Food adulteration can be either intentional or incidental, such as heavy metal contamination, pesticide residue, or packaging-related issues. When this adulteration is deliberately carried out by addition, omission, or substitution for economic gain, it is known as economically motivated adulteration (EMA), a subset of food fraud. The motivation for both EMA and food fraud is primarily financial gain. However, food fraud extends beyond EMA to other deceptive practices such as misbranding, counterfeiting, and diversion.

In late 2023, cinnamon apple puree and apple sauce products sourced from Ecuador were recalled after testing positive for elevated levels of lead and chromium¹. The FDA’s leading hypothesis was that the incident was likely due to EMA, and the contamination went undetected until it escalated into a serious public health issue. This highlights the importance of implementing robust traceability systems and conducting food authentication tests to ensure that only genuine products reach the consumer market, in compliance with all relevant food safety and quality standards.

Spectroscopy Simplified

Spectroscopic techniques such as UV-Vis Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Near-Infrared Spectroscopy (NIR), Raman Spectroscopy, and Nuclear Magnetic Resonance (NMR) Spectroscopy, when combined with chemometrics, are among the most reliable methods in verifying food authenticity. UV-Vis Spectroscopy is widely utilized in most analytical laboratories for analyzing chromophore-containing compounds, such as pigments. In the food manufacturing sector, it can be used to detect dilution of alcoholic and non-alcoholic beverages, such as juices and wines. However, it provides limited structural information, an area where FTIR performs comparatively well.

FTIR, in contrast, is ideal for routine screening in food authentication. It can be used to detect adulteration in olive oils with cheaper oils such as sunflower, palm, or soybean oils, and the addition of sugar syrup to honey². The portability of Raman and NIR is advantageous for non-destructive on-site testing. While they can provide rapid profiling, they are typically less sensitive than FTIR for trace analysis and are most beneficial when used complementarily in a laboratory setting. Since Raman relies on light scattering, it can overcome certain challenges FTIR faces in analyzing high-moisture foods, like milk. Such foods strongly absorb infrared, which can interfere with and weaken signals, impacting detection accuracy.

Large organizations with dedicated R&D laboratories may benefit from setting up an in-house FTIR. If small and mid-size organizations were to adopt product authenticity testing as a standard practice with high testing volumes, having an in-house FTIR could turn out to be an economical choice over time. For operations with low testing frequency, outsourcing could be more cost-efficient. Finally, while NMR delivers detailed information, it is time-consuming and requires expensive equipment as well as expert handling, making it better suited for confirmatory analyses. In such cases, it is practical to use specialized third-party labs, as operating costs can outweigh the benefits.

Chromatography in Action

Chromatographic separation techniques such as Gas Chromatography (GC) and High-Performance Liquid Chromatography (HPLC) are often coupled with Mass Spectrometry (MS) for detecting trace levels of adulterants in intricate food matrices that cannot typically be detected by spectroscopic methods alone. Both GC-MS and LC-MS are powerful and selective techniques, but they come with significantly higher purchasing and operating costs than FTIR. Their preference can be driven by the need for advanced research or for regulatory compliance purposes, in addition to authentication testing.

GC-MS is ideal for volatile compounds that can withstand high temperatures and can be used for identifying synthetic flavor compounds in natural flavors and juices. Flavorings and non-alcoholic beverages are among the top 10 implicated categories of food fraud, and olive oils have been frequently associated with mislabeling incidents³. In contrast, LC-MS is better suited for non-volatile, thermally sensitive, and high-molecular weight compounds. Common applications of LC-MS include detecting melamine in milk and identifying Sudan dyes in chili powder.

To prevent fraud, testing is most effective when done at the ingredient level, and raw material suppliers should be encouraged to engage in such practices. This offers multi-ingredient food manufacturers a greater reliance on their suppliers for authenticity and, depending on the scope of their operation, may reduce the need for additional testing of incoming materials.

Decoding Mass Spectrometry

MS techniques such as Isotope Ratio Mass Spectrometry (IRMS) and Inductively Coupled-Plasma Mass Spectrometry (ICP-MS) have distinct applications. IRMS measures stable isotope ratios, whose abundance varies with environmental and agricultural factors, serving as a strong indicator of growing conditions and geographical origin. With IRMS, it is possible to ascertain whether a conventional product is mislabeled as organic or if meat has been derived from a grass-fed or grain-fed cow⁴. While spectroscopic methods can cover a broader spectrum in provenance mapping, IRMS is more focused and definitive in such an approximation.

Likewise, ICP-MS analyzes the elemental composition of heavy metals and trace minerals. It is often used to detect heavy metal contamination, such as arsenic in rice or lead in water, and to estimate mineral content in supplements. Since both IRMS and ICP-MS are high-precision instruments that involve considerable capital investments, internal implementation is justified for regulatory agencies where accuracy is key. For private organizations, the choice ultimately depends on their requirements, infrastructure, and budget thresholds.

