analyzed, specifically whether the analysis is performed on the whole sample as is (expressed in L or kg) or on a representative fraction equal to or greater than 10%.

Furthermore, in compliance with international metrology standards and the requirements for accredited laboratories, the uncertainty associated with measuring particle size is rigorously calculated, ensuring the reliability of microplastics testing results.

Conclusions: Brand Protection and Risk Management

Monitoring emerging contaminants, such as microplastics in food, represents a fundamental pillar for risk anticipation and management.

Utilizing advanced analytical techniques and relying on an officially accredited method based on FTIR microscopy allows companies in the food supply chain to rigorously verify the compliance of their raw materials and finished products.

Choosing a structured analytical partner enables businesses to base their strategic decisions on solid, traceable, and unimpeachable scientific data, protecting brand reputation in a market that is increasingly attentive to transparency.