Cracking the Molecular Code

Molecular techniques such as Conventional PCR and Real-time Polymerase Chain Reaction (qPCR) are popular choices for species identification due to their speed, precision, and reliance on genetic information, which is not influenced by farming conditions. Both methods detect and amplify DNA, but only qPCR can quantify genetic material in real-time by using fluorescent probes. This offers qPCR a functional advantage over conventional PCR.

Historically, meat and dairy products have been frequently implicated in food fraud incidents³. For example, conventional PCR can detect whether beef is adulterated with pork, whereas qPCR can determine the amount of pork meat present. An alarming case of fraud occurred in 2013 when horsemeat ended up in the supply chain across Europe, labeled as beef. Similarly, qPCR can distinguish whether goat milk has been diluted with cow milk, as well as the extent of dilution.

Another type of PCR, known as multiplex PCR, allows simultaneous detection of multiple species in a single assay, which can save time and expenses, but the overall process can be complex to implement. While PCR instruments are essential for biotechnological research in pharmaceutical companies and are often favored by regulatory agencies, their routine use in food manufacturing establishments might be limited unless the company participates in applied research, such as the development of bioengineered foods.

The Analytical Dilemma

The bar graph in Figure 1 demonstrates a clear trend between the equipment cost and the depth of the analysis achieved. In summary, the more comprehensive the analysis, the higher the cost of the equipment, and the greater the technical expertise required. Food manufacturers can use these observations to determine the approach best suited to their scope and budget. UV-Vis Spectroscopy requires basic operation skills and is relatively easy to handle. Given their low cost, they can be easily integrated into an existing internal lab infrastructure.

Now, the choice between FTIR and Raman can be challenging as both techniques have distinct strengths and complement each other.  FTIR excels at analyzing a broad range of food matrices, while Raman offers a convenient application for field use. Among the mid-range category, qPCR requires careful handling during sample preparation to prevent false positives, and companies can evaluate outsourcing testing to accredited labs, collaborate with research institutions, or appoint trained specialists.

GC-MS, LC-MS, and ICP-MS tend to have considerable costs, making them ideal for confirmatory analyses. Whether they are used regularly or customarily, operational needs and budget thresholds are ultimately the deciding factors for an in-house infrastructure development. IRMS and NMR are superior and highly advanced instruments that are employed for specialized research rather than routine food authentication testing. When required, they can be selectively utilized through third-party labs.

From Insight to Action

Food authentication technologies like spectroscopy, chromatography, mass spectrometry, and PCR play a key role in ensuring the integrity of food products. While each technique comes with a cost and capability trade-off, strategically leveraging them within the existing safety and quality framework offers an additional layer of protection from food fraud. Figure 2 summarizes essential practices organizations should adopt and avoid to strengthen food fraud prevention and mitigation efforts.

Raw material suppliers must actively engage in product authenticity testing. Multi-ingredient or finished product manufacturers can adopt the following best practices depending on the nature of their supplier relationships.

• New suppliers – Request or conduct authenticity testing before initial bulk purchase.
• Domestic and/or established relationship with suppliers – Perform random raw material sampling on a rotating basis for authenticity testing.
• International suppliers and/or complex supply chains – Conduct authenticity testing at least annually.

Food fraud can quickly evolve into a food safety or a food quality issue. Investing in the right authentication tools today can prevent costly recalls tomorrow. In addition to testing, it is essential to stay informed and monitor emerging trends in the rapidly evolving supply chain landscape. Building a safer global food system requires prioritizing prevention over reaction by proactively detecting and eliminating food fraud risks before they occur.

References

1. S. Food and Drug Administration (FDA). “Investigation of elevated Lead & Chromium Levels: Cinnamon Applesauce Pouches.” Current as of March 10, 2024. https://www.fda.gov/food/outbreaks-foodborne-illness/investigation-elevated-lead-chromium-levels-cinnamon-applesauce-pouches-november-2023
2. Mendes, E., & Duarte, N. (2021). Mid-infrared spectroscopy as a valuable tool to tackle food analysis: A literature review on coffee, dairies, honey, olive oil and wine. Foods, 10(2), 477. https://doi.org/10.3390/foods10020477
3. Everstine, K. D., Chin, H. B., Lopes, F. A., & Moore, J. C. (2024). Database of food fraud records: Summary of data from 1980 to 2022. Journal of food protection, 87(3), 100227. https://doi.org/10.1016/j.jfp.2024.100227
4. Hong, E., Lee, S. Y., Jeong, J. Y., Park, J. M., Kim, B. H., Kwon, K., & Chun, H. S. (2017). Modern analytical methods for the detection of food fraud and adulteration by food category. Journal of the Science of Food and Agriculture, 97(12), 3877-3896. https://doi.org/10.1002/jsfa.8364
5. Vinothkanna, A., Dar, O. I., Liu, Z., & Jia, A. Q. (2024). Advanced detection tools in food fraud: A systematic review for holistic and rational detection method based on research and patents. Food Chemistry, 446, 138893. https://doi.org/10.1016/j.foodchem.2024.138893